Research On CO₂-EOR Associated Gas Recovery Technology In Extra-low Permeability Oil Reservoirs Of Zhenglizhuang Oilfield

The reservoir properties of block GX in Zhenglizhuang Oilfield are poor and require CO2 injection development.Research on the associated gas with high CO2 content separated from crude oil.After purification,CO2 is liquefied,pressurized and reinjected,so as to realize the recovery and utilization of CO2.The associated gas from which CO2 is separated can be used as fuel gas.This paper studies the selection of processing technology for associated gas in high CO2 oilfields,and compares low-temperature fractionation liquefaction process + membrane separation,pressure swing adsorption + cryogenic rectification process,low temperature fractionation liquefaction process,membrane separation,pressure swing adsorption,and direct pressurized reinjection And other process plans,from the comparative analysis of the advantages and disadvantages of investment and device construction and operation,it is determined that the cryogenic fractionation liquefaction process + membrane separation,pressure swing adsorption + cryogenic rectification process will be a reasonable plan,and through the comparison of energy consumption and operating costs,To determine the low-temperature fractionation liquefaction process + membrane separation program as the optimal program.HYSYS is used to optimize the process parameters of the cryogenic fractionation liquefaction process + membrane separation scheme,and perform process simulation to calculate the energy consumption.At the same time,the compressor refrigeration unit and the membrane separation device are finalized product price analysis and comprehensive comparison to determine the reasonable compressor boost Pressure,fractional distillation pressure.