煤心损失气量计算方法在页岩气中应用的适用性分析

摘要

煤心损失气量计算方法在工程条件、煤心性质等方面均有约束条件和适用范围，探讨该方法在页岩气中应用的适用性尤为重要。分析认为，该方法约束条件和适用范围的提出，主要是基于煤层气赋存状态的多样性以及不同煤心损失气、解吸气和残余气占比的差异性。煤层气赋存受控于煤层演化程度及结构，损失气、解吸气和残余气占比与工程条件密切相关。页岩与煤相比，在岩石性质、组成、孔隙结构、比表面特征等方面存在较大差异，加之页岩岩心与煤心钻取条件的不同，决定了煤心损失气量计算方法应用于页岩气的适用条件是：页岩中微孔占有明显优势；比表面积大、具有很强的气体吸附能力；页岩气赋存状态以吸附态为主；提心过程中逸散气量小。%The coal core gas volume loss estimation method has constraint conditions and scope of application on aspects of engineer-ing conditions and coal core property. To investigate the applicability of this method in the application of shale gas is particularly impor-tant . Analysis of that,the opinions on constraint conditions and scope of application are mainly based on proportional differences of coal and coal core lost gas, desorption gas and residual gas. The CBM hosting is controlled by and closely related with coal seam evolu-tion extent and structure, proportion of lost gas, desorption gas and residual gas, as well as engineering conditions. By comparison, on aspects of rock property, composition, pore geometry and specific surface characteristics of shale and coal are quite different. Together with different coring conditions of shale and coal, determined coal core gas volume loss estimation method applied on shale should pay attention to applicability analysis especially. Only under conditions of micropores in shale are in a dominant position with large specific surface area, strong gas adsorption capacity, shale gas hosting under mainly adsorbed state, and small dissipated gas volume, the estima-tion method can get better effect.