Development conditions of multiple coal seam resources and damage characteristics of co-mining reservoirs in Songhe Mine Field

In order to reduce reservoir damage during the drainage process of CBM wells, by analyzing the resource development conditions and CBM well drainage data of Songhe Mine Field, the characteristics of reservoir damage caused by unreasonable drainage control in each stage were summarized, and the reasonable mining technology countermeasures of different mining stage were put forward. The results show that the abundance of CBM resources in Songhe Mine Field reaches 2.09×10⁸ m³/km², and the development conditions of CBM resources are good; in the process of multiple coal seam co-mining in Songhe Mine Field, the unreasonable drainage and control technology has a great influence on the gas production of CBM wells; in the initial stage, the main damage is velocity sensitivity, and in the middle stage, the main damage is the gas lock and stress closure; during the period of wells workover operation and stop drainage, the possibility of damage to coal seam caused by gas lock effect and stress closure increases. Rational drainage control can effectively reduce the reservoir damage and increase the gas production of CBM wells.