缝洞向井筒供液时三重压敏介质油藏压力响应特征研究

建立由基岩系统、裂缝系统和溶洞系统组成，并考虑溶洞渗透率和裂缝渗透率随压降的增加呈指数减小的三重压敏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。讨论了溶洞和裂缝无因次渗透率模数、介质问窜流、弹性储容比、外边界条件及表皮系数对压力响应的影响。结果表明：无因次渗透率模数导致压力及压力导数明显上升，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。

Study of pressure-transient characteristic for stress-sensitive triple-medium reservoirs with fractures and vugs conveying fluids to wellbore

A welltest interpretation model consisting of matrix,fractures and vugs is presented considering permeability of vugs and fractures decreases exponentially.The mathematical model which takes into account the effects of wellbore storage and skin parameter is calculated using the fully-implicit finite-difference form.Effects of permeability modulus,interporosity flow parameter,storativity-ratio,outer-boundary and skin parameter to the pressure response are discussed.The results indicate that permeability modulus causes the increase of pressure and pressure derivative,interporosity flow parameter determines the time of the interporosity flow,storativity-ratio influences the width and depth of the "concave" on the pressure derivative curve,the effect of the outer-boundary is different from the normal triple medium,skin parameter worked on the whole time of the pressure and the "heave" of the pressure derivative,but the permeability modulus mainly worked on the late time of the pressure and pressure derivative.