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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?