Casing centralizer for well cementation construction and method

Abstract

The invention relates to the field of oil exploitation equipment, in particular to a casing centralizer for well cementation construction and a method. According to the technical scheme, a second centralizing device is arranged in the middle of a base pipe, an upper sealing device and a lower sealing device are arranged on the two sides of the second centralizing device respectively, an upper sealing cylinder sleeve of the upper sealing device is fixed to the outer wall of the base pipe, an upper sealing piston is arranged in an inner cavity of the upper sealing cylinder sleeve, and the lower end of the upper sealing piston is matched with an upper hydraulic sealing rubber cylinder arranged on the outer wall of the base pipe; a lower sealing cylinder sleeve of the lower sealing device is fixed to the outer wall of the base pipe, a lower sealing piston is installed in an inner cavity of the lower sealing cylinder sleeve, the second centralizing device adopts a four-connecting-rod adjusting centralizer, and when a water-swelling rubber block or oil-swelling rubber swells, the four-connecting-rod adjusting centralizer can be pushed to deform and adjust, so that centering and centralizing of a casing pipe are achieved; the mechanical four-connecting-rod adjusting centralizer is adopted to achieve large-amplitude deformation adjustment, and the centering and centralizing effects are better achieved when a casing pipe, a packer and the like are tripped into a shaft.

Description

technical field [0001] The invention relates to the technical field of oil exploitation equipment, in particular to a casing centralizer and method for well cementing construction. Background technique [0002] At present, in the process of oil extraction, well cementing is one of the important processes in the process of oil and gas extraction. Specifically, after the drilling is completed, it is necessary to cement the well and run the casing, and it is necessary to run the packer to carry out multiple oil layers. Separate sealing and isolation, in which the centering of the casing is the key to running the packer, it is an effective guarantee for the separate sealing of each oil layer, and it is the most important factor to ensure the quality of cementing and the effect of later development, otherwise, it will be serious. Affect subsequent oil and gas production and oil well life. [0003] The publication number of the Chinese patent document is CN211115835U, and the pat...

AI Technical Summary

Problems solved by technology

The elastic framework of this utility model can ensure the centering degree of the casing string in the well cementing construction, increase the local turbulent flow of the cement slurry at the centralizer during the cementing process, thereby improving the cementing quality, but the existing problem is: elasticity The skeleton wears a lot on the cemented well wall, and the well wall and centralizer are hard ground

The existing problem is: although rollers are used for straightening, rolling fit is realized, and the straightening method of hard grinding is eliminated, but the rollers used in this patent are of a fixed structure and cannot be expanded or contracted. Wells or horizontal wells, etc., the roller will fail, and it will still be a hard friction straightening method or no straightening function

The existing problem is: the diameter change is realized by the spring, and its range is limited, and a small diameter change can be realized, but it still cannot meet the requirements in the case of inclined wells or horizontal wells.

[0006] In recent years, studies have found that the cementation interface is weak, which may lead to micropores between the packers during the running process, and then in the long-term use, it may cause the failure of the packer between layers, resulting in the failure of different layers. Inter-channel channeling and pipe leakage affect the production efficiency and safety of oil and gas wells

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