简化局部密度理论预测页岩等温吸附曲线

Predicting the Sorption Isotherm of Methane on Shale with Simplified Local-Density Model

通过简化局部密度(SLD)理论预测了川南地区龙马溪组页岩样品在25℃、35℃、45℃下的等温吸附曲线。研究表明:SLD理论可以有效拟合绿泥石、伊利石、伊/蒙混层及Ⅱ型干酪根的等温吸附曲线,而且在同一种物质的各回归参数中仅能量参数εgs随温度变化,一旦确定εgs与温度的关系,就可借助SLD理论用已知温度下的等温吸附曲线计算出另一温度下的等温吸附曲线;预测的页岩等温吸附曲线与实验获取的等温吸附曲线误差较小。

A new approach was established to predict the adsorption isotherm of methane on shale and some conclusions were drawn： simplified local-density（SLD） model can represent the sorption of methane on chlorite,illite, illite/smectite mixed layer and type Ⅱ kerogen, and some regression parameters of SLD model are obtained for these materials, andin the regression parameters the energy parameter εgs changes when temperature varies. We also predicted the sorption isotherm of methane on chlorite,illite,illite/smectite mixed layer and type Ⅱ kerogen at given temperature by SLD model with the known relation between εgs and temperature of each material, and all the sorption isotherms of shale sample originated from prediction are close to experimental results.