聚合物驱数值模拟参数敏感性研究

Study on sensitivities of numerical simulation parameters in polymer flooding

聚合物驱数值模拟技术是指导聚合物驱方案实施的重要手段,由于聚合物驱数值模拟参数的不确定性,导致聚合物驱历史拟合难度加大。基于室内聚合物岩心驱替实验结果,应用岩心驱替数值模拟方法拟合含水率与采收率曲线,确定聚合物驱数值模拟参数,进而得到了比较可靠的岩心数值模型。在此基础上,分别分析了聚合物溶液粘度、不可及孔隙体积、残余阻力系数和聚合物吸附量等数值模拟参数对含水率曲线以及采收率曲线的影响,并引入敏感系数评价了含水率下降幅度以及采收率增加幅度对各参数的敏感性。结果表明,采收率增加幅度和含水率下降幅度对不同参数的敏感程度顺序保持一致,敏感性从强到弱依次为聚合物吸附量、聚合物溶液粘度、残余阻力系数、不可及孔隙体积。

Numerical simulation is of great importance as implementation guides of polymer flooding projects. However,there are still significant difficulties remaining in the history matching process of polymer flooding simulation due to uncertainties of some related parameters in polymer flooding. Based on laboratory experiments of polymer core-flooding,the reservoir simulation parameters for polymer flooding were determined by curve matching of water cut and oil recovery. A more reliable numerical simulation model of polymer core-flooding was then constructed. The effect of viscosity of polymer solutions,inaccessible pore volume,residual resistance coefficient and polymer adsorptive capacity and other related parameters on curves of water cut and oil recovery were analyzed. The sensitive coefficient was introduced in the model to evaluate the sensitivities of these parameters. Results show that the sensitivity order of different parameters to the increase rate of oil recovery and the decline rate of water cut is consistent. The sensitivity of these parameters from strong to weak is:polymer adsorptive capacity,viscosity of polymer solutions,residual resistance coefficient and inaccessible pore volume.