Fracture Propagation Research On Directional Hydraulic Fracturing In Fully-Mechanized Face

Taking Hongshiyan coal mine mining conditions in Shaanxi Province into consideration, based on directional hydraulic fracturing problem in fully-mechanized face,through rock mechanics experiments、theoretical analysis、numerical calculation and field observations integrated approach Studied hard seam directional hydraulic fracturing advance presplitting technology mechanism, increase and extend fracture in seam to improve lump coal rate. By analyzing the impact of the expansion of the coal formation fracture mechanical parameters and directional fracturing technology; By analyzing about stress distribution between crack directional drilling and not expanded drilling in coal evolution. Under different grooving drilling parameters, coal seam stress distribution and the evolution of cracks were researched. Obtained directional hydraulic fracture technology and mechanical specifications in Hongshiyan fully-mechanized face.By field application the results show the effectiveness of presplitting process parameters.Firstly, the physical and mechanical factors of cracks on expansion were experimental measured and analyzed. Construction of directional hydraulic fracturing process parameters Presplitting device parameters studied, connection between coal-rock mechanical parameters and the moisture were studied, as well as the pre-splitting parameters, to provide a guidance for select the construction process parameters.Then through analyzing geological conditions of Hongshiyan mine, RFPA-Flow was applied to research directional drilling and fracturing grooving grooving not drilling, grooving and drilling of different parameters in the force field of high pressure water injection should variation and evolution of seam cracks, seams come under the law of crack propagation in the directional hydraulic fracturing conditions. directional hydraulic fractures controlled within a certain range, and can form much more fracture compared with not grooving drilling crack. with Shearer disturbances and under its own weight, it will improve production.Finally, applying this directional hydraulic fracturing technology in Hongshiyan mine 12406 fully mechanized coal face, the fracturing process parameters were optimized after on-site monitoring. it has proved that not only greatly improved the production, but also the slots previously released mining stress concentration of fully-mechanized face, released the gas in coal seam, prevented the impact of disaster of face support,improved the speed of shearer cutting coal, material consumption rate has dropped, increasing coal production, reducing dust of working surface. and behaving well in hard hypotonic gassy mine, which has important significance for efficient mining and production safety of fully-mechanized face.