Tasked by DNV with developing new ideas for oil recovery at 2,500 metres depth in the Gulf of Mexico, a group of 20 international graduating master’s students have proposed a subsea concept involving a submerged tension leg processing platform midwater to evade the difficult conditions on the seabed. Additionally, storage tanks at 200 metres depth avoid the use of an FPSO and the complications of bad weather risks while still being accessible for shuttle tankers and intervention.
Taking a nuanced approach to what can be done where, the students propose combining existing technology in new ways and new places. By finding an optimal depth for the different processes, it will also be easier to standardise the equipment. This concept, called SPSO (Subsea Processing, Storage and Offloading) Cobia, would be able to operate 300 km from shore.
The proposed processing facility at a depth of 1,000 metres will have a robotic arm that can reach all platform elements for intervention and component replacement tasks, supplemented by a connected ROV to carry out intervention on the platform, seabed and crude storage tanks. The entire SPSO Cobia would be powered electrically directly from shore using a long distance low frequency power cable coupled with high voltage motors.