Damaged oil casing plugging device and method

Abstract

The invention discloses a damaged oil casing plugging device and method, and relates to the field of oil and gas. The device comprises an upper oil pipe, a well washing snapping assembly, a lower oil pipe, a cup packer assembly, a connecting pipe and a horn mouth. The well washing snapping assembly comprises an upper connector, an insertion pipe, a well washing hole and a lower connector, and the upper oil pipe and the lower oil pipe are connected through the well washing snapping assembly; in the plugging process, the insertion pipe and the lower connector are connected through a locking structure, and the well washing hole is sealed. In the well washing process, the well washing hole is exposed and used for washing redundant cement paste in the casing pipe; in the oil pipe separation process, the locking structure between the insertion pipe and the lower connector is unlocked, and the upper oil pipe is separated from the lower oil pipe; the leather cup packer assembly comprises a leather cup packer upper joint, a leather cup and a leather cup packer lower joint, and the lower oil pipe is connected with the connecting pipe through the leather cup packer; in the plugging process, the leather cup is used for bearing cement paste, and the damaged opening of the casing pipe is plugged through the cement paste; cement paste injected through the upper oil pipe is drained to the well bottom through the horn mouth.

Description

technical field [0001] The embodiments of the present application relate to the field of oil and natural gas, and in particular, to a device and method for plugging a damaged oil casing. Background technique [0002] Oil casing is a steel pipe used to support the wall of oil and gas wells to ensure the normal operation of the entire oil well after drilling and completion. For each well, the length and diameter of the casing are determined according to different drilling depths and geological conditions. [0003] In the related art, the casing is a large-diameter pipe, which plays the role of fixing the wall or hole of the oil and natural gas oil well. The casing is inserted into the wellbore and fixed with cement to help the wellbore separate the rock formations and prevent the wellbore from collapsing, while ensuring the circulation of drilling mud to facilitate drilling and mining. [0004] However, at present, most of the damaged casings are plugged with plugging agents...

AI Technical Summary

Problems solved by technology

[0004] However, at present, most of the damaged casings are plugged with plugging agent and double plugging isolator, but the compressive strength of plugging with plugging agent is difficult to meet the requirements of later fracturing construction, so double plugging isolator is used The plugging method is also difficult to achieve plugging for oil wells with large inclinations.

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