New Delhi, Sept. 17 -- State-run Oil India Ltd (OIL) plans to invest around Rs.15,000 crore over the next three years to explore offshore deep and ultra-deep blocks in the country in a bid to ensure India's energy security, said Ranjit Rath, chairman and managing director of the company.

OIL currently has a presence across multiple onshore and offshore sedimentary basins. Its offshore portfolio now includes acreages in the Andaman, Krishna-Godavari, Mahanadi and Kerala-Konkan basins, including ultra-deepwater blocks.

"We acquired 48 000 sq. km in these water and ultra deep water, two blocks in KG Basin and two blocks in the Mahanadi basin, for which we have already completed 2D and 3D seismic surveys. Data processing is underway, and we...