Adjustment Of Comprehensive Development Plan For T11 Reservoir Equilibrium Displacement

The T11 reservoir has undergone many adjustments and achieved good development results.After entering the extra high water cut period,the influence of reservoir heterogeneity is intensified.At the same time,the contradiction between the layers is prominent,and the inefficient and inefficient injection-production cycle is serious.The original water injection development program has been unable to meet the requirements for enhanced oil recovery in this stage.Therefore,for the current situation of T11 reservoirs,it is important to analyze the distribution of dominant channels between wells,comprehensively consider the reservoir parameters for layer subdivision and reorganization,and comprehensively adjust the injection and production schemes.In order to analyze the development of the dominant flow channel of T11 reservoir,starting from the static data and dynamic production data,the index calculation method(considering the water consumption per ton of oil,the cumulative water-oil ratio)and the water absorption comparison chart method are combined to score each injection well group.A system for determining the dominant channel of inefficient waterflood based on comprehensive score is formed.At the same time,based on the reservoir dynamic data,the inter-well dynamic connectivity inversion technique is used to determine the connectivity within each well group,and the comprehensive scoring system is verified.It is determined that several well groups represented by A6-2 are developed within the year.The superior flow channel provides a reference for the development of contradictory management between reservoir plane and interlayer.Reasonable interval subdivision and reorganization are the main ways to mitigate the interlayer conflicts in high water-cut period.In order to meet the efficient and accurate requirements of the field layer subdivision work,based on Buckley-Leverett oil displacement theory and twophase percolation theory,a comprehensive quantitative parameter for characterizing the oil layer potential,the layering coefficient,is combined to combine the dynamic and static factors of the reservoir.Divide and reorganize the guiding system.The technical limit of the layering coefficient is determined by the calculation of the water injection development index.Under the influence of the rhythm and the interlayer layer on the subdivision,the optimal segmentation method is used to formulate the dynamic and static combination layer subdivision scheme of the high water cut period.It was found by the digital model effect that after the layer system was subdivided,the oil production in the reservoir increased significantly,the ineffective water injection decreased,and the predicted recovery factor increased by 1.2%.Based on the contradiction of reservoir plane,three optimization schemes of injection and production optimization,production potential optimization and new site optimization are proposed.The random disturbance approximate gradient algorithm(SPSA)is used to solve the injection-production optimization model.The basic scheme of the optimization method is used as an initial iterative scheme to predict the production dynamics of the reservoir after 15 years.Through comparison of the three comparison schemes with the basic scheme,the analysis of the optimization effect of each scheme is made from the aspects of oil production,water content and NPV value of the reservoir,and the optimization of injection and production based on the production potential method is selected.Injecting water as much as possible to achieve uniform displacement,increasing the economic benefits of block mining.