A COUPLED MODEL OF THE GAS OCCURRENCE IN GEOTHERMAL FIELD OF THE DEEP COAL SEAMS

摘要

With the increasing of mining depth, the existence condition of coal seams is greatly changed. The basic theory for gas under shallow coal seams will not meet with the requirements of safe extraction of deep coal layer and the utilization of gas resource of coal bed. It is a urgent problem to study the relationship between the coupled model and gas occurrence of the dynamic fluid fields of deep coal layer,; also to investigate the distribution regularities of gas within the deep coal bed and its influencing factors, so that to provide the theoretical basis for controlling and utilizing of gas in the deep coal bed. On the basis of seepage theory of gas flow in coal seams, elastic theory of coal deformation, together with the coupling relationship between gas permeability and porosity, a mathematical coupled model of gas occurrence in the dynamic fluid fields of the deep coal seam was established.