The document discusses enhanced oil recovery (EOR) methods utilizing CO2, highlighting thermal, chemical, and miscible techniques to improve oil extraction from reservoirs. It details processes like steam-CO2 injection and the use of monoethanolamines for CO2 absorption, noting the economic and environmental challenges of CO2 capture for EOR. Conclusively, optimizing CO2 extraction from coal-fired plants is presented as both feasible and beneficial.

1. CO2 for Enhanced Oil
Recovery

2. Outline
 Introduction
 Methods
 Models
 Steam-CO2 Injection
 Chemical gas absorption by
monoethanolamines (MEA)
 Conclusion

3. Introduction
 High oil prices and concerns about future oil supply
 Enhanced oil recovery (EOR) is a group of
technologies that can increase recovery from
existing oil reservoirs
 CO2 is a good flooding agent
 The CO2 is currently discharged into the
atmosphere and could be a major contributor to the
greenhouse effect, which may lead to global
warming

4. Introduction Cont.

5. Methods
 Thermal method
 Chemical method
 Miscible method

6. Thermal method
 Injection of high temperature fluids into fractured
reservoirs to recover matrix oil
 The major recovery mechanisms ( thermal method)
include capillary imbibition, thermal expansion, gas
generation, gravity drainage, in situ steam generation,
distillation, solution gas drive, and pressure depletion
 Imbibition is defined as the displacement of one fluid
by another immiscible fluid

7. Thermal method Cont.
 f(θ), Wettability index
 K, Matrix permeability
 Lc, Characteristic matrix
size
 t, Time
 td, Dimensionless time
 Φ, Porosity
 μo, Oil viscosity
 μw, Water viscosity
 σ, Interfacial tension




 k
L
f
t
t
c
w
o
d 2
)
(


8. Thermal method Cont.
 the reduction in oil viscosity due to high
temperature fluid injection accelerates the
imbibition recovery rate
 heat injection are applied, IFT is reduced. This is
expected to reduce the capillary imbibition rate

9. Chemical method
 Surfactant
The idea of injecting surfactant solution to
improve imbibition recovery
In general, the positive effect of lowered IFT
on the ultimate recovery due to surfactant
addition (heavy oil)
A negative effect of lowered IFT (surfactant
solution) on the recovery rate (light oil)

10. Chemical method Cont.
 Polymer
Injection of polymer solution as aqueous
phase for matrix recovery
This can be attributed to the stronger
capillary imbibition drive by increasing
aqueous phase viscosity

11. Miscible method
 Gas can also be injected in order for it to
penetrate into matrix and expel the oil out. As
gaseous phase is normally the nonwetting
phase, the oil is recovered by the process
called gas oil gravity drainage (GOGD), which
occurs due to gravity difference between the
fluid in fracture and matrix

12. Miscible method Cont.
 Nitrogen is a commonly injected gas into
naturally fractured reservoirs for pressure
maintenance due to availability and lower cost
 Carbon Dioxide (CO2) has been recognized as
a preferred miscible solvent for Enhanced Oil
Recovery (EOR) methods
 Miscible flooding by CO2 has proven its
positive effectiveness through numerous
laboratory and field projects

13. Miscible method Cont.
 The minimum
miscibility pressure
(MMP) is
independent of
relative
permeabilities and
phases viscosities

14. Miscible method Cont.
 Miscible flooding is a drive process by mixing
injection fluid (solvent) and oil. Its main
mechanism is to decrease the residual oil
saturation by eliminating interfacial tension
between phases

15. Miscible Flood Numerical Models
Three
different
development
schemes are
simulated:
waterdrive,
continuous
CO2
injection,
and water
alternate gas
(WAG)
injection

16. Miscible Flood Numerical Models Cont.
The
solvent
slug size
directly
affects
the oil
recovery

17. Steam-CO2 Injection
 Steam-CO2 injection schemes are based on
simple concepts and produce good results
 Currently the cost of capturing and
transporting CO2 for EOR applications is quite
high
 One method of overcoming this economic
challenge is to produce CO2 on site for
immediate injection into an oil reservoir

18. Steam-CO2 Injection Cont.
 The procedure
 the injection of liquid CO2 into the reservoir through
the deepest wellbore
 After some time has passed, steam is injected into the
reservoir via the same deep wellbore
 When the CO2 is contacted by the steam it heats up and
expands into a gaseous state
 The pressure from the steam injection causes the CO2
gas to dissolve into the oil and the steam to condense
into water

19. Steam-CO2 Injection Cont.
 The procedure Cont.
 The resulting mixture of oil and CO2 is less viscous
and less dense than oil alone and the mixture flows
upward with greater ease
 A second horizontal wellbore above this action
receives the less viscous mixture and channels it to the
surface
 At the surface the CO2 and water are separated from
the petroleum, which is then processed and sent for
sale

20. Chemical gas absorption by
monoethanolamines (MEA)
 The absorption process using
monoethanolamines (MEA) as the scrubbing
solvent is used
 The MEA solvent is a proven technology for
CO2 separation and has been selected because
of its high reactivity with CO2 under low
pressure conditions

21. Chemical gas absorption by
monoethanolamines (MEA) Cont.

22. Conclusion
 Carbon dioxide production from coal-fired power
plants was modeled. It was found that the
production of CO2 can become technically feasible,
economically feasible and environmentally friendly
 Need optimization techniques were used to search
for optimal design and operating criteria for the
CO2 extraction plant, more economic feasible