Petty Officer 1st Class Bill Colclough says that as of early Friday morning, workers have managed to cut the flow in half.
The Bureau of Safety and Environmental Enforcement says officials lost control of the rig Thursday, but no injuries or pollution have been reported.
BSEE says most crew members were evacuated from the rig, which was drilling in 262 feet of water about 108 miles southwest of Lafayette.
The rig operator is EnVen Energy Ventures of Metairie, La.
Wild gas wells tend to be less of an environmental threat than blowouts from oil wells.