ABS, the leading provider of classification services to the global offshore industry, has granted approval in principle (AIP) for the Sevan cylindrical floating LNG (FLNG) production unit concept for offshore production, storage and transfer of LNG, LPG and condensate. The next generation FLNG design concept is based on the proven circular and geostationary Sevan FPSO design, which is being used in the Norwegian and Central UK North Sea and offshore Brazil and is under construction as the first application of an FPSO unit to be installed in the Barents Sea.

The full scope of design review for the FLNG concept includes an assessment of the feasibility of the structural strength of the equipped FLNG hull and process topside structure as well as a global performance and safety analysis conducted in accordance with the ABS Rules and Guides for floating LNG units.

"By awarding Sevan AIP, we have acknowledged that the company's innovative approach to designing and constructing a first-of-its-kind FLNG production unit is based on sound engineering practices and ABS classification standards," said Tor-Ivar Guttulsrød, Director of FLNG, Global Gas Solutions, at ABS. "ABS continues to support new FLNG concepts that, when fully developed and implemented, will strengthen the emerging FLNG market."

The Sevan FLNG production unit will have a proprietary cylindrical hull capable of operating in more than 3,000 m (10,000 ft) water depth and in harsh environments, such as extreme North Atlantic and cyclonic conditions. The unit design is based on environmental load calculations for a 100-year return storm in the Barents Sea. Similar to the Sevan FPSOs, the FLNG unit's axio-symetric hull shape enables high capacity for LNG storage and deck loads and tolerance for weather spreading and eliminates the need to weathervane in rough seas. The unit can be designed to have gas processing and liquefaction up to 4 MTPA and store up to 240,000 m3 of LNG and 36,000 m3 of condensate.

According to Sevan, some of the most significant advantages of a cylindrical hull design are the elimination of the need for a turret and swivel and the favorable motions with very little roll and pitch, as well as reduction of typical wave induced fatigue loads and minimized hull deflection, which simplifies the topsides design.

"High availability, inherent safety and simple operation should be the main criteria when selecting technology offshore," said Lars Ødeskaug, Chief Operating Officerat Sevan Marine ASA and responsible for Sevan's LNG efforts. "Sevan's cylindrical FLNG solution meets these criteria at an attractive cost. We are proud to have been granted AIP for our unique design concept, which we believe will introduce a better option for producing, storing and offloading LNG in challenging operating areas."

ABS has been the preferred classification society for the offshore and energy industry for more than 50 years. With the increasing global concern for the environment, clean gas-based energy plays an integral role within that framework. The ABS Global Gas Solutions team formed in 2013 applies its experience and knowledge to support members and clients involved in gas-related projects, including LNG and LPG transportation, the use of LNG and LPG as fuel and emerging FLNG technology projects.