【摘要】 针对缝洞型油藏提出了一种由基岩系统、裂缝系统及溶洞系统组成的三孔三渗数学模型,它考虑了井筒储集和表皮效应的影响,同时,在建立模型的时候没有忽略二次梯度项,使计算结果更加精确。采用一阶向前差分、二阶中心差分的方法获得了模型的差分方程,用解非线性方程组的Newton迭代法求得了方程组的数值解,并作出了典型压力曲线图。结果表明,由于井筒储集和表皮效应的存在,在半对数压力与时间响应曲线上,在初始阶段出现一个短时间的井筒缓冲,并且表皮系数越大,出现过渡段对应的无因次压力就越大,出现过渡段的时间越晚,晚期阶段曲线则几乎平行;而井筒储集系数的影响只是在初始阶段,且在初始阶段井筒储集系数越大,同一时间所对应的无因次压力越小;晚期曲线则汇聚于一点。更多还原

【Abstract】 The triple porosity and triple permeability mathematic model consisted of matrix,fractures and vugs was built considering the effects of skin and wellhore storage.The quadratic-gradient term was not neglected in this model,which results in more accurate conclusion.Difference equation of the model was obtained based on the method of first-order forward difference and second-order center difference.Newton iterative method solving the nonlineari-ty equation group was used for getting the numerical solution of the equation group,and typical pressure curve was determined. Because of the exist of wellbore storage and skin effect,on responsecurve of half-logarithm pressure and lime,wellbore buffer for short time appears at early stage,and more skin factor makes larger corresponded dimensionless pressure in transition period and later transition period.The curve is nearly parallel in later period.The influence of wellbore storage factor appears and biggerskin factor makes smaller corresponded dimensionless pressureat the same time at early stage.But in later period,the curve is one point.更多还原