我国深部煤层气实现了单井日产万方及规模性商业开发的重大突破，彰显出深部煤层气巨大的资源潜力，成为我国天然气增产的重要补充。然而，受“高温、高压、高地应力”影响下的深部煤层气藏地质特征与开发特征均显著区别于浅埋藏条件下的煤层气藏。目前在深部煤层气藏的成藏演化、富集模式、改造机制及开发效果评价等一些关键性基础问题上仍缺乏针对性和系统性研究。以华北地区石炭−二叠系深部煤层气的勘探开发资料为基础，重点探讨了深部煤层气赋存相态及其演化特征，揭示了深部煤层含气性与埋深的耦合关系、赋存相态识别方法及其演化模式。展望了当前深部煤层气从地质勘探到开发评价存在的主要科学问题以及未来的发展趋势。结果显示：基于保压取心、绳索取心的测试资料和煤层气井生产曲线特征是识别深部煤层气体赋存相态的3类有效手段，其中联合绳索取心的含气性测试和等温吸附试验是定量评估深部煤层气体相态准确且简便的有效方法。煤层含气性和气体赋存相态受内因（煤阶、物质组成、孔裂隙系统等）和外因（温度、压力、保存条件等）协同控制。埋深大是深部煤层富集游离气的基础，而保存条件好是深部煤层富集游离气的关键。考虑我国华北地区深部石炭−二叠系中、高煤阶煤经历了复杂的埋藏演化过程，提出了考虑温度、压力及构造改造强度的煤层含气赋存相态的4类演化模式，分别为深埋深藏−构造改造程度强、深埋深藏−构造改造程度弱、深埋浅藏−构造改造程度强和深埋浅藏−构造改造程度弱。煤层气藏经历的差异构造演化是导致不同区块甚至同一区块深部煤层含气性特征具有显著区别的重要因素。深埋深藏—构造改造弱的演化模式有利于游离气的富集，是深部煤层气勘探开发的有利区带。深部煤层气兼具“常规”和“非常规”2种属性，当前对深部煤层气的成藏、富集、改造及产出等多方面的基础性科学问题仍然认识薄弱，应重点解决深部煤层气成藏演化与产出效应的关键性基础问题，以期助推我国实现煤层气产业的新突破。

Deep coalbed methane has achieved a significant breakthrough in daily production of a single well and large-scale commercial development, demonstrating the enormous resource potential. The deep coalbed methane became an important supplement to China’s natural gas production. However, the geological and development characteristics of deep coalbed methane under the influence of high temperature, high pressure, and high crustal stress are significantly different from those under shallow burial conditions. At present, there is still a lack of systematic research on key fundamental issues such as the evolution of deep coalbed methane reservoirs, enrichment modes, transformation mechanisms, and evaluation of development effects. Based on the exploration and development data of Carboniferous-Permian deep coalbed methane in the North China, this study focuses on exploring the occurrence and evolution characteristics of deep coalbed methane, revealing the coupling relationship between the gas content and burial depth, identification methods for occurrence phase states, and their evolutionary patterns. The main scientific issues and future development trends of deep coalbed methane from geological exploration to development evaluation were discussed in order to promote new breakthroughs in coalbed methane industry. The results showed that: The gas content testing based on pressure-preserved coring and wire-line coring and characteristics of production curve are important means to identify the phase state of deep CBM. Among them, the isothermal adsorption experiment combined with wire-line coring is effective methods. The gas content and occurrence state of deep coal seams are jointly controlled by internal factors (such as coal rank, maceral and pore system) and external factors (such as temperature, pressure and preservation conditions). The burial depth is the basis for the enrichment of free gas in deep coal seams, and good preservation conditions are the key to the enrichment of free gas in deep coal seams. The middle-high rank coal in the Carboniferous-Permian in North China has undergone a complex burial evolution process. Four types of evolution models for the occurrence of coalbed methane, considering temperature, pressure, and tectonic activities, have been proposed. The differential structural evolution experienced by coalbed methane reservoirs is an important factor that leads to significant differences in the gas bearing characteristics of deep coal seams in different blocks or even within the same block. The evolution pattern of deep burial and weak structural transformation intensity is conducive to the enrichment of free gas and is a favorable zone for deep coalbed methane exploration and development. Deep coalbed methane has both “conventional” and “unconventional” attributes. Currently, there is still a weak understanding of the fundamental scientific issues related to the accumulation, enrichment, transformation, and development of deep coalbed methane. We should focus on solving the key fundamental problems of the evolution and developed effects of deep coalbed methane, in order to promote new breakthroughs in China's coalbed methane industry.