Adaptability analysis on co-exploitation based on dual-tube technology in coal-bearing gas

The development of coal-gas mixing technology is the focus of the existing non-conventional energy develop-ment. Through the analysis of the geological characteristics of coal gas and the mechanism of coal production,the cor-rect production technology and reasonable down-hole string are the prerequisites for realizing the coal gas gathering op-eration. In this paper,through the analysis of the double-pipe mixing technology,a suitable coal-gas blending process is designed for the coal-gas blending environment of the upper part of the coal seam and the lower part of the high-pres-sure gas-producing layer. The double-column coal mining system is constructed,and the selection model of the size of the column is established. Then,it is determined whether the pipe string satisfies the continuous production operation to determine the double-applicability of the operation. The results show that the dual-tube column mining technology can be used for the coal-gas gathering and production operation. Based on the geological conditions,the relationship between the maximum water production and the maximum gas production in the coal seam under different wellhead conditions is given. In-depth coal gas gathering technology provides a certain reference.