Exploration and Practice of Fracturing Technology for Deep Coal Gas Reservoir in Qaidam Basin

Abstract In recent years, the deep coal seam reservoirs in the Jurassic System of North Edge area in Qaidam Basin have emerged as a new field for natural gas exploration. By comparing the geological characteristics and exploration and development technologies of deep coal seam gas both domestically and internationally, three major challenges in fracturing and reservoir stimulation were identified: the complex expansion of coal seam fractures, the strong plasticity of coal, and the instability of coal body structure. Based on a comprehensive evaluation of coal seam structure and cleavage development oriented by the problem, three fracturing schemes were designed and tested in three wells, achieving satisfactory application effects. This has confirmed the gas content of the Jurassic coal seam strata in Qaidam Basin and unveiled a new field for natural gas exploration in the region