Hole reaming and borehole enlarging device for exploitation of coalbed methane exploitation hole bottom

Abstract

A hole reaming and borehole enlarging device for exploitation of a coalbed methane exploitation hole bottom comprises a connecting drill pipe, wherein a hole reaming drill bit is arranged at the lower end of the connecting drill pipe; an inner cavity of the connecting drill pipe serves as a flushing fluid flowing duct; a flushing fluid counterbalance valve is mounted in the flushing fluid flowing duct; a borehole enlarging oil cylinder is arranged in the flushing fluid flowing duct; the hole reaming drill bit comprises a cutting head and a guiding sleeve which is fixedly connected with the connecting drill pipe; a guiding rod which moves in the up-down direction is mounted in the guiding sleeve; and a plurality of cutting wings for hole reaming operation are uniformly distributed between the guiding sleeve outside the guiding rod and the cutting head in the peripheral direction. The hole reaming and borehole enlarging device is simple and reliable in structure, good in stability and high in safety, completely meets construction requirements of coalbed methane borehole enlarging wells, and has an excellent market prospect.

Description

technical field [0001] The invention relates to geological exploration equipment, in particular to a hole-reaming hole-digging device for coalbed methane exploitation. Background technique [0002] The coalbed methane industry is an emerging industry that has risen in the world in the past 20 years. The development and utilization of coalbed methane can not only fundamentally prevent the occurrence of coal mine gas accidents, improve the safety of coal mine production, but also turn harm into treasure. Effective utilization of natural gas can improve my country's energy structure to a certain extent, increase clean gas energy, and make up for the shortage of conventional natural gas in geographical distribution and supply in my country. Some senior experts have long proposed that the 21st century is the era of coalbed methane development, and coalbed methane is the most realistic and reliable alternative to conventional natural gas in my country. [0003] At present, most of...

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Problems solved by technology

[0003] At present, the existing reaming bits with movable blades are mostly used in the construction of coalbed methane excavation wells. With a large number of applications in the construction of coalbed methane excavation wells, the traditional movable blade reaming bits show some defects in application. Since there is no flushing fluid channel aligned with the cutting teeth, the cutting teeth cannot be flushed and cooled during the cutting operation, and self-sharpening cannot be achieved; due to structural reasons, the cuttings in the drilling fluid will stick to the mandrel, which is easy to cause The blade cannot be retracted after digging the hole, and the drill cannot be pulled out; at the same time, the use of the traditional movable blade reaming drill bit makes the hole wall of the reaming unable to be smooth and smooth, and the lower end of the cutter bar is easy to get stuck on the inner wall of the original hole during the equipment lowering process. , destroying the inner wall of the hole

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