We all know that Petrobras was given a permit by BOEMRE to produce from their deep water lease (8,000' water depth) in the Gulf of Mexico. On April 3rd, it was reported that they had lost the riser buoyancy can on one of their wells. The 130 ton can floated off and the riser pipe collapsed to the sea bed causing damage to the subsea equipment. This link gives some pictures of how the risers are set up.
The incident should raise questions about the entire design - especially the connection of the buoyancy can to the riser. I will try to watch the BOEMRE web site for an accident report. That this should happen during calm seas raises serious concerns in my mind.
For background, the Petrobras FPSO is the first FPSO permitted in the Gulf of Mexico even though they are common elsewhere in the world. The ship , the BW Pioneer, was built in 1992 in a Japanese shipyard. It was converted to an FPSO by Keppel Shipyards in Singapore. It is a turret moored design which means the well flowlines enter into a common hub and the ship is allowed to "weathervane" around this hub or turret. In bad weather, they can lower the turret and the ship can leave the area under its own propulsion. The well connections are through a hybrid riser. The riser consists of a steel pipe held in tension by a buoyancy can. A flexible pipe connects the top of the riser to the turret. The FPSO will be operated for Petrobras by a contractor. The FPSO will be flagged in Bermuda.
Most folks in the industry hold a low opinion of Petrobras' safety record. While they are industry leaders in subsea technology, they tend to have a cavalier attitude and don't do their due diligence when using new technology. The sinking of the P-36 brought some of this to public attention. Here are my concerns:
- Not operated with Petrobras personnel but by contractors whose training, experience and commitment to safety may be open to question.
- Not flagged as a US vessel meaning it was not built to USCG requirements.
- Riser buoyancy can failure may mean the entire design is suspect.
- Petrobras reputation for short cutting safety issues.