The plant is owned by state-run energy giant Petroleos Mexicanos (Pemex), and is located in Tamaulipas state, Xinhua reported.
The fire, which broke out at 11 a.m., was doused about an hour later, Pemex said in a statement. Dozens of people were injured.
About 700 people were working at the facility when the fire broke out.
Residents living within a five-kilometer radius of the plant were evacuated.
Spotted: Ajay Devgn and Kajol at an event in Mumbai
Photos: Sonakshi Sinha, Sushant Singh Rajput at Mumbai airport
Pics: Prabhas, Tamannaah Bhatia at 'Baahubali 2' first look launch at MAMI
'Ae Dil Hai Mushkil' photos: Aishwarya, Anushka, Karan get candid at MAMI
Photos: Huma Qureshi, Neha Dhupia and other celebs at MAMI