Drill string power propulsion system and method for directional drilling of near-horizontal ultra-deep holes in underground coal mines

Abstract

A drill string power propulsion system and method for directional drilling in a near-horizontal ultra-deep hole in a coal mine. A thruster, a cuttings bed cleaner, a second thruster, a second drill string group and a water stool; the present invention realizes the efficient application of drilling pressure and the safety, stability, and Efficient propulsion, solving the problem that the propulsion force of the hole drilling machine cannot be effectively transmitted to the drill bit caused by the contact friction caused by the bending deformation of the drill string in the long-distance near-horizontal directional hole, and solving the problem caused by cuttings during sliding drilling in the near-horizontal hole The problem of increased friction and increased construction risk caused by sedimentation is of great significance for improving the depth of directional drilling and the efficiency of deep hole directional drilling.

Description

technical field [0001] The invention relates to the technical field of underground drilling in coal mines, in particular to a drill string power propulsion system and method for directional drilling of near-horizontal ultra-deep holes in underground coal mines. Background technique [0002] At present, in the near-horizontal drilling of coal mines in my country, in the process of sliding directional drilling with screw motor, the power head of the hole drilling rig is used to propel. The contact force caused by gravity creates contact friction. When the hole depth reaches a certain level, the cumulative friction caused by the bending of the drill string is prominent, which prevents the effective transmission of the drilling pressure and produces a back pressure effect, resulting in a serious reduction in the efficiency of sliding directional drilling. The harder the formation encountered, the greater the WOB requirement, and the corresponding increase in the orifice feed for...

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Problems solved by technology

[0005] The purpose of the present invention is to provide a drill string power propulsion system and method for near-horizontal ultra-deep hole directional drilling underground in coal mines, which realizes the efficient application of drilling pressure and the safety, stability, and Efficient propulsion, solving the problem that the propulsion force of the hole drilling machine cannot be effectively transmitted to the drill bit caused by the contact friction caused by the bending deformation of the drill string in the long-distance near-horizontal directional hole, and solving the problem caused by cuttings during sliding drilling in the near-horizontal hole The problem of increased friction and increased construction risk caused by deposition is of great significance for improving the depth of directional drilling and the efficiency of deep hole directional drilling

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