Full-soluble fracture bridge plug with novel structure

Abstract

The invention discloses a full-soluble bridge plug with a novel structure, and belongs to a bidirectional locking single-slip full-soluble bridge plug. The full-soluble bridge plug comprises a male tap, a sealing assembly, a screw, a slip female tap, a slip ring, a shear ring pressing cap, a base, a shear ring, a shear ring seat, a soluble ball and the like. The tap surface of the male tap is sleeved with the sealing assembly and the slip female tap; the sealing assembly comprises a wedge-shaped rubber barrel, a rubber pad and a metal ring; the slip female tap is of a radial elastic claw structure; one to three rectangular ring grooves are formed in the outer portion of the slip female tap; a plurality of slip particles are assembled in the ring grooves to form the slip ring; a male ratchet and a female ratchet are arranged on the male tap and the slip female tap respectively; and during setting, the male and female ratchets are tightly engaged into a whole, the tooth tip of the slip ring is fully engaged into the inner wall of a casing pipe, and the bridge plug is bidirectionally locked on the inner wall of the casing pipe. The bridge plug can be dissolved by fracturing flow-back fluid or oil and gas reservoir well fluid, is small in size and higher in applicability, and improves the fracturing well completion efficiency.

Description

technical field [0001] The invention belongs to downhole tools in the field of oil and gas exploration and development, and in particular relates to a fully soluble fracturing bridge plug with a new structure. Background technique [0002] In the process of oil and gas development, especially in the development of unconventional oil and gas, tight oil and gas, and low permeability oil and gas, a large number of multi-stage and staged fracturing technologies with perforating guns and bridge plugs are used, and the fracturing bridge plugs are used as Isolation tools between construction sections and fracturing bridge plugs currently mostly use composite drillable bridge plugs, which require drilling bridge plugs and are costly; in recent years, dissolvable bridge plugs have appeared, which can theoretically realize bridge plug free However, the current application status is: after a well completes multi-stage fracturing, it is still necessary to clean the drilling plugs and dr...

AI Technical Summary

Problems solved by technology

[0002] In the process of oil and gas development, especially in the development of unconventional oil and gas, tight oil and gas, and low permeability oil and gas, a large number of multi-stage and staged fracturing technologies with perforating guns and bridge plugs are used, and the fracturing bridge plugs are used as Isolation tools between construction sections and fracturing bridge plugs currently mostly use composite drillable bridge plugs, which require drilling bridge plugs and are costly; in recent years, dissolvable bridge plugs have appeared, which can theoretically realize bridge plug free However, the current application status is: after a well completes multi-stage fracturing, it is still necessary to clean the drilling plugs and drill out the undissolved bridge plugs. The drilling time of a single undissolved bridge plug is more time-consuming than that of a composite bridge plug. Therefore, there are still deficiencies in the current metal soluble bridge plugs, mainly as follows: (1) Most of the sites are double-slip soluble bridge plugs, which take a long time to dissolve and produce a lot of dissolved plaster, which is easy to stick to the undissolved metal surface and block The electrochemical reaction between the well fluid and the metal surface is hindered, resulting in slow or even insoluble dissolution; (2) improper material selection or lack of good surface treatment technology, resulting in partial or even complete dissolution before construction; (3) in the anchor In terms of fixing, there are two main forms of existing soluble bridge plugs: one is the non-slip soluble bridge plug, which is anchored by the friction between the nickel alloy coated on the slip body and the casing. It is only suitable for low-pressure new wells; the other is ceramic or hard alloy cylindrical blocks obliquely installed as slip teeth. When the slips and casing are anchored, they are point-contact and stressed, and they are easy to break. Tooth, it will lead to failure of setting or slippage of setting, and the slip particles are insoluble and non-magnetic, so they cannot be salvaged with magnetic fishing tools; (4) The single-slip soluble bridge plugs that appear at present also have a long overall length , There is no two-way stuck function, and there are still functional hidden dangers of incomplete dissolution, and safety hidden dangers of being pushed out of the wellbore in the opposite direction; The remaining shear nails sometimes cause the set bridge plug to be unsealed again, and the reliability is low

In short, in addition to the above problems, the current soluble bridge plugs also have many problems such as short pressure holding time, slow or too fast dissolution, limited temperature range, low reliability, and high cost.

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