Apache reported an "abnormally pressured gas zone" during Feb. 5 drilling operations in the shallow-water Main Pass 295 in the Gulf of Mexico.
"The well was shut in and the blowout preventers are functioning properly," a company statement read.
The Bureau of Safety and Environmental Enforcement confirmed that Apache prevented the blowout. BSEE said Apache was drilling in 218 feet of water when the incident occurred.
"Non-essential personnel have been removed from the drilling rig," the agency said. "BSEE is overseeing Apache's well control efforts."
A deep-water blowout in the Gulf of Mexico in 2010 sunk the Deepwater Horizon drilling rig. Eleven workers died in the accident, which led to the worst offshore oil spills in history.
Apache said it was working with well-control company Boots and Coots to kill the well. Apache was deploying another rig to the site in the event it needs to drill a relief well.