【摘要】 建立了考虑裂缝形状和导流能力变化的压裂井不稳定渗流的数学模型,并采用有限元方法求解,获得了井底压力随时间的变化规律。同时绘制了相应的压力动态曲线,并对曲线的特征和影响因素进行了分析。研究结果表明:圆形封闭地层压裂井的压力动态曲线可以划分为6个流动阶段;在相同裂缝开口宽度和相同裂缝长度的条件下,与矩形裂缝相比,楔形裂缝压力消耗大,表现为无因次压力及压力导数曲线较高;在相同裂缝开口渗透率的条件下,与导流能力呈线性降低的裂缝以及常导流能力裂缝相比,导流能力呈幂指数降低的裂缝压力消耗最大,表现为无因次压力及压力导数曲线最高。更多还原

【Abstract】 The transient flow mathematical model of fractured wells considering fracture shape and variable fracture conductivity is developed and solved by using finite element method. And the behavior of the bottomhole pressure varying with time is obtained. At the same time, corresponding pressure transient curves are drawn. The curve characteristics and influences are analyzed. The study shows that the pressure transient curve of fractured wells in closed circular formation can be divided into six different flow regimes. In condition of the same fracture opening width and fracture length, compared to rectangular fracture, the pressure drop with tapered fracture is bigger, and the dimensionless pressure and pressure derivative curves are higher. In condition of the same fracture opening permeability, compared to linear declining and constant conductivity fractures, the pressure drop with exponential declining conductivity fracture is the biggest, and the dimensionless pressure and pressure derivative curves are the highest.更多还原