11/18/2013
ES 10
Other sources of oil / Unconventional
Nonrenewable Energy Resources
Oil Shale and Oil Sand (aka “Heavy Oils”)
11/19/13
Oil and Natural Gas
Past to Present (31 slides)
What are fossil fuels
Why use Oil / Natural Gas
Drawbacks
Where does oil come from?
Oil Traps; Source, Reservoir & Cap Rocks
Abiotic Oil?
Who has the oil & how much is there? How long will it last?
Where does US get it’s oil?
Unconventional sources of oil and gas: Oil Shale & Sand
(aka Tar Sand)
Methane Clathrates, aka Gas Hydrates
Oil still in Source Rock
Oil Shale:
Sedimentary rock containing organic
kerogen (altered org matter in Sed Rk)
– never buried deep enough to raise
temperature required to convert
Kerogen to liquid oil
– Massive deposits underlie US
(estimate 2-5 trillion barrels)
Oil Sand/ aka Tar Sand:
mixture of sand, clay, water and
Bitumen (a viscous, heavy oil, too thick
to flow out of rock, the soluble portion
of Kerogen).
– Alberta Canada extensive deposits-few in US
Green areas
are parks, etc
Monterey
Shale areas
Shown in loops
http://graphics8.nytimes.com/packages/images/newsgraphics/2013/0204‐shale/0204‐nat‐webshale.jpg
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11/18/2013
Oil Shale Booming
• Hydraulic Fracturing (Fracking) is a drilling
process designed to increase the yield of oil and/or
gas out of rock; the method involves fracturing
surrounding rock (increasing permeability) and
pumping fluids into the fractures under extremely
high pressures to force the desired gas or liquids
out.
• Web Link: Horizontal Wells and Fracking
http://www.northernoil.com/drilling
http://www.youtube.com/watch?v=VY34PQUiwOQ (6.5min)
Oklahoma Earthquakes: between 1978 and 2008 ~2- 6/yr.
In 2010 there were 1,047 earthquakes
Some Fracking Practices
http://www.propublica.org/special/hydraulic‐fracturing‐national
electrical gunshots perforate steel casing & cement, then slickwater pressure + propping
agents fracture the shale
How Fracking Can Impact The Environment
• water consumption
• Horizontal drilling
• diesel pumps, compressors, drills, etc.
• methane escape & flaring
• Steel casing, cement sleeve – protect
aquifers
• truck traffic, emissions, habitat impacts, pipelines
• Perforation
• wastewater disposal
• Water + sand + slickening agents + salt
• aquifer contamination
– underground
– untreated in streams
– burden on sewage treatment plants
• unaesthetic views
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11/18/2013
Making Fracking Greener
Resources for the Future different state fracking rules • Run equipment with cleaner natural gas rather than diesel pumps, compressors, drills
• Replace water trucks & traffic with temporary water pipelines
• fresh water withdrawals
• underground injection wells for wastewater
• “Kitchen counter” frack fluids as safe as what’s under your kitchen sink
• cementing of well
• Recycle fracking fluids – commonly done now
• all other state regulations
• Use gas as a fracking medium rather than water – CO2 or propane
‐ produces 30% more natural gas
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The Athabasca Tar Sands of Alberta, Canada
How much oil shale and oil sand?
• Global supplies are estimated to be 200X larger than
conventional oil.
• More oil is trapped in Canadian tar sands than Saudi Arabia
has in all it’s reserves.
• It is estimated that oil sand in Alberta & Orinico Oil Belt in
Venezuela contain nearly 3.4 trillion barrels of oil.
At end of 2010, world proven crude oil reserves stood at
over >1.4 trillion Barrels
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11/18/2013
Athabasca Oil Sands
• Suncore, Syncrude and Shell Canada combined
oil production in 2006 was 1,126,000 bpd (barrels
per day).
• By 2020, Canadian oil production may reach 3
million bpd & ~5 million bpd by 2030
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11/18/2013
Why not use these resources?
• Oil shale and sand extraction requires surface mining
– ecosystem disruption; forests, wetlands, grasslands
– huge volumes of waste rock-- only ~3 barrels of shale oil for 1
ton of rock processed.
– 3 barrels of H2O/1 barrel of shale oil produced
– tailing ponds created: hold leftover water, sand, clay, bitumen,
salts, metals (Ni, V, Hg, As, Pb),
– pollution floats downstream.
– land reclamation issues
– lower useful energy yield than conventional oil and gas
Web Link: http://www.nature.com/news/2010/100831/full/news.2010.439.html
Web Link: Garth Lenz: The True Cost of Oil
– http://www.ted.com/talks/garth_lenz_images_of_beauty_and_devastation.html
ES 10
Methane Clathrates
Nonrenewable Energy Resources
aka Methane Hydrates or Gas Hydrates
another source of “unconventional” fossil fuels
11/19/13
Oil and Natural Gas
Past to Present (31 slides)
What are fossil fuels
Why use Oil / Natural Gas
Drawbacks
Where does oil come from?
Oil Traps; Source, Reservoir & Cap Rocks
Abiotic Oil?
Who has the oil & how much is there? How long will it last?
Where does US get it’s oil?
Unconventional sources of oil and gas: Oil Shale, Tar Sands,
Methane Clathrates, aka Methane Hydrates, Gas
Hydrates
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11/18/2013
Newer Estimates: (2013)
~500 – 2,500
Still approx 2 – 10 X
the amount of
conventional
natural gas
Stored mostly in broad, shallow layers beneath the seafloor, methane hydrate is, by some
estimates, twice as abundant as all other fossil fuels combined. The yellow squares show
where methane hydrate has already been recovered; the blue dots, where it is thought to exist.
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11/18/2013
~1,300 trillion cubic ft off N and S Carolina,
>60X amount US uses each year (~20 trillion cubic ft/yr)
Total US gas Hydrate deposits ~320,222 trillion cubic ft, at 10%
recovery, enough to last 1600 years
Seismic Reflection Profile data on Blake Ridge showing BSR
(meters below sea level on left, meters below ocean floor on right)
P-Wave rates in hydrates
can be as fast as
3.0 – 3.6Km/s
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11/18/2013
Methane Hydrate recovered from Blake Ridge
Review Questions/Key Concepts
– Where do most reserves exist? Who is OPEC? Which member has the most
oil? Which countries (top 3) are producing the most oil?
– From what material does petroleum form? How does it form? How
long does it take? What are the necessary conditions required?
– Daily production of crude oil ~ 84 m bpd. Global conventional oil reserves ~
1.4 trillion barrels. Who uses the most? Primary use?
– Why are most petroleum deposits younger than 200 million years?
–
– List pros and cons of using fossil fuels.
– When will global conventional oil supplies be economically depleted?
– What is a Source Rock, Reservoir Rock, Cap Rock & “Oil Trap”?
– What are the drawbacks of mining tar sands?
– What geologic structures do petroleum geologists look for as high
potential areas of oil/gas?
– What are oil shale and tar sand? Who is mining these and where?
– What is Hydraulic Fracturing, aka Fracking? Drawbacks?
– What are Methane or Gas Hydrates and why are scientists interested in
them?
– Can petroleum be produced abiotically? If so, how?
– How do scientists locate Methane Hydrates? What does BSR stand for?
– What is Thermal Conversion and Thermal Depolymerization?
– What are some concerns about mining methane hydrates?
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