A system and method for downhole rapid slotting and directional hydraulic fracturing based on drilling rig power

Abstract

The invention discloses a system and method for rapid slotting and directional hydraulic fracturing in the well driven by a drilling rig. The directional hydraulic fracturing system includes a water injection pump, on which a high-pressure rubber hose is arranged to communicate with the drilling rig, and a special seal for hydraulic fracturing is installed on the drilling rig. The drill pipe, the front section of the drill pipe can be threadedly connected with the directional hole sealer, and a sealing ring is arranged at the threaded connection. The main implementation steps are drilling → slit → sealing → fracturing. First, install the integrated drilling and cutting tool at the front end of the drill pipe. After the drilling is completed, there is no need to replace the drill bit to perform hydraulic slit enhancement and pressure relief. After the slit is completed, the drill is installed and oriented The hole sealer is pushed to the predetermined position for high-efficiency sealing. After the hole sealing is completed, high-pressure water injection fracturing is carried out, focusing on "high-pressure penetration" to increase the density and range of cracks, so as to improve the water injection effect of high-pressure low-porosity coal seams, and then Effectively prevent and control rock burst, reduce dust concentration, prevent and control gas and fire disasters.

Description

technical field [0001] The invention relates to the field of disaster prevention and control of coal mining working faces, in particular to an underground rapid slotting and directional hydraulic fracturing system and method based on drilling rig power. Background technique [0002] Practices at home and abroad have proved that coal seam water injection is an effective method to actively reduce the coal seam impact tendency of the working face and reduce the generation of dust. It mainly pre-injects high-pressure water into the coal body, utilizes the fracturing, scouring and wedging effects of the pressure water on the weak surface, and the physical and chemical effects of water on the coal body to expand the original cracks and generate new cracks in the coal rock mass. Destroy the integrity of coal and rock mass, reduce its strength, and release the pressure of coal mass, so as to effectively prevent the occurrence of rock burst accidents. The water injected into the coa...

AI Technical Summary

Problems solved by technology

[0003] For a long time, people's understanding of coal seam water injection has remained at the stage of qualitative understanding, while the traditional water injection method directly seals the borehole and then injects water. This water injection method has less water injection per hole, the sealing process is complicated, and the water in the coal seam The penetration effect of the coal seam is poor, which affects the water injection effect of the coal seam

The porosity of the coal seam is an important indicator of the difficulty of water injection. The degree of development of coal seam fissures and pores is the primary factor affecting the difficulty of coal seam water injection. , low permeability, high gas content and other outstanding problems restrict the development of coal seam water injection technology

The coal seams in many mining areas in my country are coal seams with high ground pressure and low porosity. The joints and fissures of the coal body are not developed and are relatively hard. It is difficult to inject water into the coal seam, and the expected disaster prevention effect cannot be achieved. With the increase of the mining depth of my country's coal mines, the problem of water injection is more difficult. prominent, seriously restricting the application of coal seam water injection technology in my country's deep high-pressure coal seams, and hindering its prevention and control effect on rock burst and high-concentration dust hazards

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