A client in the Middle East desired zonal isolation within a horizontal well with an open hole completion. The client chose the Welltec Annular Barrier (WAB).

The WAB was an attractive option because its design allows the ability to work, rotate, and circulate the liner to TD; its annular ΔP capability of 5,000 psi maintains the full bore 7” liner ID, which also allows for future inner-string solutions to be deployed; and the annulus could be cleaned up prior to expansion.

The client wanted to selectively divide the liner into four compartments, separated by WABs, and equip each zone with a remotely-operated, hydraulic valve. The valve eliminates the need to perform a perforation job.

Welltec® mobilized to the job site with six WABs ready for deployment: two WABs to isolate the shallow reservoir for future production and four WABs for the lateral to establish zonal isolation between reservoir zones.

Prior to installation, the open-hole annulus was cleaned by full circulation through the toe. A single ball was then pumped to the liner hanger. The liner hanger was set at 500 psi, after which the liner hanger was released. The ball seat was sheared at 1,500 psi and pumped to the landing collar in the shoe.

Because of losses and gas entry during the deployment, the estimated underbalance was 1,000 psi. At this point, the remotely-operated, hydraulic valves were activated at 3,000 psi. Following confirmation of volume calculations, the WABs were expanded to 4,000 psi, and the pressure held, confirming the proper placement and setting.

This was the second successful installation of Welltec’s completion solutions for this client.

The WAB is an ideal open-hole packer for a variety of reasons, including its rugged design that endures sustained rotation during operation, serving as an expansion solution for a pre-drilled liner, its ability to seal and carry full annular ΔP while maintaining a full bore ID, its minimal running diameter that reduces drag, and a life-of-well design for the environment.