Study On Combustion Mechanism And Engineering Parameters Optimization Of Hydrocarbon Combustion In Dongxi C Ⅲ1 Reservoir

At present, most of the low permeability oil fields in China have been into the high recovery degree and high water cut development stage. Stable yield and production are difficult considering the challenge of the water-cut quickly rises, production greatly decreases and the shortage of reserve resources. Due to the particularity of low permeability reservoir, many enhanced oil recovery technologies can’t obtain ideal results. Gas injection production is one of the enhanced oil recovery methods that researchers have been paid more and more attention, and miscible gas injection displacement is the most attractive method. Its mechanism is the injected gas and crude oil reached miscible as well eliminates the interfacial tension under the condition of the reservoir, which reduces the residual oil of the capillary retention due to capillary effects. It can make the microscopic oil displacement efficiency reached one hundred percent in ideal status. Therefore, the research on the miscible mechanism of gas injection development according to low permeability reservoirs has direct guiding significance for low permeability reservoirs to enhance their recovery.DongHe reservoir has significantly water flooding development in the bottom, the upper1-sand-layer is of low and extra-low permeability reservoir and the oil is difficult to displace. This paper studied the mechanism of miscible gas displacement to enhance oil recovery, and optimized the injection-production parameters. First of all, the research started from the basic phase behavior theory, predicted and measured the minimum miscible pressure of the different gas of DongHe CIII1reservoir. Secondly, it analyzed and fitted the fluid properties of DongHe CIII1reservoir and laboratory experiment of gas injection. It studied the gas injection miscible displacement process as well as mechanism and analyzed the change of fluid phase during the miscible process. Finally, it established DongHe CⅢ1reservoir six component well group model with the method of numerical simulation, simulated and predicted the gas injection effect of DongHe CⅢ1reservoir, and then optimized the injection-production engineering parameters of the method of gas injection and the horizon of gas injection. The optimized development project is significant to the actual development for DongHe CⅢ1reservoir and it has important reference value considering the development of similar reservoir as well.