New Era for Well P&A as Largest Bismuth Plug Deployed

BiSN, the global leader in metal-to-metal downhole sealing solutions, has achieved a world first in conjunction with AkerBP and Altus Intervention, through the successful deployment of the largest-ever bismuth plug.

Following over a year of development, BiSN’s award-winning Wel-lok M2M technology – which can be utilised during well and rigless well abandonment – was deployed via E-line in collaboration with Altus Intervention in AkerBP’s Valhall A-30 well in the Norwegian North Sea.

The Wel-lok M2M technology aims to bring substantial savings to operators by eliminating rig costs and doing the work rigless.

Conducted as a field trial, the tool was set to evaluate the effectiveness of bismuth as a permanent seal for P&A operations in lieu of cement. With 3,500 kg of bismuth alloy, a gas tight surface seal was created inside 18 5/8” casing through a section milled window cut in the 13 3/8” casing, entering previously unchartered territory regarding weight, size and precise setting procedures.

BiSN chief executive officer, Paul Carragher, said: “This project is an important step towards the adoption of bismuth well sealant technology. Wel-lok M2M drastically reduces the rig time needed to complete well abandonments (P&A) through the use of thermite heaters to melt bismuth-based alloys.

“We are fundamentally changing the way downhole sealing is carried out, and through trials like this, we continue to break the mould of traditional methods, changing the way operators look at well abandonment.”

Speaking about the project, Martin Straume, P&A Engineering Manager at AkerBP told us: “AkerBP is proud to be in front of the development of Bismuth as a barrier element with respect to Plug and Abandonment. In addition, this installation is proving that there is great savings potential in performing rigless P&A.”

Cathrine Bjaarstad, President Norway & Denmark, Altus Intervention said: “This project clearly demonstrates Altus Intervention’s ability to deliver innovative solutions and assist operators in resolving downhole challenges, adding value to their operations whilst creating both cost and time-savings”.