The Accident of the P-36 Platform: The Rupture of the Emergency Drainage Tank

Abstract

On March 15, 2001, the P-36 Platform had an accident, which led to the sinking of the unit. The platform was in operation in Roncador Field, at Campos Basin, in 1360 m water depth. This paper describes the analyses performed to validate the hypothesis that the first main event in the accident was the structural rupture of the starboard Emergency Drainage Tank. This tank was located inside the aft-starboard column of the platform. With the internal shell tank rupture due to overpressure, equipment and piping inside the column were damaged, causing the flooding of pontoon and column with water, raw oil and gas, that ignited resulting in the second event, an actual explosion.

Maritime Risk Assessment and its Current Status

“…The best source of information was unavailable since the platform now lies upside down on the seabed. The analysis of the operations sequence indicated the hypothesis of an improper admission of raw oil into the starboard Emergency Drainage Tank (EDT) 10 . This tank was located inside the aft-starboard column of the platform.…”

“…P-36 was the first floating production unit operating in the Roncador field, located 130 km off the northeastern coast of Rio de Janeiro, Brazil. The platform was operating at a water depth of 1360 m, and had a capacity to produce 180 000 barrels of oil, and to handle 7.2 million m 3 of gas production per day 10 . The Inquiry Commission established by Petrobras collected data and information and established various hypotheses.…”

Risk assessment of loss of structural integrity of a floating production platform due to gross errors

“…This accident has its parallel to mobile platforms where manholes or doors, that should be closed, are standing open such as on the P36 platform in Brazil in 2001 [14,15].…”

Maritime Risk Modelling and Decision Making

“…P-36 was the first floating production unit operating in the Roncador Field, located 130 km off the north-eastern coast of Rio de Janeiro, Brazil. The platform was operating at a water depth of 1,360 m, and had a capacity to produce 180,000 barrels of oil, and to handle 7.2 million cubic meters of gas production per day [49]. The Inquiry Commission established by Petrobras collected data, information, and established various hypotheses.…”

“…The best source of information was unavailable since the platform now lies upside down on the seabed. The analysis of the operations sequence indicated the hypothesis of an improper admission of raw oil into the starboard Emergency Drainage Tank (EDT) [49]. This tank was located inside the aft-starboard column of the platform.…”