Underground coal mine water hole prevention and control high-water-pressure water jacking directional drilling tool and drilling method

Abstract

The invention discloses an underground coal mine water hole prevention and control high-water-pressure water jacking directional drilling tool and drilling method. The directional drilling tool comprises a drill string body and a directional drill bit which are connected in sequence, and an inner annular hollow flow channel is arranged around the external of the drill string body; a ''Y-type'' structure flush fluid circulation flow channel consisting of a central flow channel and the inner annular hollow flow channel and an outer annular hollow flow channel formed between the drilling tool anda bore wall, the flush liquid is always flowing in the ''low back pressure'' state, the ''reactive'' load of a mud pump is substantially reduced, the effective utilization rate of the hydraulic energy can be improved by 15% or above, and it is ensured that the normal working and output torque parameters of the hole bottom power drilling tool do not change significantly under the working conditionof large water inrush of the high water pressure formation towards the inside of a hole. The drilling tool can normally directionally drill in the formation water outlet pressure condition of 6.0MPaor above, so that the downhole directional drilling water pressure resistance is improved by 50% or above, and the water jacking directional drilling hole-forming depth is 500m or above.

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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