A fire broke out early Friday morning at the Nohoch-A offshore platform run by Mexican state oil company Pemex at the Cantarell complex, a source at the company said.
Pemex has sent four vessels to extinguish the fire and is preparing to receive potentially injured workers at a nearby hospital, the source added.
Pemex did not immediately respond to a request for comment.
Located in the Bay of Campeche, in the southwestern end of the Gulf of Mexico, Cantarell produces from one of Mexico's oldest oil fields which for decades was one of Pemex's crown jewels.
While once one of the world's largest oil deposits, production at Cantarell has since declined to just 170,000 barrels per day (bpd), according to Pemex data.
(Reuters - Reporting by Ana Isabel Martinez; Writing by Kylie Madry; Editing by Isabel Woodford)