Largest-ever Bismuth Plug Deployed

Metal-to-metal downhole sealing solutions provider BiSN said it recently deployed the largest-ever bismuth plug in the Valhall A-30 well, Norway, in conjunction with AkerBP and Altus Intervention.

BiSN’s Wel-lok M2M technology – which can be utilized 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.

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 mold of traditional methods, changing the way operators look at well abandonment.”

Martin Straume, P&A Engineering Manager at AkerBP, said, “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.”