低渗透气藏纵向缝压裂水平气井稳态产能计算方法

PRODUCTIVITY CALCULATION METHOD OF A LONGITUDINALLY FRACTURED HORIZONTAL WELL IN LOW-PERMEABILITY GAS RESERVOIRS

应用保角变换原理,将求解纵向缝压裂水平气井产能的问题转化成相对简单的单向渗流问题,以便于研究裂缝内流动和非裂缝区域拟径向流动对压裂气井产能的影响。在此基础上,综合应用渗流力学理论、质量守衡定律和压力耦合原理,推导出了纵向裂缝内变质量流动时压裂水平气井的产能公式。将计算结果与现场某气井压裂后产量相比,两者吻合程度较好。该方法的计算结果准确性较高,且简单易行,具有一定的推广价值。

By use of the isogonal transformation principle,the issue of solving the productivity of a longitudinally fractured horizontal well has been transferred to a simple question of one-way percolation,in which way how the productivity of a fractured gas well is influenced by fluid flowing pattern within and out of fractures can be easily described.Additionally,based on fluid mechanics in porous medium,mass conservation law,and coupled stress principle,a calculation formula is derived to obtain the productivity of a fractured horizontal gas well in consideration of the mass-variable seepage longitudinally within the fractures.The calculated result matches well with the real productivity of a gas well after being fractured.This method is simple and also proved to be practical with high accuracy.