Research Of Gas Injection And Technologic Policy For Carbonate Rocks Fractured-Vuggy Type Oil Reservoir Of Tahe Oilfield

Carbonates account for about half of the Earth’s oil resources,the development value is very great,but because of its geological structure of the complexity and heterogeneity to the development of great difficulties and challenges.There are usually large caves and numerous fractures in carbonate reservoirs,and complex structures form a complex fluid flow.Tahe oilfield is a typical fractured-type carbonate reservoir in China,and it has achieved some effect after pre-injection development.However,in recent years,water injection has not been developed more efficiently,so the oil field has improved the gas recovery Test,and the test effect is remarkable.In order to expand the scale of the application,the need for gas injection policy to conduct a comprehensive and meticulous discussion,including theoretical research and field applications.In this paper,we study the flow pattern of the fluid during the process of gas flooding by analyzing the microscopic numerical simulation,and analyze the process of gravity differentiation in the process of displacing the "loft oil".Combining with the theory of fluid mechanics,this paper puts forward the concept of equilibrium The results show that the effect of displacement is the best when the displacement criterion is close to "1".Based on the field data of the gas injection parameters,the effect of each gas injection parameter on the final recovery rate is analyzed quantitatively by using the numerical simulation method,and the final Gas injection parameters.The main research results of this paper are as follows:Based on the numerical simulation of gas-liquid two-phase flow,the mathematic model of single-phase flow in fracture-type medium and the method of gas-liquid two-phase flow in fracture-type medium are established,and the formula of gas head loss is deduced Analyze the energy loss mechanism in the process of flow.The model of the simulator is determined by comparing the characteristics of the black oil model and the component model.The method of determining the "smoothing parameter" is solved by using the neural network to solve the minimum miscible pressure.Using the microscopic numerical simulation software to study the gas flooding,the transverse equilibrium flooding quasi and the longitudinal equilibrium flooding quasi criterion are proposed and deduced,and the two equalities are used to study the model equilibrium displacement.The results show that when the equilibrium The closer the drive is closer to 1,the better the effect of the displacement,the less the remaining oil.Based on the data of logging,seismic and physical properties,two typical fracture models are established based on karst phasing,and the model can be used to simulate the actual geological conditions based on the phased reservoir property model.According to the parameters of the gas injection parameter,the numerical simulation scheme is proposed,and the final gas injection technology scheme is proposed.The results show that the gas flooding can be effective after the water flooding.The development of the remaining oil,but need to select the appropriate timing and other parameters,gas parameters can be very good application of the line.