Composite aluminum alloy double wall drill pipe

Abstract

The invention discloses a combined aluminum alloy double-wall drill pipe unit composed of an inner pipe, an outer pipe, an upper connector of the outer pipe, a lower connector of the outer pipe, an upper connector of the inner pipe, a lower connector of the inner pipe and seal rings. Two ends of the outer pipe are connected with the upper connector of the upper pipe and the lower connector of the outer pipe through clamping slots, respectively. The seal rings are arranged on matched cylindrical surfaces between the outer pipe and the upper connector of the outer pipe as well as between the outer pipe and the lower connector of the outer pipe. The inner pipe is arranged in the outer pipe. Two ends of the inner pipe are connected with the upper connector and the lower connector of the inner pipe through threads, respectively. As the combined aluminum alloy double-wall drill pipe units coupled, two adjacent outer pipes are in threaded connection through the upper connectors and the lower connectors of the outer pipes, and the inner pipes are in inserting connection through the upper connectors and the inner connectors of the inner pipes. The outer pipe made of aluminum alloy is 1 / 3 of steel in density, leading to light weight and carrying convenience. The combined aluminum alloy double-wall drill pipe unit is light, convenient to carry, simple in structure, easy to detach, reasonable in load distribution, accurate in the centering position between the inner pipe and the outer pipe, good in stress working condition and the like.

Description

technical field [0001] The invention relates to a double-walled drill pipe composed of an aluminum alloy outer pipe, a high-strength alloy steel inner pipe and joints, especially a composite aluminum alloy double-walled drill pipe applicable to multi-process air reverse circulation drilling . Background technique [0002] Air down-the-hole hammer reverse circulation drilling technology integrates impact, rotation, air reverse circulation and slag discharge, etc., and can realize high-efficiency drilling in hard rock formations, sandy pebbles and other loose formations, and broken complex formations, with good drilling quality , low drilling cost, high drilling efficiency and other advantages, it is widely used in the construction of foundation projects such as subways and foundation pit anchor holes, coal mining, and mineral exploration and construction. With the development of air drilling and underbalanced drilling technology, air reverse circulation drilling has been gra...

AI Technical Summary

Problems solved by technology

In order to ensure the strength of the outer pipe of the drill pipe, and have a sufficient flow area and accommodate the inner pipe, the outer pipe specification often chooses a high-strength seamless steel pipe with a larger diameter, which causes the overall weight of the drill pipe to be large, resulting in double-wall drilling. It is very difficult to carry and unload the rod, and it puts forward higher requirements for the lifting capacity of the drilling rig

[0004] In addition, the inner tube and the outer tube of the double-walled drill pipe need to meet good concentricity requirements to ensure the smooth insertion of the inner tube during the drill pipe connection process. Therefore, a complex centering structure needs to be designed between the inner and outer tubes of the double-walled drill pipe to increase Increased processing difficulty and high manufacturing cost

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