Drillship designers are looking for a market rebound to fill the order books. When it comes, Italy’s Fincantieri Offshore has a deepwater rig that is fit for both remote locations and a cost-cutting climate, Russell McCulley reports.
Fincantieri Offshore launched the Proxima drillship concept in early 2014, when a robust oil price all but guaranteed more industry investment in new technology and upgraded assets.
The subsequent downturn has put the brakes on demand for newbuild rigs. But it has not dampened Fincantieri’s enthusiasm for the Proxima design, which the company says will substantially lower costs for drilling contractors and the service providers who work with them.
“This vessel can produce cost savings of about 10%,” says Giuseppe Coronella, Finacantieri Offshore executive vice president. That sum, which he says has been verified by third-party analysts, would be shared between the driller, which typically receives about half the amount of money spent to drill a well, and the support vessel suppliers and service providers who absorb the other half of the dedicated resources.
“This drillship supports both sides of the services, because you have more storage volume and lifting capacity,” Coronella says. The drillship also has faster tripping in and out velocity and lower overall fuel consumption, he says. On the drilling contractor side, Proxima achieves savings through improved transit speed and an enhanced working environment and ship design that reduces downtime. Proxima’s innovations, he says, come not only from the new drilling tower and lifting system but also by the integration of proven technologies in new ways.
“Our aim, more and more, is to have this integration be a systemic part of the vessel. The ship can be just a container for those systems. But if you integrate properly, the ship itself becomes a real tool.
“In the offshore world, there are lots of good technologies,” Coronella continues. “But much of the time they are specialised and not integrated into an entire system. We are a system integrator.”
That meant designing the hull with the drilling package in mind. The task was made easier by Fincantieri’s 2012 acquisition of VARD, which gave the company a majority stake in Norway’s Seaonics and its Castor Drilling Solutions (CDS) subsidiary. CDS designed Proxima’s two distinctive enclosed, cylindrical towers, which have a maximum static load of 1600 tons. Each tower has a diametrical footprint of just six metres, which increases available deck space and creates a less congested drill floor.
Two moonpools are surrounded by nearly 4800 square metres of available deck space. The moonpools are smaller than most, which helps increase reduce drag during transit. The vessel will be able to sail at speeds up to 14 knots, Coronella says.
The additional velocity was a nod to drillers who are looking for a vessel mainly dedicated to exploration.
Despite its relative compactness — Proxima measures about 208 metres in length by 40 metres in breadth — the vessel has a variable deck load of 32,000 tons, he adds. “That makes it less dependent on support vessels.”
Power up
Proxima’s CDS-supplied hydraulic draw works allows the system to reach peak capacity with less energy, says Luca Ambrosio, Fincantieri Offshore’s head of special projects.
“The hydraulic system also allows you to increase the speed of tripping in and out, which is considered non-productive time,” he says. “That allows the drilling contractor to complete work quicker, and for the oil company to reduce cost.”
The digital hydraulic valves controlling the winches are based on technology proven in the offshore wind industry, says Coronella. “The core of the system is not the tower itself but the hydraulic winch.”
The vessel’s compensating systems, located below deck, raise capacity to 1000 tons from an industry average of 750 tons, he says.
Proxima will incorporate a managed-pressure drilling package developed by Weatherford and housed in a specially designed enclosure to free up deck space. The layout allows most routine material handling to be done by forklifts, reducing the use of a deck crane and the accompanying risk and time consumption. “This is probably the first drillship to operate with forklifts on all external decks,” Ambrosio says, noting that all decks are connected by dedicated forklift elevators.
One of Proxima’s distinguishing features is the automated riser handling system, which moves riser joints between the hold and the riser feeding system.
“Our designers identified the things that cause problems and inefficiencies” in many riser handling applications, Ambrosio says. “This solution allowed us to reduce the overall dimension of the riser hold while providing the same capacity.
“We have tried to create continuity from the moment when you pick up the risers,” he says. “The velocity you can achieve with this system is an order of magnitude bigger.”
Increased capacity is important for operators working in remote areas, Coronella adds. Remote operations inspired other design selections, such as the “parking spot” for an additional helicopter on the helideck, and the retractable thrusters that allow maintenance to be done at sea.
The drillship’s target areas are remote regions and the deepwater triangle of West Africa, Brazil and the Gulf of Mexico. Proxima will be capable of drilling to 50,000 feet in water depths up to 12,000 feet, and will have capacity for the next generation of subsea equipment geared to high-pressure, high-temperature wells, including 20,000 psi blowout preventers, the company says. To support its stated mission of being a systems integrator, Fincantieri works with a specialised “cluster” of companies gathered in an association known as Polo Offshore, Coronella says. And bringing the VARD group of companies into the Fincantieri tent has greatly helped the offshore business unit achieve that goal. “Our cluster of companies really allows us to leverage upon co-design, which is the way for innovating and integrating, reducing risks and knowing all the interfaces,” he says.
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