At least 12 people were injured when a major fire broke out in an ONGC well near Olpad town in the district during a repair operation.
Four of the injured are in a serious condition, fire brigade officials said.
The incident occurred when a blow-out preventer (BOP), which is installed on wells to prevent a fire, was being repaired at a well in OLPAD-31 in Ankleshwar basin.
A blowout occurred as the well got activated during repair of the BOP, ONGC's Ankleshwar Asset Manager Har Govind told PTI.
"The fire has been contained and kept to cool, that is to say it is being allowed to burnout," he said.
According to Ishwar Patel, a fire officer from Surat, for the last two days, gas was leaking from the well that was being drilled by the ONGC.
"The gas coming out of the well had spread in the surrounding villages and the residents could smell it," he said.
Today, when the ONGC team was working on the well to stop the leakage, some sort of spark resulted in a huge blast and the gas coming out of the well caught fire, the official informed.
"It is a major fire, and we rushed to the spot with our equipment, but we are unsure of how to control it. We have to remain 500 meters away from it due to the heat generation," another fire brigade official said.
The injured have been taken to private hospitals in Surat, Patel said.