A pdc drill bit for high position directional drilling in coal mine

Abstract

The invention discloses a PDC drill bit for high-position directional drilling in coal mines, which comprises an integrally formed drill body, a plurality of fixed blades, movable blades detachably mounted on the drill body, and welded to the fixed blades and the movable blades respectively. The PDC cutting teeth on the top; the cloth tooth surface of the fixed blade extends radially from the center near the front end of the drill body to the edge of the front end of the drill body, and the gauge surface connects with the cloth tooth surface and extends to the side of the front end of the drill body; the cloth tooth surface and the second The side intersection line is designed according to the modified contour fitting curve of the toe of the mole’s front paw, and the PDC cutting teeth are arranged along the intersection line; the movable blade is arranged between the adjacent fixed blades, and the movable blade includes a blade that can be installed with PDC cutting teeth. The tooth surface of the movable blade is arranged; the heights of the fixed blade and the movable blade above the front end of the drill body are the same; the main channel nozzle is arranged on the drill body, and the side blade nozzle is arranged on the fixed blade. The invention can improve the directional build-up capability of the drill bit and its drilling adaptability in complex and hard formations.

Description

technical field [0001] The invention belongs to the technical field of coal mine drilling, and in particular relates to a PDC drill bit for high-position directional drilling in coal mines. Background technique [0002] The high-level directional drilling technology in coal mines can effectively solve the problem of mining pressure relief and gas drainage in the working face, and gradually replace high-level drainage roadways to become the future drilling trend. This directional drilling technology mainly uses screw motor sliding directional drilling, which requires drilling trajectory control and branch hole construction without establishing an artificial hole bottom, so the drill bit is required to have a strong lateral drilling capability; Drilling in the rock formation is affected by the geological conditions of each region, requiring the drill bit to have a certain ability to drill into hard rock. [0003] At present, the directional drill bits commonly used in coal mi...

AI Technical Summary

Problems solved by technology

[0003] At present, the directional drill bits commonly used in coal mines have a matrix-type flat-bottomed structure, and a large water hole is set in the center of the drill bit. The density is low, the cutting ability of the cutting teeth is poor, and the design of the flow channel is unreasonable, and the mud balling of the drill bit is serious, which eventually leads to faster wear of the drill bit and low drilling efficiency

In view of the above problems, the patent document with the notification number CN 205532306U proposes a steel-body PDC drill bit for directional drilling in coal mines. The sidetracking ability of the drill bit is guaranteed; however, the bottom hole coverage of the cutter is low, and the wear of the cutter is still serious when drilling into complex and hard formations; and due to the limitation of the crown space of the drill bit, the number of water holes is limited , the effect of carrying rock at the bottom of the well is poor, and the cleaning and cooling of the cutting teeth are insufficient

The patent document of notification number CN 110306934 A has proposed a kind of double-branch top plate large-diameter high-position directional long drilling supporting drill bit, and this drill bit is inlaid with the side-drilling sub-pillar teeth on the periphery of the drill bit head between two blades, and the column teeth adopt The quadrangular pyramid cutting edge structure, in order to ensure that the apex of the cutting edge is located at the maximum diameter of the drill bit and to ensure the strength of the column teeth, it is required that the height of the sub-pillar teeth exposed to the bit body is significantly smaller than the height of the blade, so during normal drilling, the sub-pillar teeth It does not participate in rock breaking, but only plays the role of gauge; it only plays the role of assisting in cutting the lower sidewall hole when drilling small-diameter branches inside the large-diameter hole. The scope of application is small and it is not universal.

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