Prosafe Production’s Azurite unit is now in operation off the Republic of Congo. DNV was selected to provide classification and verification services.
The Azurite is meant to handle not only the production of oil, like a traditional FPSO, but also production well drilling. The Floating Drilling Production Storage and Offloading (FDPSO) unit is equipped with a modular drilling package that can be removed and reused elsewhere when the drilling work is completed. It has a storage capacity of 1.4 million barrels of oil and a process capacity of 60,000 barrels of fluid and 40,000 barrels of oil per day. It will be spread-moored in a water depth of 1,400 metres.
15-YEAR LIFE EXTENSION
“When the Azurite left Singapore’s Keppel Shipyard for West Africa, a new era of oil and gas production began, as it became the first self contained vessel with the ability to drill several wells within the first three years after its arrival on location,” says Reidar Lunde, head of Engineering and Construction at Prosafe Productio Services.
“Formerly a Very Large Crude Carrier, the Azurite underwent a conversion between July 2007 and February 2009. The life-extension programme involved assessments of global and local strength, fatigue life analysis for critical connections and the replacement of structural steel as well as preparations for periodical in-water urveys. The Azurite’s new design means she has a 15-year extension, during which she will remain in the Mer rofonde Sud block operated by Murphy West Africa Ltd, off the Republic of Congo,” says Mr Lunde.
“Challenges that required solutions during the conversion and classification processes included the physical arrangement of adjacent process and utilities modules with their associated structures, such as piping and abling. Mitigating the effect of motion was also necessary,” explains Johan Gärdin, the head of DNV’s Offshore Classification department in South East Asia.
Additionally, DNV assisted Prosafe Production in the creation of a coherent safety philosophy when combining
two ongoing activities that are subject to different regulations. Particularly interesting topics, such as the efinition of accidental loads, shut down logic, area classification and fire fighting, were examined. These were ddressed within the framework of existing DNV Offshore Specifications and Standards, with a certain amount of interpretation and prioritisation.
The process plant design was verified by DNV, guided by its Offshore Standards and Rules as templates that were modified according to Prosafe Production’s specifications. The majority of the topside equipment was also required by Prosafe Production to have DNV certification. Besides that, all the major safety aspects have been overed by the main class.
SINGAPORE OFFSHORE CLASS CENTRE
Both plan approval and site surveys were coordinated and executed by DNV’s Offshore Class Centre in Singapore, which since its inception in 2006 has been expanded to efficiently handle all aspects of conversions, newbuilds and units in operation. In most respects, the Centre now acts as a one-stopshop for customers like Prosafe Production that have local engineering offices.