Industry: Natural Resources / Subsea Storage.
Location: North Sea.
Demanding challenges require robust solutions.
In the demanding environment of the North Sea, oil extraction often involves tapping into smaller oil reservoirs where constructing extensive fixed infrastructure isn’t feasible.
To address this, subsea oil storage tanks (SOST) are employed as temporary storage solutions, positioned directly on the seabed. These tanks require continuous circulation and heating of the crude oil to maintain a liquefied state at approximately 40°C (104°F), ensuring efficient storage and transfer operations.
PLEUGER’s bespoke solution.
Commissioned to enhance a SOST system in the North Sea, PLEUGER was tasked with developing two high-performance motors and retrofitting existing pump equipment.
The primary objective was to ensure permanent circulation of the stored crude oil, with a secondary unit providing redundancy and facilitating rapid offloading when necessary.
Key specifications of the main unit included:
- Rated flow: 1,250 m³/h (5,503.6 US gpm)
- Rated discharge pressure: 20 bar (290.1 PSI)
- Motor power: 1,300 kW (1,743.3 US hp)
- Voltage supply: 6.6 kV
- Motor frame size: 30”
The project presented several challenges:
- Retrofitting constraints: Integrating new high-performance motors while reusing existing pumps and associated systems, including riser pipes where possible.
- Spatial limitations: Navigating a minimal caisson gap of only 16mm (0.6 inches) around a unit diameter of 850mm (33.5 inches).
- Cooling requirements: Implementing air cooling systems due to the unavailability of water cooling, necessitating the development of external cooling units tailored to space and noise restrictions of maximum 75 dBA.
- Operational versatility: Designing pumps capable of expelling seawater from the subsea tanks during production start-up, and efficiently handling crude oil during regular operations.
- Complex installation: Addressing tight space constraints and the intricacies of retrofitting, which required comprehensive and detailed installation procedures.
In response, PLEUGER engineered two bespoke 30” motors accompanied by dedicated cooling units, meeting all operational requirements while adhering to platform space and noise limitations. A detailed installation protocol was developed in close collaboration with the client to minimize risks during deployment.
Impact and future outlook.
PLEUGER’s expertise in advanced pumping solutions ensures reliable performance in extreme subsea environments. By delivering highly engineered, space-efficient systems, PLEUGER has enabled safer and more effective fluid management for offshore infrastructure. As industries push towards more efficient and resilient subsea operations, PLEUGER continues to drive innovation in fluid handling technology for demanding marine applications.
Discover how PLEUGER can support your subsea storage operations. Contact us today.
Made for water. Engineered for life.
Made for water. Engineered for life.
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