Sevan Deepwater Technology (Sevan DWT), the Norwegian offshore engineering specialist, has unveiled a new concept for a semi-submersible Floating Production Unit (Semi FPU). The design marks a strategic expansion of the company’s portfolio, which until now has been defined by its signature cylindrical hull solutions.
By adding semi-submersible technology to its offering, Sevan DWT is positioning itself to better address the growing diversity of requirements in offshore energy. The Semi FPU is aimed at both traditional oil and gas projects and the emerging renewable energy sector, with a focus on scalability, adaptability, and resilience in challenging marine environments.
Key Features of the Semi FPU
- Main Hull Structure: Built around a double-symmetric configuration with a ring pontoon and four vertical octagonal columns. The design minimizes curved surfaces, simplifying fabrication and improving structural efficiency.
- Topside Integration: Supports modular topside construction with a single-lift installation method. The topside frame, designed with primary trusses and dual decks, reduces weight while allowing flexible integration of production facilities.
- Maintenance Accessibility: Equipment inside the columns is minimized, with most components accessible from the top deck. Valves remain dry, reducing the need for confined-space entry and simplifying long-term operations.
- Offshore Stability: The semi-submersible form offers favorable motion behavior in rough seas, while the hull ensures sufficient air gap to withstand heavy weather conditions.
- Mooring System: Employs a semi-taut mooring arrangement, combining polyester lines with chain segments and inline tensioners. This reduces seabed footprint, lowers CAPEX/OPEX, and draws on Sevan’s established mooring expertise.
Strategic Context
The launch of the Semi FPU underscores Sevan DWT’s recognition of shifting industry demands. Offshore developers are increasingly seeking versatile production units that can serve multiple purposes across oil, gas, and renewable energy projects. Floating wind, carbon capture, and hybrid energy solutions are driving demand for platforms with greater adaptability and lower lifecycle costs.
While the company’s circular hull has delivered proven advantages in certain applications, the semi-submersible option is intended to broaden Sevan’s competitive edge. The concept emphasizes simplified fabrication, optimized transport and installation, and reduced risks through modular integration — factors that directly impact project timelines and economics.
From an operational perspective, the Semi FPU’s mooring and motion characteristics are designed to support projects in harsher marine conditions, aligning with the industry’s push into deeper waters and more challenging offshore basins.
Outlook
Although the Semi FPU remains at the concept stage, its design reflects the industry’s transition toward multi-solution approaches. By expanding beyond cylindrical hulls, Sevan DWT aims to position itself as a more comprehensive technology provider, capable of delivering tailored platforms across a spectrum of offshore energy projects.
The success of this new design will depend on future validation, classification approval, and eventual adoption in live projects. If realized, the Semi FPU could enhance Sevan DWT’s reputation as a forward-looking innovator in offshore production technology.
