页岩—气体吸附特性曲线应用研究

页岩对气体的吸附能力评价是页岩气研究的基础工作,兰氏体积数据是评价页岩气体吸附能力的重要参数,但局限于兰氏体积的应用研究不能满足工作需要,现有数据的信息挖掘和应用还有较大的空间。页岩与气体构成的吸附体系,对气体的吸附能力、特性可以利用吸附势理论进行分析和描述。实验数据分析表明,页岩与不同气体构成不同的吸附体系,具有不同的吸附特性曲线,吸附特性曲线基本不受温度影响,可以用于等温吸附曲线的预测。以川东南五峰—龙马溪组优质页岩为例,进行了地层条件下页岩气体吸附能力的预测。预测结果显示,页岩样品地层条件下的吸附气量与兰氏体积存在较大差异,这种差异反映了温度和压力对页岩气体吸附能力的影响和控制作用,暗示地层条件下页岩吸附气量预测研究具有理论和实践意义。

Application of characteristic gas adsorption curves for shales

The study of the gas adsorption capacity of shales is a basic tenet of shale gas research.The Langmuir's volume is an important parameter when evaluating the gas adsorption capacity of shales.The adsorption potential theory was applied here to study the gas adsorption capacity and characteristics of the adsorption systems in shales for different gases.Experiments showed that different adsorption curves were obtained for the adsorption systems of shales and different gases.These curves were not influenced by temperature and so could be used in the prediction of isothermal adsorption curves.Some shale samples were collected from the Wufeng and Longmaxi formations in the southeastern Sichuan Basin, and were tested to predict their adsorption capacity under formation conditions.It was found that the adsorption amount was obviously different from the Langmuir's volume, which demonstrated the controlling effects of temperature and pressure on the adsorption capacity of shales.