Engineering and services firm Claxton Engineering has been awarded a contract to riglessly casing cut and recover a total of seven wells in the southern North Sea across two normally unmanned, platforms, along with an additional subsea suspended well at one of the locations.
Work is due to start in July at the first location, about 180km off the Yorkshire coast, with work on the second platform, in the Dowsing Fault Zone of the southern North Sea, starting shortly afterwards. The project is due to take under 100 days.
The first NUI scope of work includes the removal of Xmas trees in preparation for the removal of the production tubing, wellhead preparation in readiness to also undertake the sub-mudline multi conductor/ casing cutting and recovery, and severance and conductor recovery of the suspended subsea well. Due to limited deck space, work will be conducted as a combined operation using a jack up lift barge JULB and without the use of a drilling rig.
Laura Claxton, Managing Director, Claxton, said: “Our global experience allows us to provide the most comprehensive decommissioning package for all of our clients, but always having an eye on providing the most cost-effective solution for abrasive severance, cut verification and recovery.
“We will be using a 150-tonne hydraulic proving jack package, Claxton Double Drilling Units (DDUs) for drilling and pinning and rapid cut bandsaws for cutting the combined multi strings. Marine growth stripping and removal using our purpose designed tooling will also be delivered, along with multi-string severance using our proprietary abrasive water jet cutting system SABRETM.”
The scope of work on the second platform includes Xmas tree and tubing removal, supply of blowout preventer equipment, and the use of coiled tubing for cement squeezing operations. Tubing and conductor severance and recovery will be performed using Claxton’s own SABRETM abrasive cutting system - 10ft below seabed. The limited deck space on the platform deck also means that Claxton has developed a bespoke, all-purpose work deck.
Laura Claxton continued: “As part of the provided solution our equipment is unique and can again offer the operator real savings. Our bottom hole anchor and catch tool system for example, allows recovery of the conductor stump and conductor during the surface recovery stage reducing this to a single operation and removing the need for fishing tools.
“We have also provided an engineered and aligned solution to reduce the number of slewing operations required by the JULB crane with a revision to our existing tubing laydown frame by incorporating a traveling bogie system. The frame and bogie eliminates the need for the crane to slew from the well centre while still allowing tubing to be laid out on deck. This saves valuable time on a project.”