Optimization and effectiveness assessment of hydraulic fracturing target layers using multi-source information fusion

With the rapid increase in mining depth, geological hazards such as large deformation of surrounding rock and rock burst have become increasingly severe. As a result, hydraulic fracturing has become an essential technique for pressure relief in surrounding rock. However, the complexity of underground geological conditions renders the selection of fracturing horizons critical, as it directly determines the actual effectiveness of hydraulic fracturing operations. To address this, this study introduces the pressure arch theory to reveal the dynamic evolution characteristics of the overlying strata under mining influence, and constructs a comprehensive suitability evaluation system comprising six indicators: depth suitability, strength suitability, thickness suitability, in-situ stress concentration degree, fractability index, and engineering accessibility. Based on the key stratum theory, a comprehensive evaluation method combining the Analytic Hierarchy Process (AHP) and the entropy weight method is employed to determine the weight of each indicator, thereby establishing a multi-source information fusion model for optimal horizon selection. A hydraulic fracturing horizon optimization method based on multi-source information fusion and dynamic intelligent decision-making is proposed. Furthermore, based on the composite beam theory, the theoretical solution for the optimal fracture location within a layer is derived, clarifying the mechanical mechanism governed by the elastic modulus ratio of the upper and lower layers. The results indicate that the proposed horizon optimization method can effectively integrate multi-source information and accurately identify the optimal fracturing target horizon and location. During actual fracturing operations, the total energy of microseismic events was decreased significantly, with a 28.2% reduction in the number of high-energy events and a 34.6% decrease in average energy. The maximum working resistance of the support was reduced by 9.28%, and the average weighting interval was shortened by 28.75%, effectively reducing the frequency and intensity of hazards. The research findings provide scientific support for the optimal selection of hydraulic fracturing horizons and the prevention and control of rock burst in deep mining.