Expansion pipe repair tool

Abstract

The invention discloses a tool for repairing a sleeve with an expansion pipe. The tool is used for repairing wells with broken sleeves in oil fields. The tool comprises the expansion pipe, wherein the two ends of the expansion pipe expand to form an upper expansion cavity and a lower expansion cavity, the lower end of the expansion pipe is connected with a guiding head and is sealed, an expansion head is arranged in the lower expansion cavity of the expansion pipe and located above the guiding head, the expansion head and the lower expansion cavity are sealed through a sealing piece, the upper end of the expansion head is connected with a pull rod in a sealed mode, a seal ring is arranged on the outer circumference of the pull rod in a sleeved mode and located in the upper expansion cavity of the expansion pipe, an inner hole of the seal ring and the pull rod are sealed through a sealing piece, the seal ring and the upper expansion cavity are sealed through a sealing piece, threads are arranged on the outer circumference of the portion, above the seal ring, of the pull rod, a limit ring is installed above the seal ring through the threads and fixes the seal ring into the upper expansion cavity, and the expansion pipe, the pull rod, the expansion head and the seal ring are sealed through the sealing pieces and form a sealing cavity jointly. According to the tool for repairing the sleeve with the expansion pipe, due to the fact that the low-pressure sealing cavity is adopted, force of the expansion head for expanding the expansion pipe can be greatly increased.

Description

technical field [0001] The invention relates to a workover tool used in oil field development, in particular to an expansion pipe repair tool for repairing an oil-water well with casing damage. Background technique [0002] After long-term production of oil wells or water wells in the oil field, casing perforation will occur due to corrosion; sometimes due to stress changes around the underground wellbore, well wall collapse, etc., problems such as casing rupture and fracture will occur. In order to repair downhole casing, a kind of expansion pipe repairing technology has appeared. This technology is to send the small-diameter casing to the damaged casing through the wellbore, and then expand the small-diameter casing to fix it at the damaged casing downhole, so as to repair the damaged casing. Be October 13th, 2006 as the application date, and the application number is 200610016410.0. The Chinese patent titled "expansion pipe combined repairing device" discloses such a rep...

AI Technical Summary

Problems solved by technology

The expansion head is driven by the hydraulic pressure below it to expand the expansion tube. In addition to overcoming the force required to expand the expansion tube, it must also overcome the hydraulic pressure above the expansion head. The lower hydraulic pressure required by the head is very high. Sometimes due to the capacity of the ground out equipment and other issues, it may not be able to provide the lower hydraulic pressure required for the downhole expansion head work.

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