Novel rotary casing scraper

Abstract

The invention relates a novel rotary casing scrapper. The scrapper comprises a hydraulic drive assembly and a scrapping cutter assembly, the inner wall of an inner tube of the scrapper is fixedly connected with turbines, the inner tube of the scrapper is driven to rotate by the turbines which are impacted by high-pressure water flow, so that the scrapping cutter assembly is further driven to rotate. Every two scissor rods are connected through pins as a group to form a scissor frame structure, a function of radial and straight expanding of scrapping blades is achieved through axial movement ofthe scissor frame. Six oblique holes are formed in the scrapping blades, which are used for jetting out the high-pressure flow in a scrapping process and cleaning the cutter and the inner wall of a casing. A base is connected with a housing of the scrapping cutter through screws, six oblique holes are formed in the base, the holes are used for jetting out the remaining high-pressure water flow and flushing an inner tube of the casing at the lower portion in advance to achieve pretreatment of scrapping. Compared with the traditional casing scrapper, while the function of radial expanding of the scrapping blade is achieved and the diameter of scrapping is increased, the scissor frame structure is more stable, the scrapping efficiency is more significant, the novel rotary casing scrapper also has a cleaning function, and the scrapping capacity is improved.

Description

technical field [0001] The invention relates to the technical field of oil and gas field development, in particular to a novel rotary casing scraper. Background technique [0002] In the process of oilfield exploitation, cement blocks, cement sheath, hard wax, various salt crystals and deposits, perforation burrs and iron oxide produced after casing corrosion are often attached to the inner casing of the casing. The scraper is used to clean the casing inner tube already downhole, so as to improve the success rate of tool running and operation. However, the scraper part of the traditional rubber sleeve type casing scraper adopts a fixed structure, which cannot be expanded and moved radially, resulting in small scraping diameter and low efficiency; while the blades of the spring type casing scraper are mostly supported by radial springs. The spring force is limited, and the scraping force is often insufficient; at the same time, these two kinds of scrapers have no function of...

AI Technical Summary

Problems solved by technology

However, the scraper part of the traditional rubber sleeve type casing scraper adopts a fixed structure, which cannot be expanded and moved radially, resulting in problems such as small scraping diameter and low efficiency; while the blades of the spring type casing scraper are mostly supported by radial springs. The spring force is limited, and the scraping force is often insufficient; at the same time, these two kinds of scrapers have no function of cleaning the tool, and the tool is easy to adhere to various impurities during the scraping process, and even stop the scraper, so that the scraper loses its scraping ability. Affects normal scraping operations, increasing operating costs and operating risks

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