Open-hole cement assurance and zonal isolation offshore Myanmar

Challenge
Zonal isolation
JMM19799 Ab
  • Well type Gas and oil
  • Temperature 259°F (126°C)
  • Depth to top of 7” liner 6822 ft (2079 m).

Background

A client offshore Myanmar in 2019 faced several challenges. First, the client needed to sidetrack a well from inside the 9-5/8” casing. They needed to drill an 8-1/2” sidetrack trajectory to the well’s target depth, perform liner cementing to achieve total zonal isolation behind the 7” liner and complete the well to produce gas from the third layer. Finally, the client wanted to establish the ability to produce from the second layer in the future through a bottoms-up perforation.

The client needed an open-hole, metal, expandable packer. Welltec® and the Welltec Annular Barrier (WAB®) were the client’s first choice for this operation because of Welltec’s history of success and the WAB’s status as the best open-hole, expandable packer on the market and its reliability as a life-of-well product.

Operation

Two 812 WABs were deployed to the rig as the cement assurance solutions for the 8-1/2” open-hole section. Both WABs were pressure tested prior to delivery and inspected upon arrival. The WABs were run in hole and set at the target depths:
• WAB 1 at 13,816.253 ft (4211 m).
• WAB 2 at 14,035.087 ft (4278 m).

The setting depth’s inclination was approximately 30°, and the setting temperature was approximately 572°F (300°C).
There were no issues in the WABs passing through restrictions on their way to target depth and setting with cement. After the cement pumping operation completed, expansion commenced. The pumping flow rate was maintained at 1 bbl/min with an increasing pressure from 2000 psi up to a maximum of 4000 psi. The WABs were fully expanded according to the requisite procedures.

Achievements

The rig crew performed excellent work in picking up and making up the WAB assembly to the liner string and running in hole. Welltec and the cementing personnel had great cooperation during the WAB setting operation, which enabled a safe, efficient, and successful job.

The client was extremely satisfied in the product and Welltec’s reliability. The client realized significant time savings compared to other products. Because of the success of this completion, the client awarded Welltec with a metal expandable packer contract in Malaysia.

Challenge
Zonal isolation
JMM19799 Well