Hydraulic retractable fishing spear for horizontal well

Abstract

The invention relates to a hydraulic retractable fishing spear for a horizontal well. The hydraulic retractable fishing spear for the horizontal well comprises an upper connector, a sleeve, a centralpipe, an upper piston cylinder, a lower piston cylinder, a fishing claw and a spear rod; one end of the sleeve is fixedly connected with the outer wall of one end of the upper connector, one end of the central pipe is fixedly connected with the inner wall of one end of the upper connector, and the upper piston cylinder and the lower piston cylinder are fixedly connected in a sleeved mode and forma lower liquid inlet groove from the inner wall of the lower piston cylinder to the interior of the lower piston cylinder, the lower liquid inlet groove can push the lower piston cylinder and the upper piston cylinder to slide simultaneously under action of pressure, the other end of the lower piston cylinder is connected with the fishing claw, slip inserts are formed at the tail end of the fishing claw, one end of the spear rod is fixedly connected with the center pipe and one end of the spear rod is sleeved with a spring, and when the lower piston cylinder drives the fishing claw to move inthe axial direction of the spear rod, the spring is compressed or stretched; the hydraulic retractable fishing spear for a horizontal well also comprises an inner sliding sleeve, and the inner slidingsleeve is arranged inside the center pipe in a sleeving manner and can block the lower liquid inlet groove. According to the hydraulic retractable fishing spear for the horizontal well, a conventional upward-lifting and downward-placing rotary quitting mode of the fishing spear is changed into a hydraulic quitting mode, and the limitation of a horizontal well body structure is overcome.

Description

technical field [0001] The invention belongs to the technical field of supporting tools for oil field workover, and in particular relates to a hydraulic retractable fishing spear for horizontal wells. Background technique [0002] Due to the particularity of the wellbore structure of the horizontal well, the stress on the pipe string structure is complex, and the frictional resistance during lifting and lowering and rotation increases significantly, and the torque cannot be directly and effectively transmitted to the fish, resulting in a low fishing success rate. Conventional hydraulic retractable fishing tools are usually withdrawn by lifting, lowering and rotating mechanisms. Under the limitation of the large curvature structure of horizontal wells, the fishing tools cannot be effectively withdrawn, and the success rate of withdrawing is less than 30%, which leads to more complicated downhole accidents. [0003] Therefore, based on these problems, a hydraulic retractable f...

AI Technical Summary

Problems solved by technology

[0002] Due to the particularity of the wellbore structure of the horizontal well, the stress on the pipe string structure is complex, and the frictional resistance increases significantly when lifting, lowering and rotating, and the torque cannot be directly and effectively transmitted to the fish, resulting in a low fishing success rate

Conventional hydraulic retractable fishing tools are usually withdrawn by lifting, lowering and rotating mechanisms. Under the limitation of the large curvature structure of horizontal wells, the fishing tools cannot be effectively withdrawn, and the success rate of withdrawing is less than 30%, which makes downhole accidents more complicated.

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