Carbon Dioxide-Enhanced Oil Recovery (CO?-EOR)

Satyesh Bhandari

Carbon Dioxide - Enhanced Oil Recovery (CO2-EOR) is?a technique that involves injecting carbon dioxide (CO2) into oil reservoirs to increase oil production. CO2 is injected into the reservoir rock, where it displaces the oil trapped in the rock's pores.?CO2 mixes with the oil, decreasing its viscosity and pressurizing it, which forces the oil towards production well bore.? CO2-EOR can extend the life of an oilfield by decades and increase oil production by millions of barrels.?It also helps reduce greenhouse gas emissions by trapping CO2 in the reservoir.?

New techniques are being developed to improve CO2-EOR, such as injecting larger volumes of CO2 and using novel foams and gels to control the CO2's mobility.?The CO2 which is trapped during the CO2-EOR process is often referred to as "associated CO2 storage".?

Carbon dioxide-enhanced oil recovery (CO?-EOR) has been widely used technology for decades, primarily to enhance oil production while simultaneously serving as CO? sequestration. Its success as an immediate pathway for CO? sequestration can be evaluated based on following parameters.

1.????? Technical Viability

CO?-EOR is a mature and well-understood technology. Operators have used it since the 1970s to boost oil recovery from aging reservoirs. CO? injection increases oil mobility and production by reducing oil viscosity and swelling the oil. Geological formations used in EOR can also store significant quantities of CO?, effectively sequestering it.

2.????? Economic Viability

EOR provides an economic incentive by generating revenue from additional oil production through higher recovery factor offsetting the cost of CO? capture and injection. carbon pricing mechanisms and incentives make CO?-EOR more economically attractive. However, CO? capture, transport, and compression costs can be very high. Also, Oil price volatility affects the financial viability of EOR projects with this method.

3.????? Storage Potential

A portion of the injected CO? remains trapped in the reservoir through structural and solubility trapping mechanisms. On average, 50-70% of the injected CO? can remain sequestered in the reservoir, depending on the geology and operational practices. Significant potential exists in mature oil / gas fields.

4.????? Environmental Impact

Depending on operational parameters, CO?-EOR can achieve net carbon reductions. For this, the quantity of CO? stored must be more than emissions from oil production, transportation, and combustion. However, critics also argue that the additional oil produced through EOR contributes to more CO? emissions when combusted which offsets sequestration benefits.

5.????? Geologic Challenges

All oil fields are not suitable for CO?-EOR. Reservoirs require specific geological conditions for effective CO? injection and trapping. Deployment requires extensive infrastructure for CO? capture, transport, and injection, which may not be readily available in some regions.

6.????? Future

With advancements in CO? capture technology and supportive policies, CO?-EOR can play a significant role in near-term CO? sequestration. When reservoirs reach their oil production limits, it can be transformed from CO?-EOR to CO? storage only.

CO?-EOR is a practical and immediately deployable pathway for CO? sequestration, especially in regions with suitable geology and existing oil recovery operations.

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