In-pipe packer for highly-deviated deep surface layer well cementation

Abstract

The invention provides an in-pipe packer for highly-deviated deep surface layer well cementation. The in-pipe packer comprises an upper connector, an upper pressing ring, a rubber barrel, a connectingpipe, a central pipe, an inner sleeve, an elastic claw, a lower pressing ring, a back ring, a guide sleeve, a connector and a lower connector. When the pressure borne by the in-pipe packer exceeds 80KN, a clamping claw of the elastic claw contracts inwards, the connecting pipe, the inner sleeve, the elastic claw and the back ring move downwards along the guide sleeve, and the rubber barrel expands under extrusion of the upper pressing ring and the lower pressing ring and is tightly attached to the inner wall of a surface casing pipe, so that sealing in the surface casing pipe is achieved. After well cementation is completed, a drill string is lifted upwards, the rubber barrel recovers to the original shape, and unblocking is achieved. The packer can be repeatedly used for 10 well times or more, the cost is reduced, cement paste return accidents caused by plug sealing failure or setting pressure insufficiency can be avoided, and the success rate of surface casing well cementation is greatly improved.

Description

technical field [0001] The invention relates to an in-pipe packer in the field of petroleum completion engineering devices, in particular to an in-pipe packer for high-inclination deep surface layer cementing. Background technique [0002] With the development of marine extended-reach wells, more and more oil and gas wells need to be oriented at the surface well section. The 339.7mm surface casing is drilled down to a depth of 700m, and the maximum well deviation can reach 70°. The construction risk of the technology is relatively high in deep surface wells with high deviation, and there may be "sausage filling" or "flag pole insertion" accidents caused by cement slurry reversion due to seal failure of the drill pipe plug or insufficient seating pressure, which affects the surface casing. The quality of cementing has also caused serious engineering risks and hidden safety hazards to the later development of oil and gas wells. At present, this kind of high-inclination deep su...

AI Technical Summary

Problems solved by technology

[0002] With the development of marine extended-reach wells, more and more oil and gas wells need to be oriented at the surface well section. The 339.7mm surface casing is drilled down to a depth of 700m, and the maximum well deviation can reach 70°. The construction risk of the technology is relatively high in deep surface wells with high deviation, and there may be "sausage filling" or "flag pole insertion" accidents caused by cement slurry reversion due to seal failure of the drill pipe plug or insufficient seating pressure, which affects the surface casing. The quality of cementing has also caused serious engineering risks and hidden safety hazards to the later development of oil and gas wells. At present, this kind of high-inclination deep surface casing cementing can only be cemented with conventional rubber plugs, which has low displacement efficiency and cement slurry displacement. Difficult to control, difficult to drill rubber plugs, etc.

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