ABERDEEN, UK – Equinor has trialled a new well abandonment tool on the Huldra field in the Norwegian North Sea.
Deep Casing Tools designed the Casing Cement Breaker to address problems with cement in casing, which can obstruct conventional techniques for P&A and slot recovery, when operators want to extend production. The system breaks the bond between the cement and breaks down the structure of the cement behind the casing, simplifying operations such as perforate and wash, cut and pull and milling.
Following the successful trial of the prototype at Huldra, the company is now working on a stronger, second-generation version.
David Stephenson, CEO of Deep Casing Tools, said: “This was an idea on a white board just nine months ago…We’ve proven it breaks down the bond between the cement and the casing, as well as the structure of the cement behind the casing, and that it reduces the forces needed to remove casing – by around 50% on this first trial.
“We expect to achieve 90% reduction as seen on testing with future generations of the tool. For operators, this means less time and cost. You can pull longer sections with less force, fewer trips, fewer cuts, and less rig time.”
Two more offshore trials should follow for another major oil company later this year and early in 2020.
Stephenson added: “Our expert in-house engineers have developed this technology, but it’s thanks to Archer’s support that we got it to trial so quickly.
“Very early on, they saw its potential and were instrumental in introducing us to Equinor’s well abandonment team and arranging the trial. We look forward to our continuing work with them as a technology partner.”
The hydromechanical tool is run down hole on drill pipe. It functions by using pressure and rotation to manipulate the existing casing in the well, within its elastic limits, breaking down both the bond between cement and casing and the structure of the cement behind the casing.
Equinor has indicated it would like to continue its involvement in the development, and Deep Casing Tools is working with manufacturers to bring future tools to market quicker.
Torodd Solheim, Global Advisor at Archer, said: “The Casing Cement Breaker will reduce the risk and uncertainty for operators. At the moment, the decision path around [P&A] can be unstructured.
“The condition of the cement downhole is generally an unknown, making decisions on whether to perforate and wash, cut and pull, or section mill, often based on trial and error, swelling the already prohibitive costs. Removing the guesswork will inevitably lead to a more clear and structured decision-making process across the board.”
Deep Casing Tools