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CN-116556879-B - Metal expansion type open hole packer

CN116556879BCN 116556879 BCN116556879 BCN 116556879BCN-116556879-B

Abstract

The invention provides a metal expansion type open hole packer which comprises a central pipe, an expansion cylinder, a liquid injection channel, a pressure compensation mechanism and a well bore annulus, wherein two ends of the expansion cylinder are respectively connected with the central pipe in a sealing mode through a first sealing component and a second sealing component, a sealing cavity is formed between the expansion cylinder and the radial direction of the central pipe, the liquid injection channel is formed in the first sealing component and is communicated with an inner flow channel of the central pipe and the sealing cavity, the pressure compensation mechanism is formed in the first sealing component and comprises a liquid supplementing channel, a well bore annulus above the metal expansion type open hole packer is communicated with the sealing cavity through the liquid supplementing channel, liquid in the central pipe can enter the sealing cavity through the liquid injection channel through a well head, the expansion cylinder can be expanded in the radial direction until the liquid injection channel is close to a well wall to finish setting, and when the upper pressure born by the metal expansion type open hole packer is larger than the pressure of the sealing cavity, the liquid supplementing channel is used for continuously expanding the sealing cavity, and the metal expansion type open hole packer is filled.

Inventors

  • LIAO HONGQIAN
  • YANG DEJIE
  • ZHANG RUI
  • LI HANG
  • RUAN CHENLIANG
  • CHEN WUJUN
  • SHAO ZHIXIANG

Assignees

  • 中国石油化工股份有限公司
  • 中国石油化工股份有限公司石油工程技术研究院

Dates

Publication Date
20260512
Application Date
20220128

Claims (8)

  1. 1. A metal-expanded open hole packer, comprising: A central tube (2); The expansion cylinder (3) is sleeved on the central tube, the upper end and the lower end of the expansion cylinder are respectively connected with the central tube in a sealing way through a first sealing component (4) and a second sealing component (5), the first sealing component is fixedly connected with the central tube, and a sealing cavity (6) is formed between the expansion cylinder and the radial direction of the central tube; A liquid injection passage formed in the first seal assembly, the liquid injection passage communicating the inner flow passage of the center tube with the seal cavity, and A pressure compensating mechanism (8) formed within the first seal assembly, the pressure compensating mechanism comprising a fluid make-up passage through which a wellbore annulus (101) above the metal extended bore packer communicates with the seal cavity; the well head pressurizing can enable liquid in the central tube to enter the sealing cavity through the liquid injection channel, so that the expansion cylinder radially expands until the expansion cylinder is tightly attached to a well wall to finish setting, and when the upper pressure born by the metal expansion type open hole packer is larger than the pressure of the sealing cavity, the liquid supplementing channel can supplement liquid to the sealing cavity so as to continuously expand and seal the metal expansion type open hole packer; The expansion cylinder comprises a metal inner cylinder (31) and a rubber outer cylinder (32) sleeved on the metal inner cylinder, the metal inner cylinder comprises an expansion section at the axial middle part and connecting sections at two ends, the thickness of the expansion section is smaller than that of the connecting sections, a plurality of annular grooves are formed in the outer surface of the metal inner cylinder, and the annular grooves are uniformly distributed at intervals in the axial direction; The first sealing assembly comprises an upper joint (41) and an upper end ring (42) sleeved on the upper joint, wherein the upper joint is fixedly connected with the central tube and forms sealing, a first through hole (21) is formed in the side wall of the central tube, a first runner hole (411) communicated with the sealing cavity is formed in the upper joint, and the first through hole is communicated with the first runner hole so as to form the liquid injection channel; The side wall of the upper end ring is provided with a second through hole (421), a second runner hole (412) communicated with the sealing cavity is also arranged in the upper joint, the second runner hole and the first runner hole are distributed in a staggered manner in the circumferential direction, and the second through hole is communicated with the second runner hole, so that the fluid supplementing channel is formed; The second sealing assembly comprises a lower joint (51) and a lower end ring (52) sleeved on the lower joint, and a seal is formed between the lower joint and the central tube; the lower joint is provided with a liquid injection hole (511) penetrating along the axial direction and used for injecting liquid into the sealed cavity, and the lower end of the liquid injection hole is provided with a plug (512); The two ends of the expansion cylinder are respectively provided with an anti-protruding unit (9), the anti-protruding unit comprises a first anti-protruding ring (91), a second anti-protruding ring (92) and a third anti-protruding ring (93), the first anti-protruding ring is in contact with the corresponding upper end ring or lower end ring, the third anti-protruding ring is wrapped at the axial end part of the rubber outer cylinder, and the second anti-protruding ring is located between the first anti-protruding ring and the third anti-protruding ring.
  2. 2. The metal extended bore packer of claim 1, wherein the rubber outer cylinder is attached to the outer surface of the metal inner cylinder by vulcanization.
  3. 3. The metal extended bore packer of claim 2, wherein an inner diameter of the expansion section is configured to be greater than an inner diameter of the connection section and form a circular arc transition at a junction of the expansion section and the connection section.
  4. 4. The metal extended open hole packer of any one of claims 1 to 3, wherein an upper end of the metal inner cylinder extends between and is fixedly connected to the upper joint and the upper end ring.
  5. 5. A metal extended bore packer according to claim 1, characterised in that a first non-return valve (71) is provided in the injection channel.
  6. 6. The metal extended bore packer of claim 1, wherein a second check valve (82) is provided within the fluid make-up passage.
  7. 7. The metal extended open hole packer of claim 4, wherein a lower end of the metal inner cylinder extends between and is fixedly connected to the lower joint and the lower end ring.
  8. 8. The metal extended bore packer of claim 1, wherein the third anti-extrusion ring is configured to be capable of expanding in response to radial expansion of the expansion cylinder and to always wrap around an axial end of the rubber outer cylinder.

Description

Metal expansion type open hole packer Technical Field The invention belongs to the technical field of well completion in petroleum industry, and particularly relates to a metal expansion type open hole packer. Background Open hole staged fracturing is one of the effective processes for improving single well production and realizing single well uphole production. Compared with a compression type open hole packer, the expansion type packer has the advantages of larger expansion ratio, longer sealing section, stronger irregular adaptability of the borehole and larger advantage in open hole layering. However, with the development of ultra-deep wells and hot dry rock, the temperature resistance requirement of the packer reaches more than 200 ℃. At present, most of existing open hole packers use rubber barrels or steel belt rubber barrels as sealing units for interlayer separation, and the high temperature and high pressure resistance and the reliability of the existing open hole packers are insufficient. For example, many existing open hole packer seals result in poor temperature resistance. The inner diameter of the sealing rubber cylinder is smaller, so that the inner diameter of the downhole tool is small, the large-displacement acid pressure is difficult to realize, and the operation efficiency is low. In addition, the existing open hole packer is poor in tightness, and can not realize durable and effective sealing of the packer in a high-temperature environment, so that the reliability is poor, and the open hole staged fracturing requirement of a high-temperature high-pressure well can not be met. Disclosure of Invention Aiming at the technical problems, the invention aims to provide the metal expansion type open hole packer which can remarkably enhance the temperature resistance, greatly improve the bearing and pressing reliability of the packer and realize the durable and effective sealing of the packer in a high-temperature environment. The invention provides a metal expansion type open hole packer which comprises a central pipe, an expansion cylinder sleeved on the central pipe, wherein the upper end and the lower end of the expansion cylinder are respectively connected with the central pipe in a sealing mode through a first sealing component and a second sealing component, the first sealing component is fixedly connected with the central pipe, a sealing cavity is formed between the expansion cylinder and the radial direction of the central pipe, a liquid injection channel is formed in the first sealing component and is communicated with an inner flow channel of the central pipe and the sealing cavity, a pressure compensation mechanism is formed in the first sealing component and comprises a fluid supplementing channel, a shaft annulus above the metal expansion type packer is communicated with the sealing cavity through the fluid supplementing channel, liquid in the central pipe can enter the sealing cavity through the liquid injection channel through a wellhead to enable the expansion cylinder to be expanded radially until the expansion cavity is tightly attached, and the metal expansion type packer can be further sealed with the open hole cavity through the pressure supplementing channel when the open hole is subjected to open hole pressure. In one embodiment, the expansion cylinder comprises a metal inner cylinder and a rubber outer cylinder sleeved on the metal inner cylinder, and the rubber outer cylinder is attached to the outer surface of the metal inner cylinder in a vulcanization mode. In one embodiment, the metal inner tube includes an expansion section at an axial middle portion and connection sections at both ends, and the thickness of the expansion section is set smaller than that of the connection sections. In one embodiment, the inner diameter of the expansion section is set to be larger than the inner diameter of the connection section, and an arc transition is formed at the connection of the expansion section and the connection section. In one embodiment, the outer surface of the metal inner cylinder is provided with a plurality of annular grooves, and the plurality of annular grooves are uniformly distributed at intervals in the axial direction. In one embodiment, the first sealing assembly comprises an upper joint and an upper end ring sleeved on the upper joint, the upper joint is fixedly connected with the central tube and forms a seal, and the upper end of the metal inner cylinder extends to a position between the upper joint and the upper end ring and is fixedly connected with the upper joint. In one embodiment, a first through hole is formed in the side wall of the central tube, a first runner hole communicated with the sealing cavity is formed in the upper joint, and the first through hole is communicated with the first runner hole, so that the liquid injection channel is formed. In one embodiment, a first one-way valve is disposed within the priming channel. In one embodiment,