On the Adsorption and Desorption Trend of Shale Gas
页岩气吸附解吸规律研究

Regular pattern of gas adsorption and desorption in shale is the foundation of shale gas development.An experimental device for measuring shale gas absorption and desorption was self-developed according to material balance principle.Adsorption and desorption trend of 3 shale samples from Ordos basin were measured on this device at different temperature(30℃ to 90℃) and under different pressure(0.1 MPa to 10 MPa).Results show that adsorption increases along with the total organic carbon content in shale.Adsorption of methane increases along with the pressure but decreases with the temperature.At the same temperature and under same pressure,desorption process lags behind adsorption,and is not full enough.The observed adsorption was fitted by using Langmuir isotherm adsorption model.Results show that the fitting effect is poor for shale with larger clay content.But better fitting results can be obtained by using revised double Langmuir model.