Our previous coreflood experiments—injecting pure $CO2$ into carbonate cores—showed that the process is a win-win technology, sequestrating $CO2$ while recovering a significant amount of hitherto unrecoverable natural gas that could help defray the cost of $CO2$ sequestration. In this paper, we report our findings on the effect of “impurities” in flue gas—$N2$, $O2$, $H2O$, $SO2$, $NO2$, and CO—on the displacement of natural gas during $CO2$ sequestration. Results show that injection of $CO2$ with approximately less than $1mole%$ impurities would result in practically the same volume of $CO2$ being sequestered as injecting pure $CO2$. This gas would have the advantage of being a cheaper separation process compared to pure $CO2$ as not all the impurities are removed. Although separation of $CO2$ out of flue gas is a costly process, it appears that this is necessary to maximize $CO2$ sequestration volume, reduce compression costs of $N2$ (approximately 80% of the stream), and improve sweep efficiency and gas recovery in the reservoir.

1.
Orr
,
F.
, 2004, “
Storage of Carbon Dioxide in Geologic Formations
,” SPE Paper No. 88842.
2.
Korbul
,
R.
, and
,
A.
, 1995, “
Sleipner Vest CO2 Disposal—Injection of Removed CO2 into the Utsira Formation
,”
Energy Convers. Manage.
0196-8904,
36
(
6–9
), pp.
509
512
.
3.
Mamora
,
D. D.
, and
Seo
,
J. G.
, 2002, “
Enhanced Gas Recovery by Carbon Dioxide Sequestration in Depleted Reservoirs
,” presented at
SPE Annual Technical Conference and Exhibition
,
San Antonio, TX
, Sept. 29–Oct. 2, SPE Paper No. 77347.
4.
Zhang
,
P. Y.
et al.
, 2004, “
Effect of CO2 Impurities on Gas-Injection EOR Processes
,” presented at
SPE∕DOE 14th Symposium on Improved Oil Recovery
,
Tulsa, OK
, April 17–21, SPE Paper No. 89477.
5.
International Environmental Agency
, 2004, “
The Prospects for CO2 Capture and Storage
,” Energy Technology Scenarios.
6.
Nguyen
,
D. N.
, 2003, “
Carbon Dioxide Geological Sequestration: Technical and Economic Review
,” presented at
SPE∕EPA∕DOE Exploration and Production Environmental Conference
,
San Antonio, TX
, Mar. 10–12, SPE Paper No. 81199.
7.
Seo
,
J. G.
, 2004, “
Experimental and Simulation Studies of Sequestration of Supercritical Carbon Dioxide in Depleted Gas Reservoirs
,” Ph.D. dissertation, Texas A&M University, College Station.
8.
Seo
,
J. G.
, and
Mamora
,
D. D.
, 2003, “
Experimental and Simulation Studies of Sequestration of Supercritical Carbon Dioxide in Depleted Gas Reservoirs
,” presented at
SPE∕EPA∕DOE Environmental Conference
,
San Antonio, TX
, Mar. 10–12, SPE Paper No. 81200.