Coupling Mechanism And Parameter Optimization Of Water-drive Injection-production In Fault Block Reservoirs

Most of the complex fault block reservoirs in China have entered the high water cut period.Under the influence of the original injection-production working mechanism and reservoirs heterogeneity.The problems of apparent well output decline,high water cut and low economic benefit have occurred.In this paper,the complex fault block reservoirs injection-production coupling technology combines synthesize the geological data and historical production performance.The remaining oil potential area is determined.Then,the coupling of the injection and production well working system and optimizing parameters of the injection and production volume designs development scheme of the remaining oil.It will guide the efficient exploitation of the remaining oil in the later stages of old oilfield development.Through the research of sand-filled flat plate experiments,numerical simulation,theoretical analysis and other aspects.The following achievements and understandings have been achieved:(1)In view of the serious heterogeneity of complex fault blocks,the application mechanism of injection-production coupling in plane and longitudinal direction is researched.On the plane,the mechanism of injection-production coupling researches the distribution of the development well pattern and the physical properties of the reservoirs.In the longitudinal direction,the mechanism of injection-production coupling researches the single-layer intralayer heterogeneity and the multi-layer interlayer heterogeneity.(2)The physical experiment method and numerical simulation method further researches the working mechanism of injection and production coupling.The application schemes of different injection and production coupling technologies were designed by orthogonal test method.In the final experimental and numerical simulation results,it was found that the injection-production coupling schemes such as asynchronous water injection,irregular oil production,selective opening and closing well,reasonable increase and decrease pressure can control water and stabilize oil,which can achieve the most reasonable production method and maximum recovery.(3)Combining the geological structure characteristics and energy sources of complex fault block reservoirs in DX Oilfield,the reservoirs are divided into extremely complex fault block reservoirs,lithologic fault block reservoirs,anticline fault block reservoirs and semi-closed type Side and bottom water fault block reservoirs.Based on production performance data and geological data,the evaluation index parameters of the remaining oil potential area are selected.A remaining oil potential evaluation system of oil-water two phase complex fault block reservoirs are established.According to the classification of potential area,it is divided into Weak advantage potential area,general potential area and non-potential area.(4)The injection-production coupling technology applies to the X11-80 block reservoirs.Combining the remaining oil potential area and production performance analysis,an injection-production coupling scheme is designed.The development effect of numerical simulation was predicted.The work system of injection and production well and the plan of injection and production volume is optimized.Finally,the mechanism of the optimal injection-production coupling scheme is analyzed for improving remaining oil in the reservoirs.