Downhole rapid slotting directional hydraulic fracturing system and method based on drilling machine power

Abstract

The invention discloses a downhole rapid slotting directional hydraulic fracturing system and method based on drilling machine power. The directional hydraulic fracturing system comprises a water injection pump, and a high pressure rubber hose is arranged on the water injection pump to communicate with a drilling machine. A special sealing drill pipe for hydraulic fracturing is installed on the drilling machine, and the front section of the drill pipe is connected with directional hole packers in a threaded mode. Sealing rings are arranged at the threaded connected positions. The downhole rapid slotting directional hydraulic fracturing method comprises the main implementation steps of hole drilling, slotting, hole sealing and fracturing, specifically, a drilling and cutting integrated toolis installed at the front end of the drill pipe firstly, and after the hole drilling is completed, hydraulic slotting and anti-reflection pressure relief are performed without replacing a drill bit;after the slotting is completed, the drill bit is withdrawn, and the directional hole packers are installed and pushed to the predetermined positions for high-efficiency hole sealing; after the hole sealing is completed, high-pressure water injection fracturing is carried out, and high-pressure permeation is mainly used for increasing the fracture density and range, so as to improve the water injection effect of a high ground pressure and low porosity coal seam, effectively prevent and control rock burst, reduce dust concentration, prevent and control gas and prevent and control fires and other 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...

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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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