Deformation characteristics of coal measures and gas occurrence law of coal mines in North China

Gas is not only one of the important disaster-causing factors in coal mines, but also an important clean energy. Understanding the deformation characteristics of coal measures and the occurrence of gas is the basis for coal mine gas disaster prevention and coalbed methane development. Taking the North China coal measures as the research object, taking the tectonic evolution and control as the main line, using the theory of plate tectonics, tectonic evolution and step by step control of gas-occurring structures, the deformation characteristics of the North China coal-measures and the law of coal mine gas occurrence were systematically studied. The research results show that the North China Plate is at the center of the interaction and junction of the three major tectonic domains and controls the formation and evolution of the coal measures. The interaction between the North China Plate and the peripheral plates restricted the formation, occurrence and deformation of the coal-measure strata, controlled the formation and distribution of tectonic coal, thereby controlling the generation, migration and preservation of coal mine gas; The deformation strength of the North China coal measures has a tendency to weaken from the edge of the plate to the interior of the plate, from the compression orogenic belt to the far orogenic belt; The formation and distribution of coal measures are in good agreement with the deformation of coal measures in the process of tectonic evolution. The development degree of tectonic coal also has a tendency to weaken from the edge of the plate to the interior of the plate and from the nearby compression orogenic belt to the far the orogenic belt. The tectonic coal is not developed in the extending tectonic zones, but the large detachment structures formed under the extensional background is easy to form layered tectonic coal; The gas distribution in North China coal mines has obvious regional characteristics, which can be divided into 7 high gas outburst areas and 6 low gas areas, further divided into 15 high (abrupt) gas belts and 13 low gas belts. The research results have important guiding significance for targeted gas control and coalbed methane development.