More On Enhanced Oil Recovery

Unless economically viable alternative sources of energy emerge in the foreseeable future, oil and gas will continue to provide a major portion of energy for society. As mentioned in “A Carbon Commodity,” enhanced oil recovery (EOR) using CO₂ can increase crude oil production and at the same time sequester CO₂ in underground formations (C&EN, April 28, page 23).

EOR includes other types of operations as well, such as chemical flooding and thermal recovery. The common purpose of these various types of EOR techniques is to restore pressure in depleted reservoirs and to improve oil displacement in the reservoirs, thus pushing more crude oil into production wells. Specifically, for example, in CO₂ injection, CO₂ can make oil less viscous and hence easier to sweep to production wells. With the chemical flooding, selected chemicals can optimize the interfacial forces among oil, water, and formation rock, thus enhancing oil extraction and production.

Leiming Li
Sugar Land, Texas