Optimization And Scheme Design Of Gas Drive Injection Parameters In L Fault Block

L fault block is a complex fault block reservoir with serious heterogeneity.In the later stage of water injection development,the dominant seepage channel is developed,showing the development characteristics of "five high and one low".L fault block has been developed through three stages: basic well pattern mining,injection production improvement and fine injection production regulation.As of December 2019,the comprehensive water cut has reached 96.74% and the recovery degree is 22.81%.The continuous use of water drive can not achieve the expected effect,and the economic benefit is poor.Because the field test effect of chemical flooding is not obvious,this paper puts forward the optimization of hydrocarbon gas flooding injection parameters and scheme design for the fault block.The research results have certain guiding significance for the development effect of the block.In this paper,petrel software is used to establish a three-dimensional fine geological model of L fault block by combining well and earthquake,which can accurately describe the change and morphological characteristics of faults.On this basis,the numerical simulation model is established by using CMG software,and the water drive history is fitted to clarify the types and distribution characteristics of the remaining oil,and the remaining oil in the fault block is quantitatively analyzed,so as to clarify the potential of the remaining oil in the fault block.The numerical simulation model is used to optimize the injection parameters of hydrocarbon gas drive,and the preliminary scheme is designed according to the parameter optimization results,that is,the well pattern is row staggered injection production well pattern(gas injection in high position + oil production in the middle),the well type is directional well injection + horizontal well production,the well spacing is 125 m,the injection mode is continuous gas injection,the gas injection rate is 0.6pv,the gas injection rate is 0.08pv/a,and the liquid production rate is 6%;Combined with the design results of single well production allocation and injection scheme,the optimal injection scheme of hydrocarbon gas drive in this block is determined.According to the development index prediction of the optimal scheme,the recovery of the whole area is increased by10.33%,and the hydrocarbon gas drive effect is remarkable,so as to provide theoretical support for the further efficient development of the fault block.