双区复合煤层气压力动态特征分析

摘要

Aiming at the heterogeneity of formation itself and the polluted belts around the wells in the processes of drilling, well completion and production for coal-bed gas, the well-testing interpretation model for the composite coal-bed gas with double porosities is established. The model considers not only the effects of borehole storage effect and skin effect, but also the non-equilibrium adsorption and quasi-steady seepage conditions. It gives the pressure solution under the condition of infinite outer boundary, and furthermore the typical curves of bottom hole pressure drop are drawn, the influences of each parameter on the curves are analyzed. The study achievements have provided a theoretical basis for coal-bed gas reservoir development.%针对煤层气在钻井、完井、开采过程中井周围产生污染带以及地层本身的非均质情况,建立了既考虑井筒储存效应及表皮污染的影响,又考虑非平衡态吸附及拟稳态渗流条件的分区复合煤层气试井解释模型,求出了无限大外边界条件下的煤层气藏压力解,并绘制了井底压降典型曲线,就各参数对典型曲线的影响进行了分析.研究成果为煤层气藏开发提供了理论依据.