Hydraulic Fracturing Transformation of Coalbed Methane in Well Yuji-Di 1, South North China Basin

Coalbed methane (CBM) development often requires reservoir stimulation to enhance permeability and gas recovery. This study presents a high-level overview of the hydraulic fracturing transformation techniques applied in Well Yuji-Di 1, located in the southern North China Basin. Two target intervals—a Cambrian dolomite and a Permian coal-bearing formation—were stimulated using tailored hydraulic fracturing approaches. A pulse-acid fracturing technique was employed in the Cambrian carbonate, while a combination of intermittent and indirect fracturing was applied in the coal-bearing Permian Shanxi Formation. The fracturing operations and subsequent production tests are described, and the results demonstrate the feasibility of these techniques, with the coal-bearing interval yielding a short-term gas flow (peaking at approximately 318 m3/h). A comparison with domestic and international CBM fracturing cases is discussed to contextualize the employed methods. The paper also forecasts the application prospects of these stimulation techniques for broader CBM development. The outcomes provide new insight into advanced fracturing strategies for low-permeability coal-measure reservoirs, demonstrating a novel stimulation approach that could significantly improve CBM extraction in similar geological settings.