Largest bismuth plug deployed offshore Norway

BiSN has achieved a world first in conjunction with Aker BP and Altus Intervention, through the deployment of the largest ever bismuth plug.

The company’s Wel-lok M2M technology, which can be used during well and rigless well abandonment, was deployed via E-line in collaboration with Altus Intervention in Aker BP’s Valhall A-30 well in the Norwegian North Sea.

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 kilos of bismuth alloy, a gas tight surface seal was created inside 18-5/8-inch casing through a section milled window cut in the 13-3/8-inch casing, entering previously unchartered territory regarding weight, size, and precise setting procedures.

BiSN CEO 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 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.”

Source: Offshore Magazine