Research progress in methanogenic degradation of crude oil in depleted subsurface oil reservoirs

Abstract:

China has considerable demands for crude oil and natural gas. After oil recovery by conventional methods (such as water flooding, gas flooding, chemical flooding, and microbial enhanced oil recovery), more than 50% of the crude oil remains inaccessible in subsurface oil reservoirs, unable to be recovered by conventional flooding techniques. The residual crude oil could be converted into natural gas by anaerobic microorganisms, which makes it exploitable as biogas. This innovative approach shows promise as a microbial enhanced energy recovery technology for exploiting residual crude oil in depleted oil reservoirs. This review summaries the historical development and recent advancements in the methanogenic degradation of crude oil and makes an outlook on the future research directions to facilitate the industrial application of this approach.