The Optimization Research Of Partitioned Control Technique For Reservoirs At Ultra-high Water Cut Stage

China's oilfields have been developed through long-term waterflooding and have entered the stage of high water-cut or even ultra-high water cut.The reservoir of ultra-high water-cut period is the focus of future reservoir development.Due to the reservoir heterogeneity,development mode and long-term water flushing,the residual oil and water distribution in the reservoir is complicated,which seriously restricts the tapping potential of remaining oil and related adjustment measures.Based on the numerical simulation results of reservoir,this paper establishes a quantitative and characterization method for the flow field of the ultra-high watercut reservoir and a method for identifying and controlling the reservoir partitioning measures in the ultra-high water-cut period.The paper establishes the pattern of regulation and control of flow field in reservoirs and the quantitative statistical methods of each regional index of reservoirs and studies the development policies of main areas.The mathematical model of regulation and control optimization of reservoir measures in ultra-high water-cut period is resolved by the optimization theory.Finally,the software for controlling and optimizing the ultr-high water cut period of water-flooding reservoirs was formed,which facilitated the reservoir workers to develop the ultra-high water-cut reservoir effectively and quickly.Based on the coupling of static parameters and dynamic parameters of reservoir,the abundance field and flow rate field of reservoir residual capacity are respectively used to characterize the reservoir potential field and fluid flow field.The two fields are respectively determined by parameters and finally overlapped to form the reservoir area.The evolvement regularity of subarea in the ultra-high water cut stage was studied,and the influence parameters were studied.On this basis,the technology of automatic division of reservoir area and the quantitative statistical technique of zoning index are established,and the statistics of the area and the remaining recoverable geological reserves of various reservoirs provide the basis for the research of various types of regional development policies.Combining with the optimization theory,the mathematical model of regulation and control of the reservoir during the ultra-high water-cut period is established,and the constraints are established according to the development characteristics of all kinds of zones.Taking the economic factors into consideration,the net present value is taken as the objective function.Technology to solve the control mathematical model of the reservoir measures during the ultrahigh water-cut period,and get the optimal solution of various parameters under different development modes.Under the guidance of the method of regulation and control of optimization measures and the theory of optimization method during the period of ultra-high water cut,an external interface software based on reservoir numerical simulation software is compiled.It consists of reading reservoir database module,constructing reservoir model module,Reservoir zoning statistics module and intelligent optimization control module.Realize the automatic optimization process of reservoir measures in the ultra-high water cut period and improve the measures to optimize the efficiency.