Composite soluble bridge plug

Abstract

The invention provides a composite soluble bridge plug, and relates to the technical field of oil field downhole tools. The lower end of a setting cylinder is attached to the upper end face of an upper cone, the lower end of a setting rod is in threaded connection with a releasing rod, and the releasing rod is connected with a lower cone through a shear pin; and the upper cone, the lower cone and a fracturing ball are all of hollow structures, and the wall thickness of the hollow outer portions is approximately equal to that of a sealing cylinder. The composite soluble bridge plug has the advantages that the upper cone, the sealing cylinder, the lower cone and the fracturing ball are all made of magnesium-based alloy materials, the wall thicknesses of the hollow structures are the same, the dissolution rate and the dissolution time under the same environment condition are the same, and complete dissolution can be achieved in the later period; and an alloy coating is sprayed to the outer portion of the sealing cylinder, the outer surface of the sealing cylinder and the inner wall of a casing pipe are reliably anchored, sealing is achieved through a sealing ring, the fracturing ball seals the upper pressure, the lower cone of a blind plugging structure seals the pressure of the lower stratum, bidirectional sealing is achieved, and meanwhile fine particles are formed after dissolution and discharged along with flowback fluid.

Description

Technical field: [0001] The invention relates to the technical field of oilfield downhole tools, in particular to a composite soluble bridge plug. Background technique: [0002] In the prior art, a soluble bridge plug is mainly composed of a bridge plug body, anchor slips, and a sealing rubber cartridge, among which the bridge plug body is mainly composed of a soluble metal material, which provides an installation carrier for each component and directly determines the safety of the soluble bridge. The overall reliability of the plug; the anchor slip is composed of soluble metal and alloy particles, which prevent the axial sliding of the soluble bridge plug after being anchored to the inner wall of the casing, and directly determine the axial pressure bearing effect of the soluble bridge plug; Composed of soluble rubber material, it will prevent the liquid from flowing down after being bonded to the inner wall of the casing, which directly determines the sealing effect of the...

AI Technical Summary

Problems solved by technology

[0003] The main body of the anchoring slips is composed of soluble metal and insoluble particles. After dissolution, undissolved residues such as slips and slips remain in the wellbore. In the later stage, coiled tubing strings and fishing tool strings need to be run into the well. , Salvage construction operations, long operating cycle, low salvage efficiency, affecting the construction progress on site, so now there are some soluble bridge plugs, but the structure is more complicated, too many connectors, and the connection method is unreasonable, resulting in processing difficulties and cost too high;

[0004] Notification number CN 110552659 B discloses a metal soluble bridge plug, which includes a setting cylinder, an upper vertebral body, a sealing cylinder, a lower The sealing cylinder, the lower vertebral body and the lower joint are all magnesium-based alloy materials, and the dissolution rate is the same under the same environmental conditions. However, the dissolution rate of the soluble magnesium-based alloy material in a certain solution (mg·cm-2· h-1) is the same, but the volume and thickness of each part are different, and the dissolution time of each part is still different. The pressure of the downhole formation is sealed, but the reverse pressure of the downhole formation cannot be sealed.

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