Background The founding of China United Coalbed Methane Corp., Ltd. in 1996 signals the entry of the coalbed methane (CBM) exploitation in China into the industrial development stage. A systematic summary of the development history, key technologies, and future trends of China's CBM industry is of great significance for gaining a deeper understanding of CBM exploitation patterns and promoting the high-quality development of the CBM industry. Based on a systematic investigation of relevant domestic and international literature, this study presents a comprehensive analysis of the industrial development process of CBM exploitation in China, including development stages, technological evolution, and future trends.

Progress  Since 1996, CBM exploitation in China has generally experienced three stages: (1) the development of industrial systems and the cultivation of commercial demonstrations, (2) commercial operation and large-scale development, and (3) breakthroughs in deep CBM exploitation coupled with resource type expansion. Across these stages, CBM exploitation in China has primarily evolved from technical introduction to independent innovation, from experimental demonstration to commercial operation, and from shallow to deep formations. Focusing on the complex geological conditions of coal reservoirs, China has gradually developed a technical system incorporating geological understanding, exploration evaluation, exploitation engineering, drainage and productivity control, and the combination of surface gathering and transportation with digital and intelligent operation. This system has promoted the evolution of CBM exploitation from single-technique applications to multi-technique collaborative optimization. The geological understanding of CBM has expanded from mine gas to various deep CBM systems. The CBM exploration evaluation has evolved from parametric well-based, static resource evaluation to sweet spot evaluation and integrated geology-engineering evaluation. Engineering technologies for CBM exploitation have advanced from vertical well fracturing to the fracturing of multi-branch horizontal wells, the multistage fracturing of horizontal wells, and the reservoir stimulation of deep coal seams using long horizontal sections. CBM drainage technology has shifted from empirical management to system-based, intelligent, and whole-process dynamic control. Surface systems have developed from dispersed single-well-oriented ancillary facilities to low-cost gathering and transportation, modular construction, and digital and intelligent operation systems. China has developed a complete CBM exploration technical system that is based on geology-engineering integration and sweet spot prediction, incorporates key technologies including the multistage fracturing of horizontal wells and volume stimulation, ensures efficient CBM production through intelligent drainage and multi-layer collaborative productivity control, and is supported by low-pressure gathering and transportation, as well as digital and intelligent operation.

Prospects  Regarding the trends in China's CBM industry, CBM resources will expand toward deep formations and multiple types, the technical system will become more integrated and intelligent through upgrading, and the industrial pattern will evolve toward low costs and collaboration. The CBM industry will continue to deepen in five major fields: production stabilization and increase of mature blocks, deep CBM exploitation, three-dimensional exploitation of multiple thin coal seams, integrated exploitation of coal-measure natural gas, and roof fracturing for structurally complex areas. Essentially, the 30-year industrial development of CBM exploitation in China represents a process characterized by the continuous deepening of resource understanding, the ongoing evolution of key technologies, and the gradual maturation of the industrial system. The 30-year retrospective can provide theoretical and practical references for the high-quality development of China's natural gas industry.