渗透率应力敏感影响下气井产能试井拟合图版的建立与应用

Permeability of Establishment and Application of Gas Well Deliverability Test Fitting Plateunder the Influence of the Stress Sensitivity

摘要: 总结前人对变形介质的研究成果，认为变形介质中的渗流存在渗透率应力敏感性特征。针对变形介质中地层渗透率变化的初始阶段可以近似认为是线性变化的特点，从其渗流的连续性方程、运动方程和渗透率应力敏感状态方程出发，推导了渗透率线性变化条件下产能方程，进一步得到了气井无因次产能公式。在此基础上绘制了气井无因次产能试井图版，进一步分析了渗透率应力敏感性气井产能的影响。研究表明：渗透率应力敏感性对气井产能的影响不可忽略；图版的使用具有准确、方便、快捷的特点；渗透率应力敏感影响下气井无阻流量要远大于未考虑渗透率应力敏感影响下的无阻流量。

Abstract: Based on the research of the deformable porous media, pressure sensitivity feature of the permeability exists in the deformable porous media. In this paper, the initial stage of permeability change in the deformation of the medium was a linear variation. Continuity equation, equations of motion and the permeability pressure sensitive equation of state were used, and then productivity equation was derived when the permeability changed linearly, finally dimensionless productivity formula was derived. Dimensionless productivity well test plates were drawn. On this basis, the impact of permeability stress sensitivity of gas well productivity was further analyzed. The research shows: 1) The permeability stress sensitivity on gas well productivity cannot be ignored; 2) Fitting instance of the use of the plates was accurate, convenient and fast; 3) The permeability stress sensitivity on gas well open flow capacity is much larger than that without considering the permeability stress sensitivity under the influence of the open flow.