Casing scraper for oil field

Abstract

The invention relates to an oilfield workover equipment, in particular to a casing scraper for an oilfield, which belongs to the technical field of petroleum equipment. Driven by the wellhead power part, the screw drilling tool drives the scraper to rotate in the casing, and the moving outer casing overcomes the elastic force of the spring and moves downward along the inner casing body of the fixed inner casing under the action of the high-pressure circulating fluid delivered by the upper screw drilling tool. The scraper connecting plate drives the scraper to extend outward along the scraper chute of the cylinder to scrape the inner wall of the casing within a certain diameter range. Movement, and increase the opening of the arc-shaped path plate through the path knife connecting plate, and then drive the arc-shaped path knife to carry out the path, and the scraper and the arc-shaped path knife complete the scraping and path action at the same time under the hydraulic drive , The lower diameter operation and the upper scraping operation are completed at the same time, which significantly reduces the difficulty of scraping, effectively avoids the phenomenon of knife jamming, and at the same time protects the scraper and improves scraping efficiency.

Description

technical field [0001] The invention relates to an oilfield workover equipment, in particular to a casing scraper for an oilfield, which belongs to the technical field of petroleum equipment. Background technique [0002] Casing scraping is a common procedure in workover operations and an important means of casing repair. At present, the casing scraper is often used to remove cement blocks, cement sheaths, hard wax, various salt crystals and deposits, perforation burrs, and iron oxide produced after casing corrosion on the casing inner wall, so as to Various downhole tools can be run smoothly, especially when the annular space between the downhole tool and the inner wall of the casing is small, sufficient and thorough scraping should be carried out. [0003] The existing casing scraper mainly has the disadvantages of the following three aspects: first, the scraper cannot scrape casings within a certain diameter range; When the volume or hardness of cement blocks, cement ri...

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Problems solved by technology

[0003] The existing casing scraper mainly has the disadvantages of the following three aspects: first, the scraper cannot scrape casings within a certain diameter range; When the volume or hardness of cement blocks, cement rings, hard wax, etc. are large, scraping with a scraper directly will not only easily damage the cutter and affect the scraping effect, but also easily cause the cutter to jam and affect the normal operation of scraping; When the scraper performs scraping operations, it directly scrapes the contact surface between the casing wall and the attachment. The scraper is subjected to a large scraping force, and the scraper is easily damaged. It will also be jammed due to too much scraping force, resulting in the failure of the scraping operation. conduct

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