Experimental Investigation of Fracture Behavior in Coal-Seam Hard Roofs Using Different Fracturing Fluids
Source abstract
Abstract
In fully mechanized mining faces with large mining heights, thick and hard roofs present significant challenges, including extensive overhang areas, difficult roof control, and frequent roof failures. Hydraulic fracturing is a crucial technique for roof weakening and mine pressure control, and the performance of fracturing fluids directly determines the effectiveness of pressure relief. This study conducted true triaxial hydraulic fracturing experiments using three media: clear water and low-viscosity and high-viscosity fracturing fluids. Fracture propagation patterns under varying media and roof strength conditions were systematically investigated through acoustic emission (AE) monitoring, pump pressure analysis, and rock strain measurements. The results show that both fracturing fluid properties and roof compressive strength significantly influence hydraulic fracture initiation, AE characteristics, and ultimate fracture morphology. Compared to conventional clear water, high-viscosity fracturing fluid exhibits superior performance in fracture initiation efficiency (34% higher peak pressure), propagation intensity (3.7 times more AE energy), and influence range (34% greater fracture length). These advantages make it particularly suitable for hard roof conditions requiring precise fracture management. The results provide a theoretical foundation for optimizing hydraulic fracturing parameters in hard roof control engineering applications.
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Research context
OpenAlex topics: Rock Mechanics and Modeling · Coal Properties and Utilization · Landslides and related hazards
SciVX discovery tags are terminology-based. OpenAlex topics are source-provided classifications.
Affiliations
Geotechnical Survey Company, CHN Energy Shendong Coal Group, Shenmu 719300, China
School of Mines, China University of Mining and Technology, Xuzhou 221116, China
CHN Energy Shendong Technology Institute, Shenmu 719300, China
State Key Laboratory of Coal Mine Disaster Dynamics and Control, School of Resources and Safety Engineering, Chongqing University, Chongqing 400044, China
Funding
National Natural Science Foundation of China · CHN Shenhua Energy Co., Ltd. Shendong Coal Branch
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