2019年，中石油煤层气公司通过对位于鄂尔多斯盆地东缘大吉区块埋藏深度大于2 000 m的深部8号煤层，实施了储层改造适应性技术攻关，取得深部煤层气实现效益开发的颠覆性突破，有力地推动全国加快深部煤层气勘探开发进程，由此带动中国煤层气产业进入发展史上最佳时期。5 a多来的实践证明，储层改造技术进步和迭代升级是推动深部煤层气效益开发和增储上产的关键技术路径。针对深部煤层气实现效益开发以来储层改造技术所经历的阶段与迭代历程，系统梳理出体积酸化、大规模体积、超大规模体积、地质工程一体化精益等4种压裂迭代技术，并对其分别进行了实施效果评价，也对相应压裂液体系性能进行了简要分析。从追求基质改造到大规模缝网形成，从追求极限改造体积到井网缝网精益弥合，逐步上升到多种储层改造的新技术和先进理念，将基于地质特征的精细化压裂设计在实践中应用，取得显著效果；指出深部煤储层改造仍面临5方面问题挑战和优化空间，包括：超大规模压裂水资源消耗及返排液处理难度大、智能化压裂模式攻关、协同压裂方法尚不成熟、深部中低阶煤层压裂技术体系亟待建立、压裂液功能仍不完善等。针对存在的问题和挑战，提出六大发展方向：① 深化推动减水压裂；② 开展鱼骨水平井+基质酸化大规模减水增产技术攻关；③ 加大实现人工智能技术在智能化压裂和压后评估中的应用突破；④ 开展基于井组缝网弥合协同压裂工艺研发和应用；⑤ 加强深部中低阶煤储层改造技术体系研发和实践；⑥ 研发进一步实现降本增效和提高深部煤层气采收率的新压裂材料。

In 2019, PetroChina’s Coalbed Methane (CBM) Company achieved a groundbreaking breakthrough in the profitable development of deep coalbed methane reservoirs. This was accomplished through technological innovation in reservoir stimulation for the deeply buried No. 8 coal seam in the Daji block, located on the eastern margin of the Ordos Basin, with burial depths exceeding 2 000 m. This success significantly accelerated the exploration and development of deep CBM across the country, marking the beginning of the most prosperous period in the history of China’s CBM industry. Over the past five years, practical experience has demonstrated that advancements and iterative upgrades in reservoir stimulation technologies are key pathways for driving the profitable development of deep CBM and achieving reserve growth and production increases. This paper systematically reviews the stages and iterative progress of reservoir stimulation technologies since the profitable development of deep CBM was realized. Four fracturing technologies—Volumetric acidizing, large-scale volumetric fracturing, ultra-large-scale volumetric fracturing, and integrated geological-engineering precision fracturing—are examined in terms of their implementation and effectiveness. Additionally, a brief analysis of the performance of corresponding fracturing fluid systems is provided.The technological progression evolved from pursuing matrix stimulation to achieving large-scale fracture networks, from maximizing stimulation volume to optimizing well-to-fracture network integration, and eventually to adopting innovative technologies and advanced concepts for reservoir stimulation. Practical application of finely tailored fracturing designs based on geological characteristics has yielded remarkable results.However, the paper identifies five key challenges and areas for improvement in deep coal reservoir stimulation: High water consumption and difficulties in managing flowback fluids during ultra-large-scale fracturing; The need for breakthroughs in intelligent fracturing technologies; Immaturity of collaborative fracturing methods; The urgent requirement to establish fracturing technology systems for deep, medium-to-low-rank coal seams; Incomplete functionality of fracturing fluids.To address these challenges, six development directions are proposed:① Advancing water-reducing fracturing techniques; ② Conducting research on fishbone horizontal wells combined with matrix acidizing for large-scale water-reduction and production enhancement; ③ Expanding the application of artificial intelligence in intelligent fracturing and post-fracturing evaluation; ④ Developing and implementing collaborative fracturing techniques to optimize well-to-fracture network integration; ⑤ Strengthening research and development and application of stimulation technologies for deep, medium-to-low-rank coal reservoirs; ⑥ Innovating new fracturing materials to further reduce costs, improve efficiency, and enhance recovery rates for deep CBM.