Claxton, a leading supplier of engineering and services for shallow-water, jackup-depth markets in subsea services company Acteon, has been awarded a contract to riglessly casing cut and recover a total of seven wells in the Southern North Sea across two of the operator’s, normally unmanned, platforms, along with an additional subsea suspended well at one of the locations.
Work is scheduled to commence in July at the first location, located around 180km off the Yorkshire coast, with work on the second platform, in the Dowsing Fault Zone of the Sothern North Sea, commencing shortly afterwards; the combined project completion is estimated at just under 100 days.
The first NUI scope of work includes the removal of Christmas 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 150te 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 Christmas tree and tubing removal, supply of blowout preventer (BoP) 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 travelling 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.”
Well abandonment is just one of the many services Claxton can offer to reduce the cost of your decommissioning project.