压敏效应对试井曲线特征的影响分析

Effect of Stress-sensitivity on Well Test Curve Characteristics in Sandstone Gas Reservoirs

建立了具有压敏效应的试井模型,通过长庆苏里格气田气井的实例应用,分析了压敏效应对不稳定试井曲线特征的影响。应用考虑应力敏感渗流模型,不稳定压力动态试井曲线特征表明,拟压力及其导数曲线开始时为一直线,随着无因次渗透率模量的增加,曲线往上翘起,无因次渗透率模量越大,上翘越明显,此项特征可能是气井应力敏感的反映。此外,同一口井不同时间试井曲线特征不同,第2次解释储层渗透率都明显较第1次的值低,而且双对数曲线上翘得更早更快,表现出压敏效应对试井曲线的影响。研究结果有利于明确压敏效应对不稳定试井模型特征的影响,对我国压力敏感气藏不稳定试井分析具有一定的指导意义。

In order to study the effect of stress-sensitive permeability on transient pressure in sandfacies,this paper uses the concept of permeability modulus,and presents a pressure transient well-test model for stress-sensitive fissured composite gas reservoirs,which includes strong nonlinear equations.Uses of transformation to linearize the equations have been presented to solve the nonlinear equations and to get zero-order solution.The result is as follows: at the beginning,the characteristic curves of pseudo-pr...