Gas-adsorption properties of isolated kerogen samples from Devonian gas-shale

Shale consists of several component responsible for adsorbing gas. Kerogen, insoluble organic material commonly present in shale, has been identified as one of the primary gas-adsorbing components. Kerogen has been successfully isolated from shale by a chloroform extractions to remove the soluble organic material, a series of acid treatments to eliminate the carbonate and silicate minerals, followed by a treatment using lithium aluminum hydride to remove the pyrite from the kerogen. Each isolated sample represents a different degree of thermal maturity of the kerogen contained in the shale, and displays different methane sorption characteristics. Presently, a correlation between thermal maturity and gas sorption has been determined. This correlation implies that as kerogen matures, structural changes occur which may affect the potential for gas storage. This study investigates the mechanism by which methane storage capacity of three kerogens, each of different maturity, results. A model for storage has been developed, which will assist petroleum engineers to assess the storage potential in organic materials within the reservoir.