Cased well tractor crawling device

Abstract

The invention discloses a cased well tractor crawling device used for crawling in a casing pipe. The cased well tractor crawling device comprises a gear sleeve assembly, a driving arm assembly and a brace rod assembly. The gear sleeve assembly comprises a driving bevel gear, a first driven bevel gear engaged with one side of the driving bevel gear, and a second driven bevel gear engaged with the other side of the driving bevel gear. The driving arm assembly is connected with the gear sleeve assembly and comprises a first transmission mechanism, a second transmission mechanism, a first crawling unit and a second crawling unit, the first driven bevel gear and the first crawling unit are connected through the first transmission mechanism, the second driven bevel gear and the second crawling unit are connected through the second transmission mechanism, the first crawling unit and the second crawling unit are oppositely arranged, and the first crawling unit and the second crawling unit have the same rotating speed but the opposite rotating directions and are used for grabbing or loosening the inner wall of the casing pipe. The brace rod assembly is connected with the driving arm assembly and slides in the axial direction of the casing pipe so as to drive the first crawling unit and the second crawling unit to be relatively staggered or get close.

Description

technical field [0001] The invention relates to the technical field of horizontal well logging instruments, in particular to a crawling device for a cased well tractor. Background technique [0002] With the rapid development of horizontal well drilling technology, the number of horizontal well completions has increased sharply. In recent years, the large-scale development of shale gas in China has further promoted the development of horizontal well technology. The use of logging instruments or downhole tools in shale gas horizontal wells Transportation has become an urgent technical problem in the field of oilfield logging. [0003] As a new type of logging tool delivery tool, the cased hole tractor overcomes the difficulty that logging tools are difficult to drop due to borehole curvature, and greatly improves the quality of logging and logging tools compared with conventional delivery techniques. The reliability of the well, so the research and development of the cased h...

AI Technical Summary

Problems solved by technology

[0005] 1. Since the cased well tractor works in the harsh environment in the horizontal well for a long time, the crawling device in the prior art has poor high temperature and high pressure resistance, and cannot withstand the long-term corrosion of the strong corrosive mud downhole;

[0006] 2. Some downhole operations need to transport heavy and long logging tools or downhole tools such as perforating guns and cables dragged by downhole operations, and the inner wall of the casing in the horizontal section of the oil well is dirty, the downhole mud of the oil well is too thick, and the oil well Casing deformation and other conditions, as a transport tool, the cased well tractor has a large load, and the crawling device is often unable to provide sufficient driving force; when the well deviation in the horizontal section of the oil well is particularly large, such as exceeding 105°, the crawling device cannot provide sufficient driving force. driving force, and the transmission efficiency of the transmission system is not high;

[0007] 3. Some oil wells have a particularly long crawling distance of more than 2,000 meters in the horizontal section, and sometimes need to crawl back and forth multiple times, but the reliability of the crawling device is not high, and the wear resistance is not good, so it cannot meet the requirements of multiple long-distance reciprocating crawling;

[0008] 4. The small space of the horizontal well makes the working space of the cased well tractor limited, while the crawling device in the prior art has a large volume and limited scope of application

Images