Helix Energy Solutions Group’s new well intervention vessel the Q7000 is close to being ready for the market. Now it’s time for the market to be ready for it. Elaine Maslin reports
It’s been a long time coming, but with the introduction of the Q7000 to the market, Helix Energy Solutions Group hopes to offer a step-up in efficiency, flexibility and capability to the well intervention and abandonment market. The goal is to create a nimble and efficient workhorse.
The semisubmersible vessel is nearly complete, with sea trials performed in October 2017. The unit’s intervention control and topside handling systems were commissioned in November 2017, and the intervention riser system is due to be delivered from the US this month [March 2018], said Helix Energy Solutions Group projects and business development manager Ekene Ogbechie .
For now, the vessel remains in the Jurong Shipyard while it undergoes upgrades to key pieces of equipment. The vessel, able to work in 80-3,000 m water depth, with 70 m x 61 m upper deck, is expected ultimately to enter the North Sea and West Africa markets.
The vessel’s design is all about making it more efficient and versatile, said Mr Ogbechie, starting with manoeuvrability. “During sea trials, it manoeuvred like a monohull, with its eight thrusters,” he said. “Some of the efficiencies are upfront, some infield. Mobilisation, getting to location and setting up is quick compared to a jackup or a rig,” he said, thanks to the two, ship-shaped pontoons the unit sits on, with 10 knot transit speed, compared to 5 knots for a semisub on tow. Using the unit’s DP system means there is no need for a mooring spread and tugs.
Like Helix’s recently delivered Siem Helix 1 and 2 well intervention vessels working for Petrobras in Brazil, the Q7000 sports new systems designed to make operations safer and changing between operations faster. This includes a 600-tonne active and passive heave compensated intervention tower, integrated tension frame, maintenance tower and walk-to-work system, to eliminate man-riding. It also has deck skidding and auto-pipe handling and space (with permanent pipe runs in place) for a well test package. With a permanent spread on board for coiled tubing, wireline and slickline, and easy changeout between them (and reduced testing requirements), moving between service modes will be significantly more efficient, said Mr Ogbechie.
The vessel is also expected to host the Helix and Schlumberger company OneSubsea Subsea Services Alliance’s riserless open-water abandonment module (ROAM). This gives Helix an additional decommissioning capability, as using the ROAM system could remove the need to bring a drilling rig onto a well for abandonment, as the 18.75 in large bore system would allow tubing to be pulled in open water in a safe and contained manner.
“We are trying to make decommissioning and well abandonment more efficient and cheaper,” said Mr Ogbechie. “It makes sense to look at it with a different approach. The Q7000, with the ROAM, is designed to abandon wells and pull tubing in open water. The window you need the rig for shrinks or disappears. With the ability to work through tubing, you don’t need the rig. You don’t need to deploy a 21 in marine riser any more. You could do all the upfront work with a LWIV, do the final phase work (take out the well head) with a LWIV as well then clean the seabed and including trenching/burial of pipeline where applicable with a Canyon ROV vessel (a Helix Company). The Q7000 would do the upper abandonment and tubing pull. With these assets, Helix can go right across the abandonment scope, with single source contracting. We call this TOTAL DECOM.”
Helix’s capability gives the flexibility to put production optimisation and abandonment scopes into a single scheduling pot and move from one scope to the other, providing a more flexible work approach, he said.
Other capabilities on the Q7000 include ROV deployment via a cursor system, through the air-gap and splash zone to 18.5 m water depth, increasing the working weather window to up to 5 m heavy sea-state. With no over-the-side working, the requirement for a close cover emergency response and recovery vessel is removed.
The vessel can house 130 people in the North Sea and 140 elsewhere, depending on local regulations. But once the goal of having a dedicated and multi-skilled crew aboard is achieved, up to 30% savings on crew can be made, said Mr Ogbechie. Helix estimates that on a single intervention or abandonment operation an overall time saving of 33% could be made against a mobile offshore drilling unit, or 46% compared to a jackup.