∂ Some ideas…. Petroleum Geologist Mining, minerals & resources Use geology and geophysics to locate hydrocarbons Work on drilling platforms to extract.

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Some ideas…. Petroleum Geologist Mining, minerals &

resources

• Use geology and geophysics to locate hydrocarbons

• Work on drilling platforms to extract oil and gas

• Work all over the world, on-and off-shore

• Extract minerals from the Earth• Gold, coal, metals, salts, more…• Opportunities globally

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More ideas…Environmental

Geologist/Geochemist Volcanologist

• Study how humans affect our environment

• Understand the changing climate• Prevent and mitigate

environmental damage

• Understand and witness nature’s most violent events

• Travel: Iceland, Japan, USA and more…

• Work to predict eruptions avoid disasters

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My time line

Maths; Physics; Geog

South Africa with Anglo America (Mining Engineer)

Degree in Geology - Reading

1986 1990

summer jobs….whatever paid (brick factory, mcvities, boots, etc etc)

PhD Geology - Edinburgh

summer job in oil industry experience

5 month temp geology job in Venezuela

1995 Mobil oil 2003 Cardiff U Snr. Lect

2006 Durham Professor

2014

summer job in oil industry experience

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Electricity and Gas

Domestic; 1.11

Energy Industry; 0.18Losses; 0.04

Non-Energy Use; 0.02

Other; 0.32

Power Generation; 0.78

Metals ; 0.03Minerals; 0.05

Chemical, 0.07 Other; 0.22

Gas Uses (TCF)

Where does our electricity come from?

How do we use gas?

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∂

Shale Gas and Fracking

Prof. Richard Davies

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• What does the term “Fracking” mean to you?

• What words come to mind when you think of Fracking?

• Do you think fracking should take place in the UK?

Questions:

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Some UK shales: Edale

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Some UK shales: Craster

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What is Shale?

www.oceanexplorer.noaa.gov

• Fine grained, organic rich mudstones:

• 4 main components:• Clay• Quartz silt• Organic matter (dead

plants and animals)• Calcium carbonate (shells

of dead sea creatures)

• Most common rock type on Earth

• Gas forms in small holes (pore spaces) in the shale

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What is Fracking?• Shales are impermeable, trapped

gas can’t flow out by itself

• Rocks must be cracked (fractured) to let gas escape

• Horizontal drilling is used to reach more rock

• Water used to crack the shale, sand holds cracks open

• Process is new to Europe, but well established in USA

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What is Fracking? • Wells drilled vertically up to 3 km

(length of around 30 football pitches) and then drilled horizontally

• Drilling and fracking takes about 1 month. A well will produce for years.

Preese Hall, Lancashire. 1st and only well fracked in UK. Photo: BBC News Lancashire

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Fracking is controversial: why?

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Is It safe?

Or

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Earthquakes

• Fracking can cause minor earthquakes (tremors)

• Fractures and fluids reactivate old geological faults

• Very few cases recorded

• Less severe than other man-made earthquakes

Q: Is this a serious risk?

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Water Pollution

• Claims that fracking will contaminate aquifers (the rocks that contain drinking water)

• Many reports of methane and chemical pollution in USA

But

• Fractures not large enough to reach aquifers

• In USA leak due to natural processes and well integrity

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Can Wells Leak?

• During production (most of the time) well head (christmas tree) in place.

• Abandonment – well head cut and welded shut

Watson and Bachu 2009

Well Head

Casing and Cement

Abandoned Welded Well Head

Well Pad

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Can Wells Leak?• Gas/fluids can reach surface through

wellbores

• Wells are sealed with metal casing and cement – but this degrades over time

• Many older wells have poor protection

• In Pennsylvania (USA), >6% wells have integrity or barrier failures

• Abandoned wells not currently monitored in UK

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Why could shale gas be important?• UK imports ~60% of the gas we

use• UK relies on energy imports• Shale could help UK become

less dependent on imports• Lower energy prices?

However:

• Little known about UK resources• Much public opposition/gaps in

scientific knowledge• UK would require many 1000s

wells

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Summary

• Fracking itself very unlikely cause of aquifer contamination.

• 100,000s of fracking operations and 3 cases of felt seismicity but important to avoid critically stressed faults.

• Databases and publications show that well leak is possible. Monitoring will be important.

• Uncertain what effect shale gas would have on UK.

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Questions:

• Do you think fracking should take place in the UK?