Study On The Application Of Hydraulic Fracturing To Prevent Rock Burst

Hydraulic fracturing technology is one of the effective means to prevent rock burst. In this paper, theoretical analysis, numerical simulation and field practice are used to study the impact of hydraulic fracturing in the coal seam under the condition of deep thick coal seam:(1) The cause of formation of rock burst is analyzed under the condition of deep thick coal seam, and the mechanism of hydraulic fracturing is analyzed, and the factors that affect the fracturing effect are analyzed systematically.(2) Using RFPA numerical simulation software to study the influence of the hole of the hydraulic fracture extension in different ground stress-. different borehole diamete and different distance between two drilling holes. The result shows that: hydraulic fracturing process can be divided into three stages, pre fracturing stage, the formation of micro crack stage, break stage, using curve fitting method to calculate the stress dispersion and initiation pressure values the relationship between the two. With the increase of stress difference, the fracturing pressure decline, finally to 0, when the stress difference is large enough, the coal in the surrounding rock under stress can be fractured;the water pressure of hole fracture will be decreasing continuously with the increase of the diameter. and the hole diameter should be less than 95mm. Combined with the site construction and the drilling rig, drill pipe, drill bit used to determine that 65mm is the reasonable drilling hole diameter; the numerical simulation reslut shows that 20m is considered as the optimum drilling distance of the field construction.(3) The construction parameters, construction technology and equipment are reasonably determined, and the reasonable selection of drill pipe is determined by numerical simulation method.(4) Using the method of drilling bits and microseism to monitoring the impact prevention effect. The monitored result show that:after hydraulic fracture, an amount of drillings of coal dust is far below a limit amount of coal dust which causes impact risk, wherein microseism events are significantly reduced, the frequency is lower and fluctuation is relatively very small. The results of this experiment show that hydraulic fracture can effectively reduce the rock burst.