Reservoir Engineering Parameter Optimization In Zhalaroer Oil Field By Hydrocarbon Gas Flooding

Gas flooding is an effective enhanced oil recovery technology.It has been widely used in North America and has achieved good development results.As one of the ways of gas flooding,hydrocarbon gas flooding has attracted the attention of scholars at home and abroad in recent years.Many scholars have used theoretical and experimental methods to study the phase characteristics during the gas injection process,or gas injection feasibility,and optimizing injection and production parameters.Some domestic oilfields have carried out pilot tests of hydrocarbon gas flooding and have also achieved good development results.The Zhalaroer oil field is located in the eastern edge of the Caspian Basin,and is a low-porosity and low-permeability carbonate oil field.The ? south reservoir is the main reservoir of Zhalaroer oil field.At present,the development of water injection method is affected by the heterogeneity of the reservoir,and problems such as difficulty in water injection,low pressure maintenance level,and serious degasification of the crude oil in the formation have emerged.In addition,a large amount of acid gas is contained in the produced gas.In the later stage of the oil field,the development of gas flooding using produced gas as gas source will be considered.In view of the problems in the above development process,this paper takes the South Oil Reservoir as an example to carry out the numerical simulation of acidic hydrocarbon gas flooding,and has obtained the following conclusions.(1)During the acidic hydrocarbon gas flooding,the more acidic gas in the injected gas,the greater the influence on the physical properties of the crude oil,and the increase of the acid gas content in the injected gas will greatly reduce the area of the two-phase area of the phase diagram and MMP will be lower.(2)Combining phase equilibrium calculation and mixing-cell method,a set of MMP calculation program was written in C++,the accuracy of the calculation result was 95%,and the MMP of CO2 and produced gas are 13.96 and 22.03 MPa.(3)Taking the typical well group of ? south reservoir as the research object,the main influencing factors of 10 hydrocarbon gas flooding effects were screened from reservoir parameters,fluid parameters and development parameters.Orthogonal tests were designed to analyze the main control factors,and the influence of various parameters was ranked.(4)Taking the typical block of ? south reservoir as the research object,optimizing the produced gas as the best injection gas,continuous gas injection as the best development method.A dynamic prediction of gas flooding for 30 years was conducted.The ultimate oil recovery was 32.02%.Compared with the oil recovery of 19.7% over the past 30 years of water injection development,the gas injection development effect was significant.