Optimization of Injection and Production Parameters for Water Gas Alternating Flooding in Deepwater Oilfield

Abstract

Abstract Water gas alternate flooding is a successful oil recovery method applied in mining fields. Compared with conventional water gas alternate flooding in onshore oilfields, the use of water gas alternate flooding in deepwater oilfields has certain peculiarities. Due to limited gas export in deep-water oil fields, in order to improve oil recovery and meet environmental requirements, it is necessary to inject produced gas back into the ground, using a water gas alternating drive method based on the circulation of produced gas. However, there is little research on the optimization of injection and production parameters for water and gas alternate flooding in deepwater oil fields. This article conducts long core displacement experiments based on the geological characteristics and fluid properties of the studied deepwater oil fields, and compares the effects of three displacement methods: water injection, continuous gas drive, and water gas alternate drive. Based on the results of long core experiments and PVT fitting, a mechanism model for the development of water gas alternating mixed phase flooding at the field scale was established. The optimization of injection and production parameters, such as water injection timing, pressure maintenance level, water gas ratio, injection production ratio, and water gas alternation cycle, was carried out through numerical simulation in deepwater oil fields. The results of this study can provide a reference basis for optimizing injection and production parameters for the development of water and gas alternation in deepwater oil fields.