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Storage 2- Enhanced Oil Recovery (EOR)
IEAGHG CCS Summer SchoolBeijing, China
13 – 17 August, 2012
IEAGHG CCS SUMMER SCHOOLBeijing, China13 – 17 August, 2012
JOHN KALDICooperative Research Centre for Greenhouse Gas Technologies (CO2CRC) atUniversity of Adelaide, Australia
© CO2CRC All rights reserved
What is EOR?
• EOR = Enhanced Oil Recovery
• As little as only 10-20% of the OOIP may be produced through primary recovery (natural pressure of the reservoir)
• Options include:
– Waterflooding
Gas flooding (CO )
IEAGHG CCS Summer SchoolBeijing, China
13 – 17 August, 2012
– Gas flooding (CO2)
– Thermal methods
– Plus many others
• These can do two things to assist production:
– Increase reservoir pressure
– Change the properties to increase the mobility of the oil
ENHANCED OIL RECOVERY MECHANISMS
CO
CHEMICALGAS(Miscible/Immiscible)
THERMAL
Enhanced Oil Recovery
IEAGHG CCS Summer SchoolBeijing, China
13 – 17 August, 2012
CO2
HydrocarbonNitrogenFlue Gas
Air
Steam (soak; drive)Combustion (in situ)
Hot water
PolymerAlkaline/CausticMicellar/PolymerSurfactant (foam)
OTHER
Microbial
CO2 flooding
• CO2 is expensive and can be complex to handle.
• Water is cheap easy and great for pressure
IEAGHG CCS Summer SchoolBeijing, China
13 – 17 August, 2012
• Water is cheap, easy and great for pressure maintenance.
• We need another reason to use CO2
The Size of the Prize
• Primary Production 15% recovery
• Secondary Recovery 30% recovery
IEAGHG CCS Summer SchoolBeijing, China
13 – 17 August, 2012
• Enhanced Oil Recovery 45% recovery
Worldwide EOR Production
• Production is currently 2.3 MM BOPD
• Represents 3.2% of the world’s production
• Some projections reach 30 MM BOPD by year
IEAGHG CCS Summer SchoolBeijing, China
13 – 17 August, 2012
2020
• CO2 floods will be a major contributor
2
Active CO2 EOR projects
Location Number Project BOPD EOR BOPD
World 125 373,500 285,100
U S 105* 323 100 249 700
IEAGHG CCS Summer SchoolBeijing, China
13 – 17 August, 2012
U.S. 105* 323,100 249,700
Canada 8 43,000 28,000
* additional 16 projects post- 2008/2009
US CO2 source and project locations
IEAGHG CCS Summer SchoolBeijing, China
13 – 17 August, 2012
Weyburn CO2 Project• CO2 Source: Dakota Gasification Company
• 95 mmscfd (5000 tonnes/day) injection rate
• CO2 purity 95% (primary feed)
• Currently 26% recycle.
Main CO2 pipeline enters Weyburn
ReginaReginaManitobaManitobaWeyburnWeyburn
IEAGHG CCS Summer SchoolBeijing, China
13 – 17 August, 2012
EstevanEstevan
BismarckBismarck
North DakotaNorth DakotaMontanaMontana
SaskatchewanSaskatchewan
WeyburnWeyburn
BeulahBeulah
EOR with CCS – Weyburn/MidaleOil Production: ~ 28,000 bbl/day
(approximately 20,000 bbl/d more than would be produced without the CO2 flood)
CO2 Storage: ~ 1.3 Mt/year(approximately 13 Mt total)
Objective: produce more oil (CO2 storage
secondary!)
IEAGHG CCS Summer SchoolBeijing, China
13 – 17 August, 2012
EOR through miscibility
• Miscibility is the mixing of two fluids to form a homogenous solution.
IEAGHG CCS Summer SchoolBeijing, China
13 – 17 August, 2012
Miscible: Ethanol and water Immiscible: Oil and water
Benefits of miscibility
• Reduction in viscosity
• Reduction in density (Swelling of the oil)
• Increased mobility
IEAGHG CCS Summer SchoolBeijing, China
13 – 17 August, 2012
• Improved relative permeability
3
IEAGHG CCS Summer SchoolBeijing, China
13 – 17 August, 2012
Oil Recovery: Definition
• Fraction of oil produced compared to original oil in place
• Oil Recovery (E) is the product of Microscopic (Em) and Macroscopic (EM) displacement efficiency
IEAGHG CCS Summer SchoolBeijing, China
13 – 17 August, 2012
p ( M) p y
E = EmEM
Oil Recovery: Microscopic Displacement
• Microscopic Displacement (Em)
Oil recovered =
initial oil saturation - residual oil saturation
IEAGHG CCS Summer SchoolBeijing, China
13 – 17 August, 2012
• Em is process dependent & different for – Water
– CO2
– Chemical
Oil Recovery: Microscopic Displacement
IEAGHG CCS Summer SchoolBeijing, China
13 – 17 August, 2012
Oil Recovery: Microscopic Displacement
Scale = m
IEAGHG CCS Summer SchoolBeijing, China
13 – 17 August, 2012
Oil
Water
Matrix Pore Body
OilResidual
Water
COCO
Scale: Microns
Oil Recovery: Microscopic Displacement
IEAGHG CCS Summer SchoolBeijing, China
13 – 17 August, 2012
Oil
Pore Throat
Residual Oil
CO2CO2
Pore Throat
Oil
4
Oil Recovery: Macroscopic Displacement
VAM EEE
• Macroscopic Displacement (EM)
‒ Areal sweep efficiency (EA)
‒ Vertical sweep efficiency (EV)
IEAGHG CCS Summer SchoolBeijing, China
13 – 17 August, 2012
• EM depends on
– Process
– Geologic heterogeneity
– Injector / producer
– Well Pattern
– Well spacing
• Varying horizontal sweep efficiency
Layer 1
Layer 2
Oil Recovery: Macroscopic Displacement
IEAGHG CCS Summer SchoolBeijing, China
13 – 17 August, 2012
Layer 2
Layer 3
Layer 4
Layer 5OilScale: meters
CO2
Oil Producer Oil Producer
Areal Sweep Efficiency
Oil Recovery: Macroscopic Displacement
IEAGHG CCS Summer SchoolBeijing, China
13 – 17 August, 2012
Scale: 1000’s of meters
CO2 Injector
(Plan View)
CO2 Injector
Displacement Mechanisms
• CO2 is a solvent to crude oil
• CO2 is used in core labs as a solvent to clean core of crude oil (also by dry cleaning industry….)
• Displacement Conditions
IEAGHG CCS Summer SchoolBeijing, China
13 – 17 August, 2012
Displacement Conditions
– Miscible
• Multicontact
• Miscibility Pressure
– Immiscible
Displacement Mechanisms
• Multicontact Miscibility
– Vaporizing/condensing process
– Intermediate hydrocarbons from crude oil
IEAGHG CCS Summer SchoolBeijing, China
13 – 17 August, 2012
Intermediate hydrocarbons from crude oil vaporize into the CO2
– CO2/HC enriched gas becomes miscible with crude oil
Displacement Mechanisms
• Multicontact Miscibility
Oil Intermediate Hydrocarbons
CO2 Enriched with Intermediate HydrocarbonsCO2
IEAGHG CCS Summer SchoolBeijing, China
13 – 17 August, 2012
Low viscosity CO2 moves through the crude oil vaporizing intermediate hydrocarbons. Eventually hydrocarbon enriched CO2
becomes miscible with the crude oil.
5
Displacement Mechanisms
• Multicontact Miscibility
Oil Intermediate Hydrocarbons
CO2 Enriched with Intermediate HydrocarbonsCO2
IEAGHG CCS Summer SchoolBeijing, China
13 – 17 August, 2012
Low viscosity CO2 moves through the crude oil vaporizing intermediate hydrocarbons. Eventually hydrocarbon enriched CO2
becomes miscible with the crude oil.
How it works
• Intermediate hydrocarbons vaporize into the flowing, mobile single-phase mixture
Flowing, mobile mixture
IEAGHG CCS Summer SchoolBeijing, China
13 – 17 August, 2012
• 100% oil recovery is possible if injection lasts long enough. (although this is impractical)
Residual oil is vaporized into the mobile mixture.
Reservoir Effects
• Positive effects of CO2/oil mixture
– Oil viscosity reduction
– Oil swelling
IEAGHG CCS Summer SchoolBeijing, China
13 – 17 August, 2012
Oil swelling
– Oil surface tension reduction
– Residual oil decrease
Negative effects:
• CO2 viscosity < Oil viscosity
‒CO2 viscous fingers
Reservoir Effects
IEAGHG CCS Summer SchoolBeijing, China
13 – 17 August, 2012
CO2 viscous fingers
• CO2 density < Oil density
‒Gravity over-ride
• Accentuated by reservoir heterogeneity
Field Injection Options
• Continuous CO2 or (CO2 + Water)
• Water-Alternating-Gas (WAG)
IEAGHG CCS Summer SchoolBeijing, China
13 – 17 August, 2012
Field Injection OptionsContinuous CO2
Viscous fingers / gravity over-ride / heterogeneity
Oil Producer
CO2
Injector
IEAGHG CCS Summer SchoolBeijing, China
13 – 17 August, 2012
Water Water/CO2
TransitionCO2
CO2/Oil Transition
Oil
6
Field Injection Options
• Continuous CO2 – potential disadvantages
– Early CO2 breakthrough
• Poor areal efficiency
IEAGHG CCS Summer SchoolBeijing, China
13 – 17 August, 2012
y
• Poor vertical efficiency
– Large injection volume of CO2 may result in significant recycling
Field Injection Options
Water Alternating Gas (WAG)
ProducerInjector
IEAGHG CCS Summer SchoolBeijing, China
13 – 17 August, 2012
Water Water/CO2
TransitionCO2
CO2/Oil Transition
Oil
Field Injection OptionsWater-Alternating-Gas (WAG)
IEAGHG CCS Summer SchoolBeijing, China
13 – 17 August, 2012
US DOE
Field Injection Options
• WAG-Disadvantages
– Water sensitive formations impaired
– Water injection decreases with time
IEAGHG CCS Summer SchoolBeijing, China
13 – 17 August, 2012
Water injection decreases with time
– Operational: Corrosion (producing wells)
Field Injection Summary
• Methods designed to
– Reduce CO2 velocity
– Increase macroscopic displacement efficiency
IEAGHG CCS Summer SchoolBeijing, China
13 – 17 August, 2012
Increase macroscopic displacement efficiency
CO2 Storage in Oil Reservoirs: • Replaces oil and gas volume produced
• Soluble in crude oil
– (requires post production separation)
• Soluble in water (connate and/or waterflood)
IEAGHG CCS Summer SchoolBeijing, China
13 – 17 August, 2012
• Soluble in water (connate and/or waterflood)
– (some recycling)
• Adsorption to some clay minerals
• Not economically viable today without EOR
7
EOR Summary
• CO2: gas-like viscosity, liquid-like density
• High Density CO2 (liquid or high-pressure super-critical) for larger stored mass.
• CO2 is economic to increase oil production in basins h t ll i CO i i t
IEAGHG CCS Summer SchoolBeijing, China
13 – 17 August, 2012
where naturally occurring CO2 reservoirs exist.
– Numerous commercially successful miscible field applications
– Few commercially successful immiscible field applications
CO2CRC Participants
IEAGHG CCS Summer SchoolBeijing, China
13 – 17 August, 2012
Established & supported under the Australian Government’s Cooperative Research Centres Program
Supporting Partners: The Global CCS Institute | The University of Queensland | Process Group | Lawrence Berkeley National Laboratory
Government of South Australia | CANSYD Australia | Charles Darwin University | Simon Fraser University
