The explosion happened about 4 p.m. on board an oil rig roughly 12 miles off the coast of New Orleans.
The three injured workers were undergoing treatment in a medical facility on the rig, said the BSEE. Their conditions weren't immediately released.
The oil rig is owned by Houston-based Fieldwood Energy, which reported the explosion. The rig wasn't in production at the time of the explosion, said the BSEE.
The damage was limited to the explosion area and no pollution was reported.
It was unclear what caused the explosion. The BSEE was investigating.