气井控制储量评价方法

AN EVALUATION METHOD OF GAS WELL CONTROLLED RESERVES

评价气井控制储量是调整气田开发井网的重要环节，关系到气井工作效率和气藏最终采收率。针对气体非线性渗流问题，采用Russell拟压力函数和Meunier拟时间函数对气体非线性渗流控制方程组线性化，得到了与液体渗流控制方程组参数一一对应的气体渗流控制方程组。使用Duhamel褶积和拟稳态流动方程导出了简约的广义拟稳态渗流控制方程，反映了封闭气藏中气井在变产量同时变流压条件下的拟稳态生产动态特征，由此建立了利用生产数据评价气井控制储量的计算方法，可用于普通直气井、有水力垂直裂缝的直气井以及普通水平气井。通过实例分析给出了该方法的应用步骤和主要计算公式。

Evaluation of gas well controlled reserves is an important part of well pattern adjustment in gas field, which influences the operating efficiency of gas well and the ultimate recovery of gas reservoir. Focusing on the problem of nonlinear gas flow in porous media, the nonlinear gas flow governing equations are linearized using Rus- sell pseudopressure function and Meunier pseudotime function, and finally the gas flow governing equations are ob- tained in which the parameters corresponding to that in liquid flow governing equations. Concise generalized pseudosteady state flow governing equations are derived based on Duhamel convolution and pseudosteady state flow equation, which describes the performance of pseudosteady state gas well producing under variable flow rate and simultaneously variable flow pressure in closed gas reservoir. Thereby, the evaluation method of gas well controlled reserves is established based on production data, which is fit for both vertical gas wells with or without hydraulic vertical fractures and horizontal gas wells. The application steps of the method and the main formulas are presented through case study.