Well completion pipe string

Abstract

The invention discloses a well completion pipe string comprising a bushing. Two floating couplings are arranged on a horizontal section of the bushing. Each floating coupling comprises a shell, an upper slide sleeve and a lower slide sleeve, the upper slide sleeve comprises a communication portion and a shear portion, the shear portion is supported on the upper section of the inner wall of the shell through an upper shear pin, the lower slide sleeve is supported on the lower section of the inner wall of the shell through a lower shear pin, the communication portion is disposed in the lower slide sleeve, and a discharge hole is formed in the communication portion; an annular steady flow groove is formed in the upper end face of the shear portion, and the width of the steady flow groove decreases axially along the shear portion. The floating couplings are arranged on the bushing to enable the bushing to be filled with air; since the bushing below the floating couplings is filled with air, after the section of the bushing enters a horizontal well section, gravity acting on the horizontal well wall is reduced, friction force between the bushing and the well wall is reduced accordingly, thrust pushing the bushing forward is reduced, and accordingly quality of well cementation of the horizontal section is improved beneficially, and convenience is brought to the bushing to lower to the design position.

Description

technical field [0001] The invention relates to the field of oil exploitation, in particular to a completion pipe string. Background technique [0002] The completion of extended-reach horizontal wells is characterized by high inclination, long open hole, and long section of stabilizing well. In the case of high inclination angle, the casing string is close to the lower well wall. After entering the horizontal section, the casing string will be completely attached On the lower well wall, the contact section between the casing string and the formation is very long at this time, and the casing string is loaded on the horizontal section of the well wall. The friction resistance of the formation to the casing string is quite large, and it cannot even go down to the bottom of the well by its own weight. , It needs to be pressurized to slide down, and it is easy to cause the casing string to buckle, and it may even cause the casing string to be stuck in the curved section of the w...

AI Technical Summary

Problems solved by technology

[0002] The completion of extended-reach horizontal wells is characterized by high inclination, long open hole, and long section of stabilizing well. In the case of high inclination angle, the casing string is close to the lower well wall. After entering the horizontal section, the casing string will be completely attached On the lower well wall, the contact section between the casing string and the formation is very long at this time, and the casing string is loaded on the horizontal section of the well wall. The friction resistance of the formation to the casing string is quite large, and it cannot even go down to the bottom of the well by its own weight. , it needs to be pressurized to slide down, and it is easy to cause the casing string to buckle, and it may even cause the casing string to be stuck in the curved section of the wellbore due to the high rigidity of the casing and cannot be run in

Due to the high frictional resistance of the casing string, the casing string often cannot go down to the predetermined position smoothly, delaying the construction progress, affecting the subsequent oil recovery effect, and even causing serious consequences of wellbore scrapping

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