Stratum energy of coal bed gas reservoirs include coal base, groundwater and gas elastic energies. The evolvement history of stratum energy of the reservoir i

n Qinshui Basin has synthetically been analysed, the geological developing law of its flexibility has been researched in quantitative analysis, taking the key t

ime-middle Yanshanian as limit. The results indicate that coal\|bed gas reservoir forming action is closely linked with the reservoir's energy field of differ

ent geological processes, and has been developed with dynamic balance of energy system and accumulation dissipation of energy. In the whole process, a new gas reservoir may be formed and quondam one be destroyed. Therefore, the key to evaluate and forecast formation of a coal bed gas reservoir is to research the evolvement process of the reservoir's elastic energy field in the research region.