Giving subsea a boost

A bid to reduce costs to increase subsea processing deployments is bearing its first fruit. Elaine Maslin reports on the first phase of a subsea processing joint industry project.

Subsea infrastructure. Illustration from DNV GL.

Subsea processing holds considerable promise for the offshore oil and gas industry. But, high cost levels and bespoke system design leading to relatively few deployments (there are only about 17 subsea boosting systems operating globally) has meant the industry is stuck in a bit of a chicken and egg situation: with more deployments, costs could come down, but until costs come down, deployments will be limited.

Cost inflation across the industry, up to 2013, hasn’t helped. Subsea-costs on the Norwegian Continental Shelf tripled in that period, according to calculations made by Norway’s OG21, a situation replicated elsewhere around the world.

Last year, building on several recently completed joint industry projects, targeting the standardization of forgings, documentation, and subsea electrical power, Norway’s DNV GL launched a subsea processing joint industry project (JIP), with the first target being standardization of subsea pumping. The first phase of the project, which had operators Woodside, Petrobras, Shell, and Statoil on board, alongside technology firms OneSubsea (part of Schlumberger) and FMC Technologies (now merging with Technip), completed in December. Phase 2 is set to start imminently and future phases could tackle other areas, including subsea compression, separation and injection.

“There’s considerable potential for subsea processing,” says Kristin Nergaard Berg, Principal Engineer on the JIP, with DNV GL. “It’s a technology the oil and gas industry needs, but the cost level, maybe combined with there being some decision makers who think it’s still fairly new, makes it challenging to get projects sanctioned.

“There are other options than subsea pumping and if they’re seen to be cheaper and with more experience, the decision could be to go for the more conservative solution. It is a chicken and egg situation. If the cost would go down I think the volume would go up. But that’s what we’re trying to attack in this project,” she says.

Finding out where exactly costs could be saved isn’t easy. “It’s very complex because the cost is added through the different parts of the supply chain,” Berg adds.

A mapping exercise looking at costs throughout representative pumping systems and found that there wasn’t one particular area that stood out as a cost driver. “One way of interpreting that is that the cost is spread out and that could be due to the fact that we have different standards and requirements and systems, custom made from project to project,” Berg says.

In addition to looking at areas that impact cost, the JIP is also looking to capture industry practice, through input and review from suppliers and operators, find alignment on key areas and reference standards and limit operator specific requirements (a task akin to taming a mythical sea monster).

Early December, after going through many iterations, the first phase of the project delivered a functional description, and defined classes, for subsea pumping, as a platform for working toward standardization in phase two.

“Of course there are different opinions, priorities and outlooks, different business cases and different levels of experience, but I feel we have had very positive contribution, including from the suppliers that have really broadened and supplemented the team,” Berg says. “There’s always a trade off when working with standardization. Of course each field is different and we cannot change that. So we have to tried to focus on what can been common from field to field and left space for optimization.”

As an example, module classes, welding, engineering philosophies, and documentation, have potential for commonality, and so could be standardized and save cost and time. These are some of the areas that will be focused on in the second phase of the project, as standards, functional requirements and specifications become more defined. Other areas include control systems and instrumentation, power systems, materials and qualification, work processes and test requirements.

Standard pump system data sheets, as well as standard documentation and where pump module, structures and pressure containing equipment size and interfaces could be standardized will also be looked at. “We’re not likely to standardize 100%, but we want to align on key principles to allow for as much repetition as possible,” Berg says.

It’s also important that the project leverages rather than duplicates existing work, such as the Subsea Electrical Power Standardization project, DNV GL’s Forging Material recommended practice (RP), the DNV GL Subsea Documentation RP and API’s 17X Subsea Pumps RP, Berg says.

“There’s also some work to be done on system design. We plan to look at standardizing minimum upfront tie-in solutions,” she says, i.e. future proofing. It’s also making sure that brownfield applications are covered, as subsea pumping could have an important role to play in enhanced oil recovery schemes, as well as greenfield projects.

It’s a complex project, but progress is being made, Berg says. “At last we’re getting away from talking about whose fault it was that costs became so high, to finding solutions instead.”