Mortar-injecting well cementing technology and casing pipe butting mortar-injecting device

Abstract

The invention discloses a mortar-injecting well cementing technology and a casing pipe butting mortar-injecting device. In the construction process, the casing pipe butting mortar-injecting device isconnected with a lower well casing pipe, well washing is conducted by pumping direction circulation workover fluid, a circulating channel is that the workover fluid passes through a casing pipe innercavity, a liquid inlet, a check valve, a liquid outlet and a through hole and then is returned from an outer annulus of the casing pipe to the ground, and pressure of well washing and the suspending weight of a pipe string are observed; after the pressure of well washing and the suspending weight of the pipe string are normal, the pipe string is slowly rotated and put down, so that the casing pipebutting mortar-injecting device butts joint with a lower casing pipe in a screw thread mode; and after abutting joint, mortar is injected through the circulating channel to realize well cementing, and after cement is solidified, a casing milling fishing tool is run into, so that casing milling is conducted on a blind plate on the outer side of a center pipe, and the center pipe is fished out. According to the mortar-injecting well cementing technology and the casing pipe butting mortar-injecting device, operability is high, perfect combination of casing pipe butting and the well cementing technology is effectively realized, well cementing operation is achieved while casing pipe butting is finished , and the quality of a well body is improved.

Description

technical field [0001] The invention belongs to the technical field of oil-water well workover in the petroleum industry, and in particular relates to an ash injection cementing process after casing tie-back and a special casing butt joint device. Background technique [0002] In the process of oil field development, with the prolongation of production time and the continuous deterioration of downhole working conditions, the casing in the well will be damaged in the form of dislocation, etc., and replacement of the casing is a common repair method. [0003] In the prior art, Chinese patents with application numbers 201320799497.9 and 201520888417.6 respectively disclose a casing tie-back guiding centralizer and a casing stabbing device, both of which include casing collars, centralizers and guide shoes. In the construction of casing replacement in workover operations, the damaged casing in the well is firstly taken out, and then according to the buckle type of the fish top o...

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Problems solved by technology

[0004] However, neither of the above two methods can realize the cementing operation while the casing is docked, so as to improve the quality of the wellbore

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