Research On Enhanced Oil Recovery Scheme Of M Condensate Reservior In Late Stage

M gas reservoir is a condensate gas reservoir with oil ring.It's found at 1966 and put into production at 1972 and at the phase of production decline.Because of the depletion mining at the early stage,the pressure of oil ring dropped fast.The pressures in the oil and gas areas were not equal,so the oil wells near the oil and gas interface had a gas channeling phenomenon.In order to maintain pressure balance in the oil and gas area,we began to product gas.But as a result of the pressure dropped too fast in the gas area,oil was channeling in the gas well.So,we injected water into the oil and gas surface to separate them.The water intrusion was occured due to the high-speed of gas production in gas area,and the oil and gas were mixed,the production were dropped rapidly.The potential of gas reservior and pay layers have been analysised based on the geologic information,production performance and test data to get a better understanding of the distribution of remaining oil and gas,and the reservior simulation have been done to modeling the distribution of bypassed oil and gas,and simulation measure of some programs have been announced to improve gas recovery.The following are conclusions achived.(1)M gas reservoir belongs to normal temperature and pressure condensate gas reservoir,which has good reservoir permeability,strong heterogeneity between layers,not active side water and low condensate oil content.(2)The gas reservoir and gas well were analyzed by means of production data and test data,and the geological reserve of gas reservoir was calculated by static method and dynamic method to evaluate the development potential of the gas reservoir.(3)The geological reserves of the gas reservoir are not evenly distributed,the gas is mainly concentrated in 5,6 and 8 layers,the recovery percent of reserves is 31%,so,the gas reservior still has the potential to explore.(4)On the basis of evaluation of reservoir development effect,the study shows that the remaining gas can be divided into enclosed type,incomplete pattern type,and interlayer interference type,due to the influence of interlayer inhomogeneity,areal heterogeneity,interlayer interference and the difference of the development degree of each small layer.(5)According to the remaining potential analysis and numerical model of remaining gas distribution,comprehensive proposed some solutions,predict ten years later the change of the gas production rate of gas reservoir,and selected a set of the best solutions.The prediction of optimization of M gas reservior had important guiding meaning for the development of similar reserviors.