As you have asked about the Oil and natural gas Corporation (ONGC) Bombay high, I am giving you information about it, check below for the details
It is an offshore oilfield 176 kilometres off the coast of Mumbai.
It is in about 75 m of water.
The operations are run by ONGC.

Geology

It is a carbonate reservoir, the main producing zone, L-III, consisting of
Sedimentary cycles of lagoonal,
Algal mound,
Foraminiferal mound and t
Coastal marsh, capped by a post-middle Miocene shale

Field history
Discovery 1965
Start of production 1974

Production
Production of oil 347,197 barrels per day (~1.730×107 t/a)
Year of production of oil 2009

Crude oil produced from Bombay High is of very good quality as compared to crudes produced in Middle East.
Bombay High crude has more than 60% paraffinic content while light Arabian crude has only 25% paraffin