A Scottish-designed prototype for plugging abandoned oil wells has gone on trial in the North Sea just nine months after its invention.
Aberdeen-headquartered Deep Casing Tools, established in 2008, came up with the concept last year and Norwegian operator Equinor is testing its performance in the Huldra field. Drilling services company Archer introduced the tool.
The Huldra field, discovered in 1982, is in 125 water depth, west of Bergen in the Norwegian North Sea. Well abandonment operations started there in 2016 and platform removal is expected in 2019-2020.
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The innovative Casing Cement Breaker deals with problem cement in casing, which hinders conventional methods for plugging and abandonment and slot recovery, when operators want to extend production.
By breaking the bond between the cement and breaking down the structure of the cement behind the casing, well abandonment methods are simplified and or no longer needed, saving operators significant time and cost.
Well abandonment is estimated to account for 45% of the entire cost of decommissioning. In the next decade, 1,400 wells are due to be abandoned on the UK Continental Shelf alone. With higher oil prices, operators increasingly want to re-use well slots, to drill new wells, a task the Casing Cement Breaker also makes easier.
David Stephenson, Deep Casing Tools’ chief executive officer, said: “This was an idea on a white board just nine months ago. We have now proven it works with our very first prototype. 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 seem 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.”
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Following the trial, in March, Deep Casing Tools already has two more offshore trials lined up with another major oil company, for later this year and early 2020.
Stephenson: “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.”
