Advances in enhanced oil recovery technologies for low permeability reservoirs

TLDR

Low‑permeability reservoirs contain abundant oil that remains largely unrecovered after primary and secondary methods, prompting widespread development of enhanced oil recovery technologies to boost production. The paper reviews key EOR methods—gas, surfactant, nanofluid, and imbibition flooding—and discusses their technical challenges, future directions, and outlooks. The review covers gas, surfactant, nanofluid, and imbibition flooding techniques, and introduces two gel systems for conformance control in channeling low‑permeability reservoirs.

Abstract

Low permeability oil and gas resources are rich and have great potential all over the world, which has gradually become the main goal of oil and gas development. However, after traditional primary and secondary exploitation, there is still a large amount of remaining oil that has not been recovered. Therefore, in recent years, enhanced oil recovery (EOR) technologies for low permeability reservoirs have been greatly developed to further improve crude oil production. This study presents a comprehensive review of EOR technologies in low permeability reservoirs with an emphasis on gas flooding, surfactant flooding, nanofluid flooding and imbibition EOR technologies. In addition, two kinds of gel systems are introduced for conformance control in low permeability reservoirs with channeling problems. Finally, the technical challenges, directions and outlooks of EOR in low permeability reservoirs are addressed.