压敏三重介质油藏压力响应特征

建立由基岩系统、裂缝系统和溶洞系统组成,并考虑溶洞渗透率随压降的增加呈指数减小的压敏三重介质油藏试井解释模型,采用隐式差分格式对考虑井筒储存和污染效应的情况进行了求解.研究表明:无因次渗透率模数导致压力及压力导数明显增大,窜流系数影响窜流阶段出现的早晚,弹性储容比影响压力导数曲线"凹陷"的宽度和深度,外边界条件的影响则和普通三重介质明显不同,表皮系数主要影响全部压力和压力导数早期的"凸起",而无因次渗透率模数则主要影响压力和压力导数的后期.

The Pressure-Transient Characteristics of a Stress-Sensitive Triple-Medium Reservoir

A test well interpretation model consisting of matrix, fractures and vugs is presented in which the permeability of vugs decreases exponentially with pressure drop. A mathematical model which takes into account the effect of wellbore storage and skin factor is calculated in a fully-implicit finite-difference scheme. It is shown that the dimensionless permeability modulus causes a increase of pressure and its derivative. The interporosity-flow factor determines the time of the interporosity flow. The storativity-ratio influences the width and depth of the "concave" in the pressure derivative. The effect of the outer-boundary differs from that of a normal triple medium. The skin factor affects the whole pressure and the "heave" in the pressure derivative curve, while the dimensionless permeability modulus mainly affects the later pressure and pressure derivative.