Abstract: There are abundant high-rank coalbed methane resources in China, and the high-efficiency development is of great energy, security,and ecological significances. Taking the development practice of high-rank coalbed methane in southern Qinshui Basin as an example, five main problems and challenges in the early development process are systematically analyzed: (1) A lack of advanced theory for the development of high-rank coalbed methane; (2) Low accuracy of favorable area selection; (3) Insufficient adaptability of reservoir reconstruction technology; (4) Low efficiency and poor benefit of drainage-production control regime; (5) “Three difficulties” and “three highs” of the gathering and transportation system. PetroChina Huabei Oilfield Company has adhered to problem-oriented and target-oriented approach and integrated indoor research and field practice, forming a new concept and key technologies for the high-efficiency development of high-rank coalbed methane, which include a drainage development concept, and a development mode of single-lateral horizontal well casing + multistage fracturing; The technology for optimal selection of high-yield favorable areas has been researched, achieving the transformation from large-area overall production capacity construction to precise construction mode in the favorable area; The fracturing and reservoir stimulation technology for coalbed methane has been improved and updated, which supports to form multi-level effective fracture network; The optimal,fast and high-efficiency drainage-production control technology has been innovated; The low-pressure ring surface gathering and transportation technology has been developed to achieve high benefits. The field practice shows that the success rate of new constructed production capacity has increased from 37% to higher than 84%, the average daily gas production of a single well has increased by 1.6 times, the time reaching target production has decreased by more than 20%, and the cost of surface construction investment for new projects has reduced by 20%. In addition, the coalbed methane production breakthrough has been achieved in all types of reservoirs in Qinshui Basin, with an annual production capacity of 21×10⁸ m³ in coalbed methane field in the southern Qinshui Basin, which is it the largest coalbed methane field in China, greatly boosting the strategic development of coalbed methane.

Key words: Qinshui Basin, high-rank coalbed methane, high-efficiency development, drainage development concept, optimal selection of capacity construction area, fracturing reconstruction, drainage-production control, low-pressure ring gathering and transportation