The energy major's director for HR will hold the additional role henceforth.
Saikia, kidnapped on April 21, was released by the United Liberation Front of Asom (Independent) militants near the Myanmar border in Longwa village of Mon district in Nagaland.
Surat Municipal Commissioner Banchhanidhi Pani said the fire was in the 36-inch Uran-Mumbai gas pipeline.
The well no. 5 at Baghjan in Tinsukia district of Assam has been spewing gas uncontrollably for the last 16 days and it caught fire on Tuesday afternoon, killing two OIL firefighters at the site.
The company said in a statement that it has signed an MoU with the Assam government for enhancing its exploration and production activities in the state.
Several casualties are feared amid reports of many injuries in a massive fire that raged through a storm water drainage network at the ONGC's oil and gas processing plant, in Uran, Maharashtra.