Optimization of Staged Fracturing Techniques for Deep Coalbed Methane Development in Jidong Oilfield

The deep coalbed methane (CBM) reservoirs in Jidong Oilfield exhibit promising development potential. However, the development faces unique challenges such as poor physical properties and rock mechanical properties, including low porosity and permeability, low Young’s modulus, high Poisson’s ratio, and difficulty in fracture propagation. Since 2022, an innovative staged fracturing methodology incorporating high-rate pumping, high-intensity stimulation, complex fracture network generation, and multi-scale proppant placement has been successfully implemented in horizontal wells to enhance stimulation efficiency. This study presents a comprehensive evaluation of fracturing performance based on geological background, extensive field trials in Jidong Oilfield, and analyses of engineering and production characteristics. Key operational parameters—including proppant concentration, injection rate, treating pressure, fracture half-length, and stimulated reservoir volume (SRV)—are analyzed to assess their impact on gas production. The effects of different fracturing processes and their influencing factors are also discussed. The results from experimental studies and field practices reveal that there is an optimal proppant concentration for maximizing productivity, and with higher injection rates and fluid volumes contributing to improved well production performance. However, elevated breakdown and extension pressures are also observed to inhibit fracture growth. Furthermore, innovative fracturing techniques, such as pad-free high-intensity water-controlled volume fracturing and subdivided limited-entry high-intensity volume fracturing, are tested and analyzed for their effectiveness after fracturing. Based on the results, this paper proposes optimized fracturing strategies, emphasizing geomechanics-integrated design to enhance reservoir stimulation. The study provides critical technical insights to support the efficient and sustainable development of deep CBM resources in similar geological settings.