The two companies, which jointly own the KG D6 gas block off India's east coast, today announced an agreement to deepen and expand a partnership and produce 30 to 35m cubic metres of gas a day, phased over 2020 to 2022.
"This is an important step forward for BP in India. Working closely together, Reliance and BP are now able to develop these major deep water gas resources offshore India efficiently and economically," said Bob Dudley, BP's chief executive.
BP holds a 30 per cent stake in the gas block while Reliance holds 60 per cent, and the two have invested around $1.6bn to May this year in deep-water exploration and production.
India, which today consumes over 5bn cubic feet a day of natural gas, is working to move gradually to a gas-based economy. It plans to double gas consumption by 2022.
The companies will also work on new opportunities across India's energy sector, like developing differentiated fuels and advanced low-carbon energies.
Read more: India wants to unlock $40bn in oil and gas