Theoretical and technological concepts of synergistic coal and natural gas extraction

There are a large number of overlapping coal and natural gas resources in China, and due to the requirement of resource extraction efficiency, a large number of overlapping coal and natural gas resources need to be extracted synchronously in the same time and space, and the traditional coal and natural gas extraction theories and technologies are difficult to meet the technical problems arising from coordinated extraction, and the process of coordinated extraction of coal and natural gas has been seriously constrained. Based on this, a scientific definition of coal and natural gas synergistic mining is made based on the overlapping coal and natural gas resources in China, and the existing coal and natural gas mining technologies and related theories are summarised. We have established the near-field rock mechanics theory of natural gas wells, the coupled damage theory of natural gas near-field surrounding rock, the coupled damage theory of “surrounding rock-cement ring-casing”, and the coupled damage theory of vertical surrounding rock of coal and natural gas synergistic mining, which reveal the coupled damage mechanism of surrounding rock of coal and natural gas synergistic mining, and provide a theoretical basis for the construction of the technology system of coal and natural gas. It provides a theoretical basis for the construction of coal and natural gas technology system. The three technologies of “Coal and Natural Gas Cooperative Mining Technology”, “Coal Mining through Abandoned Wells Technology” and “Natural Gas Near-Field Small Coal Pillar Retention Technology” are proposed, as well as the “Coal and Natural Gas Cooperative Mining Zoning Planning Technology”. Three major systems, namely, “Coal and Natural Gas Cooperative Mining Zoning Planning System”, “Transparent Geological and Production Information Dynamic Monitoring System” and “Coal and Natural Gas Cooperative Zone Safety Monitoring and Evaluation System”, provide technical support for coal and natural gas cooperative mining, and improve the safety of coal and natural gas production. This system provides technical support for the synergistic mining of coal and natural gas and improves the mining efficiency of coal and natural gas resources. On this basis, the theoretical and technological system of coal and natural gas synergistic mining is constructed, the future research focus of coal and natural gas synergistic mining is clarified, and the technological path and research direction for the safe, green and high-efficiency synergistic mining of coal and natural gas resources in China are proposed.