By this instrument, the major factors affecting coalbed gas preservation, such as the effects of systematic temperature and pressure changes, the diffusion, migretion and dispersion of free gas, the effects of different hy.

The geological characteristics and the coalbed methane accumulation in Fengfeng mine district;

Based on the observation of field geology and the analysis of microstructures and data of exploration,combined with regional tectonic evolution,structural control action of tectonic evolution of Taihang Mountain on coal seam occurrence in southeastern Hebei was discussed.

Based on the principle of grey association analysis,the present paper has put forward a fairly practical and readily programmed cluster method—grey association cluster method,and employed this method to demarcate coal beds and gas beds,discriminate between coal-produced gas bed,oil bed and water bed ,and make lithostratigraphic classification.