Running like a clock on the Seabed

The world’s first subsea gas compression system has now been in operation for one year on the Åsgard field. The system has been running like a Swiss clock with practically no stops or interruptions.

It was in September 2015 Statoil (STO) and its partners started up the world’s first subsea gas compression system on the Åsgard field in the Norwegian Sea.

“Quality in all sections of the project and also during operation has contributed to maintain a system regularity of close to 100% through its first year of operation,” says Halvor Engebretsen, vice president for Åsgard operations.

“Before start-up we carried out extensive testing, commissioning and verification of the technology, and thereby we could remove errors and weaknesses before the installation was placed on the seabed. We have already benefitted from this effort by stable and good operation,” he continues.

Increased recovery worth billions

With this new and ground-breaking technology, the recovery from the Mikkel and Midgard reservoirs has been increased by as much as 306 million barrels of oil equivalent (boe), corresponding to a medium-sized field on the Norwegian continental shelf (NCS) and extending the fields’ life to 2032.

“During the first year of operation we have raised production by an excess of 16 million boe. Based on today’s prices the value added amounts to more than NOK 5 billion,” says Engebretsen.

The recovery rate from the Midgard and Mikkel reservoirs on Åsgard has been raised from 67% to 87% and from 59% to 84% respectively.

“Åsgard subsea gas compression is one of Statoil’s most radical innovation projects. The technology represents a quantum leap that may contribute to considerable improvements in both recovery rate and lifetime for a number of gas fields.

Reduced carbon footprint

The technology that has been in operation for a year was matured through many years by strong in-house expertise. In close collaboration with suppliers such as Aker Solutions (AKSO.OL), MAN and Technip, Statoil has qualified more than 40 new technologies.

“We have built test facilities at K-lab, storage and maintenance capacity at Vestbase, and we have access to ships that are capable of handling installation of large subsea modules. By reusing this technology, we have great opportunities for simplification and efficiency improvements, and for reducing carbon footprints of future gas compression systems,” explains Engebretsen.

The technology also represents a significant reduction in energy consumption and carbon emissions in a lifecycle perspective on Åsgard, compared to a compression platform. This technology represents a potential for further carbon reductions through use in future subsea solutions.