考虑表皮影响的底水油藏水平井流动分析

Analysis of Horizontal Well Flow with Skin Effect in Bottom Water Driven Reservoirs

考虑变表皮系数的影响,建立了水平井井筒与底水油藏的耦合模型,可应用于非稳态和稳态流动阶段。给出了模型的求解方法,并编制了相应的计算机程序进行了实例计算。结果表明:底水油藏水平井非稳态流动阶段持续很短时间便进入稳态流动阶段;由于摩阻和加速度的影响,井筒内存在一定的压力降,与摩阻压降相比,加速度引起的压降较小;忽略井筒压降的井筒流量分布误差非稳态阶段比稳态阶段要大;表皮效应对井筒流量分布有一定的影响,随着表皮系数的增大可以使井筒流量分布更加均匀;表皮系数沿井筒变化时,井筒流量分布的均匀性比定表皮系数时差。

A coupled model of bottom water driven reservoir and horizontal well was established which van be used in steady and unsteady fluid flow with consideration of skin effects.The numerical solution is provided.Several cases studies were illustrated.The results show that flow period of horizontal well in bottom water drive reservoir is very short,and it changes into steady flow period.There is some pressure drop due to friction and acceleration.Compared with friction,acceleration causes smaller pressure drop.The error of flow rate distribution is larger in unsteady state compared to steady state by ignoring the impact of pressure drop.Skin factor impacts flow rate distribution.The increase of skin factor would cause the uniform distribution.The uniformity of flow distribution in wellbore is worse for skin factor with variation compared with constant skin factor.