The US Coast Guard and Bureau of Safety and Environmental Enforcement reported a well-control incident at Ship Shoal Block 225 Platform B, a natural gas and crude oil platform 74 miles southwest of Port Fourchon.
The well is leaking gas and water, USCG said, adding that the platform lies in 146 ft of water.
Energy Resources Technology Gulf of Mexico LLC (ERT), owner of the platform, told authorities that workers became aware of a well-control event while they were working to temporarily plug Well No. B2.
Two other wells on Platform B were producing at the time and were subsequently shut-in. All five workers on the platform were safely evacuated.
BSEE and USCG pollution responders reported gas flowed from, resulting in a rainbow sheen visible on the surface estimated to be more than 4 miles by ¾ mile wide. The incident is being investigated.
Talos Energy LLC owns ERT.