Study on Development Characteristics of Low Permeability Oil-water Horizontal Well Area in the Same Layer

Abstract

According to the development practice of horizontal wells in Putaohua reservoir of low permeability oil-water block, this paper summarizes the development characteristics of the block. At the initial stage of production, the chloride ion value of the near-wellbore formation (i.e., the fluid produced at the initial stage of production) is corrected for the large-scale fractured horizontal wells according to the fracturing fluid that is not returned, so as to judge the water breakthrough property of high water-bearing wells. After putting into production, it is found that the formation water in the block is affected by structure and lithology respectively. The water injection policies of “strengthening water injection at high position and restraining water injection at low position” and “strengthening water injection at main layer and restraining water injection at communication layer” are adopted to restrain formation water energy from plane and interlayer and reduce water cut in horizontal wells. Based on the theoretical analysis of fracture effect and water breakthrough characteristics of horizontal wells, the theoretical water breakthrough strength and theoretical hydraulic conductivity strength of fractures are calculated respectively, and the chart is drawn. According to the chart, the adjustment idea of “classification cycle water injection, zonal determination of parameters” is implemented, so that the determination of cycle water injection parameters is changed from “fixed strength, fixed cycle water quantity” to “fixed water quantity, fixed cycle water strength”, and further improved The improvement of water injection policy can provide reference for the development characteristics research and water injection adjustment of horizontal wells in the same type of oilfield in the future.