Study on fracturing fluid optimization for rockburst prevention by hydraulic fracturing in thick and hard coal mine roofs and the mechanism of fracture propagation control

The thick and hard roofs in coal mines are among the major factors inducing rockbursts, and hydraulic fracturing is a commonly used and effective method for rockburst prevention and pressure relief. However, in current coal mine hydraulic fracturing operations, the selection of fracturing fluids often lacks scientific basis and is highly arbitrary. Therefore, taking the hydraulic fracturing of the roof overburden at the 11223 working face of Shaanxi Huadian Yuheng Coal and Electricity Co., Ltd.as the research object, fracturing fluid optimization was conducted. Through physical property tests, true triaxial fracturing tests, and numerical simulations, the mechanisms by which fracturing fluid type and viscosity regulate fracture propagation were systematically investigated. The results show that temperature and pressure conditions significantly affect the physical properties of guar gum-based fracturing fluids. In comparison, water exhibited superior performance in terms of fracture propagation continuity and fracture activation extent, together with favorable field applicability. Based on these results, water was ultimately selected as the fracturing fluid for the target working face, and an alternative scheme for specific operating conditions was proposed. A small-scale field engineering test further verified the fracturing effectiveness and applicability of the selected fracturing fluid.