Cement sheath eccentric rolling extrusion crushing tool for long-service-life auxiliary sleeve recovery

Abstract

A long-service-life cement sheath eccentric rolling extrusion crushing tool assisting in casing recycling comprises a main shaft, an upper roller, a piston, a torque clamping sleeve, a movable roller, a lower roller, bearings, a centralizer and a lower connector, the movable roller is installed on the main shaft through the two sets of bearings and the torque clamping sleeve under the action of the centralizer, and the movable roller is located between the upper roller and the lower roller; an upper roller and a lower roller are mounted on the main shaft through two groups of bearings, a lower joint is mounted at the bottom of the main shaft in a threaded connection manner, a cylindrical water nozzle is formed in the lower joint, the internal throttling pressure difference of the tool can be controlled by adjusting the diameter of the cylindrical water nozzle, the total lateral thrust of a piston is controlled, and the movable roller'rolls' a sleeve in a rolling contact manner; the process is similar to the road surface rolled by automobile wheels, the radial damage width of the damage of the cement sheath is gradually increased under the upward pulling action of a drilling machine until the whole expected underground well cementation cement is completely damaged, and the method has positive reference and popularization value for improving the casing recovery operation mode.

Description

technical field [0001] The invention relates to an eccentric rolling extrusion and crushing tool of a cement sheath for auxiliary casing recovery with long life, belonging to the technical field of abandoned well casing recovery operation. Background technique [0002] The development of oil and gas wells has entered the middle and late stage, the oil and gas resources are gradually exhausted, and a large number of oil and gas wells have been permanently abandoned. The number of oil and gas wells that need to be abandoned is increasing year by year. The "GB2019 Oil and Gas Drilling Ocean Abandoning Operation Regulations" requires that the appropriate well depth should be selected for the abandonment operation, and the casing should be cut and recovered from the inner layer to the outer layer. The purpose of permanent plugging is to realize the isolation of oil and gas and prevent the leakage of residual oil and gas from causing marine ecological pollution and damage. This g...

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Problems solved by technology

[0002] The development of oil and gas wells is in the middle and later stages, oil and gas resources are gradually exhausted, and a large number of oil and gas wells are permanently abandoned. When using underwater wellhead devices, permanent well abandonment operations should be carried out in accordance with industry requirements. Temporary well abandonment and exploration wells must be permanently abandoned. The number of oil and gas wells to be abandoned is increasing year by year. The "GB2019 Oil and Gas Drilling Marine Abandonment Operation Regulations" requires that the abandonment operation should select an appropriate well depth, cut and salvage the casing from the inside to the outside, and then use cement Permanent plugging, the purpose is to realize the isolation of oil and gas, and prevent the leakage of residual oil and gas from causing marine ecological pollution and damage. This greatly increases the resistance to pulling out the casing, making it difficult or even impossible to pull out the casing from the wellbore. Cutting a small section of casing first and then pulling it out successively will increase the chance of abandoning the well. Operation cycle and cost. In short, the traditional method of recovering casing in well abandonment operation is far from meeting the market demand of well abandonment operation. It is necessary to develop new technologies based on innovative means to improve it

[0003] Publication number CN112610177A, the Chinese patent dated April 6, 2021 discloses an extrusion device and extrusion operation method for recovery of abandoned well casings. The "extrusion ring" of the patent follows the "core column" Rotate together, its "core column" is severely worn during use due to direct frictional contact with the casing, and the loss of parts is accelerated, and one end of its "extrusion block" directly bears all axial tension during eccentric extrusion operations , which will cause it to be easily deformed, which will lead to seal failure and reduce the service life of the entire tool, which is not conducive to the smooth progress of casing recovery operations

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