页岩气藏的甲烷吸附性能是页岩气藏开发的前提和基础,对页岩气资源预测、产能评价等有重要影响。根据不同温度下实测的页岩等温吸附数据,以吸附势理论为基础,对等温吸附数据进行处理分析得到ε-ω吸附特性曲线及其数学表达式。研究结果表明,页岩吸附甲烷的ε-ω吸附特性曲线是唯一的且与温度无关,可预测不同温度下甲烷吸附量,得到页岩吸附甲烷的吸附等温线;吸附相密度计算对ε-ω吸附特性曲线预测甲烷吸附量有重要的影响,吸附相密度经验公式与预测甲烷吸附量准确度有关,需进一步研究甲烷吸附相密度计算方法。
Methane adsorption properties of shale gas reservoirs are the premise and foundation for shale gas reservoir development,and have an important influence on resource forecast and productivity evaluation. Based on the measured isotherm data under different temperature and adsorption potential theory, the ε-ω adsorption characteristic curve can be drawn and is described by analyzing and treating the isotherm data. The result shows that the ε-ω adsorption characteristic curve of shale to CH4 is unique and independent of temperature, which can forecast methane adsorption at different temperature and obtain the adsorption isotherm of shale to CH4. The density of adsorbed phase plays an important role in forecasting the methane adsorption by the ε-ω adsorption characteristic curve, which is relevant to the accuracy of methane adsorption forecast. Therefore, the calculation method of the density of adsorbed phase needs further studies.