The company also said it has made three oil and gas discoveries in Krishna Godavari basin and Tripura.
ONGC said it will invest Rs 2,913.10 crore (Rs 29.13 billion) in revamping 48 ageing platforms at Mumbai High and Neelam & Heera oil and gas fields.
After the recent redevelopment efforts, these fields are expected to be in production till at least 2030 but the existing infrastructural facilities will not last that long.
"Hence revamping/retrofitting of these facilities in a phased manner is essential to maintain the production of oil and gas from Mumbai High and Heera fields," ONGC said in a statement.
The company board in its meeting yesterday approved revamp of 48 platform on these fields by mid of 2016.
Also, the board approved Rs 1,138.50 crore (Rs 11.38 billion) revamp of BPA and BPB process complexes on the giant Bassein & Satellite gas fields in the western offshore.
The two process complexes, which handle and process acidic and corrosive gas before the fuel is dispatched to Hazira Gas processing plant of ONGC, were commissioned in 1987 and 1989 respectively.
"Both the complexes have already covered the normal design life of 25
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