NEW ORLEANS (AP) - A slight sheen was visible again but quickly dissipating Friday near a damaged gas drilling rig that blew wild and burned earlier this week off Louisiana's coast, a federal agency said.
The rig blew wild Tuesday morning and the spewing gas ignited that night, burning and heavily damaging the rig owned by Hercules Offshore Inc.
Authorities believe that sand and sediment clogged the well late Wednesday, shutting off the gas flow in what is referred to as a "bridge over." Forty-four workers safely evacuated soon after the blowout and hours before the gas ignited.
The clog was holding Friday and BSEE, working with well operator Walter Gas & Oil, said assessments on how to permanently seal the well - including the possible use of another rig to drill a relief well - continued.
Once the well bridged over, industry experts have said, it became more likely that well control workers will be able to seal or cap the well itself. However, the time-consuming process of drilling of a relief well to intercept the original one and secure it with mud and cement remained a contingency.
BSEE said Walter has contracted to bring another rig in "to potentially drill a relief well."
The fire went out after the well stopped spewing gas.
The drilling rig caught fire hours after the workers were off. The fire was out Thursday morning, making it easier for authorities to begin assessing options for permanently sealing it.
Because the well was natural gas, not oil, experts said the pollution threats were far less than those posed by some previous accidents. Light sheens, quickly dissipating, have been reported each day since the blowout.
In addition to government monitoring, scientists from a multi-institutional project called the Ecosystem Impacts of Oil and Gas Inputs to the Gulf Consortium plan a cruise Saturday to gather water samples.