Successful Xpandable Steel external casing packer (ECP) installation in Plug and Abandonment application – Middle East
The context
The client faced a challenging Plug and Abandonment project in a multilateral well. They needed to isolate the lower zone, which produced water, in a 5-3/4in horizontal openhole section to increase the oil flow rate from the upper layer and evaluate the reservoir quality for future development opportunities. To accomplish this, the client needed an isolation packer as part of a P&A kit, which could isolate the water zone before installing the upper completions. However, traditional inflatable packers were not suitable due to the potential for damage during RIH through highly deviated holes and crossing sidetrack-cut windows. Schlumberger provided a robust alternative that could withstand aggressive conditions, such as circulation and rotation during RIH, with a high torque capacity. The packer also had to have a solid anchoring performance once set, enabling the launch of a mechanical release overpull in a contingency plan if the hydraulic release mechanism failed.
Challenge
In the process of plugging an open hole, it is important to have a robust open hole packer that can withstand the harsh conditions that may be encountered. The packer is designed to create a seal around the outside of the casing, which prevents fluid from flowing between the casing and the formation.
When setting an open hole plug, the packer is run into the wellbore and positioned at the desired depth. Once in position, the packer is expanded against the wall of the wellbore using hydraulic pressure, which creates a seal around the outside of the casing. This seal prevents any fluid from flowing through the annulus and up the wellbore.
Aggressive conditions such as cycles of overpull, rotation, and circulation through a cut window can put a lot of stress on the packer.
In addition to the challenges of aggressive downhole conditions, there are other factors that require a robust open hole packer. For example, the packer must be designed to withstand differential pressures. It must also be able to maintain a seal against fluid migration, even under long-term exposure to corrosive fluids and gases.
To address these challenges, open hole packers are typically made from high-strength materials and specialized alloys. They are designed with multiple sealing elements and backup systems to ensure reliable and long-lasting sealing performance.
Overall, a robust open hole packer is critical to the success of a plug and abandonment operation. It allows for an effective open hole plug to be set even after running in aggressive conditions through a cut window. This ensures that the well is safely and permanently plugged, reducing the risk of fluid migration and environmental damage.
Solution
A robust open hole packer is necessary to meet the challenges of setting an effective open hole plug after running in aggressive conditions. This requires the packer to be designed to withstand the stresses and strains of these conditions, such as cycles of overpulling, rotation, and circulation through a cut window. Additionally, the packer needs to be able to provide a reliable and effective seal in the open hole, even when faced with challenging downhole conditions such as high pressure and temperature. Therefore, the combination of a durable and resilient packer with the ability to create a dependable seal is crucial for successful plug setting in aggressive downhole environments.
Saltel Steel ECP-W [welded] 4.5in was selected as a “rapid response” solution with custom connection design, and for its robust qualities.
Xpandable Steel External Casing Packers can rotate while running in holes and pass through cut windows with no integrity risk concerns on its packer element. The strong anchoring capabilities of this technology, and the slim RIH OD, facilitate its deployment.
Result
- The ECP was successfully set at 3,400 psi [234 bar].
- Allowing rotation while RIH, the packer successfully withstood crossing cut windows without damage.
- It took several attempts to release the setting tool, and the ECP confirmed its robustness, withstanding multiple cycles of overpull (~60klbs), rotation, and circulation without being affected.