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
summer jobs….whatever paid
(brick factory, mcvities, boots,
etc etc)
My time line
summer job in oil industry
experience
summer job in oil industry
experience
1986 1990
Cardiff U Snr. Lect
1995 Mobil oil 2003
2006
∂
5 month temp geology job in
Venezuela
Maths; Physics; Geog
PhD Geology - Edinburgh
South Africa with Anglo America (Mining Engineer)
Degree in Geology - Reading
Durham Professor
2014
Electricity and Gas
Where does our electricity
come from?
How do we use gas?
Gas Uses (TCF)
Non-Energy
Use, 0.02
Losses, 0.04
Other,
0.32
Power
Generation,
0.78
∂
Metals , 0.03
Minerals, 0.05
Chemical, 0.07
Industry,
0.36
Energy Industry,
0.18
Other, 0.22
Domestic, 1.11
∂
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?
Some UK shales: Edale
∂
Some UK shales: Craster
∂
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
Fracking is controversial: why?
∂
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.
Well Pad
Well Head
• Abandonment – well head cut and welded shut
∂
Casing and Cement
Watson and Bachu 2009
Abandoned Welded Well Head
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?
∂