Intro to petroleum geology

Department of Mines andEnergy
GOVERNMENT OF
NEWFOUNDLAND AND LABRADOR
An Introduction
to
THE PETROLEUM INDUSTRY
Alphonsus Fagan
November, 1991

Page iTable of Contents
Table of Contents
Acknowledgements iv
Materials Used in Compiling This Manual v
Introductory Remarks vi
Chapter 1
Introduction to the Petroleum Industry 1-1
Terminology 1-1
A Source of Energy 1-2
Other Uses for Oil 1-3
Chapter 2
The History of Petroleum 2-1
Petroleum Used by Ancient Civilizations 2-1
The First Oil Wells 2-2
The Oil Booms Begins 2-2
The Present 2-3
Chapter 3
Part “A” 3A-1
Porous and Permeable Rocks 3A-1
Three Types of Rocks 3A-1
Porosity 3A-1
Permeability 3A-2
Part “B” 3B-1
How Sedimentary Rocks are Formed 3B-1
Erosion and Transport 3B-1
Sedimentation 3B-2
Subsidence 3B-3
Cementation 3B-3
Chapter 4
Hydrocarbon Traps 4-1
Reservoirs 4-1
Oil Floats 4-1
Natural Gas Reservoirs 4-2
Geological Structures Become Hydrocarbon Traps 4-2

Page iiTable of Contents
Table of Contents
Chapter 5
Petroleum Exploration I 5-1
Contour Mapping 5-1
Contour Maps 5-1
Chapter 6
Part “A” 6A-1
Petroleum Exploration II 6A-1
Surface Mapping, Gravity and Magnetic Surveys 6A-1
Surface Mapping 6A-1
Geophysics 6A-2
Basement Rocks 6A-2
Magnetic Surveys 6A-3
Gravity Surveys 6A-3
Part “B” 6B-1
Petroleum Exploration III 6B-1
Seismic Exploration 6B-1
Reconnaissance and Detailed Surveys 6B-1
The Seismic Survey 6B-1
Offshore Seismic 6B-4
Chapter 7
Acquiring Petroleum Rights 7-1
Surface Rights vs Petroleum Rights 7-1
Resource Ownership 7-1
The Lease 7-2
Obtaining a Lease 7-2
Chapter 8
Drilling 8-1
A Wildcat Well 8-1
Drilling the Well 8-1
Drilling Technology 8-3
Casing the Well 8-5
Logging the Well 8-5

Page iiiTable of Contents
Table of Contents
The Drill Stem Test 8-7
The Blowout Preventor 8-7
Chapter 9
Drilling Offshore 9-1
A Hostile Environment 9-1
The Technology of Offshore Drilling 9-1
Supply Vessels 9-4
Types of Offshore Drilling Rigs 9-4
Costs 9-5
Chapter 10
Field Development and Production 10-1
Delineation Drilling—How Big is our Oil Field? 10-1
Development Wells 10-2
Completing a Well 10-2
Crude Oil Treatment 10-3
Pressure Maintenance and Artificial Lift 10-3
Offshore Production 10-4
Fixed Platforms 10-5
Floating Production Platforms 10-6
Chapter 11
Current Events in the Oil Industry 11-1
Chapter 12
Public Hearing 12-1
Offshore Oilfield Development Plan 12-1
Cast of Characters 12-3
The Hibernia Production System 12-6
Appendix I - Glossary

Page ivAcknowledgements
Acknowledgements
This training manual was developed by the Department of Mines and Energy in response to an initiative
within the 4H section of Division of Youth Services, to be utilized in the province’s 4H educational pro-
gram. It is my pleasure to now recognize the individuals and organizations whose support made this project
possible. I must first thank Heather Griffin who presented the project to this Department, provided enthusi-
astic guidance and encouragement, and helped carry out a number of trial experiments, several of which
have been included as exercises. I am grateful to the members of the staff of the Department of Mines and
Energy who assisted in any way and in particular to: David Hawkins and Doug Hunt who conducted de-
tailed reviews and made valuable suggestions; Laurie Murrin who demonstrated a very keen eye in her me-
ticulous editing on the later drafts; Donna Taylor for drafting assistance; David Bazeley who assisted in
desktop publishing; and Brenda Haynes who patiently typed numerous drafts of this document. During
2002 and 2003 several figures were re-drafted by Lisa Clarke, Jonathon Larder and Lisa Benson of the De-
partment of Mines and Energy.
I would also like to thank: Dr. John Harper of the Centre for Earth Resources Research (CERR) for review-
ing the text, suggesting a number of exercises and for providing a lab in which to try some of the experi-
ments; Michelle Brazil for her detailed and insightful review; Pat Jackson of the Canadian Petroleum Asso-
ciation for assisting in locating resource materials: and Arlene Coffen (protoTYPE) for desktop publishing.
Thanks are also extended to the companies and organizations who allowed the use of figures (Shell, Exxon,
PETEX, Lamar University, Gulf Publishing Company and Mobil).
I also wish to acknowledge the contribution of the Society, Environment & Energy Development Studies
(SEEDS) Foundation whose newsletters provided the basis for a number of the exercises included in this
manual.
Alphonsus Fagan

Page vMaterials Used in Compiling This Manual
Materials Used in Compiling This Manual
(1) The Oil and Gas Lease In Canada; Second Ed.: John B. Ballem; University of Toronto Press, 1985.
(2) Handbook on Basic Land Management: Lewis G. Mosburg, Jr. The Institute for Energy Develop-
ment, Inc., 1978.
(3) Fundamentals of Petroleum; Second Edition: Petroleum Extension Service, The University of
Texas at Austin, 1981.
(4) Our Industry Petroleum; The British Petroleum Company Ltd., Fifth Edition, 1977.
(5) Oil Business Fundamentals; Robert D. Langenkamp; 1982.
(6) The Story of Petroleum, Shell Oil Company.
(7) This Fascinating Oil Business, Max W. Ball; The Bobbs-Merrill Company, 1940.
(8) An A-Z of Offshore Oil and Gas, Second Ed., Harry Whitehead; Kogan Page Ltd., 1983.
(9) The Illustrated Petroleum Reference Dictionary, Second Edition; Robert D. Langenkamp, Pennwell
Publishing Company, 1982.
(10) Petroleum Politics and Power; E.B. Brossand, Pennwell Publishing Company, 1983.
(11) Our Petroleum Challenge, The New Era; Second Edition, The Petroleum Resources Communication
Foundation, 1980.
(12) Offshore Drilling Deeper and Deeper, Shell Canada Resources Ltd., 1982.
(13) Reference Points, Canadian Oil and Gas: The First One Hundred Years; Canadian Petroleum Asso-
ciation, 1984.
(14) Mining, Oil and Gas, Northern Miner Press Ltd., 1979.
(15) The Offshore Search For Oil and Gas, Fourth Edition; Exxon Background Series; September 1980.
(16) Facts About Oil, American Petroleum Institute, 1984.
(17) SEEDS Energy Literacy Series; SEEDS Foundation, Edmonton, Alberta.
(18) Introduction To The Petroleum Industry; Seminars On The Petroleum Industry: The Newfoundland
and Labrador Petroleum Directorate In Conjunction with Van Meurs & Associates Ltd.

Page viIntroductory Remarks
Introductory Remarks
It is not known exactly when humankind first used petroleum. It is known, however, that ancient peoples
worshipped sacred fires that were fuelled by natural gas seeping to the surface through pores and cracks. It is
also known that asphalt, a very viscous form of petroleum, was used to waterproof boats and heat homes as
early as 6,000 BC. Asphalt was also used as an embalming agent for mummies and in the construction of the
Egyptian pyramids around 3,000 BC. Petroleum's usefulness, so it seems, was recognized from the very be-
ginnings of civilization.
Petroleum's importance to humankind took a giant leap in the late 1800's when it replaced coal as the primary
fuel for the machines of the industrial revolution. In today's industrialized society, petroleum means power.
It provides the mechanical power to run machines and industries and also the political power that comes from
being able to shut down the machines and industries of those who depend on you for their oil supply.
Today, petroleum remains our primary source of energy, and today, the province of Newfoundland is prepar-
ing to become an important player in the Canadian oil industry. A number of large oil and natural gas fields
were discovered offshore Newfoundland and Labrador during the 1970’s and 1980’s and more discoveries
are expected to be made with further drilling.
We are now developing our offshore petroleum resources, and this has the potential to have significant eco-
nomic and social impacts on our province. To reap the maximum benefits from petroleum developments, we
need to understand this new industry. By educating ourselves as individuals, we can be in a better position to
take advantage of the resultant employment and business opportunities. By educating ourselves as a popula-
tion, we can help ensure our governments make good decisions in relation to this industry that will serve the
long term interests of our people. This manual is intended to play a role in this education process. It at-
tempts to give a basic understanding of the petroleum industry; where it started, why it is important, and how
it works. It takes the student through the different phases of petroleum exploration, development and produc-
tion and discusses some of the careers associated with the petroleum industry. The last two chapters are
workshops which do not introduce any new material, but which require the students to draw upon knowledge
gained in the first ten chapters and conduct some research of their own.
This manual has been designed around the belief that the most enjoyable and effective means of learning is
by doing. Each chapter contains several pages of text followed by a few review questions and one or more
exercises. In most cases, it is important that the student understand the text part of the chapter to appreciate
the exercises. Each activity attempts to illustrate at least one important concept. In cases where the ideas to
be explained did not easily lend themselves to illustration by simple activities, the activities are to be re-
placed by the viewing of pertinent films.
The development of Newfoundland offshore oil is coming at a time when we have become highly sensitized
to environmental issues and yet remain very dependent on petroleum. As we proceed with offshore develop-
ment, we must bear in mind the lessons that have been learned elsewhere and the special challenge our off-
shore area presents to the oil industry. We must ensure that our offshore petroleum resources are developed
wisely and, in cooperation with the fishery so that we can reap maximum benefits from both industries.
These noble goals can best be achieved with input from a well informed public and it is hoped that this man-
ual will be useful for those who want to become informed about this increasing important sector of our econ-
omy.

What is oil? We hear about it almost every day in the news. People around the world are very concerned
with the price of oil; countries who may be at war attempt to cut off the supply of oil to their enemies; coun-
tries like Canada and the United States are concerned with obtaining a secure supply of oil. Why does the
whole world seem to be preoccupied with oil? How is oil different from other commodities which are
traded in the world market such as wheat, fish, paper or steel, all of which are important in our daily lives?
These are some of the questions we will address in this chapter.
Introduction to the Petroleum Industry
Page 1-1Introduction to the Petroleum Industry
Introduction to the Petroleum Industry
Chapter 1
Terminology
Oil, petroleum, natural gas, hydrocarbons and crude are terms we commonly hear. If we are going to study
the oil industry, we must first become familiar with the "lingo". Appendix I provides a glossary, but it will
be useful at this point to introduce youto the some of the key terms.
There are many kinds of oils. We have “oils” that are used for cooking and sun tanning. Some of these oils
come from different types of plants (such as vegetable oil) and animals (cod liver oil). The oil we are con-
cerned with here is derived from rocks within the earth. It is called petroleum, a name taken from the Latin
words meaning "rock oil". Throughout this text when we speak of oil, we will always mean petroleum.
The term hydrocarbons refers to the chemical makeup of petroleum. A detailed discussion of petroleum
chemistry is beyond the scope of this
manual, but it will suffice to say that
petroleum is a compound made up
predominantly of atoms of hydrogen
and carbon; thus the name hydrocar-
bons.
Hydrocarbons can combine in vari-
ous ways to form many different
compounds. They can form solids,
such as the asphalt that is used to
pave roads; liquids such as conven-
tional liquid petroleum, and gases
such as natural gas (not to be con-
fused with gasoline). Natural gas is
a mixture of hydrocarbons that are in
a gaseous state at normal tempera-
ture and pressure (Figure 1.1).
Figure 1.1 - Hydrocarbon Molecules
Methane is the simplest hydrocarbon molecule with only one carbon (C) atom. The
first four members of this hydrocarbon series shown here, are gases under normal
conditions. Natural gas contains mixtures of these molecules as well as certain im-
purities. Subsequent members of this hydrocarbon series represent increasingly
heavier liquid and eventually waxy solids. Hydrocarbon molecules in this group are
known to contain up to 78 carbon atoms (i.e., C78). How many hydrogen atoms
would be present in such a molecule? (ie, C78H?).

It consists mostly of methane, but also contains ethane, propane, butane and pentane, which are the simplest
and lightest hydrocarbons. The different properties of hydrocarbon compounds are determined by differ-
ences in the number and arrangement of hydrogen and carbon atoms they contain. Carbon is much heavier
than hydrogen and thus the weight of the hydrocarbon molecule is predominantly determined by the num-
ber of carbon atoms. Natural gas molecules will contain only a few carbon atoms per molecule while a
heavy petroleum such as tar or asphalt may contain a great number of carbon atoms per molecule. Petro-
leum may also contain certain impurities such as nitrogen, sulphur and oxygen.
The term crude oil refers to oil in its "crude" or unrefined state; that is to say oil as it comes out of the
ground. This crude oil must be transported to a refinery to be separated into constituents such as gasoline,
aviation fuel, fuel oil, etc. before it can be used by the consumer (Figure 1.2).
Page 1-2Introduction to the Petroleum Industry Chapter 1
Lightest
Heaviest
Natural Gas
Methane
Ethane
Propane
Butane
Crude Oil
Gasoline
Kerosene
Gas Oil
Diesel Oil
Lubricating Oil
Fuel Oil
Lubricants and Greases
Asphalt
Figure 1.2 - Petroleum and
some of its components
Crude oil, which may be a mixture of
all of the above components, is sepa-
rated into these and other petroleum
products in the refinery.
• Why is Oil so Important in Today’s World?
The answer to this question may already be obvious to you but let's try and see how big a role oil plays in
your daily life.
When you got out of bed this morning, the electricity you used to cook breakfast may have been generated
from an oil-burning generating station; or perhaps your family uses a natural gas-burning stove. You were
able to enjoy breakfast in comfort and warmth because of the oil-burning furnace in your basement. Next
you may have taken a gasoline or diesel powered car (or bus) to school. So, as you can see, before you
even started your school day you already used a certain amount of petroleum. Many of us tend to take these
conveniences for granted. Try and imagine how your life might change if we suddenly lost our supply of
oil.
A Source of Energy
Oil's primary importance lies in the fact that it is a very versatile and powerful source of energy. There are
many other energy sources that we routinely use, including firewood, coal, and hydroelectric and nuclear
generating stations. All of these sources have their advantages and disadvantages. A clean and renewable
source of energy, would certainly be the most desirable.

Oil is a non-renewable source of energy. What this means is that our natural sources of oil are finite; there
will come a time when we have used them up. One of the exercises at the end of this chapter will ask you
to calculate how long our present known supplies of oil will last at today's consumption rates.
The reason that oil has such importance is that it provides the fuel that runs the internal combustion engine.
The internal combustion engine was invented by Karl Benz in 1885-86. Gotlieb Daimler improved on this
invention and eight years later Rudolph Diesel created the engine that bears his name. These types of en-
gines are still used today in all kinds of machinery including automobiles, ships, tractors, generators and
tanks. Oil is also the raw material for the fuels that are used in jet engines and in some cases to fuel rocket
engines to propel spacecraft into outer space.
It should now be obvious why oil plays such a dominant role in today's world. If oil supplies were to be cut
off, cars, boats and planes would grind to a halt. We would have to find alternate means of heating many of
our homes and generating sufficient electricity. Our personal security would also be threatened because our
military forces and police forces would be largely immobilized.
Oil’s principle importance derives from the fact that it fuels the machines of our industrialized society.
Other Uses for Oil
Although oil is primarily an energy source, it is also used as a raw material in manufacturing more than a
thousand other products including; plastics, paints, fertilizers, detergents, cosmetics, insecticides, and even
food supplements (Figure 1.3).
Figure 1.3 - Petroleum Products
There are thousands of petroleum products in use
today. This figure shows some of the more familiar
ones. At the refinery, crude oil is separated into
“fractions” (it’s component parts) through distillation.
Some of these fractions, through simple treating, are
converted to final petroleum products at the refinery.
Other refined products require further processing at
chemical plants and factories showing up as final
consumer products.
Bottled Gas
Gasoline
Jet Fuel
Fuel Oil(for home heating)
Fuel Oil(for factories)
Diesel Oil
and others
Solvent for paints
Insecticides
Medicines
Synthetic Fibers
Enamel
Detergents
Weed Killers & Fertilizers
Plastics
Synthetic Rubber
Photographic Film
Candles
Waxed Paper
Polish
Ointments & Creams
Roofing
Protective Paints
Asphalt
Crude
Oil
Refinery
Petrochemical
Plant

As long as we depend on oil to fuel the engines of the world, it will continue to play a major role in our
lives. But research is ongoing in many countries to find ways to harness new sources of energy.
Perhaps one day our cars will have electricity powered engines and run on batteries that must be recharged
every few hundred kilometres. Or, perhaps the batteries will draw on the sun's energy and recharge even as
we drive. Who knows what the future holds?
One thing that is certain, however, is that the air pollution resulting from the combustion of fossil fuels such
as petroleum and coal is of increasing concern to the inhabitants of planet Earth. Thus, the search for a non-
polluting replacement energy source is one of the most important challenges faced by humankind.
• Will Society Always be Dependent on Oil?
Figure 1.4 (See exercise 4)

(1) What are some of the other sources of energy we use?
(2) Why have we not replaced oil with a non-polluting renewable energy source?
(3) Can you think of alternative sources of energy to fuel our cars?
(4) Why are petroleum and coal called fossil fuels?
Questions
(1) Examine some samples of conventional light oil and heavy oil.
(2) Use a blowtorch or Bunsen Burner to demonstrate the use of natural gas.
(3) Discuss the advantages and disadvantages of some of the different energy sources.
(4) Figure 1.4 is a map that divides the world into 13 major regions based on petro-
leum consumption, production and reserves. Petroleum consumption and produc-
tion rates of each region are listed in millions of barrels per day (Table 1.1). The
oil reserves are listed in billions of barrels and represent the total amount of crude
oil that has been discovered and remains to be produced. All of these numbers
are estimates that will change over time as known reserves are consumed, new oil
fields are discovered, and production and consumption rates fluctuate.
In this exercise, you will graphically illustrate the oil production and consumption pat-
terns in the world and the reserve distribution. Draw vertical bars on the map to repre-
sent the reserves, production and consumption rates (in each region). Color the bars for
better illustration. A convenient scale will be 1 inch = 10 million barrels per day for pro-
duction and consumption and 1 inch = 100 billion barrels for reserves. If a bar is too
long, just tape an extension to the page.
Study the map with the colored bars and answer the following questions:
(1) Which regions are net exporters of oil? Importers?
(2) Which regions or countries are most vulnerable to a disruption in the supply of
oil such as might occur as a result of war or political upheaval?
(3) Which region is in the best position to control the supply of oil available to the
world and hence the price of oil in the long term future?
(4) Does this illustration suggest why it may be important for the industrialized
countries to maintain good trade relations with the countries of the Middle East?
Exercises

Country/Region Oil Reserves
(Billions of Barrels)
Oil Production
(Millions of Barrels
per Day)
Oil Consumption
(Millions of Bar-
rels per Day)
1. USA 26.5 8.1 16.0
2. Canada 6.8 1.6 1.5
3. Latin America 120.3 6.2 4.6
4. Western Europe 18.2 3.9 12.4
5. Middle East 564.8 14.0 2.2
6. Africa 55.2 5.0 1.7
7. South Asia 7.0 0.7 1.3
8. Southeast Asia 12.9 1.8 2.6
9. *Japan - - 4.5
10. Australia/New Zealand 1.8 0.6 0.7
11. USSR 58.5 12.4 9.1
12. Eastern Europe N/A 1.0 2.6
13. China 23.6 2.7 2.1
Table 1.1
(5) What would be a good strategy for a country like the U.S.A. to ensure a reliable
supply of oil? Should it purchase all of its oil from one source?
(6) Break the class up into groups and have each group consult a world map and
compile a list of the countries included under the areas designated in Figure 1.4
as:
(a) Latin America
(b) Western Europe
(c) Middle East
(d) Africa
(e) South Asia
(f) Southeast Asia
(g) Eastern Europe
(7) Using the data in Table 1.1 (i.e., oil reserves and oil consumption rates), estimate
how long the world's present oil supplies will last at today's consumption rates.
No. of Years Supply Left = 1 x (Total barrels in reserve)
365 (Total barrels consumed per day)
(8) What do you think will happen to the price of oil when the known oil reserves are
almost used up? Will this help us find more oil? Will higher prices of oil make
other energy sources more viable?
* Japan’s reserves and production rates are too small to be considered. N/A—Not Available (Source: International Petroleum
Encyclopedia, 1989)
Exercises (cont…)

Various theories have been advanced over the years as to the origin of petroleum proposing an animal,
vegetable, mineral and even meteoric origin. Today, however, most scientists believe that oil and gas origi-
nated in plant and animal matter that accumulated in fine grained sediments at the bottom of ancient seas
many millions of years ago. This theory suggests that oil originated as the remains of countless organisms
that either lived in the sea or were deposited there with mud and silt from prehistoric rivers and streams.
The remains of these ancient plants and animals were transformed into oil and gas by bacterial action with
heat and pressure resulting from deep burial beneath other sediments (Figure 2.1).
It seems, then, that the story of petroleum began hundreds of millions of years ago. But when did humans
first learn to use petroleum?
The History of Petroleum
Page 2-1The History of Petroleum
The History of Petroleum
Chapter 2
Petroleum Used by Ancient Civilizations
No one knows exactly when humans
first used petroleum. It is known, how-
ever, that ancient peoples worshipped
sacred fires fuelled by natural gas seep-
ing to the surface through pores and
cracks.
The use of thick gummy asphalt to wa-
terproof boats and heat homes was re-
corded as long ago as 6000 BC.
About 3000 BC the Egyptians used as-
phalt in the construction of the pyra-
mids, to grease the axles of the Phar-
aoh's chariots, as an embalming agent
for mummies and in medicinal prepara-
tions.
There are numerous references to as-
phalt or pitch (a form of petroleum) in
the Bible, including that it served as
mortar for the builders of the Tower of
Babel, was used by Moses' mother to
waterproof his cradle of bulrushes, and
by Noah to caulk the Ark.
In early North America, Indians
skimmed oil from the surface of springs using it to waterproof canoes and in the making of war paints.
They taught the colonists to use oil for healing and self-styled "doctors" bottled "Seneca oil" or "rock oil"
and sold it as a cure-all.
When whale oil, the main source of lamp fuel in the early 1800’s, became scarce, a new source was needed.
Figure 2.1 - Formation of Petroleum

For thousands of years, the only sources of petroleum had been sur-
face seeps or tar pits. These sources were not very productive, so cer-
tain individuals decided to look for oil underground, by drilling.
In 1858, one such individual, a 39 year old carriage maker from Ham-
ilton, Ontario, named James Miller Williams made the first major
commercial oil discovery in North America at Oil Springs, Ontario.
Drilling in "gum beds" in Lambton County, 25 km southeast of
Sarnia, he struck oil at a depth of only 18 metres. Williams refined
the oil he produced and sold the product as lamp oil. In the following
year, Colonel Edwin L. Drake discovered oil in Titusville, Pennsyl-
vania by drilling to 21 metres (Figure 2.2). This discovery signalled
the birth of the modern petroleum industry in the United States*.
Inventors began to distill illuminating and lubricating oils from natural petroleum seeps and from coal.
Despite the varied and inventive uses being recognized, petroleum was still thought to be a substance of
only minor importance. Some thought it was suitable only for use as a lubricant, patent medicine, asphalt
and kerosene (for lamps) and nothing else. Others even argued that removal of petroleum from beneath the
earth's surface would put out the fires of Hades. But changes were occurring in the world. Changes that
would make the continued development and growth of the petroleum industry inevitable.
Page 2-2The History of Petroleum Chapter 2
Figure 2.2
Drake’s well at Titusville, Pennsylvania, marked the start
of the U.S. oil industry in 1859.
(Courtesy of Shell Oil Company).
The First Oil Wells
The Oil Boom Begins
As a result of the oil discoveries of the 1850's, numerous refineries were built to turn crude oil into kerosene
for lamps and into lubricating oils for the machines of the industrial revolution. Oil began to replace coal as
the fuel for steam engines.
The invention of the gasoline engine (1885) and diesel engine (1892) allowed inventors of horseless car-
riages to adopt a new power source to replace steam and electricity. Gasoline which had previously been
considered a useless by-product of the distillation of crude oil would now take on a new importance as ad-
vancements in technology made possible the mass production of the automobile in early years of the twenti-
eth century.
In 1903, at Kitty Hawk, North Carolina, the Wright brothers utilized petroleum to realize what could only
be imagined by previous generations - flight. Since that first flight at Kitty Hawk, North Carolina, petro-
leum has fuelled every type of aircraft from Lindberg's "Spirit of St. Louis" to today's jumbo jets.
____________________
* The Chinese are recognized to be the first civilization to drill for oil. As early as 300 BC they pounded
holes in the ground withheavy, bronze bits suspended from spring poles (Figure 2.3)

3The History of Petroleum Chapter 2
The Present
Today, we are well into the space age, but petroleum is still the dominant source of energy used by human-
kind. This is especially true in the transportation industry.
This versatile fuel that is so easily transported and poured into the fuel tanks of our cars and planes has also
been largely responsible for the rapid technological advances we have experienced in the past 100 years.
It was less than 500 years ago, in 1519, that Ferdinand Magellan set out with five ships on one of the great-
est expeditions in human history; to circumnavigate the world. This voyage cost the lives of most of Ma-
gellans' men, including his own, and took three years to complete. Today, it would not be considered a
great accomplishment to go around the world, using modern air travel, on a three week vacation. Indeed
the world has become a much smaller place, largely due to petroleum - that smelly, oily substance that had
its beginnings in ancient seas millions of years before men and women walked the earth.
Figure 2.3 - Spring Pole Drilling
Drilling technique of ancient Chinese. The
spring pole eliminated some of the manual
labor in raising and dropping a heavy
bronze bit. Early drillers in the “modern”
oil industry used a variation of this tech-
nique called “cable tool drilling” which
utilized a steam or internal combustion en-
gine to raise and lower a wooden or metal
beam from which the bit was suspended.
Questions:
(1) How is petroleum formed?
(2) Why do you think whale oil became scarce?
(3) What invention in the late 1800’s lead to petroleum becoming a substance of
great importance?
(4) Find out the difference between a gasoline powered and a diesel powered engine.

(1) Split the class up into teams and debate some of the positive and negative ef-
fects of the industrial revolution on people and the environment.
(2) (To be performed by Teacher in Front of the Class). In this exercise you will
compare three sources of light; the candle, the kerosene lamp, and the electric
light bulb.
Oil provides the raw material to produce candles as well as kerosene. Candles
have been widely used as a light source and kerosene is the fuel that burns in
kerosene lamps. Kerosene lamps were the most common sources of light before
electricity. Indeed, many of your parents or grandparents studied their school-
books by the old kerosene lamp. These lamps are still in common use today,
especially during power failures.
Page 2-4The History of Petroleum Chapter 2
Exercises:
Procedure:
Draw the curtains and darken the classroom. Light the candle. Observe the quality of
the light. Is it bright or dull? Try and read something. Extinguish the candle.
Light the kerosene lamp. Observe the quality of the light. Try and read in this light.
Extinguish the lamp.
Turn on the electric lamp. Compare the quality of the light with that of the candle and
the kerosene lamp. Try and read in this light.
Questions:
(1) Which gave the best quality of light?
(2) Which was the cleanest source of light?
(3) What is the process by which the wax in the candle burns? Does it burn the
same way as a match burns or is something slightly different happening?
(4) What is the process by which the fuel in the kerosene lamp burns? What causes
the kerosene to rise up through the wick?
Materials:
• kerosene lamp (with fuel)
• candle
• matches
• electric lamp
(Caution: Only kerosene fuel should be used in a kerosene lamp. Do not use camp fuel).

5The History of Petroleum Chapter 2
Questions (cont…):
(5) Of what chemical element is the black soot that is deposited on the lamp glass
composed? (Hint: It is not hydrogen).
(6) What makes the light bulb glow? Is it also burning a fuel?
(7) Is the electricity that lights the bulb generated by the burning of petroleum or
by a hydroelectric plant?
(8) When did electricity first come to your area?
(Adapted from SEEDS Energy Literacy Series)

Petroleum is not found in underground rivers or caverns, but in pore spaces between the grains of porous
sedimentary rocks (Figure 3.1). But what does the word porous mean? This is most easily explained by il-
lustration.
We have already established that petroleum is found by drilling holes into the ground. Our curiosity must
now lead us to wonder what is going on down underground that allows us to drill a hole and suddenly have
this "black gold" come flowing conveniently to the surface for our use. Are we drilling into underground
rivers or lakes of oil? Caverns filled with natural gas? We will begin to answer these questions in this
chapter. When we reach an understanding of where the oil comes from, it will become apparent why oil is
found in some areas and not in others. This information can then be used in the search for new places to
drill for petroleum.
Porous and Permeable Rocks
Page 3A-1Porous and Permeable Rocks
Porous and Permeable Rocks
Chapter 3A
Three Types of Rocks
Before we proceed to discuss where oil is found in the subsurface, we must become familiar with some new
terminology; namely, the three types of rocks; igneous, sedimentary and metamorphic.
Igneous rocks are rocks that have solidified from a molten or liquid state. These rocks can be formed deep
in the earth or at the surface from the cooling of volcanic lava. Igneous rocks do not normally contain hy-
drocarbons.
Sedimentary rocks are formed by the laying down of sediment in seas, rivers or lakes. The particles of sedi-
ment that accumulate are eventually cemented together to form sedimentary rock by the percolation of min-
eral rich waters through the spaces between the particles. It is these sedimentary rocks in which hydrocar-
bons are normally found. This type of rock will be discussed in more detail in Part "B" of this Session.
Metamorphic rock is formed by the metamorphosis of existing rock, be it igneous or sedimentary, by ex-
treme heat and pressure. These factors cause recrystallization of the minerals in the rock. Metamorphic
rocks do not normally contain hydrocarbons.
Figure 3.1 - Porosity
Porosity
A piece of porous sedimentary rock. The pore spaces are the
white areas between the dark grains. It is within such pore
spaces that fluids such as oil, natural gas, or water can be found
in the subsurface.

Figure 3.2 - Permeability
For oil or gas to be able to flow freely through a rock, that rock must possess permeability as well as poros-
ity. The permeability of a rock is a measure of the ease with which fluids can flow through a rock. This de-
pends on how well the pore spaces within that rock are interconnected (Figure 3.2). If none of the pore
spaces were connected to other pore spaces, then no oil could flow through the rock. The only oil that
would come into the well would be from the pores that were actually in contact with the well bore. This
would obviously not make for a very profitable oil well. On the other hand if the rock has good permeabil-
ity oil can flow to the well from pores that are thousands of metres from the well bore.
A sponge is a good example of a household object that is porous or in other words possesses porosity. If
we take a dry sponge and dip it in water, the sponge will soak up the water. The water that is soaked up is
absorbed into pore spaces within the sponge. The sponge has porosity. If we now squeeze the sponge, we
will close up some of these pore spaces and water will be forced out of the sponge.
In the same way as the sponge, certain types of sedimentary rocks can also be porous and contain oil and
gas within pore spaces . It may not be obvious that a solid piece of rock can act like a sponge, but if we
were to take a piece of porous sandstone (a type of sedimentary rock) and weigh it before and after we al-
lowed it to sit in a pail of water, we would find that it weighed more after. This is because it would have
soaked up some of the water, just as a sponge would. We cannot squeeze the water out with our hands be-
cause we are not strong enough, but you can imagine that if the rock could be squeezed by some giant
hands without being crushed, some of the water would come out.
Porous rocks that contain oil and gas buried thousands of metres below the earth's surface are being
squeezed in this fashion by the weight of the overlying rock and the water contained in that rock. That is
why the oil flows out of the rock and up to the surface when the rock is penetrated by a well.
Page 3A-2Porous and Permeable Rocks Chapter 3A
Permeability
In sketch A above, the pore spaces are well connected allowing fluids to flow quite easily. This rock has good permeability.
In sketch B, the pore spaces are largely isolated from one another giving this rock poor permeability. Sketch A may be some-
what confusing as it appears that the grains are being held in free suspension with nothing to support them. Remember, how-
ever, that this is just a simplified two dimensional sketch. The grains make contact with other grains somewhere out of the
plane of the sketch.

A-3Porous and Permeable Rocks Chapter 3A
Questions
(1) In what kind of rocks is petroleum found?
(2) What does porosity mean? Permeability?
(3) Which type of rock is likely to be more permeable, a sandstone which is
formed from sandy sediment or a shale which is formed from muddy sediment?
Exercises
(1) Examine some samples of igneous, metamorphic and sedimentary rocks.
(2) “Porosity and Permeability”.
Purpose:
To examine the porosity and permeability of various sediments.
Materials:
• four large glass jars (at least 750 ml)
• measuring cup
• wire mesh window screen
• water
• about 2 kg of dry gravel
• about 2 kg of sand
• about 2 kg of clay or potting soil
Fill each of the glass jars as shown in the illustration following; one with clay, one
with sand, one with gravel and one with two thirds gravel on the bottom and one
third clay on top. Pack each one firmly.

A-4Porous and Permeable Rocks Chapter 3A
Questions
(1) Spaces between particles are called pore spaces and their percentages of the total
volume of sediment is called the porosity of the material. Which jar took the most
water and which the least? Which type of sediment had the greatest porosity?
Why?
(2) Permeability is a measure of the ease with which a fluid can flow through a mate-
rial. It is related to how well the individual pore spaces are interconnected.
Which jar did the water flow out of the fastest? The slowest? Which sediment
has the greatest permeability? The least? Are they the same ones that had the
greatest and least porosity?
(3) What happened when water was added to the jar with the clay overlying the
gravel? Is the clay an impermeable seal?
(4) Name the sedimentary rock formed from sand; from clay.
Using the measuring cup add water to each until no more will soak in and it just covers
the surface. Record the volume added in each case.
Using the wire mesh to hold the sediments in place, pour the water out of each jar into
the measuring cup and record the amount that comes back, and take note of how quickly
the water pours out.

All rocks including igneous, metamorphic and sedimentary that are exposed to the elements of wind, rain,
heat and cold eventually give way to wear and tear and are eroded. Some are simply broken up into small
pieces by frost and running water while others are dissolved slowly as weak acids in ground water react
with the minerals contained within the rocks. In either case, the debris or sediment, as it is called, is gradu-
ally carried downhill by the forces of gravity and running water.
As the sediment is washed further and further "downstream", it is broken into smaller and smaller pieces.
Eventually, these rock fragments are deposited in sediment traps such as ponds or lakes. Sediment traps on
land, however, are relatively short-lived. A pond, for example, in which sediment is continuously being de-
posited and not being removed will eventually become filled with sediment. So, inevitably, most sediment
moves on until it is finally deposited into a large body of water such as a very large lake or the ocean itself.
A large depressed area in which a lot of sediment has been or is being deposited is called a sedimentary ba-
sin. Figure 3.3 shows where the main sedimentary basins are located in Canada.
Erosion and Transport
How Sedimentary Rocks are Formed
How Sedimentary Rocks are Formed
Chapter 3B
Figure 3.3 - Sedimentary Basins of Canada
(After the Canadian Petroleum Resource Foundation)
Page 3B-1
Areas with Sedimentary Basins

As sediment is continuously dumped into the ocean, it gradually sinks to the bottom and starts to form lay-
ers. Coarser, heavier material (gravel) is deposited close to the shore and finer grained sediment (fine sand
and clay particles) is deposited further out, in the deeper water (Figure 3.4) Over millions of years, these
layers become thicker and thicker. Sea levels rise and fall because of worldwide changes such as the start
and end of ice ages or as a result of the raising or lowering of the land in the area by powerful forces from
within the earth (the same forces that cause earthquakes). This means that an area that was, at one time in
deep water, can at other times lie in shallower water, and vice versa. Varying the water depth and environ-
mental conditions of an area results in different types of sedimentary layers being deposited in the area at
different times. The result is that in any given area there can be many different layers, containing different
kinds of sedimentary rock. This fact, as we will come to appreciate later, is very important to a person who
wishes to explore for petroleum.
During transport, the sedimentary particles become sorted by size and density. This means that the larger
and heavier fragments will settle faster than the lighter ones. The very smallest particles (fine sand and
mud particles) can be carried hundreds of kilometres out to sea before settling to the bottom in the quiet
deeper waters. The larger pieces (sand, gravel and boulders) will be deposited closer to the shore such as
along beaches (Figure 3.4). Sedimentary rocks that are formed primarily from fragments of other rocks are
called clastics and include sandstones (from sand-sized particles), conglomerates (from gravel-sized pieces)
and shales (from clay particles). But in addition to the rock fragments being transported into the sea, the
flowing waters also contain dissolved minerals such as calcium and salt. These minerals will eventually
come out of solution and form precipitates (solids) when the conditions are right. Sedimentary rocks
formed primarily from this precipitation process include limestone, gypsum and salt.
Page 3B-2How Sedimentary Rocks are Formed Chapter 3B
Sedimentation
Figure 3.4 - Sedimentation

B-3How Sedimentary Rocks are Formed Chapter 3B
Subsidence
As millions of tons of sediment are deposited onto the seabed in an area, the weight of the sediment can
cause the underlying ground to subside or buckle downward (Figure 3.5). This subsidence allows the area
to stay under water even as thick layers of sediment are deposited over millions of years. Subsidence of the
seabed allows thousands of metres of sediment to be deposited in an area even though the water depth may
never exceed a few hundred metres.
Figure 3.5 - Subsidence
Cementation
We now know how sediment is created, transported and deposited. But how is this material transformed
into the solid rocks that we call sedimentary rocks?
As sediment becomes more deeply buried, it is squeezed by the weight of the overlying material. This
pushes the sedimentary particles very close together, forcing out much of the water. The temperature of the
material also increases with the depth of burial and this combination of increased heat and pressure accom-
panied by chemical action of certain dissolved minerals in the ground water cements the sediment into solid
rock.
Why Is It We Find Sedimentary Rock On Dry Land? Shouldn’t It Always Form Underwater?
The answer to this puzzling question lies in the fact that, as previously mentioned, sea levels have risen and
fallen throughout the geologic ages. This combines with the fact that forces within the earth cause the land
to rise up at certain times and subside at other times. Indeed, sedimentary rocks containing marine fossils
that were formed in ancient oceans, eons ago, can now be found at the peaks of the highest mountains.
So it seems that areas that are dry land today may have once been part of the seabed. It is known, for exam-
ple, that the province of Alberta, which we know to be rich in oil and gas resources, was underwater
throughout much of its history.

Questions:
(1) What causes erosion?
(2) What are clastics; precipitates?
(3) What can cause sea levels to rise and fall over the ages?
(4) Where is most sediment deposited?
(5) How is sediment that is eroded from rocks thousands of miles from the coast carried
to the sea?
(6) What is subsidence?
(7) Why is it that we can find fossils of ancient creatures that lived in the sea at the peaks
of mountains?
Exercises:
(1) Field Trip to a River Mouth
Figure 3.4 shows the formation of a delta by sediment being carried to the coast by a river.
Deltas are common throughout the world, especially when the river is very long and carries a
lot of fine sediment. Longer rivers will tend to carry a greater proportion of fine sediments
because they tend to have large drainage areas and the rock fragments will tend to be broken
down into smaller pieces by the many collisions with the river bed and with other rock frag-
ments that take place over a long distance. A river that carries a lot of fine sediment may be-
come overloaded and choke up at the mouth, creating a delta. The size of the sedimentary
fragments is also very much influenced by the type of rock that is being eroded. If the rocks
being eroded are soft and easy to break (sandstone or shale for example), the sediment cre-
ated will be fine. If the rocks are very hard (like granite), the fragments will not break down
into small pieces as easily.
In Newfoundland, most of our rocks are very hard and our rivers are not very long compared
to other areas of the world. As a result, we don't often get the fine sandy beaches that are
common in some other areas. Most of our beaches are largely made up of coarse gravel. We
also don't often get the type of delta shown in Figure 3.4 but are more likely to find a barrier
beach (or spit) as shown in Figure 3.6.
The barrier beach is created when coarse sand and gravel being dumped into the ocean by
the river is driven back by the waves so that it piles up as shown.
In this exercise, you are to visit a beach where a river meets the ocean and observe the proc-
ess of sedimentation first hand. It will be best to go at low tide.

Exercises (cont…):
(2) Precipitation of Salt
We mentioned in this chapter that sedimentary rocks can be formed by the precipitation of
minerals (such as salt) out of water. In other words, minerals that have been dissolved in
water as it moved downstream toward the ocean can later become "undissolved" or precipi-
tated out of the water to form solids again. This exercise illustrates how this can happen
with salt. Warm 500 ml of water to boiling then carefully add salt until no more will dis-
solve. When no more salt will dissolve the water is said to be "salt saturated". Pour off the
solution into a container leaving behind any excess salt. Place a frying pan on a hot plate,
pour in some salt solution and heat it until it evaporates. Continue to pour small amounts of
salt solution into the frying pan until it is all used up. Observe what happens. (It may be
preferable to have the instructor demonstrate this experiment to the class).
(1) What process occurs in the frying pan? The same process is occurring along
the shores of the Dead Sea.
(2) Why are the oceans filled with salt water instead of fresh water?
(3) Under what environmental conditions would you expect to find thick layers of salt
deposited as part of the sedimentary sequence?
Questions:
When you arrive have a good look around. Look for different types of sediment (mud, fine
sand, gravel, etc.). Note where each kind of sediment is found. Have a look at any cliffs or
rocks outcrops nearby. Can you match any of the beach rocks with the types of rock in the
cliff? Can you guess where some of the sediment may have been eroded from?
Draw a simple sketch of the area showing where each type of sediment is found. Why was
the sediment deposited where it is?
Collect samples of different kinds of rocks that can be found at the beach. From what you
have learned so far, try and determine which ones are fragments of sedimentary or igneous
rocks.

Figure 3.6 - Barrier Beach
A
Ocean
Mud .
~ .+ +
!'II + +
Bedrock
PLAN VIEW
Land
Salt Water Pond
Ocean
A
CROSS-SECTIONAL VIEW
Gravel
Sand
----- ...
+ + +- -,;--
Sand and Mud
Gravel
•
.~...
+

Chapter 3 explained how oil and gas are found in porous sedimentary rocks within sedimentary basins. But
does this mean that if you drill a well anywhere at all in a sedimentary basin you will strike oil or gas? The
answer to this question is, of course, no. There are only certain places within sedimentary basins where hy-
drocarbons will tend to accumulate or become “trapped”. This chapter explains why.
Reservoirs
Page 4-1Hydrocarbon Traps
Hydrocarbon Traps
Chapter 4
If you wanted to find a large supply of water, where would you look? You would, of course, go out and
look for a lake or a pond. But, have you ever thought of why ponds and lakes are located where they are?
To understand why water collects where it does, we must consider the forces that are acting upon it.
The force of gravity makes water run downhill. Therefore, water collects in low bowl-shaped depressions
in the land. These bowl-shaped depressions provide traps in which water collects and become lakes and
ponds. Fortunately for us, there are many such natural water traps or reservoirs that conveniently store
large amounts of water for our use.
In a similar fashion, when we look for oil, we must look for places that oil is likely to accumulate in large
quantities. To understand where oil will collect, we must consider the forces that are acting on droplets of
oil buried deep within the earth.
Oil Floats
Anyone who has ever seen oil spilled in a water puddle will notice that it creates colourful patterns in the
sunlight. This is because the oil, which is less dense than water, forms a separate layer which actually floats
on the surface of the water. The different light refracting properties of the two layers create a prism effect,
and hence, the colour patterns.
Droplets of oil in rocks buried deep underground will also float above the water that is also present within
these rocks. Chapter 3 explained how the sedimentary rocks containing these oil droplets formed under
water. Hence, these rocks must still contain some water. So, instead of running downhill as surface water
does under the force of gravity, oil droplets in the subsurface tend to move upward, under the force of buoy-
ancy, so as to float above the water that shares the same pore spaces. Driven by buoyancy, these oil drop-
lets migrate upwards toward the surface through pores and cracks within the layers of rock. If these drops
of oil encounter an impermeable surface through which they cannot flow, they will continue to flow upward
along the underside of this impermeable sealing rock and collect in traps as shown in Figure 4.1. If no traps
are encountered, the oil droplets will migrate all the way to the surface creating an oil seep. Oil seeps(1)
are
quite common in areas of petroleum potential and were used by the earliest oil prospectors to identify drill-
ing locations.
Oil reservoirs in the subsurface in many ways resemble inverted ponds or lakes. Unlike ponds and lakes,
however, accumulations of hydrocarbons are contained inside the pore spaces of solid rock.
____________________
(1)
Oil seeps are common throughout the western portion of the island of Newfoundland especially in the Port au Port and Par-
sons Pond areas.

Natural gas, being less dense than either oil or water, tends to float above water and oil in the subsurface.
Sometimes, the natural gas is dissolved in the oil, but it very often forms a separate layer of its own which
floats above the oil layer. In such a case, we get a layer of natural gas floating upon a layer of oil which is
in turn underlain by a layer of water (Figure 4.1C).
Page 4-2Hydrocarbon Traps Chapter 4
Natural Gas Reservoirs
Figure 4.1
Reservoirs occur in places where fluids tend to collect.
Geologic Structures Become Hydrocarbon Traps
In Chapter 3, we talked about how sedimentary rocks are formed from sediment settling on the floors of
oceans and lakes. Common sense suggests that these sedimentary layers will tend to be laid down more or
less horizontally over large areas. We also know, however, that we need traps to provide areas in which oil
and gas can collect. This means that the layers of rock must somehow become buckled and bent to provide
the geologic structures that may become traps. Fortunately for oil prospectors, forces within the earth itself
create these geologic structures. These powerful forces that tend to stretch, squeeze, bend and break the
rock layers are the same forces that cause earthquakes. The geologic structures that are created (ie., bends

3Hydrocarbon Traps Chapter 4
and breaks or faults in the rock layers) can become hydrocarbon traps where certain conditions are present:
(1) There must be hydrocarbon source rock in the area. Source rock is the fine grained rock
in which the organic material originally present has been converted into hydrocarbons.
(2) There must be a porous and permeable rock layer to provide a reservoir in which the hy-
drocarbons can accumulate.
(3) There must be an impermeable sealing rock overlying the reservoir rock to trap the hy-
drocarbons.
Figure 4.2 shows some examples of geologic structures that commonly form hydrocarbon traps. Note that
there are both structural traps and stratigraphic traps. Stratigraphic traps are traps that are formed by
changes in the characteristics of the rock formation such as a loss of permeability or porosity or a break in
continuity of a layer. Structural traps on the other hand are caused by the bending or breaking of the sedi-
mentary layer. The most common and simplest type of structural trap is the anticline which is a structure
formed when the layers of rock have been buckled upward.
In oil exploration, it is the job of the geologist and geophysicist to find these geologic structures which are
potential hydrocarbon traps and thereby recommend drilling locations. We speak of "potential" hydrocar-
bon traps because not all structures contain hydrocarbons. Many structures contain no reservoir rock, and
so no oil or gas can accumulate. Many contain excellent reservoir rocks, but are full of water. In other
structures, the lack of a good sealing layer prevents oil and gas from accumulating. In other areas, the lack
of a good source rock could be the problem. The only way to know for sure if oil or gas is present in a
structure is to drill a well.
Figure 4.2 - Hydrocarbon Traps
A and B are both examples of struc-
tural traps. C is an example of a
stratigraphic trap formed when a po-
rous rock layer is encased in non-
porous impermeable rock. Revisit
Figure 3.4 and see if you can see
how a stratigraphic trap might be
formed along a coastline.

Questions:
(1) From where else do we get fresh water other than lakes, ponds and rivers?
(2) Why does water accumulate in lakes and ponds?
(3) What causes oil to move upward in the subsurface?
(4) What prevents all of the oil in the subsurface from leaking out at the surface?
(5) What two properties are needed for a rock to be a reservoir rock?
(6) What are the two classifications of hydrocarbon traps?
Exercise:
(1) Oil Floats
Purpose:
To demonstrate that oil floats on water and forms an emulsion with the water when agitated.
(1) Why does oil float in water?
(2) What happens when the oil and water were mixed together by shaking the jar?
(3) What would happen to an oil slick in the ocean that was being tossed about by the
waves? Would it form a completely separate layer from the oil or form an oil/water
emulsion?
(4) Fill an empty glass jar with coarse sand. Now add water until it's half full. Fill the
rest of the jar with motor oil. Can you now picture how oil and water can co-exist in
solid rock in the subsurface?
Materials:
• glass jar with cover
• water
• motor oil
• coarse sand or gravel
Half fill the jar with fresh (or salt) water. Slowly pour motor oil into the jar and observe
what happens. Continue to pour oil until it forms a layer approximately one centimetre
thick. Observe how the oil floats in a separate layer. Now, put the cover on the jar and
shake well for a few seconds. Allow the jar to stand for a few seconds and observe what
happens.
Questions:

Materials:
• large glass jar
• dry sand and gravel
• plasticine (or silly putty)
• length of rubber tubing (attached to a funnel)
• two glass tubes (drinking straws will do in a pinch)
• water
• wire screening taped to the lower end of each tube would be useful, but it is not
necessarily required.
(1) Make a sketch of the model and trace the path of the water.
(2) What happened when you blew air into the gravel? Does this suggest a way
of increasing the amount of oil that can be recovered from an underground
reservoir?
Questions:
Wire screening
Gravel layer
Plasticine layer
Sand layer
Jar
Rubber tubing
Funnel
Tubes
(2) Build a Model Oil Well
Purpose:
To demonstrate how a fluid such as oil or water can flow out of an underground reservoir
and up to the surface.
Procedure:
Place the tubes in the jar as shown in the diagram. Pack
gravel into the bottom half of the jar around the tubes.
Firmly pack a layer of plasticine on top of the gravel and
seal tightly around both the tubes and the edge of the jar.
Fill up the rest of the jar with sand.
Attach a rubber tubing to one of the tubes as shown in the
diagram and pour water slowly into the funnel. Raise the
funnel higher above the can to apply more pressure. Ob-
serve what happens. Blow some air down the funnel (use
your lungs) and observe what happens. Blow harder. What
happens.?

We have now become familiar with the basic concepts of how petroleum is formed in underground sedi-
mentary rocks and how it migrates into underground traps. We will now proceed to learn some of the basic
methods of petroleum exploration. In other words, we will study the techniques by which geologists and
geophysicists search for geologic structures that may be good places to drill for oil and gas.
Contour Maps
Page 5-1Petroleum Exploration I
Petroleum Exploration I - Contour Mapping
Chapter 5
Contour maps are one of the most effective means of displaying information about the geologic structure
(ie., the degree of buckling and faulting of the layers) of an area. A contour is a line on which every point is
at the same level above or below a chosen reference surface. In most maps the reference surface is sea
level. If a contour line represents an elevation on the surface of the ground, it is a topographic contour. A
map showing topographic contours for an area would be called a topographic map.
If such a contour represented an elevation of a rock stratum (layer), then it is called a structure contour. A
map showing structure contours for a certain rock layer throughout an area would be called a structure con-
tour map (Figure 5.1). Such maps are used to illustrate the size, shape and location of geologic structures.
Figure 5.1 - Subsurface Structure Contour Map
Well
Sealing
Rock
Reservoir Rock
-440 m
These contours represent the
depth of the top of the
reservoir layer relative to
sea level
-440 m
-430 m
-420 m
Outer Limit of the Oil Field
(Oil-water contact)
-430 m
-410 m
-400 m
Water
Sea Level
Oil
-400 m
-410 m

For example, suppose you are a geologist working in a given area and you know that approximately 500
metres below the surface there is a porous and permeable sandstone layer overlain by a thick impermeable
shale. And suppose that somewhere in the area the sandstone was arched up in the shape of a dome or anti-
cline. Aha - you say, this is a perfect candidate for a hydrocarbon trap. But now you must somehow con-
struct a structure contour map to determine the size and exact location of the anticline. You will need to
know this so that you can acquire petroleum rights for all of the land overlying the structure before you drill
it and also to determine the best drilling location.
But how can you determine the elevations of a sandstone layer that is buried under 500 metres of rock?
This is something we will address in Chapter 6. For now, we will imagine that you can shovel off the 500
metres of rock and walk around on top of the sandstone layer. Suppose you (with your surveyor) found that
the top of the dome was at an elevation of – 400 metres (the minus sign indicates that an “elevation” below
sea level). Then, if you walked 10 metres down the dome to an elevation of – 410 metres and started paint-
ing a line on the surface of the sandstone at that elevation, you'd find you would paint a line clear around
the dome and end up back where you had started painting. The line you had painted would be the – 410
metre contour on the sandstone layer. Drop down another 10 metres and paint the – 420 metre contour.
You will have a longer walk and use more paint this time. Nevertheless, keep dropping down and painting
a line at each ten-metre elevation until the whole structure has been contoured. You will know that you
have completed contouring the structure when the line you are painting no longer "closes" or in other words
no longer comes back to the point at which you started painting it.
Now that you have contoured the whole structure with your paint brush, hire a plane, fly over the area and
take a photograph. The picture you get will be a contour map of the structure.
Page 5-2Petroleum Exploration I Chapter 5
Contour Maps (cont…)
Questions
(1) What is a contour?
(2) Why do geologists and geophysicists make contour maps?
(3) What’s the difference between a topographic map and a structure contour map?
Exercises
(1) Geologists can rarely get elevations for every point on the surface of a forma-
tion that they wish to map. Instead, through various ingenious methods to be
discussed later, they determine elevations for as many points as possible, plot
these values on a map (as in Figure 5.2) and then construct a contour map. In
this exercise, you are to construct a contour map on the " " sandstone
using the data supplied in Figure 5.2. You can name the sandstone. Usually
a rock layer or "rock formation" is named for the locality in which it was first
recognized and described. (You may use your own name or surname if you
wish).

3Petroleum Exploration I Chapter 5
(2) Superimpose Figure 5.3 on Figure 5.2 and determine who owns the most prospective
land. Which farmer would you be most eager to talk to about the possibility of
obtaining petroleum rights? Where would you drill?
(3) Study a topographic map of an area that is very familiar to you (your own community
perhaps). What is the major difference between this map and the type of map you
have just contoured?
Exercises (cont…)

4Petroleum Exploration I Chapter 5
Figure 5.2
+
-1030
-1040
+
+-1030
-1020 -ltlO
+
-1040
+
-1040
-1030 + +
+
-1020
+ -1030 +
+
+ -1010
+-1020
-1010 + +
-1000 -1010
-1000
+ +
-1030
+
-1020
+ -1030
+
-1000
+ -1020
+-1000 +
-1010
-1020
+
+
+-1010
+-1010
-1020 -1020
-1020+ +
-1010
+
-1020
+
-1020
+
-1030
+
+
-1030
+
-1040
-1020
+
-1040 -1020
-1030
+ -1040

Figure 5.3
Petroleum Exploration I Chapter 5 Page 5-5
-------------- ~~ ~~
---- ~~~
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0HO USE
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"OLD rvIACDONALD" S RANCH"
DUCK
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FLI;C[
--FARMER BROWN'S LAlTD"
Ell MR'

In the last chapter, we were given a map to contour that provided us with all of the necessary data points.
To determine the geologic structure, all we had to do was draw the contours. But contouring is the easy
part. The tough and expensive part is in acquiring the data that allows us to contour such a map. In this
chapter, we will study some of the methods by which oil prospectors obtain such data.
Surface Mapping
Page 6A-1Petroleum Exploration II
Petroleum Exploration II
Surface Mapping, Gravity and Magnetic Surveys
Chapter 6A
In some areas, the presence of subsurface geologic structures, especially anticlines, is evident at the surface.
In such a case, geologists can search for anticlines by studying topographic maps and air photographs, and
by going into the field and studying the rock layers that are exposed (i.e. outcrops) at the surface. Anti-
clines are not, however, always represented as ridges or hills on the surface. An anticline is an upfold of
rocks, true, but the land surface is a product of erosion and may not reflect the underlying structure. Some-
times the crest of an anticline is represented by a topographic low (Figure 6.1) such as a river valley.
To determine the subsurface structure from the surface geology, the field geologist must study every possi-
ble outcrop in the area and determine the angle and direction at which the formations or layers are dipping.
He or she must sometimes dig holes through the surface sediments, climb down into water wells or dive
into rivers and lakes to acquire the precious data points that are needed to construct a contour map.
Figure 6.1 - Eroded Anticline
Sometimes geologists can estimate the subsurface structure by studying the rock layers that “outcrop” on
the surface. The subsurface does not always match the surface topography. In this example, a topog-
raphic low (river valley) overlies a subsurface high (an anticline).

In most areas, the subsurface structure cannot be determined from studying the surface alone. In such areas,
the formations may have been eroded and then covered by thick layers that do not parallel the underlying
beds (Figure 6.2); or the area may be covered by swamps or jungle or may even be under the ocean as is the
case on the Grand Banks of Newfoundland. Fortunately, the geologist has a friend to help out in these
situations. That friend is the geophysicist.
The geophysicist uses physical phenomenon such as magnetic attraction, the pull of gravity, the speed of
sound waves through different types of rocks, and the behaviour of electric currents to determine the sub-
surface structure. Here we will discuss two of the more important exploration methods used by geophysi-
cists; namely, gravity mapping and magnetic mapping. But first we must introduce a new term; basement
rocks.
Page 6A-2Petroleum Exploration II Chapter 6A
Geophysics
Figure 6.2
In many areas there are no clues to the subsurface structure visible at the surface. Geophysical methods
must be utilized to estimate subsurface structure in such areas. Here the geophysicist is recording grav-
ity and magnetic measurements to determine the topography of the basement rocks. Hydrocarbon traps
are often formed over basement highs as shown here.
Basement Rocks
A sedimentary basin is normally underlain by igneous and/or metamorphic basement rocks (Figure 6.2).
These basement rocks have two important properties that distinguish them from sedimentary rocks in the
eyes of a geophysicist. (1) They are more magnetic than sedimentary rocks; and (2) They are more dense
than sedimentary rocks. These two differences provide the basis for two very useful geophysical tech-
niques; magnetic surveying and gravity surveying.

A-3Petroleum Exploration II Chapter 6A
The magnetic properties of basement rocks create distortions and anomalies in the earth’s magnetic field.
The magnitude of these anomalies as measured at the surface, is proportional to the depth of burial of the
basement rocks (Figure 6.3). In other words, when the basement rocks are close to the surface, the mag-
netic distortions (measured on an instrument called a magnetometer) are stronger. When the basement
rocks are buried deeper, the magnetic distortions seen at the surface will be weaker. The geophysicist, by
taking magnetic measurements throughout an area, can estimate the geologic structure of the basement
rocks, as well as the thickness of the sedimentary cover rocks.
Figure 6.3 - Gravity and Magnetic Profiles
Magnetic Surveys
This simplified schematic shows how gravity and magnetic measurements taken at the surface can pin-
point the location of a subsurface anticline.
Gravity Surveys
Since basement rocks have a higher density than sedimentary rocks, they have a stronger gravitational at-
traction. The tiny differences in the earths gravitational field that are measured in gravity surveying are too
small to be noticeable to humans. In other words, you would not feel heavier if you were standing in an
area where the basement rocks were close to the surface. These gravitational differences can only be de-
tected using a very sensitive instrument called a gravity meter.
The principles employed in gravity surveying are very similar to those of magnetic surveying. That is,
when basement rocks are close to the surface, the gravitational distortions will be greater; when the base-
ment rocks are deeply buried, the gravitational distortions will be less pronounced (Figure 6.3). Once again

Gravity Surveys (cont…)
the geophysicist, using the gravity meter, takes hundreds (or even thousands) of measurements throughout
an area. The values are plotted on a map at the appropriate locations and then, after making a number of
mathematical corrections, the geophysicist is able to make a map that will show the structure of the base-
ment rocks which may be thousands of metres below the surface.
Questions:
(1) Is it possible to sometimes find a good place to drill for oil just from surface
mapping?
(2) In what kinds of areas is surface mapping not very effective?
(3) What do we mean by basement rocks?
(4) What characteristics of basement rocks are important to geophysicists?
(5) What is the instrument used in magnetic mapping?; gravity mapping?
Exercise:
(1) Gravity Mapping
Table 6.1 contains a list of gravity values acquired during a gravity survey. Figure 6.4
shows the location of the "gravity stations"; ie., the exact locations where gravity measure-
ments were taken. The gravity values listed do not represent the absolute gravitational pull
at each station, but are rather a measurement of the gravitational distortion created by the
basement rocks. The unit of gravity measurement is the "milligal". One milligal equals one
millionth of a "g". One g is the gravitational force we normally experience at the surface of
the earth.
Using the data provided in Table 6.1, plot the gravity values at the appropriate stations on the
map (Figure 6.4). When all of the values have been plotted, contour the map using a 10 mil-
ligal contour interval (ie., use values of 10, 20, 30, etc., for contour lines). Note that contour
lines need not always go through the stations. If, for example, a certain station had a value
of 5 milligals and the next station had a value of 15 milligals then we would know that the
10 milligal contour should go halfway between these stations.

Table 6.1
Data for Gravity Mapping Exercise
Station # Gravitational
Value
(milligals)
Station # Gravitational
Value
(milligals)
Station # Gravitiational
Value
(milligals)
11 80 33 73 56 21
12 74 34 60 57 12
13 67 35 28 61 7
14 60 36 21 62 60
15 30 37 10 63 28
16 25 41 78 64 23
17 20 42 68 65 15
21 82 43 60 66 7
22 76 44 28 67 6
23 72 45 18 71 60
24 60 46 10 72 27
25 27 47 7 73 19
26 20 51 77 74 12
27 12 52 70 75 8
31 82 53 60 76 7
32 77 54 28 77 6

Figure 6.4 - Location of Gravity Stations
11
+
31
+
51
+
71
+
21
+
41
+
61
+
12 13 14 15
+ + + +
22 23 24 25
+ + + +
32 33 34 35
+ + + +
42 43 44 45
+ + + +
52 53 54 55
+ + + +
62 63 64 65
+ + + +
72 73 74 75
+ + + +
16 17
+ +
26 27
+ +
36 37
+ +
46 47
+ +
56 57
+ +
66 67
+ +
76 77
+ +

Reconnaissance and Detailed Surveys
Page 6B-1Petroleum Exploration III
Petroleum Exploration III - Seismic Exploration
Chapter 6B
Geophysical surveys can generally be classified into two categories: reconnaissance surveys, which are run
to define broad areas of interest that contain the thick sedimentary layers that have the potential to contain
hydrocarbon traps; and detailed surveys which are conducted to locate individual geologic structures which
can then be drilled.
The gravity and magnetic surveys discussed in Part "A" of this chapter would generally be classified as re-
connaissance type surveys. Magnetic surveys are often done from an airplane flying a grid pattern over a
large area. These “aeromagnetic” surveys define the areas where sedimentary rock is thick enough to war-
rant further, more detailed work.
Gravity and magnetic surveys are also frequently done from ships to find sedimentary basins in offshore ar-
eas. Once again, these surveys would be followed up by a more detailed type of survey before well loca-
tions could be chosen. The most common geophysical technique for obtaining the detailed geologic struc-
tural information needed to pick well locations is, however, the seismic survey.
The Seismic Survey
The most accurate and widely used means of finding good drilling locations is the seismic survey. Seismic
surveying involves sending sound waves down into the ground and recording the echoes that bounce back
off the various sedimentary layers.
The sound or shock waves are generated by; setting off small explosive charges just below the surface; hit-
ting the ground with a heavy weight; or shaking the ground using large vibrator trucks. The echoes return-
ing from the subsurface are detected by sensitive instruments called geophones which are strung out along
the ground in a straight line. The geophones are connected by electrical cable to a recording system. The
recording system precisely records, to the nearest one thousandth of a second on magnetic tape, the time it
takes for the echoes to return to the surface. By knowing the amount of time it takes for a sound wave to
reach a certain layer and then bounce back to the surface, as well as the speed of sound through the rock
layers in between, the geophysicist is able to determine the depth to that layer at that location. By determin-
ing the depth at a large number of points along the seismic line, the geophysicist is able to create a profile of
the underground layers along the line.
A good analogy to the seismic method is the sonar system used on ships to determine water depth and
sometimes to locate schools of fish. The sonar system works by sending a small sound wave downward
from the ship, which bounces off the seabed. The time it takes for the echo to return indicates the water
depth. The principal involved is exactly the same as seismic, except that the sonar waves do not penetrate
deeply into the seabed to give information about underlying layers. The more powerful seismic waves, on
the other hand, can penetrate deeply into the subsurface and bring back information on rock layers tens of
kilometres below the surface.
Figure 6.5 shows the basic setup used in seismic surveying. Note that many geophones are laid out in a
straight line so that the depths for many subsurface points can be determined all at once. Also, notice that
all of the energy in a seismic wave does not bounce back from the first layer encountered. Some energy

B-2Petroleum Exploration III Chapter 6B
The Seismic Survey (cont…)
Figure 6.5 - Seismic Exploration
bounces back, but some of the energy continues its downward journey to bounce off other, deeper layers.
Some rock layers will reflect very little energy back to the surface while others, such as limestone, reflect a
lot of energy. It is these strongly reflecting layers that are most useful to the geophysicist in mapping the
subsurface structure.
Figure 6.6 is an example of a seismic section. The seismic section is the most common method of display-
ing and interpreting the massive amounts of data that are acquired during a seismic survey. The horizontal
scale in this display represents a straight line along the surface of the ground. The vertical scale represents
the time it took for the echoes to return from different sedimentary layers. From this display, one can read-
ily see the subsurface geologic structure along this line.

B-3PetroleumExplorationIIIChapter6B
Figure 6.6
Seismic section across the Hibernia Field within the Jeanne d’Arc Sedimentary Basin offshore Newfoundland. The lines on the section show
how the geophysicist has interpreted the section. The darkened circles on the well on the right identify the different zones in which oil was dis-
covered. Note that the Hibernia field is a structural trap; an anticline bounded by two faults.
(Seismic line courtesy of Geophysical Services Incorporated).
Hibernia
Hibernia
Oilfield

Offshore Seismic
Figure 6.7 shows how a seismic crew operates in the offshore. In this case, the aquatic equivalent of the
geophone, the hydrophone is used to detect echoes returning from the underground layers. The hydro-
phones, which are essentially underwater microphones, are attached to a buoyant cable and towed behind
the ship. The shock waves are generated by a high pressure air gun towed near the back of the ship. Al-
though the equipment used in recording offshore seismic is somewhat different than that used onshore, the
principles involved are exactly the same.
Hydrophones
(under-water microphones)
Seabed Echo
Sedimentary
Layers
Energy Source
(High Pressure Air Gun)
Soundwaves
Figure 6.7 - Offshore Seismic Exploration
Questions:
(1) What’s the difference between a reconnaissance and detailed survey?
(2) How are seismic energy pulses generated on land?; in the ocean?
(3) On what principle is seismic exploration based?
(4) How is a bat’s navigation system and a whales sonar system similar to the seismic
technique?
(5) What’s a geophone?; a hydrophone?

Exercises:
(1) Examine the sample seismic section in figure 6.6. Can you see why the Hibernia
field is located where it is? Can you find any other good drilling locations?
(2) Go to an area where a good clear echo can be generated. A starters pistol can be
used as an "energy source". Using a stopwatch (accurate to 1/100 of a second),
measure the time it takes for the echo to return. Now calculate the distance to
the echoing object using the following.
distance = 1/2 x (time for echo to return) x (speed of sound in air)
speed of sound in air at sea level = 330 metres per second
(3) Vary the distance from the echoing object and repeat exercise 2.

Acquiring Petroleum Rights
Page 7-1Acquiring Petroleum Rights
Petroleum Exploration III - Acquiring Petroleum Rights
Chapter 7
Up to this point in our study of petroleum exploration, we have met two important characters; the geologist
and geophysicist. These are the people who are diligently mapping the countryside using all of the tech-
niques at their disposal to find new geologic structures to drill. But before any drilling can take place, pe-
troleum rights must be acquired for the land areas under which these structures are located. This is the job
of the landman.*
Surface Rights vs Petroleum Rights
When a petroleum landman talks about acquiring land, he or she is really talking about acquiring the petro-
leum rights below the surface of that land. The landman does not usually wish to acquire the surface rights
as well, but does want to obtain the right to perform work on the land in order to explore for petroleum.
For example, a landman may approach a rancher who owns both surface and petroleum rights on the ranch.
The landman will negotiate a deal whereby the oil company can drill and produce any oil or gas found on
that property. The rancher, however, still owns the surface rights and continues ranching on the property.
This is a beneficial arrangement to both parties, because if oil is discovered, a certain percentage will be-
long to the rancher who will get a share of the profits. The oil company, on the other hand, saves the cost of
having to buy expensive surface rights.
Resource Ownership
In Canada, surface rights and petroleum rights are usually owned separately, by individuals, by corpora-
tions, by the federal government or by a provincial government. If surface or petroleum rights are owned
by a government, they are said to belong to the Crown and are called Crown lands. If surface or petroleum
rights belong to an individual or company, they are called freehold lands. In most areas in Canada, the
Crown owns the petroleum as well as other types of mineral rights even though the surface rights may be-
long to individual citizens. Surface rights may change hands repeatedly on these lands, but the petroleum
and mineral rights remain the property of the Crown.
Freehold petroleum rights (freehold lands) originated in the early years of settlement in this country. Dur-
ing those times, when homesteaders were granted lands by the government, the grant included the rights to
petroleum or any other mineral that might be present on or beneath the land. Eventually, the government
changed this policy so that petroleum and mineral rights were excepted from those grants. Freehold lands
that exist today usually belong to the descendants of these original freeholders. Individuals who owned
these freehold lands and were fortunate enough to have oil discovered on their property often became rich.
Freehold land is much more common in the United States than in Canada. The State of Texas which has
been the most important oil producing state in the U.S. has witnessed the creation of many millionaires who
were lucky enough to have oil discovered under their property.
___________________
* The term “landman” is a “term of trade” that applies to both male and female members of the profession.

In today's oil industry, there are a variety of agreement types that
allow for the exploration and the production of oil. The most im-
portant type of agreement and the most widely used is the lease
(Figures 7.1 and 7.2).
In most cases, when a company acquires a lease, it does not pur-
chase the surface rights. The surface rights remain with the surface
owner who is usually compensated in some way for the inconven-
ience of having petroleum operations carried out on the property.
A number of variables are associated with individual leases, includ-
ing: the term, rentals, royalties and bonus payment. The bonus pay-
ment is a one time lump sum payed up front when the lease is
signed. The drilling delay rental, or rental, is a fee paid to the les-
sor when the lessee is delayed in commencing drilling a well. It
may vary from a few cents per hectare to several dollars per hectare,
depending on the level of activity in the area. The royalty is the
percentage of the oil and gas produced that is the property of the
lessor (the person, company or government that is granting the
lease). This is usually handled as a regular cash payment to the les-
sor, but is sometimes a quantity of the petroleum itself. Histori-
cally, the royalty has been 1/8th (12.5%), but it varies widely today.
Page 7-2Acquiring Petroleum Rights Chapter 7
The Lease
Figure 7.1
The lease is a widely used type of
agreement between the owner of
the petroleum rights and the oil
company that allows the oil com-
pany to explore for petroleum on
the lessors land and produce any
petroleum discovered.
(Courtesy of Petroleum Extension Ser-
vices (PETEX), The University of Texas at
Austin).
Obtaining a Lease
Every exploration lease has a term or time limit attached. The term represents the amount of time in which
the company has to find petroleum on the property. If no oil or gas has been found by the end of the term,
the lease expires and petroleum rights revert to the original owner. The terms of leases vary, depending
mainly on the level of activity in the area. In easily accessible areas of high activity, the term may be as
short as 2 years. In remote areas of little activity, the term may be as long as 10 years or greater.
But what if petroleum is discovered during the term of the lease? In this case, the lease does not expire.
The company will be allowed to produce the petroleum for as long as possible, until no more can be eco-
nomically recovered. In other words, the company will maintain the petroleum rights for "the life of the
field". The life of an oil or gas field will depend on many things, including the size of the field and the rate
of production. It may last only a couple of years or may last for decades. For example, the life of the
Hibernia field on the Grand Banks is expected to be from 20 to 25 years at an average production rate of
110,000 barrels of oil per day.
The landman's job of acquiring leases will vary according to whether the petroleum rights are freehold or
crown (Figure 7.3). If they are freehold, he or she will have to search the title of the property, discuss the
company's anticipated operations with the owners, negotiate the terms and conditions of the lease, and en-
sure the proper recording of the agreement.

3Acquiring Petroleum Rights Chapter 7
Obtaining a Lease (cont…)
In the case of crown lands the landman does not deal with individual citizens but with government agencies.
Most crown leases are not acquired by negotiation, as is the case for freehold leases, but must be acquired
through a competitive bidding process. Usually what happens is that an oil company indicates to the gov-
ernment that it is interested in acquiring lands in a given area. The government then makes an announce-
ment that these lands are available for leasing and will be awarded to the highest bidder. Interested compa-
nies will then submit their bids in sealed envelopes to the government agency at a set time and place. The
envelopes are then opened, the highest bidder is determined and the lease is awarded.
Figure 7.2 - Typical Lease Provisions
Lease
On the _________ day of Our Lord 19__, I ______ (lessor) grant petroleum rights on land outlined
in the attached map (A map plus legal description of land would normally be attached) to _____
(lessee).
This lease shall come into effect on _____, 19__ and shall have a term of __ years.
The bonus payment for the lease is $ _____.
If the _____ (lessee) has not commenced drilling a well by the end of the first year of this lease the
lessee shall be required to pay a drilling delay rental of $ _____ per hectare per year to the lessor un-
til a well is commenced drilling on the lease.
If _____ (lessee) should discover petroleum on the lease then the term of the lease shall be extended
until all petroleum that can be commercially recovered from the lease has been produced.
The lessee shall be required to pay to the lessor on a monthly basis a royalty equal in value to ___ %
of all of the petroleum produced from the lease. The lessee reserves the right to take the royalty pay-
ment in kind (i.e., as a quantity of petroleum instead of cash).
Signatures
Lessor __________________ Witness _________________
Lessor __________________ Witness _________________

Obtaining a Lease (cont…)
1. Companies inform the appropriate government
agency of the lands they would like to see made
available.
2. Government agency publishes a map showing
which lands are available for biding.
3. Companies submit bids for the different parcels
of land in sealed envelopes at a set time and place.
4. Envelopes are opened and the winning bids are
announced.
5. Government issues leases to companies who
submitted the winning bids for different parcels of
land, for a set period of time.
Figure 7.3 - How Petroleum Rights Are Usually Acquired
Questions:
(1) What is the job of the landman?
(2) What’s the difference between surface rights and petroleum rights?
(3) What do we mean by Crown lands?; freehold lands?
(4) Is most of the land in Canada Crown or Freehold?
(5) What are the usual components of a lease?
(6) What happens to the term of a lease when a lessee makes a petroleum discovery?
1. Company landman approaches the owner of the
land of interest to try and negotiate a lease.
2. If the landman is successful, the owner agrees to
sign a lease and give the company petroleum rights
for a set period of time.
3. Landman must register the lease with the appro-
priate government agency.
Crown Land Freehold Land

Exercises:
(1) Split the class up into groups of three. One of the three will be a farmer who
owns some freehold land, the other two will be landmen from competing compa-
nies who wish to negotiate a lease on the farmer's land. The farmer wants to get
the best deal possible in terms of a bonus payment, royalty rate, rentals and
length of term. The farmer also wants to ensure not being inconvenienced too
much by the petroleum operations on the property. After all, a drilling rig with
all the associated equipment and traffic can get in the way during the harvest.
The landmen, too, wish to negotiate the best possible deal for their companies.
They do not wish to give too much away because every other farmer would want
the same deal. However, they also want to be fair, because an unhappy lessor is
no asset to their company, especially if they wanted to negotiate leases with
other farmers in the area at a later date.
The farmer will talk to each of the landmen individually (twice) and then choose
which company will get the lease. Use Figure 7.2 to seal the deal. Each group
will report the details of the winning deals to the class and discuss.
(2) An oil scout is a person employed by an oil company to "keep an eye on" what
the competition is doing. Oil scouts are not really "spies" as they are not to do
anything illegal, but there is much that can be uncovered quite legally by an ex-
perienced oil scout with a good set of eyes and ears.
For example, the rig hand that likes to head to the local tavern at night and brag
about all of the oil "he" is finding is someone the oil scout would probably like
to have a few drinks with. Of course, the oil scout would never admit to who he
or she really is, as that would put everyone on their guard. They'd probably pose
as a salesman of some sort that's just passing through. But there is nothing ille-
gal about that, is there?
Assume you are an oil scout in the employ of the Desperate Oil and Gas Com-
pany. Your company hasn't had much luck (except bad luck) in discovering any
oil or gas in the last couple of years. You've heard rumours of a couple of dis-
coveries in the Stephenville area, and your boss wants you to find out what's go-
ing on. Armed only with your wits, a desire to remain employed and what
you've learned thus far in this manual, what would you do and what are the types
of things and people you would look for?
(3) In Chapter 11, groups of students will be required to present an oil and gas news
mural consisting of pictures, headlines from newspaper and magazine articles,
hand drawings, etc. The mural should be constructed by pasting these items to a
poster size piece of cardboard or construction paper. So skip ahead now, read
Chapter 11, and have the students get started on compiling the needed materials.

1Drilling
Drilling
Chapter 8
Now that we have found a promising geological structure and acquired the petroleum rights, it is time to go
ahead and drill. Regardless of all the sophisticated geological and geophysical mapping that has been done,
the only way to find out if there is any oil or gas present under your land is to drill a well (Figure 8.1).
A Wildcat Well
Anticlines and other potential hydrocarbon traps can be located using seismic and other techniques, but
the only way to find out if petroleum is present is to drill a well. Here we have two identical geologic
structures side by side and only one of them contains oil. Only about one in ten wildcat wells is a discov-
ery.
Figure 8.1 - Luck Does Play a Role!
* Any well that does not find petroleum in commercial quantities is called a dry hole; even if the well does,
as in this case, find water.
The well that we are about to drill is called a wildcat well. This means that we will be drilling into a geo-
logic structure in which no oil or gas has yet been discovered. We will be attempting to discover a new oil-
field. If a discovery is made on this geologic structure, we will need to drill more wells (delineation wells)
to determine the size of our oilfield. Drilling wells is an expensive and risky business. The costs can run
into millions of dollars and the chance of success for wildcats is only about one in ten.
Drilling the Well
Drilling a well involves a whole new cast of characters. The drilling engineer, the driller, the tool pusher,
the roustabouts, the roughnecks, the logging crew and many others. We will not get into detail regarding

the responsibilities of each of these individuals, as this reaches beyond the scope of this manual, but we will
provide a generaldescription of the drilling process and its challenges.
The overall objective of drilling is to bore a hole (the well bore) into the ground until you penetrate a target
rock formation, that has been identified by the geologists and geophysicists as having the potential to con-
tain commercial hydrocarbons. We know from Chapter 3 that the formations through which we will be
drilling may be porous and permeable, and may contain fluids (oil, water or natural gas) at very high pres-
sures. If we were to drill into such a formation without taking the appropriate precautions, the fluids would
spew violently out of the hole and we'd have what's called a blowout. Blowouts can be extremely danger-
ous as well as damaging to the environment. In the early days of the oil industry, before drilling technology
had evolved significantly, when a well struck oil it often blew out. These blowouts frequently caught fire,
destroyed the rig, and sometimes cost rig workers their lives.
Figure 8.2 is a picture of a major oil blowout at the Spindletop field near Beaumont, Texas in 1901. This
field went on to become one of the greatest oil producers in U.S. history.
Page 8-2Drilling Chapter 8
Drilling The Well (cont…)
Figure 8.2 -Blowout
The Spindletop Blowout in Texas
spewed 50,000 barrels per day for 9
days in 1901 before the well could
be controlled. Oil drillers were ill
prepared to deal with the pressure
in this reservoir as no blowout of
this magnitude had ever before been
witnessed.
(With permission of the University of
Texas at Austin and the Spindletop/
Gladys City Museum).

3Drilling Chapter 8
Drilling the Well (cont…)
In today's drilling industry, blowouts are very rare. The entire technology of today’s drilling industry is fo-
cused on the ideal of drilling safely and economically into the pressurized underground formations, without
allowing any uncontrolled flow of fluids out of the well. The well is allowed to flow through a series of
valves only under controlled conditions.
But how do we accomplish this? What are the basic techniques of oil well drilling?
Figure 8.3 -Drill Bit
Drilling Technology
Drilling a well is, in many ways, similar to drilling a hole into a
piece of wood using a rotating drill bit. The bit, in this case is
much larger and is attached to the bottom of a hollow steel pipe
called a drill string (or drill pipe) that can be thousands of metres
long (Figure 8.4). The drill string is rotated by an engine at the
surface.
The rock drill bit is not the screw-shaped type, but is a roller-type
bit made up of three cone-shaped, toothed cutters (Figure 8.3). As
this bit rotates, under several tons of downward pressure, it
crushes the rock. The drill string is composed of a number of 9
metre lengths of high strength steel pipe that are screwed together
end to end. As the well is deepened, the drill string is lengthened
by screwing additional lengths of pipe to the top. But now a cou-
ple of questions should come to mind.
(1) How do we get these pieces of crushed rock (rock cuttings) up out of that hole, which may be thousands
of metres deep? (2) How do we keep the high pressured liquids and gases, that may be present in the rock
formations, from blowing out? Both of these concerns are addressed by the drilling mud.
Drilling mud, which is a mixture of clay, high density solids (weighting material), water and chemical addi-
tives is pumped down through the inside of the hollow drill string (Figure 8.5). Because the drill bit, and
hence the borehole, is larger in diameter than the drill string, a hollow space (the annulus) exists between
the drill string and the walls of the borehole. The mud that is being pumped down squeezes through holes
in the drill bit and circulates back to the surface through the annulus, carrying the rock cuttings along with
it. Back on the surface, the rock cuttings are mechanically removed from the drilling mud in the “shale
shaker” and can be examined by the wellsite geologist. The same mud can then be recirculated through the
drill string and the process continues while drilling is in progress.
___________________
Figure 8-3, from An A-Z of Offshore Oil & Gas by Harry Witehead. Copyright 1983 by Gulf Publishing Company, Houston,
Tx. Used with permission. All rights reserved.

4Drilling Chapter 8
Drilling Technology (cont…)
Figure 8.4 -Drilling Rig
Derrick
Swivel
Mud Hose
Mud Pump
Engine
Rotary Table
Blowout Preventor
Drill Bit
Drill Pipe
Casing

5Drilling Chapter 8
Drilling Technology (cont…)
Drilling mud is also the key to preventing blowouts. If the drill bit penetrated a porous and permeable for-
mation containing oil and gas under high pressure, the oil and gas would naturally tend to rush out of the
formation and up the borehole. But in order to do this, it would have to overcome the downward pressure
exerted by the thousands of kilograms of slowly circulating mud. What usually happens in such a case is
that only small traces of oil or gas will flow out of the formation and circulate back to the surface with the
mud. This result is actually useful to the wellsite geologist as oil returning with the mud is a good indica-
tion that there are hydrocarbons down below.
Drilling mud also helps to cool and lubricate the drill bit and provides a protective and stabilizing coating
on the walls of the borehole, which helps to seal off porous formations and keep the wellbore from caving
in.
Casing the Well
Logging the Well
Although the drilling mud does help prevent the wellbore from caving in and does help to seal off porous
formations that have been drilled, a more permanent and reliable method to accomplish this is to case the
well. Casing the well involves lining the borehole with steel pipe (Figure 8.4) and cementing it in place.
To case a well, the drill string and bit are removed from the hole. The drill string, of course, cannot be re-
moved in one piece. Every third joint in the drill string will be unscrewed and the stands of pipe will be
stacked against the derrick. When all of the drill string and the bit have been removed, the casing is low-
ered into the mud-filled hole by screwing together the 12 metre lengths of casing pipe end to end. The cas-
ing is slightly smaller in diameter than the borehole and is secured in place by pumping cement into the an-
nular space between the outside of the casing and the borehole. When the cement sets, drilling will con-
tinue using a slightly smaller bit than before. As the well is deepened, additional casings of concentrically
smaller diameters are added as needed to seal off the deeper formations.
Although the wellsite geologist can get many hints of the types of rock formations in the well from the rock
cuttings, and sometimes gets hints of the presence of oil or gas by the small amounts that come up with the
drilling mud, more information is needed to properly analyse the rock formations that have been drilled. To
help obtain this information, the geologist has some associates who go by the name of the logging crew.
This logging crew does not come equipped with chainsaws or axes, but with geophysical logging devices.
These logging tools are lowered into the mud-filled hole (usually prior to casing being set in that part of the
hole) and measure the electrical, acoustic, and radioactive properties of the different layers of rock. The re-
sults of these logging measurements are analyzed to determine which of these layers are porous and perme-
able, and likely to contain hydrocarbons.

6Drilling Chapter 8
Casing The Well
Figure 8.5 - Circulation Path of Drilling Mud
This figure shows the circulation path of the drilling mud. The mud is pumped from the storage
tank through a hose and swivel and down through the drill string. It then passes through the
drill bit and starts to move upward through the annulus carrying rock cuttings with it. Back at
the surface, it travels through a hose and “shale shaker” (which removes the rock cuttings) and
ends up back in the storage tank.

7Drilling Chapter 8
The Drill Stem Test
In the old days before the use of drilling mud, the drilling crew immediately knew when they had hit a good
oil reservoir because the well would blow out. This would be an event of great excitement as well as great
danger. Fortunately, things are done differently today. The excitement and tension of finally determining if
the well is a discovery are still present, but much of the danger has been removed.
After the geologist has analyzed the logs and identified a formation that appears (from the log analysis) to
be porous, permeable and contain hydrocarbons, the excitement begins to build. This is the time of reckon-
ing for the well. It is time to do a drill stem test (DST). The DST involves the lowering of specialized
equipment into the well bore that isolates the formation of interest from the pressure exerted by the drilling
mud so as to allow the fluids within the formation to flow to surface. This determines the flow capability
and the type of fluids (oil, natural gas or water) present in the formation. The DST also records valuable
information on the formation pressure, which is critical to determining whether the well can produce at a
high enough rate and for a long enough time to be profitable. For example, if a well flowed oil at a rate of
100 barrels an hour for 24 hours and showed very little decrease in reservoir pressure, one could conclude
that this was a pretty good well and should produce for a long time. If, however, at the end of the test the
pressure had dropped off by 50%, it would mean that this oil reservoir was small and could not produce for
a long enough time to be profitable. A well that cannot produce hydrocarbons in commercial quantities is
called a dry hole.
The Blowout Preventor
It should be evident, from our discussion thus far, that a drilling rig is a very complex piece of machinery
containing a broad range of specialized equipment. Although we won’t go into a detailed discussion on the
workings of every part of a drilling rig here, there is one special piece of equipment that is critical to the
safe operation of the rig and warrants special mention. Have you considered what would happen if the bit
drilled into a porous and permeable formation, in which the pressure was so great that the weight of the
mud column could not hold the formation fluids back? What would happen is that the fluids in the forma-
tion would enter the annulus and start heading for the surface. The first indication at the surface would be
that the mud level would start to rise in the mud tanks because the mud would be coming out of the hole
faster than it is being pumped back down the drill pipe. This is called a kick. If proper and decisive action
is not taken by the driller, such a kick could lead to a blowout. When a kick occurs the driller immediately
activates the backup system - the Blowout Preventor (BOP).
The BOP (Figure 8.4) is a system of powerful hydraulic rams anchored to the casing which can, at the flick
of a switch, be closed and sealed around the outside of the drill pipe preventing any further flow of mud or
formation fluid up the annulus. When the flow has stopped, weighting material is added to the mud making
it heavy enough to hold back the formation fluids. When this is accomplished, drilling resumes.

(1) Is it possible to determine if petroleum is present in a geologic structure using only
seismic data?
(2) Why do wells sometimes blow out?
(3) How is drilling mud used to prevent blowouts?
(4) What is the purpose of the casing in the well?
(5) How does a well site geologist figure out which zones should be drill stem tested?
Page 8-8Drilling Chapter 8
Questions:
Exercise:
(1) Watch a video on oil well drilling. You may approach your local library, media
outlets or large oil companies working in your area to see which videos are available.

1Drilling Offshore
Drilling Offshore
Chapter 9
Since the modern oil industry began in the 1850's, hundreds of thousands of wells have been drilled.
Gradually, the most easily accessible onshore areas have been drilled up and most of the easy-to-find fields
have been found. The result is that it has now become increasingly difficult to find new oil and gas fields in
the old familiar areas. This has lead to the search for new frontiers in which to explore for oil and gas.
These new frontiers include offshore areas on the continental margins; areas like the Grand Banks of New-
foundland and the Labrador coast.
As stated in Chapter 8, the drilling industry is a major industry in its own right. This being the case, the off-
shore drilling industry is a major industry within the drilling industry. It is an extension of that industry
into the unfamiliar and often unfriendly setting of the open ocean.
A Hostile Environment
Offshore drilling came about gradually as explorers first built jetties out from the land and later mounted
entire rigs on barges that could drill in quiet shallow waters (Figure 9.1). Today, offshore drilling takes
place on the open ocean and, in addition to dealing with the usual difficulties associated with drilling on-
shore, it must also contend with waves, currents, fog and deep water. In some areas, as on the Grand
Banks, there are the additional complications of cold temperatures, icebergs, pack ice, storms that bring
winds of more than 160 kilometres per hour, and waves that can be more than 30 metres high. In this chap-
ter, we will learn how the drilling industry meets the challenges of drilling in such a hostile environment.
The Technology of Offshore Drilling
Perhaps the most obvious difference between drilling offshore and onshore is that an onshore rig sits di-
rectly on the surface through which it is to drill. However an offshore rig can be floating anywhere from a
few tens of meters to a couple of thousand metres above the sea bed, and must therefore be attached to the
sea floor by a large steel pipe called a marine riser (Figure 9.2). The riser then acts as a conduit for the drill
string and the drilling mud. In essence, it is an extension of the casing that allows the drilling mud and rock
cuttings to be isolated from the water column and circulated back to the rig.
Another complication in offshore drilling is that, since the sea is seldom calm, the rig is constantly heaving
and rolling in the swell. Tensioners and motion compensators allow the riser and drill string to remain rela-
tively stationary, and keep a constant weight on the drill bit while the rig moves with the swell. But what of
the winds and currents that tend to move the rig off the drilling location? It is easy to imagine the problems
that even a small amount of drifting would cause when the drill pipe is extended thousands of metres into
the sea bed. The industry has adopted two solutions to this problem. The first involves an elaborate system
of 8 to 12 anchors, each weighing up to 20 tons. Mooring lines comprised of heavy steel chains can extend
a mile or more, depending on water depth.
A second system that is being increasingly used is the dynamic positioning system or DPS. The DPS can
either supplement or replace the anchors with a computer controlled system of propellers or thrusters.
Through an array of motion sensors, the computer can immediately detect any movement of the rig and then
apply just enough power to the appropriate thrusters to compensate and keep the rig exactly on location.
This type of system makes it possible to drill in much deeper water, where anchors would not be feasible.
Wells can now be drilled in water depths exceeding 2000 metres.

2DrillingOffshoreChapter9
Figure 9.1 -Evolution of Offshore Drilling
(Modified after Shell Oil)

3Drilling Offshore Chapter 9
The Technology of Offshore Drilling (cont…)
Another important advantage of DPS is that it allows the drilling rig to quickly disconnect the riser and
move off the location in case of an emergency (such as the approach of an iceberg). As you can imagine,
the retrieval of several twenty-ton anchors would be quite time consuming and would require a lot more
lead time when making the important decision to leave the drilling location. The significance of such a de-
cision becomes apparent when one realizes that it costs in the neighbourhood of $250,000 per day to oper-
ate a rig on the Grand Banks. In this kind of operation, any time lost becomes very expensive.
Figure 9.2 -Semisubmersible Drilling Rig
When drilling offshore, a drilling rig must be attached to the seabed by a marine riser. The drillpipe and
drilling mud are isolated from the water column by the marine riser.

Supply Vessels
An offshore drilling rig located hundreds of kilometres from land with a crew of about 100 people, needs a
lot of supplies. These include food for the crew, fuel for the engines and generators, sacks of cement and
sacks of bentonite and barite which are mixed with water to make the drilling mud. It needs hundreds of
tons of drill pipe, casing, and, of course, the huge and massive sections of pipe that are put together to form
the riser. It is not always possible for a rig to store all of these provisions on board and so each rig has a
supporting cast of two or three supply vessels.
The supply vessels, in addition to delivering supplies and equipment to the rig, perform other important du-
ties. They assist in the deployment and retrieval of anchors and at least one vessel stands by the rig at all
times in case it must be abandoned. They sometimes participate in the transfer of personnel to and from the
drilling rig (the crew changes every 3 weeks), although this is usually handled by helicopters. They tow the
rig, when it is not self-propelled, from one location to the next and in some areas, as on the Grand Banks,
they are required to tow icebergs that may be drifting into the vicinity of the rig.
Types of Offshore Drilling Rigs
There have been many types of drilling rigs used since the industry took
its first steps into the offshore areas. Figure 9.1 shows some of these
variations. Today, however, there are three important types of mobile
offshore drilling rigs that operate in the open marine areas. These are
the jackup, the semi-submersible and the drillship (Figures 9.3, 9.4 &
9.5).
Jackup rigs (Figure 9.3) are usually towed to the drilling location. At
the site, the legs are lowered to the seabed and the platform is jacked up
to a safe level above the sea. When drilling operations are completed,
the legs are "jacked up" high enough so that the rig can float freely and
be towed to the next location. The maximum water depth in which
jackup rigs are used is about 90 metres.
Figure 9.3
Jack-Up Drilling Unit
The semi-submersible rig (Figure 9.4) is comprised of a drilling platform mounted on columns above two
large pontoons. During rig moves, only the pontoons are submerged. At the drillsite, the pontoons are par-
tially flooded so that the rig rides deep in the water providing a remarkably stable drilling platform. Most
semi-submersibles in existence today are moored by anchors, but an increasing number are adopting dy-
namic positioning systems.
The third type of mobile rig, the drillship (Figure 9.5), is comprised of a drilling platform mounted on a
conventional ship's hull. These drilling units have also been moored by anchors in the past, but today most
are using DPS technology. The drillship experiences greater heaving and rolling motion than the semi-
submersible and, therefore, is more limited in the severity of seas in which it can operate. On the other
hand, the greater mobility of the drillship gives it advantages in areas where it may have to move off loca-
tion under short notice, such as in areas with a high iceberg population.

Types of Offshore Drilling Rigs (cont…)
Drillships and semi-submersibles have not yet reached their limits with regard to the water depths in which
they can operate. Using dynamic positioning systems, they have been able to drill in water depths exceed-
ing 2000 metres. Both semi-submersibles and drillships have been used on the Grand Banks. The jackup
has not been used in the Newfoundland offshore, but has been routinely used off Nova Scotia.
Figure 9.4
Semi-Submersible Rig
(Courtesy of Exxon
Corporation)
Figure 9.5
Drillship
(Courtesy of Exxon
Corporation)
Costs
Drilling offshore is much more expensive than drilling onshore. The cost of drilling is very much influ-
enced by environmental conditions. Factors such as distance from land, water depth, well depth, weather
conditions, the presence of pack ice and icebergs all affect the cost of an offshore well. For example, on the
Grand Banks of Newfoundland, in 1991, the average well takes from 60 to 70 days to drill and costs ap-
proximately $16 million. These well costs can only be justified in areas where there is a good chance of
finding very large fields. Offshore Newfoundland and Labrador is one such area. Figure 9.6 shows other
areas in the world where offshore drilling has occurred.
Questions:
(1) Which is more expensive, drilling onshore or offshore?
(2) Why did the oil industry start drilling offshore?
(3) What are the major differences between drilling offshore and onshore?
(4) What types of drilling rigs have been used offshore Newfoundland and Labrador?
(5) Which is better suited to very deep water, an anchor system or a dynamic positioning
system?

Types of Offshore Drilling Rigs
Figure9.6-AreasWhereOffshoreDrillinghasOccurred

Exercises:
(1) View the film entitled “Shotpoint 260”; (30 minutes).
(2) Offshore wells have been drilled in water depths exceeding 2,000 metres (2 kilome-
tres). Think of a couple of locations that are 2 kilometres apart so that you can get
a feel for this water depth.
(3) An offshore well on the Grand Banks today costs approximately $16 million dollars
to drill. In some situations, where problems were encountered and when oil
prices were higher, certain wells cost more than $100 million to drill. By taking the
average house price in your area, figure out how many houses you could buy for the
average cost of an offshore well.
(4) A typical semi-submersible rig is about 95 metres long, 80 metres wide and approxi-
mately 95 metres high to the top of the derrick. Go to an open field and measure off
these dimensions to get a feel for the size of these rigs.

1Field Development and Production
Field Development and Production
Chapter 10
We have now covered the major aspects of petroleum exploration. First of all, we had the geologists and
geophysicists doing surface, gravity and magnetic mapping (reconnaissance work) to identify some areas of
general interest. Then the geophysicists returned to do the detailed seismic work and found some geologic
structures that looked good enough to drill. All the while the landman, who was in constant communication
with the geologists, geophysicists and the company's head office, was acquiring the petroleum rights for the
more attractive areas. Finally, we drilled a wildcat well and against long odds discovered oil.
Now that a field has been discovered, it must be developed so that it can be put into production and gener-
ate some cash. Developing a field involves the drilling of additional wells into the geologic structure and
installing production equipment throughout the field to facilitate commercial production of the oil or gas.
The production phase essentially involves getting the fluids (oil and/or gas) out of the ground, treating the
fluids to remove impurities (such as sediment, sulphur and water), and taking whatever steps are necessary
to keep the wells producing at a profitable rate for as long as possible. But we must now backtrack for a
moment - for in between the exploration phase and the development phase there is quite often one other
phase: the delineation phase.
Delineation Drilling - How Big is our Oil Field?
Thus far, we have drilled only one well (the discovery well) into the oil field. Seismic data is very helpful
in mapping the size of the underground structure, but the only way to be certain of what parts of the struc-
ture contain oil is to drill delineation or stepout wells. Figure 10.1 shows us an example of a delineation
drilling program. The first well (the discovery well) was drilled at the very crest of the structure. The wells
chronologically numbered 2 to 8 were drilled in strategic locations to further define the extent of the oil res-
ervoir. Each new well added more information about the field. This information was then used in planning
the location of the next delineation well until finally there were enough wells to show the limits of the field.
This figure shows a map and cross sec-
tional view of an oilfield. The trap type is
an anticline. Well number 1 was the dis-
covery well. Wells numbered 2 to 8 are de-
lineation wells that were drilled sequen-
tially to determine the size of the field.
Each successive well added more informa-
tion that could be used in planning the next
well location.
Figure 10.1 -Delineation Drilling Program
W
ater
8
1
Oil

2Field Development and Production Chapter 10
Development Wells
Now that we've determined the size of the oil field, the geologists, geophysicists and reservoir engineers
must put their heads together and plan the location of the rest of the wells – ie., the development wells.
The object, at this stage, is to get the maximum amount of oil out of the ground with the minimum number
of wells.
A key parameter to be considered is the drainage area, which is the area that can be drained by one well.
Depending on the permeability and the pressure within a reservoir, a well may be able to draw oil from as
far away as a couple of kilometres or from as near as only a few hundred metres. Taking these factors and
the geology into account, a well spacing grid, showing the planned location of future wells, is designed.
Having settled on the position of future wells, the company must plan the sequence in which they should be
drilled with two factors in mind. First, the wells must be placed so they can be produced into the gathering
system as it develops. A gathering system is a system of pipelines that collects the oil as it is produced from
different wells throughout the field and brings it to a central location. Secondly, each well should add the
maximum amount of new information about the oil reservoir. As new wells are drilled and the knowledge
of the field is refined, the original drilling plans can be adjusted in accordance with the new information.
After a well has been drilled to total depth (TD) and has proven by drillstem test (DST) to be capable of
producing oil or gas, it must be completed. “Completing a well” means installing equipment in the well to
allow a safe and controlled flow of petroleum from the well. In addition to the casing that lines the well
bore (recall Chapter 8), tubing and a system of flow valves must be installed (Figure 10.2). Tubing is a
smaller pipe through which the oil or gas flows to the surface during production. It may be two to six
inches in diameter, depending on the flow capability of the well.
Completing A Well
Figure 10.2 -The Completed Well
(Courtesy of Petroleum Extension Ser-
vice (PETEX) The University of Texas at
Austin)

Crude Oil Treatment
Crude oil usually contains impurities such as sediment, water, natural gas and sometimes hydrogen sul-
phide. Before the oil can be sold or delivered into a tanker or pipeline, these extra constituents must be re-
moved to bring the crude up to the proper quality. To accomplish this, processing equipment must be in-
stalled, including such things as separators, to separate oil and gas from water and sediment. Where hydro-
gen sulphide (H2S) is present, special chemical treatment facilities are required to remove it. Hydrogen sul-
phide is a very dangerous poisonous gas which also is highly corrosive to pipelines and tankers. It smells
like rotten eggs, and if inhaled in high enough concentrations can cause death within two minutes.
Figure 10.3 -Artificial Lift
Schematic illustration of the typical “horsehead” type sucker rod pump widely used for artificial lift in
many onshore fields.
Pressure Maintenance and Artificial Lift
When an oil well first starts producing oil, it can usually flow to surface naturally because of the high pres-
sure in the reservoir formation. As oil is produced over the months or years, however, the reservoir pres-
sure gradually decreases. This phenomena is normally counteracted by establishing a pressure maintenance
program which involves injecting water or natural gas into the reservoir to balance the oil removed.
Without pressure maintenance, some form of artificial lift may be required to help raise the crude oil to the
surface and obtain the maximum production from the field. A common form of artificial lift is to install a
pump to pump the oil up to the surface. Figure 10.3 shows an example of a widely used type of sucker rod
pump.
RESERVOIR
To Storage Tank
Oil & gasOil & gas

Offshore Production
Production of oil and gas offshore is similar to production onshore with the following major differences:
(1) There is a need to provide some form of production platform; (2) Some of the production equipment
must be installed on the seafloor instead of on dry land and; (3) Development wells are more often direc-
tionally drilled from the permanent platform in the offshore (Figure 10.4). These special needs create both
enormous challenges and enormous costs.
Offshore platforms can be of a floating or fixed design. Fixed platforms, as the name suggests, are attached
to the seabed (Figure 10.4). Floating platforms are held in place by some form of anchoring system or by a
dynamic positioning system.
Figure 10.4 - Steel Tower Production Platform
(Modified after Petroleum Extension Service (PETEX), The University of Texas at Austin)
1,500 to
2,000 meters
3,000 to
5,000 meters
Directional Wells
Seabed
Up to
100 meters
Crew
Quarters
Drilling Rig
Production
Equipment

Fixed Platforms
Figure 10.5 - Gravity Base
Structure Production Platform
(From An A-Z of Offshore Oil and Gas by
Harry Witehead. Copyright 1983 by Gulf
Publishing Company, Houston, Tx. Used
with permission. All rights reserved.
Fixed platforms have been built of both steel and concrete. Steel platforms (Figure 10.4) are simply steel
tower structures resembling oversized transmission towers with drilling and production facilities mounted
on top. They have been used extensively in the Gulf of Mexico, the Persian Gulf and the North Sea.
Concrete platforms are built of massive semi-hollow cylinders of concrete (Figure 10.5). These platforms
are floated into place and then ballasted with sea water to sit firmly on the bottom. They are held in place
by their sheer mass and are, hence, called Gravity Based Structures.
The concrete platform to be built for the Hibernia field is to be of a new design (Figure 10.6). It will consist
of drilling and production facilities mounted on one massive semi-hollow concrete cylinder. This design
has been chosen for Hibernia because of the icebergs that are known to drift into the area. The system is
designed to withstand the impact of icebergs of the size that are known to frequent this area.
The oil produced at Hibernia (up to 150,000 barrels per day) will be treated on the platform and stored in-
side the concrete column. It will then be transported from the site by shuttle tankers.

Floating Production Systems
Figure 10.6 - Production System Components-Hibernia Field
(Courtesy of Mobil Oil)
Some offshore fields are not large enough to justify the construction of either a concrete or steel platform.
A cheaper method of development is to install production facilities on a semi-submersible platform or upon
a ship-shaped hull (Figures 10.7 and 10.8).
Such floating production platforms are more weather sensitive than the fixed systems. They are also lim-
ited in their productive capacity by the limits on the weight of equipment that can be safely mounted on the
floating platform.
These types of systems have been used in a number of offshore areas in the world, including Brazil, Spain
and the North Sea. Floating platforms are expected to be used to develop some of the smaller fields on the
Grand Banks.

7FieldDevelopmentandProductionChapter10
Figure 10.7

Production
Equipment
Shuttle Tanker
Shipshaped Floating Production System
Risers
Gathering
System
Subsea Wellheads
Page 10-8Field Development and Production Chapter 10
Figure 10.8

Questions:
(1) What are delineation wells?; development wells?
(2) What does it mean to “complete” a well?
(3) What impurities must be removed from crude oil as soon as it comes out of the
ground?
(4) What is artificial lift? When is it necessary?
(5) Which is more expensive, offshore or onshore development?
Exercises:
(1) View the video entitled; “The Hibernia Development Project” (10 minutes).
(2) Study figure 10.1 and see if you can follow the logic that was used in choosing the
locations of wells numbered 2 to 8.
(3) Oil Spill
Offshore oil development holds the promise of great economic benefit to the province of Newfound-
land and Labrador. But, as with most major industrial development, it also presents certain risks to
the environment. One of those risks is an oil spill.
This activity illustrates problems with oil spills, including their effects on wildlife and the difficul-
ties involved with their clean-up.
There is no more obvious example of ocean pollution than that of a major oil spill. It spreads. It
floats. And it is black. It also provides vivid examples of its impact on wildlife:
• a bird coated in oil cannot fly or float, and loses its insulation against temperate changes,
• oil which seeps into sand can remain there for years, and cause harm to coastal life,
• oil sometimes smothers communities of animals living on the ocean floor, and some or-
ganisms, particularly some shellfish cannot survive,
• oil kills seaweeds and other plants that animals such as birds feed on,
• oil can seep into eggs and kill unhatched animals.
Not only does an oil spill have negative consequences on animals and their environment but it is
also extremely difficult to clean up. This activity allows students to act out the role of environ-
mental managers, deciding on different ways of handling the oil spill clean-up. It also gives them an
awareness of how seabirds are potentially harmed. It is very important to follow the exercise with a
discussion of what was observed.

• motor oil
• eye droppers
• hand lens
• bird feathers
• 10 cm lengths of string
• cotton batting
• container of sand
• shallow pans (e.g., aluminum pie plates)
• paper towels
• 3 hard-boiled eggs
• dishwashing detergent
Page 10-10Field Development and Production Chapter 10
Materials:
Method:
(1) Divide class into small groups. Give each group a pan with a small amount of water
in it, a pan with a small amount of oil, some paper towel, a magnifying glass, and a
bird feather. Have the students take turns looking at the feather under the lens.
Sketch it as seen. Dip feather in water for one to two minutes. Remove, examine un-
der the hand lens, and sketch. Place the feather in oil for one to two minutes.
Remove, examine with the lens and sketch. Compare all three sketches. Try to wipe
the oil off the feather with the paper towel. Examine the feather again. What effect
do you think the oil could have on a bird’s activities?
(2) (This demonstration could be done, by the instructor or a student, in conjunction with
the class activity). Place 3 hard-boiled eggs in a container of motor oil. After 5 min
utes remove one egg. Peel off the shell and examine. After 15 minutes, remove an
egg and do the same. After 30 minutes, examine the third egg. What did you ob-
serve? What effect do you think an oil spill could have on the eggs of birds that nest
near the water?
(3) (Keep the same groups of students as in first part of activity. Discard feathers). Give
each group an eye dropper, a small container of dishwashing detergent, a 10 cm piece
of string, some sand, and a piece of cotton batting. Have students fill their eye drop-
pers with oil, and add 5 to 6 drops to the middle of their pan of water. What happens
to the oil? Does it look like more or less than when it was in the dropper?
Once your students have had a chance to experiment with different techniques, have
them discuss their observations, and implications for their use with a real oil spill.
String:
The string may have been used, by some, to contain the oil. This in fact is often
practiced after a spill, until something else is done with the oil. (The string is called a
boom).
Discussion:

Discussion:
Eye Dropper:
If students did not contain the oil, they may have tried to remove it from the water with the
eye dropper. (How much oil was able to be removed? Was there water mixed with the oil)?
Detergent:
Detergent removes oil from dishes and clothing but does it remove oil from water? Deter-
gents are sometimes added to an oil spill to disperse the oil and reduce the concentration in
any given area. This can have advantages in that the environment can deal more quickly
with lower oil concentrations, but it has the disadvantage of spreading the spill over a larger
area.
Sand:
If sand was added, most of the oil may have sunk. However, it does not disappear; it is
merely displaced.
Cotton Batting:
If cotton batting is added to the oil, the oil sticks to all its surfaces. If dipped and removed
several times, it should remove most of the oil from the water surface. This is the most ef-
fective method of the above options, but procedures based on this principle are often difficult
to execute on the open ocean.
Everyone agrees that the best way to prevent damage from oil spills is to not allow them to
occur. But we must also face the reality that oil is our primary source of energy and most of
the ports of the world (including those in Newfoundland and Labrador) are frequented by oil
tankers. In addition to the risk of oil spills from tankers, in Newfoundland we have the risk
of blowouts in offshore wells. Recognizing that these environmental risks accompany the
substantial economic benefits that come with offshore oil development, what can we do to
minimize these environment risks? Be as imaginative and creative as possible.

1Current Events in the Oil Industry
Current Events in the Oil Industry
Chapter 11
For this chapter, the students are to have been divided into small groups and each group is to have compiled
a poster sized mural of headlines, photographs, drawings, short newspaper or magazine articles, write-ups
of stories they heard on the news etc., that are associated with the oil industry. Items should touch the fol-
lowing facets of the petroleum industry:
(1) Exploration; Geophysical Surveys, Drilling.
(2) Development; News on field developments in Newfoundland’s offshore within Canada or
around the world.
(3) Price; What’s happening with the price of oil?
(4) Transportation; News stories on oil and gas pipelines or oil tankers.
(5) Security of supply; Are we in danger of losing our supply of oil?
(6) Environmental; Any recent environmental incidents or studies released.
(7) Any other petroleum related topics that the students encounter and would like to work into
their presentations (e.g., refineries, social impact of oil developments, alternate energy
sources, etc.)
Students may go as far back in time, as they wish, to find articles to support a position or theme they may
wish to express. But keep in mind that the goal of this exercise is to introduce the students to current issues
in the oil industry. Too many older articles may give them a less than modern perspective. The students
should be encouraged to use their imaginations to make the mural both informative and artistic. They
should strive to grab people’s attention and make a statement.
Perhaps a plan to display the murals in the school hallway for a few days would be useful in that it will give
the artists a larger forum in which to display their talents and facilitate feedback from the school population.
Presentation of Murals
Each group should give an oral presentation and explanation of their mural of at least 10 minutes. Each
member of the team should participate in the presentation and cover one or more of the topics addressed.
The final speaker should give a brief summary and clearly state any positions or conclusions the team has
reached as a result of the project.
Discussion
After all of the presentations have been made, initiate discussions on what has been said. Ask questions
about what each person learned from the exercise. Did they enjoy it? Do they disagree with any positions
taken or statements made by the other teams? Differing opinions is a healthy sign that the students are truly
learning something and are willing to defend their ideas.

1Public Hearing
Public Hearing
Chapter 12
A public hearing provides a forum in which a company, organization or government can listen to presenta-
tions from members of the general public on an issue. Public hearings are often held by governments to get
the public's opinion and to help assess the impact of some decision or action that the government is about to
take. The government then takes into consideration the information presented at the hearing when making
its decision. An example of where a public hearing might be utilized is when the government is considering
approval of a large offshore oil field development submitted by a company. Such a development plan
would outline the type of production system to be built, where it was to be built, other related work in-
volved in the construction and operation of the production system. It would also discuss the benefits to the
province in terms of jobs and the measures that will be taken to mitigate the environmental and social im-
pacts.
In a public hearing on such a development, people would present arguments for or against the approval of
the plan, identify concerns, and perhaps suggest changes to the plan to address these concerns.
Exercise
In this exercise, the class will hold a mock public hearing on an offshore oilfield development. You are
given a basic description of the development plan and a cast of characters. Students will be assigned roles
as these characters in making their presentations to the hearing. Since there will probably be more students
in the class than there are roles to assign, more than one student can be assigned the same role. Each stu-
dent will just bring his or her own personality into the role. Also, there is no need to limit the roles to be
played to the charters described here. It may be more meaningful to take on the role of real characters from
within your own community.
The instructor will chair the hearings and should make notes on each speaker. Each presentation should be
about 10 minutes long. Students should be encouraged to use diagrams, maps or other visual aids to help
articulate their positions. When all of the presentations have been completed, the chairperson should take a
few minutes to review the notes and then report what recommendation will be made to the government.
Students should be encouraged to challenge the chairperson’s conclusions and try and influence the final
recommendation. Once again, differing opinions will be a healthy sign.
Offshore Oilfield Development Plan
Oilfield Name: (Use your school's name)
Type of Production System: Fixed Concrete.
Details; Construction Phase: The production system will be constructed entirely in your area and
will involve the following:
(1) The local docking facilities will have to be substantially upgraded to handle the increased
ship traffic. This will involve dredging the harbour as well as upgrading the existing pier.

2Public Hearing Chapter 12
(2) A large dry dock will have to be built. This is where the base of the GBS will be con-
structed. About 3 hectares (7.4 acres) of land will be required.
(3) A large cement mixing facility will be constructed adjoining the drydock.
(4) The main road into the area will have to be substantially upgraded to handle the increased
traffic of very heavy equipment into the area.
(5) A portable work camp will have to be built near the community to house the nearly 2000
workers that will have to be brought in during the construction phase, which will last 5
years.
(6) A large wharf will need to be built for assembling the modules that will become the top-
sides. The individual modules will be constructed elsewhere.
(7) A small airstrip will need to be built. There will be significant traffic in helicopters and
small aircraft.
(8) Ship traffic in the area will increase significantly and this will prevent fishing in one of
the traditional areas.
(9) Fishing will also have to be shut down for a three year period at the sheltered deepwater
site where the GBS will be completed approximately 200 metres offshore, 2 kilometres
up the coast from the dry dock.
(10) A tanker terminal will have to be constructed a couple of miles from the community.
The terminal itself will be one kilometre from the shore and the oil will be pumped
ashore through a pipeline (yet to be constructed) where it will be stored in a number of
large tanks (yet to be constructed).
(11) A pipeline will have to be built to transport the oil to the refinery (already in place) 30
kilometres away.
(12) The oil tankers that will be used will be built at the shipyard 200 kilometres away.
Details; Operating Phase: When the production system is in place 300 kilometres offshore,
the field will start producing oil and is expected to produce for 20 years at an average rate of
100,000 barrels per day. Your community will be affected in the following way:
(1) When the construction phase ends, all of the construction related jobs will be lost. The 2000
imported workers will leave and the portable camp will go as well. (It is possible, however,
that as new fields are to be developed offshore, there will be other systems constructed in
your area, using the new facilities that will be in place).

(2) Ship traffic will decrease somewhat but will still be quite brisk, as your port is also the
offshore supply base. Supply boats will therefore dock frequently to pick up supplies for
the offshore platform and to sometimes bring the crew ashore during crew changes.
Crew changes will, however, usually be handled by helicopter.
(3) Two to three times per week, a tanker will dock at the terminal. It will take 24 hours to
unload its cargo of oil. Fishing in the tanker shipping lanes and near the terminal will not
be allowed.
(4) Fishing will not be permitted within a 10 mile radius of the production system 300 km
offshore.
Note: Also read the article entitled; "The Hibernia Production System" included in this chap-
ter's text.
CAST OF CHARACTERS
Environmentalist
You are the leader of a local organization that is concerned with protecting the environment. You
fear that a potential blowout or tanker accident could pollute the local beaches, kill thousands of sea
birds, and damage the fishery.
High School Student
You will soon be graduating from high school and you are uncertain what you want to do after
graduation. You are considering going to university, but you don't like the idea of leaving home.
Ideally, you would like to find a well-paying job in your home community, but you are wary of the
five year time limit on most of the jobs associated with this project. You have an older brother and
sister who have both found steady work in the fish plant. They are doing reasonably well for them-
selves, but are always faced with the unpredictability of the fishery. Besides, you want to do some-
thing different with your life.
Hotel Owner
In anticipation of this major development, you have invested everything to build a small hotel in the
community. If the project does not proceed, there is a substantial risk that you will lose everything.
Politician
You are the MHA for the area. Most of your constituents are fishermen. You want to create jobs in
the area, but many of the fishermen are uneasy about the risk of oil spills and the loss of some of
their traditional fishing grounds. On the other hand, unemployment in the region has been running
about 30% for a number of years. This project will provide thousands of construction jobs in the
area. Your political party, which is presently in power, also strongly supports proceeding with the
development. This project is so large that it promises to benefit the economy of the entire province.

Construction Worker
You were raised in this community, but spent a number of years in Toronto working in the construc-
tion industry. You returned to Newfoundland 3 years ago to work on a major project in Corner
Brook. Since returning, you have married your childhood sweetheart, built a house in your home
town and you have a child on the way. Work has been intermittent since the project in Corner
Brook finished last year, but you are reluctant to return to Toronto. You don't want to raise a family
in the big city if you can help it.
Teacher
You are married and settled in this community, although you originally came from another part of
the province. You have made this community your home and taken an active role in the affairs of
the community. You have always encouraged your students to further their education after high
school. You are pleased to see that this project will create a lot of jobs in the area, but you fear that
students leaving high school will be tempted to forego their education for the quick dollars to be
made from the construction jobs. You are especially concerned that most of these jobs will poten-
tially disappear after 5 years and the students will then be unlikely to resume their education.
Local Contractor
You started your business 20 years ago when the refinery was being built. When times were good,
you had a variety of equipment and employed 10 people full time. Times have been tough for the
past ten years though, and you now own one backhoe, one bull dozer and one dumptruck. You em-
ploy one person on a part-time basis. If this project proceeds, it will be a major boost for you.
You've already made arrangements to lease more equipment from one of the larger centers should
the project proceed and have contacted your former employees.
Fish Plant Owner
You are quite concerned about the possible loss of some of the traditional fishing grounds. You de-
pend on a steady supply of fish to keep the plant operating. You are also very concerned about the
potential loss of your employees to the construction jobs. You understand that these will be high-
paying jobs and there is no way you will be able to compete in terms of salaries.
Social Scientist
You are a social scientist who was born and raised in the area and who has been hired by the com-
munity council to look at the possible social consequences of the project. You realize that the popu-
lation of the area has been gradually declining over the past thirty years, as most of the young peo-
ple have had to leave to find jobs. Some of the communities in the area are already close to becom-
ing ghost towns. This project has the potential to revitalize the entire area. On the other hand, you
know that there will be a social cost. People in the area will be drawn away from their traditional
occupations, the influx of outsiders will cause disruption, and the high salaries that are paid to the
oil workers compared to those who stay with the traditional industries may cause inflation and some
dissention within the community.

Fisherman
You are an inshore fisherman. You are concerned about the possible environmental consequences
of an oil spill and about the loss of some of your traditional fishing grounds. You are pleased, how-
ever, to see that there will be some substantial improvements made in the dock. You have 4 chil-
dren (2 boys & 2 girls). The oldest son went to Calgary three years ago to work in the oil industry.
The oldest daughter is with a computer firm in Montreal. You would love to see the other two find
employment in your area so that they will not have to leave as well.
Other characters you may wish to consider are;
− Shopkeeper
− Mayor
− Doctor
− Chairperson of the Local Business Association
− Police Officer
− Fishplant Worker
− Senior Citizen
− Tradesman
− The Community’s Religious Leader
In each case try and visualize how the project will affect the character you are playing personally. It
may even be useful to talk to the type of person you will be portraying to get his or her opinion on
such a hypothetical development.
Consider the entire project and let your imagination go. There are many potential effects that have
not been described above. Some of them are not obvious and may only come into play because of
the uniqueness of the area in which you live. When you have weighed all the pros and cons, decide
to either support or reject the project. If you are going to support the project, but have certain con-
cerns, state those concerns and try to think of ways of dealing with your concerns. In other words,
say "I believe the government should approve this project, but under the following conditions ..." If
you reject the project you should also state your reasons clearly.

The Hibernia Production System
Figure 12.1 - Construction Sequence for GBS
Courtesy of Mobil Oil
At the time of the writing of this manual, Mobil Oil and its partners had submitted and received approval
for a development plan for the Hibernia field in the Newfoundland offshore. The production system is the
fixed concrete type consisting of a cylindrical base (the GBS) and topsides supported by four shafts.
Frames 1 and 2 of Figure 12.1 show how the base of the Gravity Based Structure (GBS) will be built in the
drydock. When the "lower base raft" is completed, the drydock will be flooded allowing the base to be
floated out to the deepwater site. Frames 4 to 8 show how the rest of the GBS will be constructed at the
deepwater site using a concrete slipforming technique. The four shafts are also to be installed at the deep-
water site.
The concrete to be used in the construction will be mixed in a concrete mixing facility to be constructed
near the drydock. Cement from this plant will be transported to the deepwater site, possibly by barge.

Figure 12.2 - Assembly Sequence for Topsides Facilities
At the same time that the GBS is being built, the modules that will be assembled to form the topsides will
be constructed. These topsides modules will be brought together and assembled as shown in Figure 12.2.
Figure 12.3 shows the mating of the topsides to the GBS. The partly hollow GBS is first ballasted with wa-
ter so that it sinks below the surface thus exposing only the top of the shafts above water. The topsides are
then floated over the submerged GBS using a specially shaped barge. The GBS is then gradually debal-
lasted so it rises up and connects with the topsides. The now completed production platform is then further
deballasted and towed to the Hibernia field approximately 300 km offshore. At the pre-planned site on the
field, the platform is ballasted again so as to submerge it to sit firmly on the seabed. The platform is now in
a position to drill the required development wells and be prepared for the production phase. It will produce
oil for an estimated 20 to 25 years.

8Chapter 12
Figure 12.3 - Deck Mating and Platform Installation
Public Hearing

Glossary
Glossary
Appendix I
ABANDONED WELL
A well no longer in use; a dry hole that, in most jurisdictions, must be properly plugged.
AEROMAGNETIC SURVEY
A magnetic survey, made from an aircraft.
AIR GUN
A seismic signal source which utilizes compressed air to create a sonic wave.
ANNULUS
The annular space between the drill pipe and the well bore.
ANTICLINE
A subsurface geological structure in the form of a gentle arch or an elongated dome. Historically
this type of formation has been found favourable to the accumulation of oil and gas. The ideal loca-
tion to find production is on the crest of the anticline; less favourable are the flanks where one may
encounter less oil as well as quantities of salt water which usually underlie the oil in the reservoir.
APPRAISAL OR DELINEATION DRILLING
Wells drilled in the vicinity of a discovery or wildcat well in order to evaluate the extent and the im-
portance of the find.
ASPHALT
A solid hydrocarbon found as a natural deposit. Crude of high asphaltic content when subjected to
distillation to remove the lighter fractions such as naphtha and kerosene leave asphalt as a residue.
Asphalt is dark brown or black in colour and at normal temperatures is a solid.
BARREL
A unit of measure for crude oil and oil products equal to 42 U.S. gallons (159 litres).
BASEMENT ROCK
Igneous or metamorphic rock lying below the sedimentary formations in the earth's crust. Basement
rock does not contain petroleum deposits.
BASIN
(See Sedimentary Basin).

Glossary Appendix I
BLOWOUT
A well that comes in with such great pressure that the oil blows out of the well and up into the der-
rick, like a geyser. With improved drilling technology, especially the use of drilling mud to control
downhole pressures, blowouts are rare today.
Out of control gas and/or oil pressure erupting from a well being drilled; a dangerous, uncontrolled
eruption of gas and oil from a well; a wild well.
BLOWOUT PREVENTER
An assembly of heavy-duty valves attached to the top of the casing to control well pressure.
BONUS
The bonus is the money paid by the lessee for the granting of an oil and gas lease by the landowner.
BUNKER "C" FUEL OIL
A heavy, residual fuel oil used in ships' boilers and large heating and generating plants.
CASING
Steel pipe used in oil wells to seal off fluids from the borehole and to prevent the walls of the hole
from sloughing off or caving. There may be several strings of casing in a well, one inside the other.
The first casing put in a well is called surface pipe which is cemented into place and serves to shut
out shallow water formations and also as a foundation or anchor for all subsequent drilling activity.
CASING SHOE
A reinforcing collar of steel screwed onto the bottom joint of casing to prevent abrasion or distortion
of the casing as it forces its way past obstructions on the wall of the borehole. Casing shoes are
about 3 cm thick and 25 to 40 cm long and are about 3 cm larger in diameter in order to clear a path
for the casing.
CEMENT
To fix the casing firmly in the hole with cement, which is pumped through the inside of the casing
and up into the annular space between the casing and the walls of the well bore.
CLASTIC ROCK
One of the categories of sedimentary rock; a so-called secondary rock which consists of particles
that are fragments of pre-existing rocks. They may range in size from blocks the size of boxcars
down to particles so fine as to remain in suspension almost indefinitely. The three classes of clastic
sedimentary rocks are sandstone, conglomerate and shale.

Glossary Appendix I
COMMERCIAL WELL
A well of sufficient production that it could be expected to pay for itself in a reasonable time and
yield a profit for the operator. A shallow, 50-barrel-a-day well in a readily accessible location on
shore could be a commercial well whereas such a well in the North Sea or on the Grand Banks
would not be considered commercial.
COMPLETE A WELL
To equip a well so that it is ready to produce oil or gas. After reaching total depth (TD) casing is
run and cemented; casing is perforated opposite the producing zone, tubing is run, and control and
flow valves are installed at the wellhead. Well completions vary according to the kind of well,
depth, and the formation from which it is to produce.
CONDUCTOR PIPE
A well's surface pipe used to seal off near-surface water, prevent the caving or sloughing of the
walls of the hole, and as a conductor of the drilling mud through loose, unconsolidated shallow lay-
ers of sand, clays, and shales.
CONTOUR LINE
A line (as on a map) connecting points that have the same elevation above or below sea level.
CONTOUR MAP
A map showing elevations by the use of contour lines. Structure contour maps are used by geolo-
gists and geophysicists to depict the "topography" of underground layers.
CROWN LANDS
Lands for which petroleum or mineral rights belong to the government. The government can then
lease these petroleum or mineral rights to a company who may wish to explore for petroleum or
minerals.
CRUDE OIL
Oil as it comes from the well; unrefined petroleum.
DELAY RENTAL
Money payable to the lessor by the lessee for the privilege of deferring drilling operations or the
commencement of production.
DELINEATION WELL
(See Stepout Well).

Glossary Appendix I
DERRICK
A wooden or steel structure built over a well site to provide support for drilling equipment and a tall
mast for raising and lowering drillpipe and casing; a drilling rig.
DERRICK FLOOR
The platform (usually 3 metres or more above the ground) of a derrick on which drilling operations
are carried out; rig floor.
DERRICK MAN
A member of the drilling crew who works up in the derrick racking tubing or drillpipe as it is pulled
from the well and unscrewed by other crew members on the derrick floor.
DEVELOPMENT
The drilling and bringing into production of wells in addition to the discovery well on a lease. The
drilling of development wells may be required by the express or implied covenants of a lease.
DEVELOPMENT WELLS
Wells drilled for the purpose of producing petroleum from a proven field. Development wells are
strategically located to get maximum production from the field.
DIESEL ENGINE
A four-stroke cycle internal combustion engine that operates by igniting a mixture of fuel and air by
the heat of compression, and without the use of spark plugs.
DIESEL FUEL
A fuel made of the light gas-oil range of refinery products. Diesel fuel and furnace oil are virtually
the same product. Self-ignition is an important property of diesel fuel, as the diesel engine has no
spark plugs; the fuel is ignited by the heat of compression within the engine's cylinders.
DIESEL, RUDOLPH
The German engineer who invented the internal combustion diesel engine that bears his name.
DIRECTIONAL DRILLING
The technique of drilling at an angle from the vertical by deflecting the drill bit. Directional wells
are drilled for a number of reasons: to develop an offshore lease from one drilling platform; to reach
a pay zone beneath land where drilling cannot be done; eg., beneath a railroad, cemetery, a lake; and
to reach the production zone of a burning well to flood the formation.

Glossary Appendix I
DISCOVERY WELL
An exploratory well that encounters a new and previously untapped petroleum deposit; a successful
wildcat well. A discovery well may also open a new producing formation in an established field.
DISSOLVED GAS
Gas contained in solution withthe crude oil in the reservoir.
DRAINAGE
The movement of oil and gas toward the well bore of a producing well.
DRAINAGE AREA
The maximum area in an oil pool or field that may be drained efficiently by one well so as to pro-
duce the maximum amount of recoverable oil or gas in such an area. A reservoir with good perme-
ability will have a larger drainage area than one with less permeability.
DRILL BIT
The tool attached to the lower end of the drillpipe; a heavy steel "head" equipped with various types
of cutting or grinding teeth, some are fixed, some turn on bearings. A hole in the bottom of the drill
permits the flow of drilling mud being pumped down through the drillpipe to wash the cuttings to
the surface and also cool and lubricate the bit.
DRILLER
One who operates a drilling rig; the person in charge of drilling operations and who supervises the
drilling crew.
DRILLING CONTRACTOR
A person or company whose business is drilling wells. Some wells are drilled on a per foot basis,
others are contracted on a day rate.
DRILLING MUD (MUD)
A special mixture of clay, water and chemical additives pumped downhole through the drillpipe and
drill bit. The mud cools the rapidly rotating bit; lubricates the drillpipe as it runs in the wellbore;
carries rock cuttings to the surface; and serves as a plaster to prevent the wall of the borehole from
crumbling or collapsing. Drilling mud also provides the weight or hydrostatic head to prevent reser-
voir fluids (oil, gas or water) from entering the well bore and to counter the downhole pressures that
can lead to a blowout.

Glossary Appendix I
DRILLING PLATFORM (STEEL)
An offshore structure with legs anchored to the sea bottom. The platform, built on a large-diameter
pipe frame, supports the drilling of a number of wells from the location. As many as 60 wells have
been drilled from one large offshore platform.
DRILLING RIG (MECHANICAL)
The most common type of drilling rig is the mechanical compound rig. Mechanical rigs use diesel
engines coupled directly to the equipment or through compound shafts to drive the rotary, draw
works, and mud pumps. Separate engine-AC generator sets provide lighting and power for auxiliary
functions.
DRILLPIPE
Heavy, thick-walled steel pipe used in rotary drilling to turn the drill bit and to provide a conduit for
the drilling mud. Joints of drill pipe are about 10 metres long are screwed together to form the drill-
stem.
DRILLSHIP
A self-propelled vessel; a ship equipped with a derrick amid ships for drilling wells in deep water.
A drillship is self-contained, carrying all of the supplies and equipment needed to drill and complete
a well.
DRILLSTEM (OR DRILLSTRING)
The drillpipe. In rotary drilling, the bit is attached to the drillstem or drill column which rotates to
"dig" the hole.
DRILLSTEM TEST (DST)
A method of obtaining a sample of fluid from a formation using a "formation-tester tool" attached to
the drillstem. The tool consists of a packer to isolate the section to be tested and a chamber to col-
lect a sample of fluid. If the formation pressure is sufficient, fluid flows into the tester and up the
drillpipe to the surface.
The DST is used to determine if any oil or gas is present, the reservoir pressure and the possible
flow rate of the well. This information is critical in determining if the well will be a commercial
discovery or a dry hole.
DRY HOLE
An unsuccessful well; a well drilled to a certain depth without finding petroleum in commercial
quantities; a "duster".

Glossary Appendix I
DYNAMIC POSITIONING
A method of keeping a drillship or semisubmersible drilling platform on target, over the hole during
drilling operations where the water is too deep for the use of anchors. This is accomplished by the
use of thrusters activated by underwater sensing devices that signal when the vessel has moved
slightly off its drilling station.
EXPLORATION ACTIVITIES
The search for oil and gas. Exploration activities include aerial surveying, geological studies, geo-
physical surveying, coring, and the drilling of wildcat wells.
EXPLORATION VESSEL (SEISMIC VESSEL)
A seagoing, sophisticated research ship equipped with seismic, gravity, and magnetic systems for
gathering data on undersea geologic structures. On the more advanced vessels of this type there are
onboard processing and interpretation capabilities for the information gathered as the vessel cruises
the oceans of the world.
FAULT
A fracture in the earth's crust accompanied by a shifting of one side of the fracture with respect to
the other side.
FIELD
The area encompassing a group of producing oil and gas wells; a petroleum pool. An oil field may
include one or more petroleum pools, and have wells producing from several different formations at
different depths. A roughly contiguous grouping of wells in an identified area.
FOSSIL FUEL
Includes oil, natural gas and coal. Fossil fuels are formed in sedimentary beds from the remains of
plants and animals that lived millions of years ago.
FREEHOLD LAND
Land for which the petroleum or mineral rights are owned by a person rather than the government.
The owner of the land then has the right to lease such petroleum or mineral rights to a company who
may wish to explore for petroleum or minerals.
GAS
(See Natural Gas).

Glossary Appendix I
GASOLINE
A volatile flammable liquid hydrocarbon mixture used as a fuel for internal combustion engines.
GATHERING SYSTEM
A system of pipelines within an oilfield that collects oil from the different wells and brings it to a
central location where it can be treated to remove impurities.
GEOLOGICAL STRUCTURE
Layers of sedimentary rocks which have been displaced from their normal horizontal position by the
forces of nature. Folding, fracturing, and faulting are geological processes that often form structural
traps that are logical places to look for accumulations of oil and gas.
GEOLOGIST
A person trained in the study of the earth's crust. A petroleum geologist, in contrast to a hard-rock
or mining geologist, is primarily concerned with sedimentary rocks where most of the world's oil
has been found. In general, the work of a petroleum geologist consists of searching for structural
traps favourable to the accumulation of oil and gas. In addition to deciding on locations to drill, he
or she may supervise the drilling, particularly with regard to coring, logging, and running tests.
GEOLOGY
The science that deals with the history of the earth by studying the evidence preserved in rocks.
GEOPHONES
Sensitive sound-detecting instruments used in conducting seismic surveys. A series of geophones
are placed along the ground to detect and transmit, to an amplifier-recording system, the reflected
sound waves created by explosions set off in the course of seismic exploration work.
GEOPHYSICIST
A person who applies geophysical methods to the study of the earth. A specialist in geophysics.
GEOPHYSICS
The application of certain familiar physical principles - magnetic attraction, gravitational pull, speed
of sound waves, the behaviour of electric currents - to the science of geology.
GRAVIMETER (GRAVITY METER)
A geophysical instrument used to measure the minute variations in the earth's gravitational pull at
different locations. To the geophysicist, these variations indicate certain facts about subsurface for-
mations.

Glossary Appendix I
GRAVITY BASESTRUCTURE
An offshore drilling and production platform made of concrete and of such tremendous weight that
it is held securely on the ocean bottom without the need for piling or anchors.
GRAVITY MAP
The results of a gravity survey contoured and displayed on a map.
HYDROCARBONS
Organic chemical compounds of hydrogen and carbon atoms. There are a vast number of these
compounds and they form the basis of all petroleum products. They may exist as gases, liquids, or
solids. An example of each is methane, hexane, and asphalt.
HYDROPHONES
Sound-detecting instruments used in underwater seismic exploration activities. Hydrophones are
attached to a cable towed by the seismic vessel. Sound waves generated by blasts from an airgun
reflect from formations below the sea bottom and are picked up by the hydrophones and transmitted
to the mother ship.
IGNEOUS ROCK
Rocks that have solidified from a molten state. Those rocks that have reached the surface while still
molten are called lavas; they can form volcanic cones or spread out in flows or sheets, they can be
forcibly thrust up between beds of other kinds of rocks in what are called sills, or they can fill crev-
ices and then solidify as "dikes." Rocks that have solidified deep beneath the earth's crust are re-
ferred to as plutonic, from the Greek god of the lower regions, Pluto. Granite is an example of plu-
tonic rock.
INTERNAL-COMBUSTION ENGINE
A heat engine in which the combustion which generates the heat takes place inside the engine itself
instead of in a furnace. Examples are the gasoline or diesel-powered engines used in automobiles.
JACKUP RIG
A barge-like, floating platform with legs at each corner that can be lowered to the sea bottom to
raise or "jack up" the platform above the water. Towed to a location offshore, the legs of the jack-
up rig are in a raised position, sticking up high above the platform. When on location, the legs are
run down hydraulically or by individual electric motors.
JET FUEL
A specially refined grade of kerosene used in jet propulsion engines.

Glossary Appendix I
LANDMAN
A person whose primary duties are managing an oil company's relations with its landowners. Such
duties include securing of oil and gas leases, lease amendments, and other agreements.
LEASE
The legal instrument by which a leasehold is created. A contract that, for a stipulated sum, conveys
to an operator the right to drill for oil or gas. The petroleum lease is not be confused with the usual
lease of land or a building. The interests created by a petroleum lease are quite different from a re-
alty lease.
MARINERISER SYSTEM
A string of specially designed steel pipes that extends down from a drillship or floating platform to
the subsea wellhead. Marine risers are used to provide a return fluid-flow conductor between the
well bore and the drill vessel and to guide the drillstring to the wellhead on the ocean floor. The
riser is made up of several sections including flexible joints and a telescoping joint to absorb the
vertical motion of the ship caused by wave action.
METAMORPHIC ROCK
Rocks formed by the metamorphosis of other rocks. When either igneous or sedimentary rocks are
subjected to enough heat, pressure, and chemical action, their character and appearance are changed.
These factors act to cause recrystallization of the minerals of the rock. Granites may become
gneisses or schists; sandstones become quartzites; shales become slates; limestone becomes marble.
MUD
(See Drilling Mud)
MUD HOSE
The flexible, steel-reinforced, rubber hose connecting the mud pump with the swivel and kelly joint
on a drilling rig. Mud is pumped through the mud hose to the swivel and down through the kelly
joint and drillpipe to the bottom of the well.
MUD PITS
Excavations near the rig into which drilling mud is circulated. Mud pumps withdraw the mud from
one end of a pit as the circulated mud, bearing rock chips from the borehole, flows in at the other
end. As the mud moves to the suction line, the cuttings drop out leaving the mud "clean" and ready
for another trip to the bottom of the borehole.

Glossary Appendix I
MUD PUMP
A large, reciprocating pump that circulates drilling mud in rotary drilling. The duplex (two-
cylinder) or triplex (three-cylinder) pump draws mud from the suction mud pit and pumps the slurry
downhole through the drillpipe and bit and back up the borehole to the mud settling pits. After the
rock cuttings drop out in the settling pit, the clean mud gravitates into the suction pit where it is
picked up by the pump's suction line. In rotary drilling there are at least two mud pumps, sometimes
more. In case of a breakdown or other necessary stoppages, another pump can be immediately put
on line.
MUD TANKS
Portable metal tanks to hold drilling mud. Mud tanks are used where it is impractical to dig mud
pits at the well site (as in the case of offshore drilling).
NATURAL GAS
Gaseous forms of petroleum consisting of mixtures of hydrocarbon gases and vapours, the more im-
portant of which are methane, ethane, propane and butane; gas produced from a gas well.
OIL
Crude petroleum and other hydrocarbons produced at the wellhead in liquid form.
OIL SPILL
A mishap that permits oil to escape from a tank, an offshore well, an oil tanker, or a pipeline. Oil
spill has come to mean oil on a body of water where even small amounts of oil spread and become
highly visible.
OIL-SPILL BOOM
Any of various devices or contraptions to contain and prevent the further spread of oil spilled on wa-
ter until it can be picked up. A curtain-like device deployed around or across the path of a drifting
oil spill. The curtain is weighted on the bottom edge to hold it a foot to two below the surface and
has floats on the upper edge to hold the curtain a foot or more above the surface. Once surrounded,
the oil is sucked up by a vacuum cleaner-like suction pump.
OPEN HOLE
An uncased well bore; the section of the well bore below the casing; a well in which there is no pro-
tective string of pipe.

Glossary Appendix I
ORGANIZATION OF PETROLEUM EXPORTING COUNTRIES (OPEC)
Oil producing and exporting countries in the Middle East, Africa, and South America that have or-
ganized for the purpose of negotiating with oil companies on matters of oil production, prices and
future concession rights.
OUTCROP
A subsurface rock layer or formation that, owing to geological conditions, appears on the surface in
certain locations. That part of a strata of rock that comes to the surface.
PERMEABILITY
A measure of the resistance offered by rock to the movement of fluids through it. Permeability is
one of the important properties of sedimentary rock containing petroleum deposits. The oil con-
tained in the pores of the rock cannot flow into the well bore if the rock in the formation lacks suffi-
cient permeability.
PETROLEUM
In its broadest sense, the term embraces the whole spectrum of hydrocarbons - gaseous, liquid, and
solid. In the popular sense, petroleum means crude oil.
POROSITY
The state or quality of being porous; the volume of the pore space expressed as a percent of the total
volume of the rock mass; an important property of oil-bearing formations. Good porosity indicates
an ability to hold large amounts of oil in the rock. And with good permeability, the quality of a rock
that allows liquids to flow through it readily, a well penetrating the formation should be a good pro-
ducer.
PRECIPITATE
A substance separated from a solution by chemical or physical change such as a change in tempera-
ture or salinity. Examples of precipitate rocks are salt, limestone and gypsum.
PRESSURE MAINTENANCE PROGRAM
A program whereby fluids or gases are injected into a reservoir to maintain the pressure required to
keep the petroleum flowing to the surface.
PRODUCTION PLATFORM
An offshore structure built for the purpose of providing a central receiving point for oil produced in
an area of the offshore. The production platform supports receiving tanks, treaters, separators, and
pumping units for moving the oil to shore through a submarine pipeline or by shuttle tanker.

Glossary Appendix I
RECONNAISSANCESURVEY
A general survey of an area to ascertain its main features, usually preliminary to a more detailed sur-
vey.
RESERVOIR
A porous, permeable sedimentary rock formation containing quantities of oil and/or natural gas
overlain by a layer of less permeable or impervious rock.
RESERVOIR ROCKS
Sandstone, limestone, and other porous, permeable rock formations in which petroleum has accumu-
lated.
ROUGHNECKS
Members of the drilling crew; the driller's assistants who work on the derrick floor, up in the derrick
racking pipe, tend the drilling engines and mud pumps, and operate the pipe tongs when unscrewing
the sections of drillpipe.
ROUSTABOUT
An oil rig worker who works on a lease or around the drilling rig doing manual labour.
ROYALTY
A share of the minerals (oil and gas) produced from a property belonging to the owner of the prop-
erty. Originally, the "royalty" was the percentage of the gold or silver taken from the realm that be-
longed to the king or queen. Today, the "sovereign" is the landowner who traditionally receives
12.5 percent or one-eighth of the oil and gas produced from his or her land. Although 12.5 percent
has been the traditional royalty on oil and gas lease, this varies widely today. In very profitable ar-
eas, the royalty may be much higher. In marginally profitable areas, it may be much lower and in
some cases there may be zero royalty.
SAMPLE
Cuttings of a rock formation broken up by the drill bit and brought to the surface by the drilling
mud. Rock samples are collected from the shale shaker and examined by the geologist to identify
the formation and the type of rock being drilled.
SCOUT
A person hired by a company to seek out information about the exploration activities of other com-
panies, including the location of geophysical surveys and the results of wells being drilled.

Glossary Appendix I
SEDIMENTARY BASIN
An extensive area (often covering thousands of square kilometres) where substantial amounts of
sedimentary rocks are present. Most sedimentary basins are geologically depressed areas (shaped
like a basin). The sediment is thickest in the middle and tends to thin out at the edges. There are
many kinds of such basins, but it is in these areas that all the oil produced throughout the world has
been found.
SEDIMENTARY ROCK
Rock formed by the laying down of sediment by seas, streams, or lakes; sediment (mineral frag-
ments, animal matter) deposited in bodies of water through geologic ages. Limestone, sandstone,
shale and salt are examples of sedimentary rock.
SEISMIC SECTION
A plot or display of data acquired during a seismic survey with surface locations plotted horizontally
and reflections from subsurface layers displayed vertically (See Figure 6.6).
SEISMIC SURVEY
The investigation of underground rock layers by analyzing shock waves artificially produced at the
surface and reflected from the subsurface layers ofrock.
SEMI-SUBMERSIBLE
A large floating drilling platform with a buoyant substructure; part of which is beneath the surface
of the water. Semi-submersibles are virtually self-contained, carrying on their main and lower decks
all supplies and personnel for drilling and completing wells in hundreds of metres of water at great
distances from shore. Some of these huge platforms are self-propelled and are capable of moving at
6 to 8 knots. As they often drill in waters too deep for conventional chain and cable anchors, they
sometimes maintain their position over the borehole by the use of propellers or thrusters, controlled
by onboard computers.
SEPARATOR
A pressure vessel (either horizontal or vertical) used for the purpose of separating well fluids into
gaseous and liquid components. Separators segregate oil, gas, and water with the aid, at times, of
chemical treatment and the application of heat.
SET CASING
To cement casing in the hole. The cement is pumped downhole to the bottom of the well and forced
up a certain distance into the annular space between casing and rock wall of the drillhole. It is then
allowed to harden, thus sealing off upper formations that may contain water. The decision to set
production casing is an indication that the operator believes the well is a commercial discovery.

Glossary Appendix I
SHOT HOLE
A small-diameter hole typically of 10 to 30 metres depth, usually drilled with a portable, truck-
mounted drill, for "planting" explosive charges in seismic operations.
SOURCE ROCKS
Those sedimentary layers that contain the organic material that has been transformed into hydrocar-
bons by heat, pressure, and time.
STEP-OUT WELL
A well drilled adjacent to a proven well but located in an unproven area; a well located a "step out"
from proven territory in an effort to determine the boundaries of a producing formation.
STRATIGRAPHIC TRAP
A type of reservoir capable of holding oil or gas, formed by a change in the characteristics of the
formation - loss of porosity and permeability, or a break in its continuity - which forms the trap or
reservoir.
STRUCTURAL TRAP
A type of reservoir containing oil and/or gas formed by movements of the earth's crust which seal
off the oil and gas accumulation in the reservoir forming a trap. Anticlines, salt domes, and faulting
of different kinds form structural traps.
SUBSIDENCE
The process whereby the earth's crust buckles downward under the weight of sedimentary layers be-
ing deposited in the area.
SURFACE SEEP
A location where petroleum is seeping out of rocks at the surface.
TAR PIT
An area where a significant amount of petroleum has seeped out of the surface rocks and collected
in a depression or pit. The lighter, more liquid fractions would have evaporated leaving a heavy
tarry deposit.
THRUSTER
A propeller used in manoeuvring a ship.

Glossary Appendix I
TOOL PUSHER
A supervisor of drilling operations in the field. A tool pusher may have one drilling well or several
under his or her direct supervision. Drillers are directed in their work by the tool pusher.
TOPOGRAPHIC MAP
A map which shows in detail the physical features of an area of land, including rivers, lakes,
streams, roads, and the elevation of those features.
TRAP
A type of geological structure that retards the free migration of petroleum and concentrates the pe-
troleum in a limited space. A mass of porous, permeable rock which is sealed on top and down both
flanks by nonporous, impermeable rock thus forming a trap.
WELL
A hole drilled or bored into the earth, usually cased with metal pipe, for the purpose of discovering
or producing gas or oil. Also, a hole for the injection under pressure of water or gas into a subsur-
face rock formation for the purpose of maintaining the necessary reservoir pressure to keep the pe-
troleum flowing to the surface.
WELL COMPLETION
The work of preparing a newly drilled well for production. This is a costly procedure and includes
setting and cementing the casing, perforating the casing, running production tubing, hanging the
control valves, connecting the flow lines, and erecting storage tanks.
WELL SPACING GRID
A plan showing the best locations for the drilling of wells into a field with regard to getting maxi-
mum production for minimum cost.
WILDCAT WELL
A well drilled in an unproved area, far from a producing well; an exploratory well in the truest sense
of the word; a well drilled out "where the wildcats prowl and the hoot owls mate with the chickens".

Intro to petroleum geology

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Intro to petroleum geology