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Powered by Rock. Earth's Energy Systems. Dr Liam Herringshaw lgh865@hotmail.com. Class 3: Oil & Gas. Origins. Organic matter Burial generates hydrocarbons by 'cracking' Depth/temperature: Oil window (60–120 'C) Gas window (>100 'C). Methane = CH4. Kerogens. Type I – Sapropelic
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Powered by Rock Earth's Energy Systems Dr Liam Herringshaw lgh865@hotmail.com
Origins Organic matter Burial generates hydrocarbons by 'cracking' Depth/temperature: • Oil window • (60–120 'C) • Gas window • (>100 'C) Methane = CH4
Kerogens Type I – Sapropelic Cyanobacteria, freshwater algae = oil Type II – Planktonic Mostly marine, mixed oil/gas Type III – Humic Terrestrial plant matter, produces gas
UK Oil & Gas - offshore Gas discoveries late 1960s Oilfields 1970s onwards
Your arguments in favour (with reference/s) The case for oil & gas
Your arguments in opposition (with reference/s) The case against oil & gas
The economics of oil Increasingly expensive, increasingly imported
Britain for shale? (Figure from DECC report)
UK targets Carboniferous NW England Jurassic SE England
Carboniferous (Image from BGS report)
Jurassic (Image from BGS report) * BGS/DECC currently investigating resources * Durham/Newcastle – new NERC catalyst grant
Does fracking cause earthquakes? Yes Professor Pete Styles, Keele University
Should we be worried? Not really Professor Pete Styles, Keele University
Induced Seismicity Redrawn from Davies et al. (2012)
Mitigation techniques Structural geology: • Understand tectonic history • Avoid unidirectional weaknesses
Does fracking pollute aquifers? From 'Gasland'
Fracture propagation <1% risk of vertical frack >350m 600m minimum safe separation distance Redrawn from Davies et al. (2012)
Well density Carboniferous • Bowland Shale thicker than US shales • 1300 Tcf resources? • 5% recoverable = 65 Tcf • 2.5-5 Bcf per well • = 13,000-26,000 wells • 10 wells per pad • = 1300-2600 pads But many uncertainties
Well integrity Leakage rate? Is UK well-prepared?
24 Jan 2013 Consensus? 23 Jan 2013
Resources www.refine.org.uk Research briefs Translations Videos News
Next week: Nuclear FOR – make an argument in favour of nuclear power AGAINST – make an argument against Is nuclear part of our future energy mix?