A directional drilling tool and drilling method for preventing and controlling water holes under high water pressure jacking water in coal mines

Abstract

The invention discloses a directional drilling tool and a drilling method for preventing and controlling water holes in coal mines with high water pressure and jacking water, wherein the directional drilling tool includes a drill string body and a directional drill bit connected in sequence, and an inner annular air flow is arranged around the outside of the drill string body Channel; the "Y-shaped" structure flushing fluid circulation channel composed of the central channel, the inner annular channel and the outer annular channel formed between the drilling tool and the hole wall, and the flushing fluid is always in the "low back pressure" state Down flow greatly reduces the "reactive" load of the mud pump, and its effective utilization rate of hydraulic energy can be increased by more than 15%, ensuring that the power drilling tool at the bottom of the hole can work normally under the condition of a large amount of water gushing into the hole from the high water pressure formation . The output torque parameter has no obvious change. The drilling tool can normally drill directionally under the condition of formation water pressure above 6.0MPa, which improves the water pressure resistance of downhole directional drilling by more than 50%, and the hole depth of top water directional drilling is more than 500m.

Description

technical field [0001] The invention relates to the technical field of drilling, in particular to a directional drilling tool and a drilling method for preventing and controlling water holes with high water pressure and jacking water in underground coal mines. Background technique [0002] Coal mine water damage has long been one of the most serious disasters restricting the safe and efficient mining of coal resources in my country. According to incomplete statistics, 30% to 40% of my country's raw coal reserves are threatened by water hazards, including water hazards in coal seam roof aquifers, coal seam floor water hazards in pressurized water-filled aquifers, karst subsidence column water damage, outburst water damage in fault fracture zones, old voids, etc. Permeable water damage, surface water body permeable water damage, etc. Among them, water hazards in the confined water-filled aquifers of the floor have a high frequency of occurrence in coal mines in my country, and...

AI Technical Summary

Problems solved by technology

For directional drilling for underground exploration and drainage of coal mines for water prevention and control, under the condition of high-pressure water gushing in the formation, directional drilling with top water is difficult, and the depth of the hole often fails to meet the design requirements, and the effect of water prevention is poor. High cost and long cycle

For underground grouting reinforcement and transformation of coal mines for water prevention and control directional drilling, under the condition of high-pressure water gushing in the formation, directional drilling with top water is difficult, so the length of a single grouting hole section can only be shortened, and the drilling and grouting are frequently carried out, which requires a large amount of auxiliary engineering , grouting and waiting for solidification and other additional operations take a long time, the comprehensive drilling efficiency is low, and deep hole drilling is difficult

However, when the formation water inrush pressure reaches 6 MPa or more, the existing directional drilling technology and equipment can no longer be used for top water construction, which limits the further application of underground near-horizontal directional holes in the field of mine water disaster prevention and control to a certain extent.

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