Project Title:Key Technologies for Economical Development of Deep Coalbed Methane and Their Large-Scale Application

Participating Enterprise: China United Coalbed Methane National Engineering Research Center Co., Ltd.

Award Received: Scientific and Technological Progress Award - Gold Award

Achievement Level: International Advanced Level

Project Number: ECF-2025-SET-1007

Main Participants: Wang Chengwang, Wu Jianjun, Wang Yuan, Liu Chuanqing, Han Jinliang, Zhu Weiping, Zhen Huaibin, Yuan Pu, Chen Gaojie, Feng Yanqing, Ge Tengze, Wang Wei, He Pengbo, He Yanxiang, Liu Danlu

Expert Review Comments:
International Advanced Level. This project addresses the global challenge of developing coalbed methane (CBM) resources deeper than 2,000 meters. It systematically reveals the accumulation and enrichment mechanisms of deep CBM, innovatively establishes an integrated geological–engineering “dual-sweet-spot” evaluation and development technology system, and forms the core processes of efficient drilling and completion, as well as the “Black Gold Target” dense fracture network fracturing technology. These breakthroughs have significantly improved single-well productivity and overall development efficiency.

The project has overcome major bottlenecks such as long horizontal drilling sections, complex fracturing operations, and low permeability in deep CBM reservoirs, achieving large-scale demonstration applications with daily gas production exceeding 10 million cubic meters and cumulative proven reserves of over 100 billion cubic meters. The results have been successfully promoted in Liaohe, Changqing, and Jidong oilfields, driving China’s deep CBM industry from exploration to large-scale development. This provides key technological support for sustained unconventional gas reserve and production growth, with remarkable economic and social benefits and broad prospects for industrial application.

Main Innovations

Innovation 1: Revealed for the first time the enrichment and accumulation mechanisms of deep CBM, supporting major strategic breakthroughs in China’s deep CBM exploration.

Innovation 2: Integrated and innovatively developed geological evaluation and development design technologies, supporting the establishment of China’s first one-million-ton oil-equivalent deep CBM field.

Innovation 3: Established efficient drilling and completion technologies for deep, complex coal seams, filling the domestic gap in rapid drilling and completion for deep formations.

Innovation 4: Created the “Black Gold Target” dense fracture network fracturing technology, promoting deep CBM as a new strategic replacement domain for China’s natural gas development.

Main Uses and Technical Principles

A replicable and promotable series of technologies for efficient deep CBM development has been established. Based on an integrated framework of “innovation–application–benefit,” the project has driven China’s deep CBM from resources to reserves and from reserves to production, initiating a revolution in the national CBM industry. Deep CBM has thus become a new strategic replacement field and growth point for natural gas.

Ensuring National Energy Security: As of the end of 2024, the Daji Deep CBM Field had accumulated 985 million cubic meters of gas production, ensuring stable gas supply for the Daning–Jixian region and surrounding areas, securing winter heating for residents.

Contribution to National Energy Transition and Emissions Reduction: Cumulative additional deep CBM production reached 104.818 billion cubic meters, equivalent to saving 1.3 million tons of standard coal, reducing CO₂ emissions by 2.12 million tons, SO₂ emissions by 97,900 tons, and particulate emissions by 798,000 tons.

Technical Applications

(1) Deep CBM Enrichment and Accumulation Theory, Reservoir Characterization, and “Geological–Engineering Dual-Sweet-Spot” Evaluation Technology
These technologies supported major breakthroughs in deep CBM exploration and development in the Daning–Jixian Block, cumulatively submitting 112.162 billion cubic meters of proven reserves. They supported China’s first deep CBM pilot test and the formulation and implementation of a 1 billion m³/a development plan, driving a national CBM industry revolution and positioning deep CBM as a new strategic domain and growth driver for natural gas. The technology has also guided the implementation of evaluation wells in Liaohe, Changqing, and Jidong oilfields.

(2) Efficient Drilling and Completion Technology for Complex Deep Coal Seams
The project developed advanced fast drilling and completion technologies suitable for deep, complex coal formations, supporting platform-based, multi-well cluster development in the eastern Ordos Basin.

• 135 wells completed with an average horizontal section length of 1,230 m, an average encounter rate of 98.04%, and an average drilling cycle of 37.82 days, reducing drilling time by 47%.

• These technologies have supported breakthroughs in deep coal seam development in Changqing, Dongying, and Liaohe oilfields, providing strong technical support for pilot deep CBM development in the Ordos Basin.

(3) Large-Scale Precision Fracturing Technology
The “Black Gold Target” dense fracture network fracturing technology has been successfully applied in 180 CBM and coal-gas wells across China United CBM, Changqing, Liaohe, and Jidong oilfields.

• Horizontal wells achieved daily gas production exceeding 160,000 m³/day, and vertical wells exceeded 67,000 m³/day, with total daily gas production surpassing 10 million m³/day.

(4) Integrated Full Life-Cycle Production Technology for Deep CBM
This technology supports the development of horizontal wells deeper than 2,000 m in the eastern Ordos Basin, providing integrated production solutions.

• It has been applied to 84 wells in self-operated blocks, achieving normal production with liquid rates decreasing from 500 m³/day to 5 m³/day and gas rates decreasing from 100,000 m³/day to 10,000 m³/day.