(Editor’s note 2016: After restructuring Kongsberg Oil & Gas into Kongsberg Digital, the patent for Subsea Storage Unit patent was sold to National Oilwell Varco)

Subsea Storage Unit (SSU) can save oil companies large sums of money. Storing oil on the ocean floor is a solution for the future, according to SSU Vice President Arne Roar Holden.

“The idea builds on Statoil’s vision to build an installation where all production and processing of oil and gas takes place under water. An important part of this is storing the oil. KONGSBERG has a patent for an idea to store oil inside a flexible bag surrounded by a protective structure made of steel or cement. The advantage here is that you keep the oil and water separate, thereby avoiding an emulsion layer of oil and water. This leads to bacterial growth and is one of the problems with today’s conventional solutions.” 

“Is this also a solution that will make it much less expensive to store oil than what we use today?” 

“Yes, absolutely. The most common way is to store oil on board a vessel next to the platform. This involves costs for fuel, personnel costs and costs for helicopter transport. We believe that by storing oil on the ocean floor, this will save between NOK 1 and 1.5 billion over the course of 25 years.”

“What about safety? What is being done to prevent leaks?”

“You could compare this with a conventional vessel that has two hulls. Our SSU is made of a flexible bag that is surrounded by a protective structure that can capture the entire oil volume if the flexible bag should leak. Sensors will catch whether there are leaks when filling and discharging. This means that our solution is just as safe as a two-hulled vessel. Our concept is centred around the flexible bag. This is not a new material. The material is also used for storing fuel for military purposes, among other things. Using it on the ocean floor in this way is a new application, but this is no more complex than storing fuel.” 

“Subsea Storage Unit is still under development. What can we expect further ahead?” 

“In April 2015, we had the bag verified for use in this type of application. We will also build a scale model where we will test the principle by draining and filling the bag inside the protective structure. This will also be completed in April 2015. We are also looking at concrete fields where these might be installed. Internal funds from KONGSBERG are what allow us to run extensive design developments. In Q3 of 2015, we should be able to give a fixed price for the system. We are also working to land the first contracts by Q3–Q4 of next year.

“How do the central initiatives for driving innovation at KONGSBERG support this project?” 

“The Subsea Storage Unit was part of the first pilot that was launched under “Innovate With KONGSBERG”. Experiences from the pilot have been positive. We received many good suggestions and some of them have been incorporated further in the work. The funds that have come from the company have allowed us to take the concept much further than we can traditionally do when relying only on external financing.”

“Have you already noticed any customer interest?” 

“Yes, we have seen a relatively large amount of interest. We have been working closely with Statoil ever since starting up in 2012. Several other customers have also shown great interest. We are planning for a session in January where we will show the scale testing of the SSU (1:4), which will be held in Hokksund.” 

“Is the Subsea Storage Unit a project that also involves different parts of KONGSBERG?”

“Yes, it is. This is an exciting project in the sense that it involves interdisciplinary co-operation across different parts of the KONGSBERG system. We are not just talking about a structure that will stand on the ocean floor. We need to have systems to control discharging and filling, protection against leakages, communication with the platform, panels for management, knowledge of the installation and not least a simulation of the process. We do not have all of these competences in oil and gas, so we have to procure skills from other places in the KONGSBERG system.”