During the construction of a North Sea exploration well, a well integrity solution was required on the 9-5/8” production casing string to isolate the lower annular below the 13-3/8” casing shoe. Having previously used a third-party casing packer that requires cement to provide anchoring, the operator was looking for a solution that could eliminate the costs and risks associated with secondary cementing – for example, losing integrity if unable to position cement above the packer.

With a delivery window of just five weeks, Welltec® proposed a 1214 Welltec Expandable Anchor (WEA) for Inner-String Packer, combined with a Welltec Light Packer (WLP) to provide an ISO14310 V0 barrier – without the need for secondary cement.

This solution also addressed the client’s desire for flexibility, with the Inner-String Packer serving as a base for setting a whipstock to sidetrack the well in the event of unfavorable exploration results.

The 1214 WEA/WLP combination was installed onto a 9-5/8” base pipe and set within the 13-3/8” casing above the shoe. Primary cementing procedures, including pumping cement to anchor the 9-5/8” casing shoe, plug bumping, followed by the simultaneous expansion of the WEA/WLP packers via 5,000 psi, with shoe testing, were all executed without issue.

The packer underwent a pressure test up to 1,000 psi, enabling the continuation of drilling the 8-1/2” section to complete the well construction phase.

Cementless isolation of the B-annulus was achieved without the need for secondary cementing.

Moreover, the solution was selected to provide maximum differential pressure capabilities and to re-instate integrity of the 9-5/8” casing bore throughout drilling and completion operations.

All of the operator’s specified criteria were successfully met through the deployment of a global first in the 1214 WEA+WLP completion.

Beyond meeting the primary objective of annular isolation, the innovative solution brought about significant cost efficiencies by eliminating the need for secondary cementing above the packer, reducing overall risk, and delivering rig time savings of 12 to 16 hours.

The 1214 WEA/WLP completion provided an ISO14310-V0 barrier to isolate the B-annulus, and presents a ground-breaking solution in well construction methodology.

Client feedback underscores a collaborative effort, and the additional achievement of product delivery within a five-week window.