Unstable stratum variable-diameter casing pipe hole-protecting drilling process

Abstract

The invention discloses an unstable stratum variable-diameter casing pipe hole-protecting drilling process. The unstable stratum variable-diameter casing pipe hole-protecting drilling process can realize hole-protecting directional drilling in an unstable stratum, and solves the problems of hole collapse, hole shrinkage and the like in unstable stratum drilling, under the hole protection effect ofa variable-diameter casing pipe, the situations of hole collapse, hole shrinkage and the like in an unstable stratum hole section during subsequent drilling are avoided, drill jamming and drill falling accidents are avoided, smoothness of a directional drilling channel is guaranteed due to the hole protection effect of the variable-diameter casing pipe 2 in the unstable stratum hole section, therequirements of a mine for gas control, water damage prevention and the like are met, and the method is good in effect in the construction process, high in stability, high in unstable stratum hole protection drilling efficiency and good in hole forming performance.

Description

technical field [0001] The invention relates to the technical field of coal mine machinery construction technology, in particular to a drilling technology of variable-diameter casing protection holes in unstable formations. Background technique [0002] With the continuous improvement and application of underground directional drilling technology in coal mines, it is easy to encounter unstable formations when performing directional drilling underground in coal mines, such as structural formations, broken formations, soft formations, etc., and directional drilling in such formations is often Collapsing holes and shrinking diameters can easily cause drill drop and lead to large economic losses, reduce the hole formation rate of directional drilling, and block the drilling channels due to hole collapse and shrinkage, which will affect the effects of gas control and water damage prevention, and affect the safety of coal mines Efficient production will lead to mine safety acciden...

AI Technical Summary

Problems solved by technology

[0002] With the continuous improvement and application of underground directional drilling technology in coal mines, it is easy to encounter unstable formations when performing directional drilling underground in coal mines, such as structural formations, broken formations, soft formations, etc., and directional drilling in such formations is often Collapsing holes and shrinking diameters can easily cause drill drop and lead to large economic losses, reduce the hole formation rate of directional drilling, and block the drilling channels due to hole collapse and shrinkage, which will affect the effects of gas control and water damage prevention, and affect the safety of coal mines High-efficiency production, which will lead to mine safety accidents in severe cases

[0003] At present, there are few researches on the drilling technology of variable-diameter casing for hole protection in unstable underground coal mine formations, and there are no relatively mature products for large-scale industrial application. Only relevant technologies have been applied in the fields of petroleum and geological exploration and development, but due to The working environment, drill tool assembly, target stratum and process characteristics in the field of coal mine underground and surface oil drilling and geological exploration are quite different, which cannot meet the needs of coal mine directional drilling construction

[0004] Therefore, in order to solve the above problems, there is a need for an unstable formation variable-diameter casing protection hole drilling technology, which can realize the directional drilling of the protection hole in the unstable formation, and solve the problem of collapsed holes, shrinkage, etc. diameter and other issues

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