大庆五站低渗气藏数值模拟研究

NUMERICAL SIMULATION STUDY OF DAQING WUZHAN LOW-PERMEABILITY GAS RESERVOIR

目前变形介质气藏数值模型方面已有大量研究,但这些模型中只考虑了渗透率对压力的敏感性,而忽略了孔隙度对压力的敏感性。大庆油田五站低渗透气藏通过岩心应力测试表明,孔隙度和渗透率均具有应力敏感性,因此在得到大庆五站气藏岩心孔隙度、渗透率随净围压的变化规律基础上,建立了同时考虑孔、渗介质变形的低渗气藏数值模拟型,并采用IMDES方法进行求解。通过大庆五站气藏5口气井的产量历史拟合分析表明,综合考虑渗透率和孔隙度应力敏感时历史拟合更符合开采实际,说明模拟方法可在类拟气藏中应用。与此同时,通过气藏模拟表明目前气藏井控动态储量较低,要提高气藏开发效果应在有潜力和储层有效厚度增大的地区部署新开发井。

Numerical models of gas reservoir with deformation media have been widely studied at present.However,these models only consider the sensitivity of permeability to pressure and neglect the sensitivity of porosity to pressure.Core stress test in Daqing Wuzhan low-permeability gas reservoir indicates that both porosity and permeability are sensitive to pressure.Thus,on the basis of change law that core porosity and permeability in Daqing Wuzhan gas reservoir are varied with net confining pressure,a numerical simulation model considering media deformation caused by porosity and permeability has been established and is solved by using the IMDES method.Through the analysis on history matching with yields by 5 gas wells in Daqing Wuzhan gas reservoir,it is found that the history matching is consistent with mining field when considering the sensitivity of permeability and porosity to pressure comprehensively,and proved that the simulation method can be applied in analogous reservoirs.Meanwhile,simulation of gas reservoir has also showed that the well control dynamic reserves of gas reservoir are relatively low and new development wells should be deployed in areas with great potential and with highly-increased thickness of reservoirs so as to improve the development efficiency of gas reservoirs.