INIO2014 Presentation

Marine Pipeline Engineering
Short Course
(12 -14 Jan 2014 - Tehran)
INIOAS
(OETRC)
Tahmasbi
1
A Glance Through
from Conceptual Design to Detail Engineering
in
Submarine Pipeline Projects
Prepared by :
Hadi Tahmasbi Ashtiani
Lead Offshore Structural Engineer, Pars Oil & Gas Company
MSc., Structural Engineering, University of Tehran
MBA, Construction Management, The Petroleum University of Technology
PMP certified by Project Management Institute (PMI)

Short Course
(12 -14 Jan 2014 - Tehran)
INIOAS
(OETRC)
Tahmasbi
2
Content :
1. Introduction & Overview
2. Relevant Codes & Standards
3. Different Phases in a Submarine Pipeline Project
4. DNV Standard (Limit State Design Methodology)
5. Route Selection Study
6. Flow Assurance Study
7. Material & Grade Selection
8. Pipe Manufacturing
9. Pipe Anti-corrosion Coating & CP Design
10. Wall Thickness Calculation
11. Local Buckling Criteria - Combined Loading
12. Fracture Criteria
13. On-bottom Stability of Pipeline
14. Pipeline Installation Studies
15. Shore Approach Design
16. Free Span Analysis
17. Riser Design – Rigid Pipeline
18. Pipeline Global Buckling (Lateral & Upheaval)
19. New Technologies in Submarine Pipeline Industries
20. Verification & Certification Services
21. Cause Study of Pipeline Incidents (PARLOC)
22. Description of SPM System
23. Applicable Software Programs in Pipeline Design
24. References

Short Course
(12 -14 Jan 2014 - Tehran)
INIOAS
(OETRC)
Tahmasbi
3
1. Introduction & Overview – Historical Perspective
 Pipelines are generally the most economical way to transport large
quantities of oil, refined oil products or natural gas with competitive
advantages such as safer mode of transportation & higher reliability.
 Oil was transported by wooden barrels until
1870s. As the volume was increased, the
product was transported by tank cars or trains
and eventually by pipelines.
1 barrel (US, Petroleum) ~ 159 litter
 The first onshore pipeline was built in the United States in 1859 to
transport crude oil from an oil field in Pennsylvania to a railroad station.
(2 inch in size, 9.7 km in length)
 The first offshore pipeline (PLUTO) was built in Europe in 1944 between
England and France as alternative to oil tankers. (Prototype tested on 1942)
(3 inch in size, 130 km in length)

Short Course
(12 -14 Jan 2014 - Tehran)
INIOAS
(OETRC)
Tahmasbi
4
1. Introduction & Overview – Today Achievements
 Total Length of pipelines (gas, oil & petroleum products) up to 2010 was
estimated about 2 millions km. About 50 times of the earth's circumference.
 About 10 percent of total pipeline are submarine pipelines.
1-USA about 800,000 km
2-Russia about 250,000 km
3-China about 75,000 km

Short Course
(12 -14 Jan 2014 - Tehran)
INIOAS
(OETRC)
Tahmasbi
5
 Generally the most deepwater flow lines carry very high pressure and high
temperature (HP/HT) fluid.
 The deepest pipeline installed is 2,775 m water depth in 2007.
 By the year 2005, Statoil’s Kristin Field in Norway holds the HP/HT record
of 911 bar and 167oC in 330m of water.
 Blue Stream submarine pipeline:
Natural gas
Between Russia & Turkey
1550 MMSCFD
Maximum WD : 2150 m
2 @ OD 24” & thickness 31.8 mm
In length of 396km x 2
250 bar & X65
Commissioned on 2005
About 1.7 billion USD (2.15 MUSD/km) Onshore : 48” & 56” Offshore : 2 x 24”

Short Course
(12 -14 Jan 2014 - Tehran)
INIOAS
(OETRC)
Tahmasbi
6
 Langeled submarine pipeline:
Natural gas
Between Norway & UK
2500 MMSCFD
Maximum WD : 385 m
OD 42” (29.1/33.3/34.1 mm) & OD 44” (23.3/24 mm)
In length of 1166 km
250 bar & X70
About 3 billion USD (2.5 MUSD/km)
 Nord Stream submarine pipeline:
Natural gas
Between Russia & Germany
5300 MMSCFD
Maximum WD : 210 m
2 @ OD 48” (26.8 to 41 mm)
In length of 2 x 1220 km
220 bar & X70

Short Course
(12 -14 Jan 2014 - Tehran)
INIOAS
(OETRC)
Tahmasbi
7
1. Introduction & Overview
 Offshore pipelines can be classified as follow:

Short Course
(12 -14 Jan 2014 - Tehran)
INIOAS
(OETRC)
Tahmasbi
8
 Three disciplines mainly involve in field of offshore pipeline engineering:
1- Thermo-Hydraulics
Multiphase flow assurance study & line sizing
2- Material Science
Material selection & corrosion study
3- Mechanics
Structural mechanics
Hydrodynamic mechanics
Soil mechanics
Offshore
Pipeline
Eng.

Short Course
(12 -14 Jan 2014 - Tehran)
INIOAS
(OETRC)
Tahmasbi
9
1- Flow assurance study & line sizing
API RP 14E (ISO 13703 ): Recommended practice for design and
installation of offshore production platform piping systems
2- Material Science
API Spec 5L (ISO 3183) : Petroleum and natural gas industries, Steel
pipe for pipeline transportation systems
NACE MR0175 (ISO 15156) : Petroleum and natural gas industries,
materials for use in H2S-containing environments in oil and gas production
DNV-RP-F106 : Factory applied external pipeline coatings for corrosion
control
DNV-RP-F103 : Cathodic protection of submarine pipelines by galvanic
anodes
3- Structural /Hydrodynamic /Soil mechanics
Large number of standards, e.g.:
ASME B31.4, ASME B31.8, BS 8010, EN 14161, ISO 13623,
API RP-1111, API RP-2SK, DNV OS-F101, DNV RP-F105,
DNV RP-F109, DNV RP-F110, DNV RP-C203, DNV-OSS-301,
0029/ND, 0032/ND, etc.

Short Course
(12 -14 Jan 2014 - Tehran)
INIOAS
(OETRC)
Tahmasbi
10
Following table gives a comparison between different pipeline codes and
standards with respect to mechanical design of pipeline:
ASD: Allowable Strength Design LSD: Limit State Design RBD: Reliability Based Design

Short Course
(12 -14 Jan 2014 - Tehran)
INIOAS
(OETRC)
Tahmasbi
11
Concept
Design
Construction
Operation
 Feasibility Study
 Business Development
 Basic Design
 Detail Design
 Line Pipe
 Component & Assemblies
 Corrosion Protection & Weight Coating
 Pre-intervention
 Installation
 Post-intervention
 Pre-commissioning
 Commissioning & Startup
 Integrity Management
 Inspection & Repair
 Re-qualification
 Abandonment

Short Course
(12 -14 Jan 2014 - Tehran)
INIOAS
(OETRC)
Tahmasbi
12
Conceptual Engineering
 Feasibility study :
 Technical e.g. identifying potential routes, reviewing of new
technologies & recourses
 Economical e.g. cost/benefit studies, IRR analysis, sensitivity
analysis (studying of factors could have positive/negative effects
on profitability), etc.
 Political, legal ,etc. (e.g. territorial waters is extended up to 12
nautical miles from shore line)
 Risk analysis e.g. identifying of high level risks & prepare risk
response plan
 Prepare rough schedule and cost estimate (-25% to +75%)
 Reviewing of all existing alternatives in all aspects and eventually
enter into go/no-go decision process & project selection.

Short Course
(12 -14 Jan 2014 - Tehran)
INIOAS
(OETRC)
Tahmasbi
13
 Meteorological and Oceanographic survey
 Geophysical survey (bathymetry, faults, etc.)
 Geotechnical survey (soil engineering parameters)
 Environmental Baseline Study & Environmental Impact Assessment
Basic Engineering
 Prepare design basis and design procedure (select the applicable Code)
 Route selection study
 Flow assurance study:
line sizing, pressure profile, temperature profile, etc.
 Hazard Identification & operability study (HAZOP & HAZID study)
 Material/grade selection & wall thickness calculation
 Construction specification & methodology
 Procurement engineering of long lead items (LLIs)
 Prepare a more precise time schedule/cost estimation (-5% to +10%)
 Tendering strategy & preparing tendering documentation (e.g. EPC)

Short Course
(12 -14 Jan 2014 - Tehran)
INIOAS
(OETRC)
Tahmasbi
14
Meteorological and Oceanographic survey
Metocean (METeorological-OCEANographic) survey consists of
collecting of wind, waves, current, tide and other oceanographic &
meteorological parameters in order to characterize the engineering
parameters required for pipeline design.
For example:
 Wave height & relevant wave period with 1,10,100 years return
period in eight directions.
 Current speed profile with 1,10,100 years return period in eight
directions.
 Wind speed with 1,10,100 years return period in eight directions.
 Tide level (astronomical, storm surge, etc.)
 Wave scatter diagram
 Temperature profile of seawater
 Salinity and seawater resistivity

Short Course
(12 -14 Jan 2014 - Tehran)
INIOAS
(OETRC)
Tahmasbi
15
Geophysical survey
The geophysical route survey objectives were as follows:
 Select a coordinate system (e.g. world geodetic system, WGS84)
 Bathymetry : obtain accurate water depths along the pipeline
route with a reasonable survey corridor width (e.g. 1000 m)
 Identify and locate any existing subsea installations (e.g. pipeline,
cable), features, debris or obstructions.
 Obtain information about the shallow sub-seabed morphology and
lithology and give a brief description of soil in seabed surface
using drop core along the route
 Study of active earthquake faults in area & evaluation of related
design parameters

Short Course
(12 -14 Jan 2014 - Tehran)
INIOAS
(OETRC)
Tahmasbi
16
Geotechnical survey
The geotechnical survey will typically encompass the following:
 Coring and sampling for material identification, description and
subsequent laboratory testing. (UU triaxial compression test)
 In situ testing for accurate stratification and determination of
key geotechnical parameters. (CPT )
The main objectives of geotechnical survey is to determine the soil
engineering parameters required for pipeline design. For example:
 Undrained shear strength for cohesive soil, i.e. clay
 Angle of friction for cohesionless soil, i.e. sand
 Soil density, water content, liquid and plastic limit, grain size
distribution, carbonate content, soil classifications, etc.

Short Course
(12 -14 Jan 2014 - Tehran)
INIOAS
(OETRC)
Tahmasbi
17
 Route optimization and finalization (alignment sheets)
 Metallurgy & welding study
 Pipe coating selection & pipeline cathodic protection study
 Pipeline on-bottom stability analysis (weight coating)
 Free span analysis (VIV damage analysis)
 Pipeline end expansion analysis (Tie-in spool design)
 Pipeline global buckling analysis (lateral or upheaval)
 Riser analysis
 Shore approach analysis (Trenching/backfilling, vertical profile)
 Pipeline crossing analysis (e.g. rock dumping, steel/concrete supports)
 Pipeline installation study (e.g. lay-ability)
 Material specifications, data sheets & MTOs
 Construction spec. (Coating, Installation, Pre-comm., Comm., etc.)
Detail Engineering
 Review and verifying of basic engineering (Endorsement)

Short Course
(12 -14 Jan 2014 - Tehran)
INIOAS
(OETRC)
Tahmasbi
18
Maximum application extent of DNV OS-F101 :

Short Course
(12 -14 Jan 2014 - Tehran)
INIOAS
(OETRC)
Tahmasbi
19
Categorization of fluids :
Fluids to be transported by the pipeline system shall be categorized according
to their hazard potential as given bellow :

Short Course
(12 -14 Jan 2014 - Tehran)
INIOAS
(OETRC)
Tahmasbi
20
Applicable for offshore section :

Short Course
(12 -14 Jan 2014 - Tehran)
INIOAS
(OETRC)
Tahmasbi
21
Applicable for onshore section :

Short Course
(12 -14 Jan 2014 - Tehran)
INIOAS
(OETRC)
Tahmasbi
22
Limit State Categorizations :
 Serviceability Limit State (SLS):
A condition which, if exceeded, renders the pipeline unsuitable
for normal operations.
 Ultimate Limit State (ULS):
A condition which, if exceeded, compromises the integrity of
the pipeline.
 Fatigue Limit State (FLS):
An ULS condition accounting for accumulated cyclic load
effects.
 Accidental Limit State (ALS):
An ULS due to accidental (in-frequent) loads.
The design format is based on partial safety factors methodology,
also called Load and Resistance Factor Design format (LRFD).
The load and resistance factors will be defined based on limit state
& safety class of pipeline in each design case.

Short Course
(12 -14 Jan 2014 - Tehran)
INIOAS
(OETRC)
Tahmasbi
23
 Example of partial safety factors applied for loading :

Short Course
(12 -14 Jan 2014 - Tehran)
INIOAS
(OETRC)
Tahmasbi
24
 Example of partial safety factors applied for resistance :

Short Course
(12 -14 Jan 2014 - Tehran)
INIOAS
(OETRC)
Tahmasbi
25
 Minimize the pipeline distance from initiation to termination; economically
the shortest route possible is the most advantageous.
 Avoid wherever possible restricted offshore areas such as anchorages,
shipping lanes, military reservations, etc.
 Follow a smooth seabed profile; avoiding, wherever possible, coral growths,
rock outcrops, soft or liquefiable soils, unstable seabed area (sand ripples)
and other seabed obstacles.
 Avoid pipeline/cable crossings. Where this is not possible, crossings should
be as perpendicular as commercially possible.

Short Course
(12 -14 Jan 2014 - Tehran)
INIOAS
(OETRC)
Tahmasbi
26
 Example of route selection in Georgia Strait (Canada)
Cutting

Short Course
(12 -14 Jan 2014 - Tehran)
INIOAS
(OETRC)
Tahmasbi
27
Bridge
Embankment

Short Course
(12 -14 Jan 2014 - Tehran)
INIOAS
(OETRC)
Tahmasbi
28
Flexible spool connected by flanges
Welded spool connected (Hyperbaric welding)

Short Course
(12 -14 Jan 2014 - Tehran)
INIOAS
(OETRC)
Tahmasbi
29
More thorough survey showed later that in fact there is a pass
across the ridge a broad curving valley (“Valdes Gap”) with plenty
of space for two pipelines.
 The shortest route is not necessarily the best route.

Short Course
(12 -14 Jan 2014 - Tehran)
INIOAS
(OETRC)
Tahmasbi
30
6. Flow Assurance Study
 Flow assurance is required to determine the optimum size (ID) based on
required flow rate and pressure & considering erosion velocity limitation.
 The pressure drop will drastically increase with decreasing the pipe size.
 If the pipeline is to transport a sour fluid containing H2S, CO2, etc.,
corrosion inhibitors should be applied or a special corrosion resistant
alloy (CRA) pipe material should be used and/or a corrosion allowance
can be added to the required pipe wall thickness.
 Pigging requirements in order to wax/condensate buildups removal.
 Mitigation or Prevention Strategies for deposition and line plugging
due to hydrate, wax, asphaltene & scale to be reviewed and selected.

Short Course
(12 -14 Jan 2014 - Tehran)
INIOAS
(OETRC)
Tahmasbi
31
Materials & Grade Requirements for Pipeline :
 Strength: The ability to withstand an applied stress without failure.
 Ductility: is a solid material's ability to deform under tensile stress.
 Toughness: The ability of a material to absorb energy and plastically
deform without fracturing.
 Weld-ability: As the equivalent carbon content rises, the weld-ability
of the alloy decreases. (Set limitations on CE & Pcm)
 Corrosion Resistance
 Existence of H2S & CO2 (pH, pressure & ppm)
 Resistance to Cracking
 Hydrogen Induced Cracking (HIC)
 Hydrogen Induced Stress Cracking (HISC)
 Stress Corrosion Cracking (SCC)
 Operating Temperature
 Tests (tensile, hardness, CVN impact,
guided bend, etc.)

Short Course
(12 -14 Jan 2014 - Tehran)
INIOAS
(OETRC)
Tahmasbi
32
Chemical composition recommended by TOTAL (% weight, maximum)
C-MnSteel
SweetService
C-MnSteel
SourService

Short Course
(12 -14 Jan 2014 - Tehran)
INIOAS
(OETRC)
Tahmasbi
33
Materials of Construction :
 Carbon Manganese steel
 Carbon Manganese steel + Corrosion Allowance
 Carbon Manganese steel + CA + Corrosion Inhibitor
 Corrosion Resistant Alloys (CRAs)
 Inconel alloy (625, 825, etc.) – Nickel base
 Weld-able high Chromium steel
• Standard duplex stainless steel (22% Cr)
• Super duplex stainless steel (25% Cr)
 Martensitic stainless steel (13% Cr-2Mo & 13% Cr-2.5Mo)
 Internally clad C-Mn steel (more applicable for OD>18”)
 Flexible pipe

Short Course
(12 -14 Jan 2014 - Tehran)
INIOAS
(OETRC)
Tahmasbi
34
Typical Materials Cost Comparisons :

Short Course
(12 -14 Jan 2014 - Tehran)
INIOAS
(OETRC)
Tahmasbi
35
Flexible Pipeline :
 Flexibility & superior dynamic behavior for risers: A typical 8'' internal
diameter can safely be bent to a radius of 2m or less. (10D)
 High Speed laying : Because it comes in a continuous length spooling on a reel,
laying speed commonly averages 500m per hour. (12 km/day)
 Modularity : The independent layers of a flexible structure enable it to be
tailored to the precise needs of a specific development.
 Water depth up to 3000m, Temperature up to 170oC , Pressure up to 460 bar
for 10” ID. (Based on Technip’s presentation)

Short Course
(12 -14 Jan 2014 - Tehran)
INIOAS
(OETRC)
Tahmasbi
36
Manufacturing Process :
Seamless, UO, UOE, TRB, ERW, Spiral/Helical
U Forming O Forming Expansion
 For manufacturing processes which introduce cold deformations, a fabrication factor
to be applied to compensate the weakening of pipe against external pressure.
The fabrication factor may be increased through heat treatment or external cold sizing.

Short Course
(12 -14 Jan 2014 - Tehran)
INIOAS
(OETRC)
Tahmasbi
37
Example of One Mill’s Pipe Production Range

Short Course
(12 -14 Jan 2014 - Tehran)
INIOAS
(OETRC)
Tahmasbi
38
9. Pipe Anti-corrosion Coating & CP Design
 Pipeline external corrosion protection is based on combination of anti-corrosion
coating and cathodic protection system.
 Different types of anti-corrosion coating applicable for offshore pipeline:
 3-layer polypropylene (PP) Max. temperature : 140oC
 3-layer polyethylene (PE) Max. temperature : 110oC
 Hot enamel coating + CWC Max. temperature : 90oC
 Polychloropene (Neoprene) Max. temperature : 90oC
 Dual layer Fusion Bonded Epoxy (FBE) Max. temperature : 90oC
 The two main methods of cathodic protection system are :
 Sacrificial anodes (Aluminum anode & Zinc anode)
 Impressed current systems (less practical for offshore pipeline)
 Pipeline anti corrosion coatings are the first barriers of defense against
corrosion, however, due to probable damages could be made on coatings
(coating breakdown), CP System shall be applied in parallel.
 Maximum anode distance of 300 m is advised for pipeline CP design.
 CP design should be done as per formulation and methodology defined in :
DNV-RP-F103 (Cathodic Protection of Submarine Pipelines by Galvanic Anodes)

Short Course
(12 -14 Jan 2014 - Tehran)
INIOAS
(OETRC)
Tahmasbi
39
For thin wall pipe (D/t>20)
Hoop Stress
Longitudinal Stress
DNV-OS-F101 (Oct 2013)
(Submarine Pipeline System)
DNV &
ISO
ASME
(B31.8)
API
1111
LC 1 0.77 0.72 0.72
LC 2 0.67 0.5 0.6
Comparison between different
standards (fluid : gas)
Stresses Due to Internal Pressure
t1= t-tfab-tcor
= 0.96 for pressure test

Short Course
(12 -14 Jan 2014 - Tehran)
INIOAS
(OETRC)
Tahmasbi
40
Local buckling – external over pressure only
t1= t-tfab-tcor
Ovality
Example : OD 32”, t=20.6mm, Grade X65, UOE, LC1
fo =0.1% : Pc= 93.3 bar
fo =0.5% : Pc= 84.9 bar , Pe = 71 bar
fo =1% : Pc= 76.9 bar

Short Course
(12 -14 Jan 2014 - Tehran)
INIOAS
(OETRC)
Tahmasbi
41
Propagation buckling cannot be initiated and then propagated unless local
buckling has occurred.
Propagation buckling pressure (Ppr) is always less than collapse pressure (Pc)
Example : Grade X65, D/t=40, LC1, Calm sea
Pipe Seamless UO,TRB UOE
Allowable
W.D.
125 m 116 m 106 m
 Buckle arrestors should be applied if
pipeline to be installed in water depth
more than above.
t2= t-tcor
Buckle
Arrestor
Propagation buckling

Short Course
(12 -14 Jan 2014 - Tehran)
INIOAS
(OETRC)
Tahmasbi
42
LoadControlled
Condition
DisplacementControlled
Condition Internal Overpressure
External Overpressure
External Overpressure
Internal Overpressure
DNV-OS-F101(Oct2013)
Strain concentration factor
shall be considered.
t2= t-tcor
t2= t-tcor

Short Course
(12 -14 Jan 2014 - Tehran)
INIOAS
(OETRC)
Tahmasbi
43
Internal Pressure, Operation Case External Pressure, Pre Operation Case
LCC - Combined Loading Calculation based on DNV-OS-F101 (2013)
An example :
OD=32 inch, Thickness=20.6mm, X65, Gas, Location 1, UOE
Pb=258.3 bar, Pc=84.9 bar, Mp=567 ton-m, Sp=2248.4 ton

Short Course
(12 -14 Jan 2014 - Tehran)
INIOAS
(OETRC)
Tahmasbi
44
DCC - Combined Loading Calculation based on DNV-OS-F101 (2013)
An example :
OD=32 inch, Thickness=20.6mm, X65, Gas, Location 1, UOE
Pb=258.3 bar, Pc=84.9 bar
Internal Pressure, Operation Case External Pressure, Pre Operation Case

Short Course
(12 -14 Jan 2014 - Tehran)
INIOAS
(OETRC)
Tahmasbi
45
Moment
Strain (or Curvature)
Safety factor for DCC
SF for LCC
Bending + Internal Pressure Bending + External Pressure

Short Course
(12 -14 Jan 2014 - Tehran)
INIOAS
(OETRC)
Tahmasbi
46
12. Fracture Criteria
Appendix A (Fracture Limit State of Girth Weld)
The purpose of the fracture limit state evaluation of girth welds in pipelines is to avoid
failure (fracture, tearing and fatigue crack growth) during the installation and operation
stages by determining the criticality of possible weld flaws.
Supplementary requirement (P)
Additional tests during the steel production and pipe manufacturing to be performed.
Sufficient capacity in elongation of steel before failure and strain-hardening (YS/TS) shall
be assured.
(Strain concentration factor shall be considered)

Short Course
(12 -14 Jan 2014 - Tehran)
INIOAS
(OETRC)
Tahmasbi
47
 Submarine On-bottom stability refers to the resistance of a submarine
pipeline to movement on the seabed under extreme environmental
conditions.
 The effective way to stabilize the submarine pipeline on the seabed is to
apply the weight coating mostly from high density concrete
produced from iron ore.

Short Course
(12 -14 Jan 2014 - Tehran)
INIOAS
(OETRC)
Tahmasbi
48
 Bare submarine Pipelines with D/t over 31 will float in seawater water.
 Flowline in deep water might be stable on seabed with no requirement
of weight coating .
 The following methods can be adopted to keep the pipeline stable on the
sea floor:
 Concrete weight coating
 Trenching (Specially in shore approach area and shallow waters)
 Burial
 Covering (e.g. rock dumping, concrete mattress, etc.)
 Design criteria and guidance for calculation of required thickness of CWC
and density of concrete with considering the wave and current loading,
load reduction due to trenching and pipe embedment in seabed
are well defined in:
DNV-RP-F109
(On-Bottom Stability Design of Submarine Pipelines)

Short Course
(12 -14 Jan 2014 - Tehran)
INIOAS
(OETRC)
Tahmasbi
49
14. Pipeline Installation StudiesSurfaceTowMid-depthTowOff-bottomTowBottomTow

Short Course
(12 -14 Jan 2014 - Tehran)
INIOAS
(OETRC)
Tahmasbi
50
Overbend Area:
Creation I : Static Loading
Creation II : Dynamic Loading & SNCF
Sagbend Area:
Dynamic Loading & SNCF may be ignored.

Short Course
(12 -14 Jan 2014 - Tehran)
INIOAS
(OETRC)
Tahmasbi
51
Stress Strain Curve for X65 materialExample of Pipe Stress Analysis Results
 At sagbend area the pipe is hard to control, so more stringent stress criteria
(lower stress limit) is applied.
fy (Yield Stress)
87% fy

Short Course
(12 -14 Jan 2014 - Tehran)
INIOAS
(OETRC)
Tahmasbi
52
Pipeline Diameter (inches)
MaximumWaterDepth(m)
 The installation vessel's limitation such as tensioner capacity, stinger
geometry, etc. should be checked in pipeline install-ability evaluation.
 Tensioner range : from 70 ton to 1050 ton (Solitaire)
Limitation

Short Course
(12 -14 Jan 2014 - Tehran)
INIOAS
(OETRC)
Tahmasbi
53
15. Shore Approach Design
 The effects of wave and current forces in shallow water is more
dominate than in deep water.
 In shore approach area, it is recommended that pipeline to be buried
same as onshore pipeline.
For example, according to MMS regulations applicable on USA
coastal areas (water depth less than 60m):
 If OD<8 inch pipeline to be buried to a depth of minimum 1m cover
 If the pipeline leakage may have serious hazard to others, all
pipelines (regardless of pipe size) must be buried.
 Pipeline stress analysis to be done to calculate the allowable vertical
curvature of pipeline in shore approach area.
R=1000.D is equal to about 0.05% strain or 1000 kg/cm2 stress in pipeline.
Pipeline exposed on seabed
Pipeline in trenching area

Short Course
(12 -14 Jan 2014 - Tehran)
INIOAS
(OETRC)
Tahmasbi
54
1-Local buckling criteria – combined loading (Load Controlled Condition)
2-Fracture criteria
Loading includes wave, current, self weight, thermal expansion, internal
overpressure, external overpressure, pipeline curvature , residual tension, etc.
Dynamic stress due to VIV (cross flow & inline flow) to be added to above,
according to formulation and methodology defined in :
DNV-RP-F105
Recommended practice for free spanning pipelines (Feb 2006)

Short Course
(12 -14 Jan 2014 - Tehran)
INIOAS
(OETRC)
Tahmasbi
55
3-Fatigue Limit State (DNV-RP-F105)
 The submarine pipeline system shall have adequate safety against fatigue failures
within different phases of the design life of the system.
 Typical causes of stress fluctuations in a pipeline system are:
 Direct wave action (mainly for risers)
 Vibrations of the pipeline system due to VIV (mainly for pipeline in seabed)
 Movements of installation vessel during laying (installation phase)
 Fluctuations in operating pressure and temperature (shutdown/startup)
 A common split for fatigue capacity in the different phases is as below:
 Installation : 10%
 As-laid (flooded, hydro-test ) : 10%
 Operation : 80%

Short Course
(12 -14 Jan 2014 - Tehran)
INIOAS
(OETRC)
Tahmasbi
56
17. Riser Design – Rigid Pipeline
Major Criteria to be checked :
1- Local buckling criteria
(Combined Loading, LCC)
2- Fracture criteria
3- Fatigue Limit State
Major Loading :
1- Wave & Current
2- Thermal expansion
3- Internal Pressure
4- External pressure
5- Jacket movement
6- Self weight
7- Soil-pipe interaction

Short Course
(12 -14 Jan 2014 - Tehran)
INIOAS
(OETRC)
Tahmasbi
57
 Effective axial force of a totally restrained pipe in the linear elastic stress
range is:
For example:
OD 32”, t 20.6 mm, MOP 120 bar,
temperature increase : 50oC
Temperature share = 72%
Pressure share = 28%
 Identifying the susceptibility to buckling:
Minimum force to initiate buckling :
(Based on Hobbs formula)
Susceptible to buckling
Effective axial force in pipeline route

Short Course
(12 -14 Jan 2014 - Tehran)
INIOAS
(OETRC)
Tahmasbi
58
Side-scan Sonar Image of a Lateral Buckled Pipeline (Offshore)
Upheaval Buckling of Gas Injection Pipelines (Onshore)

Short Course
(12 -14 Jan 2014 - Tehran)
INIOAS
(OETRC)
Tahmasbi
59
 Design methodology & criteria has been comprehensively described in :
DNV-RP-F110
Global Buckling of Submarine Pipelines Structural Design
due to HT/HP
 SAFEBUCK (Safe Design of Pipelines with Lateral Buckling Design
Guideline) is another reference which has been developed in frame of
JIP (Joint Industries Program)
 Design concept in both guidelines (DNV & Safebuck) is as below :
1. Identifying the susceptibility to buckling
2. Ensure the pipeline keep in place and not buckle or,
3. Allow and facilitate the pipeline to buckle in a controlled manner.
 Local buckling criteria, fracture criteria and fatigue Limit state shall be
satisfied.
 Increase in thickness as a solution for global buckling phenomena
could not be effectively helpful because it increases the effective
axial force due to thermal expansion as well.

Short Course
(12 -14 Jan 2014 - Tehran)
INIOAS
(OETRC)
Tahmasbi
60
In order to control or mitigate the global buckling problems, such
methods can be adopted as follows:
 Snake lay
 Buckle initiators (sleepers, buoyancies, etc.)
 Buckle arrestors (Rock dumping, burial, anchor, etc.)
 Expansion loop
Typical Vertical Sleeper ArrangementTypical Snake Lay Configuration
(exaggerated vertical scale)

Short Course
(12 -14 Jan 2014 - Tehran)
INIOAS
(OETRC)
Tahmasbi
61
Submarine pipeline is a live industry with rapidly changing in technological
advances, so keeping updated on the latest is essential. As instance, some items
are presented here:
New Built or Upgraded of Lay-barge:
Solitaire modifications as below made in 2005 to meet the requirements of
the ever-deeper water pipe laying :
 Increase the stinger length and strength from a three-section (110m)
to a four-section (140m)
 Double the tension capacity from 525 tons to 1050 tons.
 Upgrade the A&R system capacity from 400 tons to 1050 tons.
In 2007 she set the world record for pipeline installation at a depth of 2,775 m

Short Course
(12 -14 Jan 2014 - Tehran)
INIOAS
(OETRC)
Tahmasbi
62
Technological Solution for Ultra- High Strength Pipeline
 Applying C-Mn steel with grade up to of X70 for sour services (Europipe)
 Applying C-Mn steel with grade up to X120 for sweet services (Europipe)
Advanced Connection Technologies
Zap-Lok connection utilizes high-strength mechanical interference
connections to provide a safe and reliable pipeline connection as well as a
fast and low-cost method for constructing steel pipelines in sizing between
2” to 12”.
INSTALLATION PRESS

Short Course
(12 -14 Jan 2014 - Tehran)
INIOAS
(OETRC)
Tahmasbi
63
Advanced Connection Technologies
With Smart Flange connector subsea pipeline repairs are easier and take
less time without the need for hyperbaric welding and can be installed in
diverless applications and for variety of from 2 inch up to 24 inch.

Short Course
(12 -14 Jan 2014 - Tehran)
INIOAS
(OETRC)
Tahmasbi
64
New Concept to Deal with Pipeline Expansion
SliPIPE works to reduce the end force
expansion exerted at the tie-in point
due HT/HP effects by absorbing the
end expansion through sliding within
itself and simultaneously reducing or
eliminating the effective axial
compressive force in the pipeline.
There are many similar examples of innovations,
advancements and changes in pipeline industries. So we
should keep ourselves updated on the latest continuously.

Short Course
(12 -14 Jan 2014 - Tehran)
INIOAS
(OETRC)
Tahmasbi
65
Based on DNV-OSS-301 ( Certification and Verification of Pipelines):
 Verification is used where DNV’s scope applies to the verification of only a single (or
more) phase of the project, for example, verification of the design but not of
construction, installation or testing. Verification results in the issue of a DNV
statement of compliance.
 Certification is used only where DNV’s scope covers the integrity of the entire
pipeline system and results in the issue of a DNV pipeline certificate.

Short Course
(12 -14 Jan 2014 - Tehran)
INIOAS
(OETRC)
Tahmasbi
66
 GL merged with Noble Denton in 2010.
 DNV and GL have merged to form DNV GL Group in Sep 2013.

Short Course
(12 -14 Jan 2014 - Tehran)
INIOAS
(OETRC)
Tahmasbi
67
21. Cause Study of Pipeline Incidents (PARLOC)
 PARLOC is a report describes studies performed regarding loss of containment
from offshore pipelines operated in the North Sea.
Damaged Categorized
By Diameter Range
52.2% < 9”
47.8% > 9”
Total database : ~ 24,800 km & ~ 328,800 km-years operating life
73%
27%
62.6%
37.4%
38.7%
61.3%
62.2%
37.8%
23%
51%
26%
17.4% : anchor, impact, corrosion,
material, natural hazard, etc.
82.6% : leakage in flange, seal,
valves, etc.

Short Course
(12 -14 Jan 2014 - Tehran)
INIOAS
(OETRC)
Tahmasbi
68
Single Point Mooring (SPM ) is used for loadingunloading of tankers, providing a
weathervane mooring in open sea conditions.

Short Course
(12 -14 Jan 2014 - Tehran)
INIOAS
(OETRC)
Tahmasbi
69
Submarine
Hoses
PLEM
CALM
System
Anchor Piles
VLCC (Very Large Crude Carrier)
Length = 350 m
Beam= 55 m
Draft = 28 m
Tanker Maneuvering Area

Short Course
(12 -14 Jan 2014 - Tehran)
INIOAS
(OETRC)
Tahmasbi
70
Turntable Buoy Type Turret Buoy Type
FP
FP
RP
RP
Main Bearing provides the mechanical connection
between the fixed and the rotating parts
Product Swivel provides the fluid transfer
between the fixed and the rotating parts
Three-race roller type

Short Course
(12 -14 Jan 2014 - Tehran)
INIOAS
(OETRC)
Tahmasbi
71
23. Applicable Software Programs in Pipeline Design
Engineering Software Application
Mathcad,
Microsoft Excel
Spread sheet for mathematical calculation
Sesam Pipeline (FatFree,
StableLines, etc)
AGA/PRCI , etc.
Engineering tools & in-house softwares for
general calculation
AutoCad
SAGE Profile
Route Selection study
Preparation of project drawings
OLGA
PIPESIM
Pipeline flow assurance analysis
ABAQUS
ANSYS
SAGE Profile
Pipeline nonlinear (both geometric & material)
stress analysis
OFFPIPE
SAGE Profile
OrcaLay
OrcaFlex
Pipeline installation stress analysis
Dynamic motion analysis of floating body
subject to environmental loads.
AutoPIPE
CAESAR II
Riser Stress analysis (Rigid pipeline)

Short Course
(12 -14 Jan 2014 - Tehran)
INIOAS
(OETRC)
Tahmasbi
72
24. References
 Subsea Pipeline Engineering (2nd Edition), by Andrew C. Palmer, Roger A. King
 Offshore Pipelines: Design, Instillation and Maintenance, by Shanhong Song, Ali
Ghalambor, Jacob Chacko, Boyun Guo
 Mechanics of Offshore Pipelines: Volume 1 Buckling and Collapse, by Stelios
Kyriakides, Edmundo Corona
 Design and Installation of Marine Pipelines, by Mikael Braestrup, Jan B. Andersen,
Lars Wahl Andersen, Mads B. Bryndum, Niels-J Rishøj Nielsen
 Subsea Pipelines and Risers, by Yong Bai, Qiang Bai
 Introduction to Offshore Pipelines and Risers, by Jaeyoung Lee, P.E.
 SAFEBUCK JIP: Safe Design of Pipelines with Lateral Buckling Design Guideline, by
Malcolm Carr
 DNV Rules & standards
 PARLOC 2001: The Update of Loss of Containment Data for Offshore Pipelines, by
Mott MacDonald Ltd.
 Free access websites related to engineering of submarine pipeline & SPM.

Short Course
(12 -14 Jan 2014 - Tehran)
INIOAS
(OETRC)
Tahmasbi
73

INIO2014 Presentation

More Related Content

What's hot (20)

Similar to INIO2014 Presentation (20)

INIO2014 Presentation