Alliance Rig Collapse; Cameron, Louisiana

Cameron, Louisiana | 1991-Jun-04

Initial Notification: On June 4, 1991, the Alliance Operating Consolidation and Production Platform located in the Gulf of Mexico suffered structural failure. The platform, located about 7 nautical miles east-southeast of Cameron, Louisiana, supports a 5,000-barrel consolidation tank that serves as an intermediate holding reservoir for three or more wells that produce a very light (API 47) sweet oil. Pipelines (8- inch and smaller) are part of the facility leading to and from the tank and are used to collect product and transfer it to shore. About 1020 on June 4, 1991, the fishing vessel LADY FRAN, operating east of the rig reported a large (1.5 to 2 miles) slick coming from the west. The report indicated that the rig had collapsed and dumped the large deck into about 10 feet of water. Investigation verified the incident. Steems Oil Production Company of Lafayette, Louisiana reported that the tank had been sounded the previous day and had contained 5,033 barrels. More than half had been transferred ashore before the collapse. USCG district 8.