Research On Gas (CBM) Occurrence Geological Controlling Factors And Grading Extraction Blocks Of Coal Seam 7~# In Suxian Mining Area

With 7~# coal seam of Suxian mining area as the object of the research and adopting Gradual Control Theory of Gas Occurrence Structure,to analyze the Huaibei coalfield regional geological structure and its effect on the control of the coal field.As a result,revealing that the regional tectonic evolution on the control characteristics of gas occurrence.Studies have shown that Suxian mining area experienced multiphase tectonic movement in the past for period of geologic history,and each tectonic movement had great influence on the gas occurrence.Especially since the early Tertiary crustal movement provided the secondary biogas to generate favorable conditions,so that the coalbed gas had been added.By the method of gas geology theory and research,I analyzed the factors what influencing gas occurrence like geological structure of Suxian mining area,lithology and buried depth of coal seam and so on.The result shows that geological structure and buried depth of coal seam make the main control function on gas occurrence 7~# coal seam of Suxian mining area: the coal bed gas content decreases near big faults,and gas content with coal seam buried depth are highly correlated.On the basis of the theory of gas geology,according to occurrence characteristics and structure characteristics of 7~# coal seam of Suxian mining area,7~# coal seam of Suxian mining area is divided into 8 gas geological unit.On this basis,the five gas extraction blocks are determined.From the perspective of beneficial to the gas extraction,to consider the natural factors(gas content,gas pressure,gas(CBM)resources,the resources abundance,coal thickness)as the limited conditions,to make use of dialectical qualitative evaluation and quantitative evaluation method of combining the AHP method,by the principle of fuzzy mathematics to assess and grade the five gas extraction blocks,and making determinations: the best for the gas extraction,the better the gas extraction and not conducive the gas extraction blocks,to provide gas geology basis in gas control and extraction optimization design of 7~# coal seam of Suxian mining area.