Local reverse circulation coring drill tool for loose and broken strata

Abstract

The invention provides a local reverse circulation coring drill tool for loose and broken strata. The local reverse circulation coring drill tool comprises a joint, an outer pipe, a negative suction element, a transition element, a rock core pipe joint, a transition communicating element, an inner pipe, a reamer, an elastic clamp and a drill bit. The upper end of the negative suction element is connected with the lower end of the joint and the outer pipe while the lower end of the negative suction element is connected with the transition element through a supporting ring, the transition element is connected with the inner pipe through the rock core pipe joint, the elastic clamp is disposed in the inner pipe, the inner pipe is situated on an inner-wall step of the drill bit and connected with the drill bit through the reamer, and the transition communicating element is arranged in a manner of penetrating the supporting ring, the transition element and the rock core pipe joint. A structure similar to a gear pump is adopted to form negative pressure to generate local reverse circulation of drilling liquid, so that scouring of a hole wall by the drilling liquid in the process of full-hole reverse circulation is avoided, a rock core is facilitated to enter a rock core pipe, and rock core recovery rate can be improved effectively in the process of drilling; the local reverse circulation coring drill tool is suitable for being used for drilling in strata which are loose, broken and prone to corrosion and erosion.

Description

technical field [0001] The invention relates to engineering fields such as mineral resource exploration and oil well drilling, and in particular to a partial reverse circulation core drilling tool for loose, broken and other complex formations. Background technique [0002] At present, mineral resources around the world are becoming increasingly depleted, which requires drilling companies to develop mineral resources more economically and effectively. Deep core drilling is the most effective means to understand the structure and direction of mineral resources in the formation. As an important tool in drilling operations - drilling tools, its working performance directly affects the quality, cost and efficiency of drilling operations. [0003] During the drilling operation, complex formations such as loose and broken are often encountered. It is very difficult to obtain cores when drilling such complex formations. It is difficult for ordinary core drilling methods to obtain ...

AI Technical Summary

Problems solved by technology

[0005] The problem to be solved by the present invention is to provide a local reverse circulation core drilling tool for loose and broken complex formations, aiming at the above-mentioned shortcomings of existing full-hole reverse circulation or jet-type hole bottom local reverse circulation drilling tools for drilling and coring. Improve the core recovery rate in loose and broken complex formations, and achieve high-efficiency and high-quality core recovery

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