Research progress on gas resource evaluation, extraction and utilization in abandoned coal mines in China

China has a large number of abandoned coal mines, many of which are highly gassy mines. Considering the pros and cons of gas occurrence in abandoned coal mine and its timeliness characteristics, it is considered that there is an urgent need to develop and utilize gas resources in abandoned coal mines. This paper starts with two key steps of gas resource development and utilization in abandoned coal mine: gas resource evaluation, gas extraction and utilization in abandoned coal mine, to systematically summarize and analyze the current research progress in gas occurrence scope, gas source and gas occurrence state, gas resource estimation model, gas enrichment distribution law and optimization of extraction well distribution. The existing problems in the evaluation, extraction and utilization of gas resources in abandoned coal mines are obtained, and the next research direction is pointed out.