Gas Geological Characteristics And Occurrence Regularity Of Main Coal Seam In Qinglong Mine,guizhou

Qinglong Mine in Guizhou is a high-gas mining area with complex geological conditions.It is of great significance to explore the distribution and storage of gas and understand the structural characteristics of tectonic coal for guiding the production safety of coal mines.On the basis of systematic study on strata,structural characteristics and development law of Qinglong Coal Mine,coal samples of different types and deformation degrees of 16,17,18 coal seams in main coal seams were collected.The pore characteristics and gas adsorption performance of coal samples were studied by mercury intrusion test,macroscopic sample description and microscopic observation under microscope.Combined with the gas distribution data of 16,17,18 coal seams,the influence of various factors on the gas occurrence law of Qinglong Mine was discussed from the aspects of coal seam thickness,roof mudstone thickness,coal seam depth and structural index.And achieved the following main results and understanding :1.Structural coal is widely developed in Qinglong coal mine,from broken coal to mylonite coal,coal deformation is gradually intense.Microscopic characteristics of the original structure gradually reduced or invisible,coal pores gradually increased,cracks gradually dense.With the increase of deformation degree,the pore structure of different tectonic coal changes obviously.The brittle deformed coal is mainly composed of micropores and transition pores,while the large pores and mesopores are rarely developed.The scale coal,crumpled coal and mylonite with ductile deformation are mainly developed with mesopores and macropores,and most of them are open and fine neck bottle holes,with few micropores and transition holes.2.The main coal seam 16,17,18 coal seam gas composition is nitrogen-methane zone,methane zone category.The coal seams are deeply buried in the northeast and southwest,mostly belonging to medium and high gas content areas.Qinglong coal mine16,17,18 coal seam through the mine statistical method to predict the gas emission is more in line with the application conditions,16 coal : q=0.0137H-0.0598,17 coal : q=0.0304H-3.1791,18 coal : q=0.0112H-0.6436,linear fitting better reflects the absolute gas emission and the relationship between the main coal seam buried depth,that is,with the increase of buried depth,absolute gas emission is also relatively increased.3.The buried depth of coal seam,lithology of roof and floor,thickness of coal seam and structural complexity are the main factors affecting the distribution of gas occurrence in the study area.Through analysis,there is basically a linear relationship between coal gas content and various factors.The results of grey correlation analysis show the influence degree of each influencing factor on gas content.The weight of each influencing factor is analyzed by grey correlation method.The correlation between each influencing factor and gas content in 16 coal seam is T>H ? S>D;17 coal seam correlation size :T>H>D ? S;The correlation degree of 18 coal seam is T>D ? H>S.The results of multiple linear regression also show that each factor is the main influencing factor of coal seam gas content and shows high correlation.