Anticipating future developments and a production increase in Congo, Perenco has converted an oil vessel into a floating production storage and offloading unit (FPSO). La Noumbi will replace the Conkouati currently in operation on the Yombo field. This conversion perfectly illustrates the know-how and the ingenuity of Perenco’s teams.
Making the choice of a conversion
When the Production Sharing Contract (CPP) in Congo was renewed, Perenco committed to install a new floating terminal on the Yombo field to replace the Conkouati, a facility acquired in 2002 and in place since 1992.
At the launch of the project at the end of 2013, Perenco first contemplated the construction of a new floating production storage and offloading unit. But following the crisis that affected the entire sector, the group re-oriented the project on a much more rational conversion in terms of costs and planning.
Perenco subsequently acquired an icebreaker petroleum vessel in excellent state, the M/T Tempera, former property of a Finnish oil company. This vessel had the perfect dimensions to suit the needs of the company, a reinforced hull and a diesel-electric propulsion unique in its kind for an oil ship.
A technical challenge and a human experience
The project started almost five years ago. It was essential to take enough time to carefully define the needs of the subsidiary in the short, medium and long term, seize the best opportunity and select the right partners and a suitable team.
The upstream phase, conceptual studies and definition of the specifications lasted two years, following which in 2016 the detailed in-depth study and preparation phase for the execution could start. The project team was initially based in Paris before being involved in Singapore from mid-2017.
Works in Singapore lasted just over a year in a partner shipyard that Perenco had already used to complete four prior conversions.
The last installation phase in Congo off Pointe-Noire coast is scheduled for the last 2018 quarter. La Noumbi will transit on its own at a speed of 10 knots to preserve its equipment and limit its fuel consumption.
Innovative and bold technical choices
For this conversion, given the expected volumes to be processed, Perenco chose to use two existing storage tanks on the ship to improve fluid separation efficiency and to considerably reduce the quantity of process equipment to be installed on the deck. This new technical solution required numerous studies to validate fluid diffusion, fluid behaviour and also to define fluid regulation and transfer. The new facilities will provide large savings while offering an effective and scalable system.
The FPSO offers many competitive advantages. Maintenance costs for the old building had become disproportionate when compared to expected profits, while process facilities were no longer in line with the needs of the Congolese subsidiary. Yombo generates more and more water so it was crucial to review fluid separation capacities and cope with future water increase. The new FPSO will also allow Perenco to start producing on the adjacent Masseko field.
Last but not least new life quarters will offer a better working environment and significantly increase accommodation capacity, thereby reducing living barges charter costs and special operations costs (development, works, maintenance and drilling etc.). The 90 staff members working on site who currently operate the field are to settle in their new quarters from November 2018.
La Noumbi in figures
• Installation date: 31 October 2018
• Design life (or Estimated life span); 20 years
• Main dimensions: L=225m x W=44m
• Storage capacity: 750,000 barrels
• Installed Electrical Supply; 23.2 MW
• Treatment capacity: 12,000 oil barrels per day
• Treatment capacity: 120,000 barrels of water per day
• Accommodation capacity: 140 people