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Some ideas…. . Petroleum Geologist. Mining, minerals & resources. Extract minerals from the Earth Gold, coal, metals, salts, more… Opportunities globally. Use geology and geophysics to locate hydrocarbons Work on drilling platforms to extract oil and gas
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Some ideas…. Petroleum Geologist Mining, minerals & resources • Extract minerals from the Earth • Gold, coal, metals, salts, more… • Opportunities globally • 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
More ideas… Environmental Geologist/Geochemist Volcanologist • Understand and witness nature’s most violent events • Travel: Iceland, Japan, USA and more… • Work to predict eruptions avoid disasters • Study how humans affect our environment • Understand the changing climate • Prevent and mitigate environmental damage
My time line summer jobs….whatever paid (brick factory, mcvities, boots, etcetc) summer job in oil industry experience summer job in oil industry experience Cardiff U Snr. Lect Durham Professor 1986 1990 1995 Mobil oil 2003 2006 5 month temp geology job in Venezuela 2014 Maths; Physics; Geog PhD Geology - Edinburgh South Africa with Anglo America (Mining Engineer) Degree in Geology - Reading
Electricity and Gas Where does our electricity come from? How do we use gas?
Shale Gas and Fracking Prof. Richard Davies
Questions: • 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?
What is Shale? • 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 www.oceanexplorer.noaa.gov
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
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
Is It safe? Or
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?
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
Can Wells Leak? • During production (most of the time) well head (christmas tree) in place. • Abandonment – well head cut and welded shut • Well Pad • Well Head • Casing and Cement • Abandoned Welded Well Head • Watson and Bachu 2009
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
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
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.
Questions: • Do you think fracking should take place in the UK?