Coal facies distribution features of No.2 seam in Qinyuan Block and gas content control

In order to reveal the contral role of the coal facies to the gas content of the coal reservoir, based on the conventional logging curve, taking No.2 seam i n Qinyuan Block at the central part of Qingshui Basin as the study object, with a study on the logging curve and the coal industrial components, the coal industrial comp onents and lithotype, the lithotype and macro lithotypic type as well as the relationship between the macro lithotypic type and coal facies, the combination of the princip al component analysis, multiple regression analysis, Logistic regression and other methods was applied to establish the logging interpretation model of the coal facies. Based on the coal facies features analysis on the single well and linked wells, the distribution features of the coal facies space in No. 2 seam of the study block were re covered and the relevant relationship between the coal facies and the coal reservoir gas content was revealed. The results showed that the gas content of the coal rese rvoir in the deep water covered forest-swamp distribution area was highest and the main distribution was located in the southeast of the study block. The gas content of the coal reservoir in the dry forest swamp facies distribution area was lowest and the main distribution was located in the northwest of the study block. The gas content of the coal reservoir in the water covered and wet forest-swamp distribution area was between above two gas contents and the main distribution was located in the cent ral and east of the study block.