Sgcp13davies
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The document discusses the potential and risks associated with shale gas and oil development in the UK, highlighting the Bowland Shale's significant natural gas resources and the high number of wells needed to reduce reliance on imports. It underscores the importance of social acceptance and economic factors in determining the feasibility of drilling. While hydraulic fracturing is deemed unlikely to contaminate drinking water, it can induce minor earthquakes, necessitating long-term monitoring for well integrity.
![∂
But
-‐
Long
Term
Legacy
• Wells
can
leak
over
Eme
• Note:
lots
of
wells
needed
• Need
long
term
monitoring
for
leak
and
resealing
if
leaks
found
• Issue
in
the
USA
and
Canada
and
probably
[to
some
extent]
in
the
UK.
• Note:
250,000
abandoned
mine
shams
vs.
2100
hydrocarbon
boreholes
in
the
UK.](https://image.slidesharecdn.com/sgcp13davies-130614062212-phpapp01/85/Sgcp13davies-11-320.jpg)
Sgcp13davies
- 1. ∂ Shale Gas and Oil: Risks and Rewards Prof Richard Davies and Mr Sam Almond richard.davies@dur.ac.uk 5th Smart Grids & Cleanpower Conference 5 June, Cambridge www.cir-strategy.com/events
- 2. ∂ Shale Gas and ‘Fracking’ • Organic maBer trapped during the deposiEon of fine-‐grained shale rocks. • Low permeability • Hydraulic fracturing since 1940, applied with horizontal wells from 1990 onwards (BarneB, Texas). • Widespread use is new and therefore cauEon is appropriate Aquifers 0-‐1 km Shale Gas Reservoirs 2-‐5 km unconvenEonal reservoir
- 3. ∂ Stages of Development Stop Poor Geology Good Stop Poor Good A few years Drilling and Casing Fracking Frack Fluid Flowback Seismic Data Explora<on Well Drilling and Hydraulic Fracturing Produc<on Abandonment Weeks to months Years to decades UK
- 4. ∂ BGS report DECC 2012 UK : How Much? • Bowland Shale (Lancashire) alone could be 200 trillion cubic feet (TCF) underground (resources) and 10% (20 TCF) recoverable (reserves). • Igas announced 170 TCF (resource) in the Cheshire Basin on Monday 3rd June. • UK imports 1.4 TCF per year, so in theory the Bowland shale alone could fill our gas gap for decade/s • Reserves depend on social and economic factors as much as geology. • So we don t know. In the hands of communiEes, poliEcians? 200 TCF 170 TCF
- 5. ∂ How Many Wells? • 4 TCF shale gas producEon in USA, 25,000 wells per year • So 100s to 1000s of wells required in UK to make a dent on reliance on imports Source: Department of Energy and Climate Change, From IoD Report (2013) ~1.4 TCF ~1.4 TCF
- 6. ∂ 0 20 40 60 80 100 120 140 160 180 1880 1900 1920 1940 1960 1980 2000 2020 Number of wells drilled Year History of Hydrocarbon Well Drilling in UK ? ? ? • The biggest increase in drilling acEvity since the World War II? • Development of supply chain World War II
- 7. ∂ Fracking Issues www.oceanexplorer.noaa.gov • Water contaminaEon • Earthquakes • Others?
- 8. ∂ Fracking -‐ ContaminaEon of Drinking Water? • BarneB shale (Texas) • 1000s of hydraulic fracturing operaEons completed • Fractures not tall enough to cause contamina<on of water
- 9. ∂ Earthquakes Energy due to fracking • Energy due to fracking cannot be felt at the surface • Three excepEons from 100,000s of fracking operaEons -‐ including 2.3 M event in UK (April 2011)
- 10. ∂ • Hydraulic fracturing is not significant • Geothermal, reservoir impoundment, mining and convenEonal oil and gas are more significant 198 Published Examples of Induced Earthquakes from All Known Triggers Since 1929 From Davies, Foulger, Bindley, Styles Marine and Petroleum Geology, 2013
- 11. ∂ But -‐ Long Term Legacy • Wells can leak over Eme • Note: lots of wells needed • Need long term monitoring for leak and resealing if leaks found • Issue in the USA and Canada and probably [to some extent] in the UK. • Note: 250,000 abandoned mine shams vs. 2100 hydrocarbon boreholes in the UK.
- 12. ∂ Summary • Very likely UK has significant potenEal in oil and gas from shale. • How much will be determined by industry gaining a social licence to drill and frack wells, economics etc. • Fracking very unlikely cause of drinking water contaminaEon. • Fracking causes earthquakes – but very small ones. • But shale gas and oil development would require alot of wells. • So long term monitoring needed