253 / 2018-06-27 11:33:45

Study on the mechanism and influence range of carbon dioxide phase-change fracturing

Liquids CO2 phase-change fracturing; Mechanism of the fracturing; Radius of the influence；Blasting parameters;

矿井瓦斯与煤与瓦斯突出 > 煤矿瓦斯

Based on rock mechanics and gas explosion theory, this paper systematically studies the mechanism of liquid carbon dioxide phase-change fracturing, introduces the formula for fracture length and number of cracks in phase-change fracturing. The fracturing parameters were measured in the laboratory by using a pressure sensor, and the actual fracturing pressure was determined and the cracking action time was about 120 seconds. At the same time, the fracturing wave diagram of the fracturing was obtained. It was found that the fracturing was different from the traditional blasting, and no detonation wave was generated, which verified the accuracy of the proposed mechanism. Based on the theory and experimental results, it was determined that the carbon dioxide fracture radius is 4.95m. The filed test of the fracturing range was carried out in the Yao coal mine, Xin Zhou, and the damage of the observation hole under different distances was investigated through the borehole viewer, and the influence radius of the cracker was determined to be between 4m and 6m, its consistent with theoretical values. The results of the dissertation lay a foundation for the study of the mechanism of carbon dioxide phase-change fracturing, and the study of the radius of influence of fractures provides a reference for the promotion and application of this technology.