GAS CONTENTS OF DIFFERENT COAL RESERVOIRS IN QINSHUI BASIN AND RESERVOIR FORMATION INFLUENCING FACTOR ANALYSIS

The coal reservoir stratum in Qinshui Basin has the characteristics of high coal rank, strong adsorption capacity, high gas content, low porosity factor, double peak pore structure, low permeability, reservoir stratum pressure gradient, etc. In the research area, the tectonic stability and the tectonic heat event in Yanshan Period, the favorable coal gathering environment, the dynamic area of the viscous and weak underground water and other geologic processes comprehensively controlled the reservoir formation characteristics of the coal bed gas. Specifically, the paper aimed to establish the coal bed gas non-enrichment mode to simplify the reservoir formation definition problem and directly face to the coal bed gas development area selection, thus guiding the coal bed gas exploration and development area selection at the south of Qinshui Basin. Moreover, the paper was focused on the "bottleneck" problem ---- per well yield improvement to develop and perfect the exploration evaluation, the drilling & completion, the reservoir stratum transform, the expulsion and mining process, the digital gas field and other relevant technologies. The five major core technologies have supported the construction of the coal bed gas energy production base at the south of Qinshui Basin.