Petrobras may include supersize floating production units in a new phase of development in the pre-salt fields
Petrobras may include supersize floating production units in a new phase of development in the pre-salt fields, building on successes that have already been notched up using tried-and-tested concepts, CIMC RAFFLES OFFSHORE said in its media release.
Executive manager for pre-salt assets Carlos Tadeu Fraga outlined some of the advances made in the ultra-deepwater pre-salt province, including a halving of drilling and completion time to 92 and 96 days, respectively, on two recent wells.
Fraga told a topical lunch audience at Rio Oil & Gas that deployment of four buoyancy supported riser (BSR) systems by Subsea 7 was a sign of progress that has opened the door to more improvements.
The installation time for the BSRs serving the Cidade de Sao Paulo FPSO and the Cidade de Paraty FPSO fell from 174 days to just 40 days on the last buoy, Fraga said.
This project has also hosted some of the biggest well flows, which are now averaging 25,000 barrels per day in the wider pre-salt, Fraga said.
These prolific flows are already prompting Petrobras to modify its plans for fields such as Libra, where the company is now carrying out design studies looking at much bigger floating production units.
“This is still in the conceptual phase, but we are looking at units that would be at least as big as any seen in the world so far,” Fraga said.
The biggest FPSOs on order at present are destined for Nigeria, with capacities to offload up to 240,000 bpd and with storage for 2.3 million barrels.
“Naturally this has to be aligned with the capacity of the yards to build these units,” Fraga added.
Integrated project management, multiplex intelligent drilling, qualification of flexible risers in ultra-deep waters, ocean bottom sensors, real-time monitoring, and advanced CO2 membranes were all highlighted as technological advances in the pre-salt, where output has climbed to more than 500,000 barrels per day in the eight years since the first discovery.
Petrobras is also keen on working with the best new technologies for stripping out CO2 and starting to look at the potential for subsea separation of these corrosive gases to lighten topside loads.
Petrobras is taking a fairly conservative approach to its technological advances in the medium term, but more futuristic projects such as high pressure separation for bulk CO2 gas removal, the use of nanotechnologies and laser drilling remain on the R&D portfolio, Fraga said.