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Zonal Isolation Packers

 AZIP 0 0

Zonal Isolation with Steel Packers: working principles

Annulus Zonal Isolation Packers (AZIP) are slid onto the completion casing, and sealed by welding or crimping. Hydraulic pressure is applied in the completion casing, to expand the metallic sleeves through an inflation port, up to the contact with the formation or casing there are set in. The stainless steel plastic deformation creates a solid and permanent annulus seal.

 

Zonal Isolation - Features and benefits with Saltel Packers

Saltel Expandable Steel Annulus Zonal Isolation Packers are robust to run, set quickly, and ensure high pressure life of well seal. This is the ideal solution for annulus zonal isolation. the expandable steel zonal isolation packer seals effectively, including in oval, out-of-gauge, and irregular boreholes. It provides a cost-effective solution for the life of the well. The packer seals reliably through thermal cycling and temperature fluctuations. It minimizes cost with no special well fluid requirements for expansion, and saves time with on-demand expansion and immediate sealing.

Annulus Zonal Isolation Packers : More details

Saltel Zonal Isolation Packer uses proprietary expandable stainless steel technology and a patented thin layer of bonded elastomer to achieve zonal isolation during injection, production, and cementing operations. Each Zonal Isolation Packer displays specific features and performances depending on the application and the well configuration.

Injection and production

Saltel Zonal Isolation Packer is made up to a casing string, which is run into an open or cased hole. The lower end of the string is sealed with a plug and the internal pressure increased by pumping from surface. This pressure is transmitted to the packers’ integral stainless steel sleeve through the expansion port. The sleeve expands out into the annulus between the casing and borehole or outer casing string, conforming to the shape of the wellbore or casing and isolating the annulus below the Zonal Isolation Packer from the annulus above. Alternatively, one or more packers can be used for selective multizonal production or to prevent zonal crossflow, conduct multizonal acidizing, seal off a water zone, or perform other remedial operations.

 Applications

  • Zonal Isolation Horizontal, deviated, and vertical open hole
  • Annulus integrity Vertical, deviated, or horizontal open hole
  • Stage cementing 
  • Cement backup

Off-bottom cementing

For off-bottom cementing, the packer is again run in as part of the casing string and expanded to isolate the annulus below from the annulus above. Cement is pumped above the packer through the side ports of a stage collar or differential valve (DV) tool; the ports are closed when cementing is complete.

Off-bottom cementing can be used, for example, to place primary cement above an uncemented completion that is subsequently subjected to high-pressure hydraulic fracturing. Saltel Zonal Isolation Packer can be set in the previous casing or in open hole. During stimulation operations, it forms a high-pressure barrier that both seals the annulus and protects the cement.

Stage cementing

A similar process is used for stage cementing (e.g., to bypass a thief zone or avoid formation breakdown due to high hydrostatic pressures). The first (or bottom) cement stage is pumped through the stage collar to the end of the casing and up the annulus to the calculated height. Subsequently, the Zonal Isolation Packer is expanded, the side ports of the stage collar are opened, and the second cement stage is pumped above the packer. The isolation packer forms a barrier between the two annular sections.

Cement backup

Set in the uncured cement sheath, Saltel Zonal Isolation Packers can be used to compartmentalize the annulus into independent parts, preventing channeling and micro annulus from spreading. The permanent expanded metal sleeves enhance the integrity of the annular seal and provide backup to the cement during the life of the well.

Robust construction

The packer is built on a one-piece mandrel by welding or crimping, with no hidden internal connection. Both ends are fixed and protect the expandable sleeve while running into the well. In addition to providing zonal isolation, expansion of the packer also centralizes the casing string.

Welded Zonal Isolation Packers are available in standard materials and provide life-of-well isolation in sweet environments.

Crimped Zonal Isolation Packers are available in both standard and customized materials, and are suitable for sour environments.