Tar Sands

4/29/2015
Unconventional Resources 2
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Coal Bed Methane
Water/Gas production history
Coal is the most abundant fossil fuel
 Produce Methane adsorbed to coal
surfaces
 Fundamentally different from free gas in
pore space
 Coal stores 6 times more gas than a
conventional reservoir by volume
 Gas content is 100-800 SCf/ton of coal
 Economic production from 0.5 ft-thick
coal is possible

Coal bed methane production model
Coals has
fractures (cleat)
 Pump out water to
lower pressure
 Gas will desorb

Coal Bed Methane Extraction
Drill well
Pump water out to decrease pressure
 Produce desorbed gas


Water Production
170K bbls/day
1 Million bbls/day
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Coal-Bed-Methane Produced
Waters
Athabaska Tar
Sands
(or oil sands)
Reserves: 1.7 trillion
barrels (assuming
10% recovery)
Venezuelan Oil
Sands:
500 billion barrels
The Oil Sand Crude: Bitumen
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Tar Sands
Tar Sands- Strip Mining
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Canadian Tar Sand Production
Tar Sand Extraction method
Open Pit Mining
Crush
 Mix with hot water
 Bitumen floats (60% bitumen, 30%water,
10% solids)
 1200 SCF of gas needed to process 1
bbl of bitumen (about 5x energy gain)
 Upgrading: remove water, sand,
impurities, sulfur, catalytic
hydrocracking, hydrogenation


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Bitumen Separation Cell,
Alberta
Canadian Oil Data
Total Production 2,600,000 Barrels/Day
Exports to US 2,500,000 Barrels/Day
 Today, about half is from the Oil Sands
 #1 foreign supplier for USA


Suncor Energy Inc.
Steam Assisted Gravity Drainage (SAGD)
Proposed Keystone Pipeline
Burn some of the oil to extract the rest
Japan Canada Oil Sands Limited (JACOS)
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Oil Shale


Kerogen-rich immature shale
Heating the shale releases oil by
pyrolisis
Oil Shale Production Method
Mining and crushing
Retorting
 Oil Upgrading
 Refining



Green River Shale- USA
Economics

Viable at $70 to $95/bbl in USA

Energy Produced/Energy Used = 3 to 4

Environmental impact is significant
Water usage is a problem

Green River Shale Resource



Disposal and reclamation
Stuart Oil Shale Facility,
Queensland, Australia
1.2 to 1.8 trillion barrels in place
Recoverable?
Global Resource: 2.8 to 3.3 trillion
barrels
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In-Situ conversion (unproven)
Stability
Electric heaters in holes
 2-3 years heating to 650-700 degrees C

www.nrcan.gov
Methane
Hydrates
(Clathrates)
Why the Interest in Gas
Hydrates?
 Safety:
Hydrates plug flowlines
Hydrates can be geohazards for submarine
structures
 Resource:
 Methane Hydrates are a source of natural
gas
 Environmental:
 Sensitive Communities use hydrates as food
 Methane Hydrates can contribute to global
warming
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Impact on Production Facilities
Crystal Structures
1 mole
methane for
5.75 moles
water
 1 liter
hydrate=
168 liters
methane at
STP

Hydrates Form On
Exterior of Subsea
Equipment
Heat From Buried
Pipelines Cause
Hydrate Dissociation
Hydrates Dissociation
Affects Foundation of
Surface Facilities?
Heat From Production
Wells Causes Hydrate
Dissociation
Modified from Boatman
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Resource
Gas Seeps on the Seafloor


Twice the amount found in all fossil fuels
How can we produce it?
hydrate
Bottom-Simulating Reflector
(BSR) Off Shore Brazil
Sea water
BSR
Hydrate zone
Free Gas zone
Take Home Points
Coal bead methane (CBM) is adsorbed to coal
 Disposal of produced water is one of the main
challenges for CBM
 Tar sands require open pit mining and have
high energy costs
 Environmental impact of Tar sands is
considerable but reserves are large
 Oil shale production is technically possible but
not economical now
 Gas hydrates are abundant but we don’t have
the technology to produce them efficiently

Gas Hydrate Occurrence
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