Apache said it started work to plug a well at its East Cameron block oil platform in the Gulf of Mexico during the weekend after workers spotted bubbling on the surface of the water near the platform. An oil sheen was observed Monday, the company said.
The company said it dispatched a remotely operated vehicle to the area to identify what it described as a "water disturbance." Apache added that, as of Tuesday, no sheen or other evidence of hydrocarbons were visible.
Wells on the platform haven't been in production for several years, the company said. Regulatory authorities were notified of the incident and results from the ROV survey will determine the company's next step.
Work in the Gulf of Mexico is under scrutiny after the April sinking of the Deepwater Horizon oil platform.
Washington imposed a moratorium on deep-water drilling after the disaster, which resulted in the one of the worst environmental catastrophes in the history of the oil industry. The moratorium was lifted in October but the White House hasn't issued any new drilling permits.
The White House last week said more than a dozen projects approved or under way in the Gulf of Mexico before the April disaster could resume work soon.