Adsorption Studies of Natural Gas Storage in Devonian Shales

Abstract

Summary Significant amounts of natural gas exist as an adsorbed, or condensed, phase in Devonian shale formations and other unconventional gas resources. The amount of the adsorbed phase depends on the pressure and temperature. The Langmuir isotherm has been used to describe the pressure dependence. However, temperature dependence has not been explored. This is important to evaluate thermal stimulation as a recovery method and to extrapolate laboratory measurements to reservoir conditions. We investigate adsorption as a function of both pressure and temperature. We found that the effects of temperature are significant and that the Langmuir model does not describe adsorption adequately. We reconciled the data with bi-Langmuir models.