Case Study Expandable Steel Packers Prove 30% More Cost-Effective for Stage Cementing
Lost circulation zone successfully isolated in 10 deviated, undergauge boreholes.
External casing packer
Expandable packer provides an effective and dependable steel barrier in the casing-borehole annulus, irrespective of hole shape and condition
Overview
Applications
- Cement backup
- Primary cement improvement
- Single-stage, multistage, or off-bottom cementing
Use cases for the external casing packer include stage cementing (left), off-bottom cementing above a low-pressure completion (center), and cementing above a lost circulation zone (right).
Benefits
Our external casing packer provides an effective steel barrier between the casing and borehole to prevent fluid migration in the annulus, eliminate crossflow during cementing, and stop gas migration during cement setting. It seals in any hole shape and condition, including oval, out-of-gauge, and irregular boreholes. The packer maintains casing rating by avoiding extra connections or casing ID reduction.
Rapid installation, on-demand expansion, and immediate sealing save rig time. The robust construction withstands reciprocation and rotation to pass through doglegs and tight spots, minimizing NPT.
Features
- Simplified setting process with no moving parts
- Compatibility with standard casing
- Burst and collapse ratings equivalent to casing ratings
- HNBR elastomer to ensure sealing even in washed-out zones
- Self centralization during expansion
Case Studies
FAQs
Schematic of the setting process for an external casing packer.
How is the packer set?
The packer sleeve is expanded between the casing and borehole by applying pressure in the casing. This pressure is transmitted through the expansion port to the packer’s integral stainless steel sleeve. As the sleeve expands, it conforms to the shape of the wellbore. A patented thin layer of bonded elastomer ensures sealing in irregular boreholes. The expanded sleeve also serves to centralize the casing string.
The packer is built on a one-piece mandrel by crimping, with no hidden connections. Both ends are fixed and protect the expandable sleeve while running in hole. The robust construction allows the packer to be rotated and worked through doglegs and tight spots; full casing characteristics are maintained.
The expansion port features a valve system that permanently closes the port after the packer is set and a predetermined pressure is reached. This activation pressure can be modified by replacing an easily accessible shear pin. The valve also serves as a safety feature; if the packer is expanded in front of a severe washout, the valve closes, which prevents fluid loss.