灰色理论结合专家系统预测煤层气井压裂效果

Using the Gray Theory and Expert System to Predict Coalbed Gas Wells Fracture Result

煤层气井水力压裂效果受煤层条件、煤层气井条件、压裂施工参数等影响,压裂效果难以预测.通过对煤层气井压裂后累积增产量分析,从中确定出煤层厚度、煤层深度、煤层渗透率等26个影响煤层气井压裂效果的因素.运用灰色关联法筛选主要因素和次主要因素,并分别建立不同的隶属函数用于专家系统的知识库建立,形成一种灰色理论结合专家系统的煤层气井压裂效果预测方法.将方法运用与鄂尔多斯某区块,对200组测试数据进行计算,预测错误率仅为3.5%.计算结果表明,方法预测结果准确可靠,可为煤层气井压裂优化提供指导.

The hydraulic fracturing result of coal-bed methane well is usually affected by the conditions of coal-bed,the conditions of coal-bed methane well,fracturing operation parameters and so on.As a result,the fracturing operation result is difficult to predict.This paper confirmed 26 factors including coal seam thickness,the depth of coal seam,and permeability of coal seam et al.and selected main factors and secondary main factors by using gray correlation analysis theory.Established membership functions of expert system for main factors and secondary main factors respectively.Using the gray theory and expert system formed a method of coalbed gas well fracturing result prediction.We calculate 200fracturing result in X block of Erdos based on this method.The prediction error rate is only 3.5%.The prediction results are accurate and reliable,and can provide guidance for coal-bed methane wells fracturing optimization.