Rising to the salt extraction challenge

A salt extraction operation had to move quickly from an onshore to an offshore site supplied by 5 km of pipework. The company turned to flow control partner Celeros to help meet the unique circumstances encountered at the new salt well.

Overview of the two new water injection pumps for single and parallel operation, following installation and commissioning at the Frisia Zout BV site.
Overview of the two new water injection pumps for single and parallel operation, following installation and commissioning at the Frisia Zout BV site.

A new salt extraction plant off the north coast of Holland has been brought online ahead of schedule, preventing a potential halt in production when the existing onshore well developed issues. Frisia Zout BV, part of K+S Minerals and Agriculture GmbH, was able to overcome the time and technical challenges of accelerating the project by working in partnership with Celeros Flow Technology (Celeros FT).

The bulk of the salt produced by Frisia Zout BV goes loose to a 40,000-tonne storage facility for delivery in bulk to industry. The remainder is packed in smaller quantities for use in food production or made into cubes for water purification.

The salt is extracted under licence from the Dutch government. The existing borehole licence
allowed K+S to extract salt from underground on the mainland. Due to regulatory changes, the new licence would only permit extraction from subsea sources off the coast. Consequently, a new borehole and associated plant was required at the Frisia Zout BV site.

New challenges
K+S began planning for a new pump building in 2017, and construction began in April 2020 with the aim of bringing it onstream before the existing extraction licence expired at the end of 2021. However, unforeseen difficulties arose with the existing onshore well, which meant that production would cease sooner than anticipated. To bridge the gap, Frisia Zout BV began bringing in salt water by tanker, but this was an expensive alternative. As a result, it became imperative to bring the new offshore well onstream as soon as possible.

Time pressures were not the only challenges the company faced. Due to the natural geology, the extraction route to the new offshore resource was not a straight bore: it changed direction twice before reaching the salt deposits. In fact, the new plant is fed by one of the deepest wells in the world and has 5 km of pipework beyond the water injection pumps. As a result, the process water has to be pumped in at high pressure (250 barg) and at a high flow rate (450 m3/h) to extract the amount of salt required, making the choice of pumps critical to success.

Total solution
Frisia Zout BV has a long and established relationship with Celeros FT through the ClydeUnion Pumps brand, based not only on the high quality of ITS OEM pumps but also on its ability to respond quickly to any operational issues. The company turned to its trusted flow control partner once again for help in meeting the unique circumstances encountered at the new salt well.

Celeros FT brand ClydeUnion Pumps assessed the flow requirements for the water injection process at the new plant and verified that CUP-BB3 pumps could be made to meet requirements. The pumps were specified with Duplex stainless-steel casings because they would be operating in a salt-laden environment. Celeros FT manufactured, supplied, installed and commissioned the mission-critical pumps for injecting water into the new offshore salt cavern, meeting unusual requirements for high pressure and high flow rates. In addition, they supported Frisia Zout BV in bringing an older pump back into service as a spare: assessing it and upgrading the casing to ensure it met the new duty requirements.

Jouk Riemer, project manager for Frisia Zout BV, explained: “We have used CUP-BB3 pumps in the past and found that their multistage centrifugal design gives better performance, compared to plunger pumps, for this application. We wanted to use them again for the new project. The Celeros FT team responded to the challenges magnificently, using their engineering expertise to identify the best solution to meet the pressure and flow rates we required, delivering the pump skids to meet the new construction schedule and helping us keep the project on track.”

Future assured
The new salt extraction plant came online in December 2020. Its CUP-BB3 pumps meet the high pressure and flow rates required for the application and can run in parallel, which has improved productivity. The availability of a spare pump gives extra confidence that production downtime will be minimal. The company’s ability to meet the accelerated project deadline is particularly impressive when you consider that the Covid-19 pandemic was already affecting supplies of materials and components. The Celeros FT team worked hard to ensure that this did not have any impact on their customer.

Celeros FT also provided specialist engineering expertise throughout the installation and commissioning phase and will continue to ensure the pumps operate satisfactorily throughout the plant’s 15-year lifespan, though the pump building may be required to serve more than one well in future as demand for K+S high purity salt continues to grow. Easy replacement of wear parts and ongoing service support from Celeros FT will ensure that the BB3 pumps continue to meet operational parameters throughout the extraction plant’s lifetime.

Riemer said: “The combination of high quality OEM equipment and practical engineering skills offered by Celeros Flow Technology was instrumental in delivering this project ahead of time. I’m convinced it would have taken a lot longer to get what we required from another pump manufacturer. The company’s responsiveness was crucial in meeting our revised deadline, reducing costs and keeping extraction at this site viable.” Riemer concluded: “This is the first offshore extraction well we have developed but it has been a largely positive experience thanks to Celeros Flow Technology. They brought invaluable engineering expertise and specialist pump knowledge to this project and are a fundamental part of its success.”