Down-the-hole hammer reverse concentric casing drilling tool

Abstract

The invention relates to a down-the-hole (DTH) hammer reverse concentric casing drilling tool. A hollow DTH hammer is connected to a guiding drill through a semicircular block and a spline housing, wherein an outer spline which is arranged on the axial direction of the guiding drill is matched with an inner spline of an annular sleeve drill; the guiding drill 3 is designed as a reverse structure;and an annular casing drill is hung on the lower end of the sleeve through a pipe boot. Compared with the prior art, the guiding drill crashes rock in advance and transmits an impact load to the annular casing drill and drives the drill to rotate, in order to realize simultaneously performing three processes of concentrically crashing, wall protection through the casing and reverse slagging. The double air piping can simultaneously cool the spherical gear alloy of the inner and outer drills and prolong the service life of the drill. Reverse slagging can efficiently clean the hole bottom rock debris, avoid repeated crashing and prevent the drill from being blocked by the rock debris. After ending the casing drilling, the reverse drilling can be performed without exchanging the drill. The casing drill tool has simple structure, low processing cost, long service life and high drilling efficiency.

Description

Technical field: [0001] The invention relates to a rock and soil drilling machine tool for drilling in complex formations, in particular to a down-the-hole hammer for reverse circulation and pipe drilling. Background technique: [0002] The down-the-hole hammer and pipe drilling technology is an efficient drilling method for drilling holes in complex formations such as broken, lost, pebbles, lost and collapsed. It uses the down-the-hole hammer to efficiently break rocks, and uses synchronous follow-up casing to protect the hole wall, so that the three processes of drilling, wall protection and slag discharge can be carried out simultaneously. Existing tubular drilling tools are mainly divided into two categories: eccentric tubular drilling tools and concentric tubular drilling tools. Practice has proved that the existing down-the-hole hammer eccentric heel pipe drilling tools have certain defects, such as: large torque required for drilling, poor concentricity of the drilli...

AI Technical Summary

Problems solved by technology

The above drilling tool systems all adopt the positive circulation slag discharge method. When the hole diameter is large or the formation is complex, the positive circulation slag discharge is difficult, resulting in a decrease in drilling efficiency, a shortened life of the drill tool and an increase in drilling cost; when drilling in a complex formation, it is necessary When obtaining rock ore samples, it is difficult to obtain the rock samples required for mineral exploration; the structure of the drilling tool is complex and the cost is high, and the valve is easily stuck by cuttings when the drill is lifted, which brings inconvenience to the drill

CN1651711A discloses a down-the-hole hammer reverse circulation follow pipe drill bit, which uses two valve structures to change the drilling diameter and realize reverse circulation concentric follow pipe drilling, but the drill bit structure is complicated and the processing cost is high

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