Analysis on borehole instability and control method of pore- forming of hydraulic fracturing in soft coal seam
Abstract：Borehole instability deformation mechanism of soft coal seam in coal mine was analyzed, and stresses in roadway surrounding rock and the secondary stress of borehole as the main cause of borehole deformation instability of hydraulic fracturing in coal seam was pointed out. Proposed an effective regional curing pore-forming method, simula- ted and analyzed the borehole stress field,displacement field and change of plastic failure zone in soft coal seam and the coal seam which cured with high strength material. The results show that the area of displacement and plastic fail- ure zone is bigger while drilling in soft coal seam, and it is prone to instability and failure. Based on regional curing pore-forming method, the cracking in the soft rock surrounding borehole wall can be filled with grout, the strength of the surrounding rock can be steadily reinforced. Thus that area of displacement and plastic failure zone can be de- creased and the rate of pore-forming can be enhanced.
Keywords：gas drainagehydraulic fracturingborehole instabilitycuring pore-formingsoft coal seam
Publication Date：2012-01-01
Online Publishing Date：2025-08-15(First online date of this platform, not the publication date of the document)
Pages：6( 1431-1436 )