Test Study on the Multi-Pulse Loading Fracturing Technology for Development of Shallow CBM
In China, the coal gas formation is characterized as low permeability, low pressure and low water saturation. The coal bed methane (CBM) has strong adsorption and is difficult to develop. Hydraulic fracture is currently the main measure to improve its permeability, drain the liquid and lower the pressure, which promotes desorption of CBM. But it is not efficient. Based on the principle of high energy gas fracturing (HEGF) and the study of new methods, we proposed the test application of the multi-pulse loading fracturing technology for development of shallow CBM. The mechanism of the technology is that it generates high-temperature and high-pressure gas in the target coal bed to produce a long multi-fracture system with effects of multi-pulse loading. It can also produce strong impulse oscillation acting on formation matrix to loose formation pressure, improve the pore connectivity and permeability of coal bed, which promotes pressure drawdown and desorption of CBM. Thus, the goal of increasing the yield of CBM wells is achieved. This paper focuses on the research ideas, mechanism, process design and feasibility. We carried out analysis combined with field test applications. The study provides a new direction to explore new technologies for China’s CBM development.
Qunjie Xu, Honghua Ge and Junxi Zhang
J. J. Wu et al., "Test Study on the Multi-Pulse Loading Fracturing Technology for Development of Shallow CBM", Advanced Materials Research, Vols. 361-363, pp. 212-216, 2012