Formation Mechanism Study of Preponderant Seepage Channels in Natural Water Flooding and Artificial Water Flooding Co-development Reservoir

Regardless of natural water flooding or artificial water flooding in sandstone reservoir, due to the existence of reservoir heterogeneity, the long-term erosion of fluid leads to the formation of preponderant seepage channels, which intensifies reservoir water flooding and reduces oil recovery factor. Based on core data and field production data, applying geology and reservoir engineering analysis, this paper clarified the formation mechanism of preponderant seepage channels in large layered sandstone reservoirs with co-development of natural water flooding and artificial water flooding. A numerical simulation model considering time-varying permeability of reservoir was established. Key indexes of geology, fluid and development were selected to study the influencing factors of preponderant seepage channel formation, and orthogonal experimental analysis was used to determine the main controlling factors. It is important for preponderant seepage channel identification and remaining oil distribution study.