Controllable reverse circulation structure

Abstract

The invention discloses a controllable reverse circulation structure, which comprises an upper joint, a shear pin, a steel ball, a sliding sleeve, a valve seat, an inner barrel, a filter element, an upper channel, an outer barrel and a lower channel, wherein the upper part of the upper joint is provided with a joint buckle for connecting an upper drill pipe, and a water hole channel is formed in the middle of the upper joint so that drilling fluid and the steel ball pass through the water hole channel; external threads and internal threads are respectively arranged at the inside and outside of the lower part of the upper joint, and the external threads are in screw-thread fit connection with the upper end of the outer barrel; the internal threads are in fit connection with the sliding sleeve, and the upper part of the valve seat is in sliding seal with the sliding sleeve; the outline structure of the interior space of the valve seat is a conical surface matched with the steel ball, and the lower part of the valve seat and the outer barrel form a seal; the shear pin is respectively connected with the sliding sleeve and the valve seat, and the shear pin is broken by downward pressure when the downward pressure of the upper part of the valve seat reaches the threshold valve pressure; the upper part of an inner sleeve is in seal connection with the valve seat, and the lower part of the inner sleeve and the inner wall of the outer barrel are welded together to form a whole; the filter element is detachably and fixedly connected with the inner barrel.

Description

technical field [0001] The invention relates to some reverse circulation tools used in oil and gas mining accident salvage operations, in particular to an improved controllable reverse circulation structure of the reverse circulation tools. Background technique [0002] With the increasing demand for energy and the scarcity of oil and gas resources, the difficulty of development is also increasing, and the accident rate is also increasing. Among them, operations related to the bottom of the well often occur, such as fishing while drilling, grinding and milling. Salvage, reverse circulation salvage, etc. The development of reverse circulation fishing technology has driven the progress and development of workover tools. Due to the development and progress of reverse circulation salvage technology, the requirements for reverse circulation tools are becoming more and more stringent, and the functionality, usability, safety and applicability of tools are required to develop toge...

AI Technical Summary

Problems solved by technology

[0006] In view of the above-mentioned defects in the prior art, the technical problem to be solved by the present invention is to provide a controllable reverse circulation structure, which improves the reverse circulation mechanism in the existing old-fashioned reverse circulation tools, and can meet the requirements of complex operations such as horizontal wells and vertical wells. Reliability and controllability of the application of reverse circulation in the well, can use this reverse circulation structure to achieve the purpose of reverse circulation, and can maintain the positive circulation of drilling fluid when not in use

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