Experimental Study on the Influence of Hydraulic Fracturing Path on Crack Propagation of Hydraulic Fracturing
In order to deeply explore the effect of coal rock mass elastic-plastic deformation on structu-ral weak planes,fracturing experiments were conducted according to the combination relationship of crack initiation position,fracturing direction,and bedding direction.Non-metallic ultrasonic detectors and acoustic emission were used to monitor the fracturing process,and the fracturing effect was compre-hensively evaluated from the aspects of crack propagation morphology,crack width,and permeability flow rate.Corresponding explanations were given from the perspective of energy.The experimental re-sults show that the fracturing of the overlying strata is better than that of the coal seam,and vertical bed-ding fracturing is better than parallel bedding fracturing.The fracturing effect is best in the vertical bed-ding direction,and the crack propagation morphology is more complex,forming an"O"shape.Its ave-rage permeability coefficient is 6.6 mm/s,which is 1.10 times that of parallel bedding.The cracks propagate from the overlying rock of the roof to the coal block,and under the same initiation energy,3.08 to 338 times equivalent length cracks can be formed in the coal block.
coal bed methanehydraulic fracturingfissure networkcoal bedding
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