Study On Coal Accumulation Characteristics Of Coal Bearing Strata In Buriqi Minefield,Dongsheng Coalfield,Inner Mongolia

Buriqi minefield is located in the deep region of the southwest of Dongshengcoalfield.The overall structure of minefield is a monocline structure that moves toward the north-south and westward.The formation of the formation is gentle,the dip angle is generally 0² degrees,and the structural complexity is a simple type.The coal-bearing stratum is the middle and lower middle Yan'an formation(J_1-2ya)of Jurassic,and the 13 layers of the coal seam can be found,including 5 layers of coal seam,3 layers of coal seam?2-2,3-1,4-1 coal seam?,the secondary coal seam 2layer?upper 5-2,6-2 coal seam?.Coal quality is very low ash,low to medium sulfur,high calorific value of non sticky coal,weak sticky coal.Based on the analysis methods of petrology,sedimentology,tectonic geology,coalfield geology and sedimentary basin analysis,this paper uses the analysis methods of petrology,sedimentology,tectonic geology,coalfield geology and sedimentary basin analysis,and summarizes and extracts the achievements of previous research through the synthesis and analysis of drilling data,logging data,seismic data and coal quality data.According to the sedimentary cycle of Yan'an formation,the combination characteristics of rock and coal seam and physical properties,the formation is divided into three rock sections.According to the sequence stratigraphic analysis,the characteristics of coal seam development and the difference of coal bearing property,the sedimentary environment of coal bearing strata is divided into five genetic units.According to the sedimentary history of Yan'an formation can be divided into initial filling,overlap period of expansion and recession in three phases of sedimentary evolution.The control role of coal controlling factors such as paleoclimate,paleostructure and intensity of organic sedimentation on coal seam is analyzed.According to the characteristics of sedimentary environment,the main coal accumulation characteristics of Yan'an formation in coal bearing strata can be divided into three types.