Pipe string for well completion and cementation and method

Abstract

The invention discloses a pipe string for well completion and cementation and a method, and belongs to the field of oil exploitation equipment. The pipe string comprises a sleeve string, an upper packer, an annular hollow casing, a lower packer, a ball base casing and a float shoe which are connected and communicated with one another from top to bottom. The pipe string also includes a ball base arranged in the ball base casing through shearing nails, a cement slurry outlet hole is formed in the upper end of the upper packer, and a cement slurry inlet hole is formed in the lower end of the lower packer. An annular cavity is formed in the wall of the annular hollow casing, and the upper and lower ends of the cavity are communicated with the cement slurry outlet hole and the cement slurry inlet hole respectively. By using the upper and lower packers to isolate an oil layer, cement slurry is not directly in contact with the oil layer, pollution caused by the cement slurry to the oil layeris avoided, the cement slurry is prevented from extruding the oil layer and causing a leakage problem, and the leakage problem of the oil layer is solved. In short, the pipe string for the wall completion and cementation and the method can not only ensure well completion and cementation operation but also increase the success rate of the well completion and cementation operation.

Description

technical field [0001] The invention relates to the field of oil exploitation equipment, in particular to a cementing and completion pipe string and a method thereof. Background technique [0002] As an essential part of oilfield exploitation, cementing and completion operations are not only related to whether the oil well can be successfully completed, but also affect the quality, life span and production of the oil well after it is put into production. In order to improve the quality of cementing and completion and reduce the accident rate, it is necessary to provide an effective cementing and completion string. [0003] The prior art provides such a cementing and completion string: the string includes a completion casing, a rubber plug, a cement injector, a packer outside the casing and a blind plate. The completion casing is lowered into the wellbore, and its lower part is installed and connected with a cement injector, a casing outer packer and a blind plate in sequenc...

AI Technical Summary

Problems solved by technology

[0005] During the cementing and completion process, the cement slurry entering the wellbore may cause pollution to the oil layer, and the pressure bearing capacity of the oil layer is limited. The cement slurry with a high density can easily leak the oil layer, causing serious leakage, resulting in the failure of the cementing and completion operation

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