Jan 08, 2016
Class 3: Oil & Gas
Origins
Organic matterBurial generates hydrocarbons by
'cracking'Depth/temperature:
– Oil window– (60–120 'C)– Gas window– (>100 'C)
Methane = CH4
KerogensType 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 1960sOilfields 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
CarboniferousNW England
JurassicSE 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 techniquesStructural 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 safeseparation distance
Fracking fluids?
4000 holes in Blackpool Lancashire?
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
23 Jan 2013
Consensus?
Resources
www.refine.org.uk
Research briefsTranslationsVideosNews
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?