水平井瞬时压力动态分析

TRANSIENT PRESSURE BEHAVIOR IN A HORIZONTAL WELL

本文用分离变量的方法,给出了水平井在有底水的油藏中二维不定常渗流、Laplace变换空间解,用数值反演的方法,计算了井筒因素(C_D、S_D),双孔隙介质参数(ω、λ)以及水平井位置参数α/h等等;对水平井中压力动态的影响,作出的压力诊断曲线大致可分为:早期的线性流阶段(不考虑井筒■存效应时,压力与时间的二分之一次方成正比;考虑时.压力与时间的一次方成正比),中期的岩块补给裂缝系统的平缓过渡阶段及晚期的稳定阶段(α/h值愈小,压力稳定值愈大)。

This paper presents the solutions of a two-dimensional unsteady state flow equation for a horizontal well in a reservoir with double porosity media with bottom water in Laplace domain, by using the methods of integral transform and variable separation. The effects of wellbore storage C_D, skin S_D, the ratio of storages ω, interporosity flow parameter λ and the position of the horizontal well a/h on the pressure behaviors of the horizontal well are cal- culated and investigated by using the method of numerical inversion. The new log-log pressure diagnosis graphs are given and analysed.