New Understanding of Pebbled Sandstone Reservoir Development

The X22 fault block in the study area belongs to a layered fault block structural oil reservoir surrounded by faults and structurally fractured. The main oil bearing series is the Lower Sha si Member of the Shahejie Formation in the Lower Tertiary, which is divided into three oil formations: V, VI, and VII. This reservoir has the characteristics of significant differences in physical properties between horizontal and vertical reservoirs, as well as significant differences in production conditions. The fault block has been explored for more than thirty years. The multiple oil layer extraction has been jointly produced for many years. In recent years, the complex situations due to Multi-layer mining appeared frequently. This article focuses on the new understanding of the development of the VII oil formation in the gravel sandstone reservoir. Starting from the analysis of the remaining oil and oil-water interface, targeted measures are taken to improve the recovery rate of the VII oil formation and achieve the redevelopment of the gravel sandstone reservoir.