Powered by Rock Dr Liam Herringshaw Earth's Energy Systems

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 Cyanobacteria, freshwater algae = oil Type II – Planktonic Mostly marine, mixed oil/gas Type III – Humic Terrestrial plant matter, produces gas

Conventional hydrocarbons

UK Oil & Gas - onshore

UK Oil & Gas - offshore Gas discoveries late 1960s Oilfields 1970s onwards

The case for oil & gas Your arguments in favour (with reference/s)

The case against oil & gas Your arguments in opposition (with reference/s)

The economics of oil Increasingly expensive, increasingly imported

Unconventional hydrocarbons

Britain for shale? (Figure from DECC report)

UK prospects?

UK targets Carboniferous NW England Jurassic SE England

Carboniferous (Image from BGS report)

Jurassic * BGS/DECC currently investigating resources * Durham/Newcastle – new NERC catalyst grant (Image from BGS report)

Fracking seismicity

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 Redrawn from Davies et al. (2012) <1% risk of vertical frack >350m 600m minimum safe separation distance

Fracking fluids?

4000 holes in Blackpool Lancashire?

Well density Carboniferous – Bowland Shale thicker than US shales – 1300 Tcf resources? – 5% recoverable = 65 Tcf – Bcf per well – = 13,000-26,000 wells – 10 wells per pad – = pads But many uncertainties

Well integrity Leakage rate? Is UK well-prepared?

24 Jan Jan 2013 Consensus?

Resources 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?