ONGC surged 8.02% to Rs 98.95 after a global brokerage firm reportedly upgraded the stock to 'overweight' from 'equal weight' and raised its price target to Rs 115 from Rs 84 earlier. As per reports, the brokerage cited higher probability of recovery in average selling prices, improved outlook on domestic production and upside in refining associates post closures. On Thursday, Brent Crude prices crossed $50 per barrel for the first time since March 2020. The February 2020 settlement contract gained $1.39 or 2.84% to settle at $50.25 in yesterday's trading session. The contract was currently trading 5 cents higher at $50.30 a barrel. Firm crude oil prices could increase realizations from crude sales for oil exploration firms like ONGC.