Fishable free falling tubing plug and use method thereof

Abstract

The invention discloses a fishable free falling tubing plug. The improvement is performed on the basis of a ZL201420608036.3 patent, the deformation of an expansion rubber tube is produced after being pressed and the diameter of the expansion rubber tube is increased through the pressure medium energy in an underground tubing, a reliable sealing structure is formed between the expansion rubber tube and an inner hole of the tubing, and the effect plugging is performed on the tubing. The sealing of the plug cannot be affected by the reduction of the external pressure due to the characteristic of the band direction sliding of an open thread locking block. The anchoring with the wall of the inner hole of the tubing is implemented due to the matching of an inclined wedge type slide column and a sliding block slip. Only a fishing head needs to be pulled upward to open a pressure channel when the fishing is required, a protection pressure sleeve and the sliding block slip are driven by the fishing head to move upward relative to the slide column through an underground pressure medium, and accordingly the unlocking is implemented. The effective plugging can be performed on the tubing and the fishable free falling tubing plug can be taken out of the tubing conveniently.

Description

Technical field:

[0001] The invention relates to a blowout prevention plugging device in a high-pressure oil pipe, in particular to a multifunctional oil pipe plug. Background technique:

[0002] When oil wells or water injection wells are used for downhole operations, if there is pressure downhole, it is usually necessary to kill the well or blow out to reduce the pressure.

[0003] For the killing operation, during the operation, the killing fluid will produce sediments and pollute the bottom of the well, and some of them will even seep into the formation along the pores or fractures, blocking the air flow channel, polluting the production layers near the bottom of the well, and affecting the permeability of the formation. , resulting in reduced production and reduced recovery. In addition, for low-pressure oil and gas wells, it is difficult to discharge the killing fluid after operation, which will cause greater damage to the production layer and even kill the well. At ...

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