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Wireline wonders

Written by  Elaine Maslin Saturday, 01 April 2017 00:00

Oceaneering International’s acquisition of Blue Ocean Technologies is set to reap returns in terms of new technology. Elaine Maslin reports.

IRIS and BORIS. Images from Oceaneering.

When Oceaneering International bought Blue Ocean Technologies last year, it was a strategic move. Buying the Texas-based firm adds a strong track record of wireline intervention to Oceaneering’s own record, including setting deepwater wireline intervention operation records. The move is also set to give Oceaneering the capability to roll out what could be a riserless industry “first” in late 2018.

Blue Ocean was originally set up to perform downed well remediation after hurricanes Katrina and Rita – category 5 storms that hit the Gulf coast states of Texas and Louisiana in 2005. “We couldn’t get a rig to kill the wells,” says Neil Crawford, now vice president of OceanNext for Oceaneering, and one of the founding members of Blue Ocean. “We had to do it riserless, so we installed flexible lines to the well to do what we needed.”

Blue Ocean then developed a system for downed wells for work on undamaged wells. The result was the interchangeable riserless intervention system (IRIS), which interfaces with the Xmas tree to allow a wide range of intervention operations, including using e-line, slickline or braided wire; running, setting and pulling tubing and tree plugs; pumping cement plugs; and logging while flowing, perforating and fishing. It incorporates a hydraulic control system, a patented grease injection/sealing system and electric hydraulic controls through an Oceaneering umbilical system.

IRIS can be deployed from a 328ft-long (100m) DP2 vessel of opportunity (through the moon pool or over the side) with a knuckleboom crane, and is rated for 10,000ft (3048m) of water depth and 10,000psi. The system can work on both horizontal and vertical trees.

Oceaneering, meanwhile, has a track record of hydrate remediation and rigless well stimulation work. With Blue Ocean, Oceaneering acquired the IRIS, along with wireline capability, and is set to launch the Blue Ocean riserless intervention system (BORIS). This system is similar to IRIS, but its four main barriers – two gate valves (one at the top and one at the bottom) and two rams – are split into two sections, with a connector, so that the smaller (compared to IRIS) 7-1/16in upper section with a ram and gate valve can be removed. The lower 13-5/8in bend capacity section with a 7-1/16in gate valve and ram remains on the well and interfaces with a riser package.

These systems are noteworthy as they are able to work in deepwater and ultra-deepwater, because the grease supply to the pressure control head is subsea, Crawford says. Wireline services in shallower water supply the grease from the surface, but this wouldn’t work in deeper waters. On IRIS and BORIS, hydraulic power is used from the surface to hydraulically pressurize the grease subsea.

“Because we are able to put all types of wire through our pressure control head, such as big braided wire all the way to slickline, we are able to deploy tools that others are developing in order to do more in the well,” Crawford says. These tools range from the most basic wireline tool to electric tools that can run into the well.

This IRIS system has already proved itself in up to 8200ft (2499m) water depth, where it set a record for the deepest water wireline intervention. The tools, which included both wireline and e-line, then ran a further 8000ft (2438m) downhole, where they performed operations. Blue Ocean has also done a lower abandonment in 6700ft (2042m) water depth.

“It is sometimes easier for us without the riser because we can adjust the pressure in the lubricator as we need to depending on what’s going on in the hole,” Crawford says. “The key to what we do is the way we supply grease to the grease head, which allows us to transmit grease in deepwater and ultra-deepwater depths.”

Subsea Pressure Control Head.

Riserless coil

But, there’s more to come from this technology. With its well control package foundation and subsea line management, Oceaneering now has what it needs to make the step to riserless coiled tubing (CT), Crawford says.

Riserless CT has long been a goal for the industry. “With riserless wireline, there is a set amount of things you can do,” says Ben Laura, vice president of Service, Technology & Rentals for Oceaneering. “Coiled tubing gives you an ability to circulate inside the well. If you do a standard stimulation job, you can circulate to the tree. With coil, you can circulate all the way down to the production zone. A second driver is that you can push and pull a lot more than you can with wireline. This opens up more scope. You cannot pull as much as a rig, but CT has advanced to 60–70% of what a rig can do.”

But, so far, riserless CT has not been achieved. “No one has really been able to run the coil riserless,” Laura says. “Several companies have tried, and there are several patents on ways to use CT in open water without a riser and to properly seal the interface subsea.”

Oceaneering will be deploying riserless coil in 2018. However, Laura points out that wireline would still be the core intervention tool, with riserless CT an option for where it was needed. “Ultimately, riserless wireline is getting close to being able to do anything you could do through wireline with a riser,” he says.

“This includes setting and pulling plugs,” Crawford says. “Opening and closing sleeves – check. Milling – check. Logging – check. Perforating – check. Anything we can do with a wireline unit conventionally, using a riser or from surface, we can do riserless. It’s more about building a track record now.”

Such a move adds to the argument for using these systems on vessels of opportunity, by enabling mobilization with smaller spreads, minus the risers, Laura adds. These could help reduce costs on the likes of costly plugging and abandonment (P&A) campaigns, which are finally looming in the North Sea.

“P&A work in this area has been talked about for a long time,” Crawford says. “The North Sea has some really large P&A campaigns about to kick off, and the capability to do them is exceeded by the amount to do. We will see riserless systems coming into their own. There is no magic bullet to P&A. But there is a large section of P&A that can be done riserless.”

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