India's Hydrocarbon Outlook – 2022-2023

66 DGH: 3 DECADES OF UNLOCKING INDIA'S HYDROCARBON POTENTIAL Bengal-Purnea is placed at Category III, to be intensively appraised and explored. In the event of the significant onland discovery (Asokenagar-1) and reallocation of old discoveries from earlier North East Coast (NEC) to newly mapped Bengal offshore part, the basin is proposed for upgrade to Category II during the next periodical assessment of country-level hydrocarbon resources. The basin has an area of 121,914 sq. km. with 42,414 sq. km. onland area, 33,465 sq. km. shallow water area and 46,035 sq. km. deepwater area. In the basin, 5 plays exist within Gondwana-Cretaceous-Tertiary in the Onland part, 8 plays within Eocene-Pliocene in Offshore part and 3 plays within Gondwana (Karharbari-Barakar-Raniganj) of Purnea sub- basin. Bengal-Purnea basin has three sub-basins namelyBengal onland, Begal offshoreandPurnea onland. The basin is a potential hydrocarbon- bearing province, characterized primarily by siliciclastic shelf margin sediments, situated along the East Coast of Indian peninsula. passive margin set up in the offshore region. This basin hosts thick pile of sediments of 10 km and more, ranging from Permo-Triassic to Recent. The basin’s onland part is mostly covered by the Mesozoic sediments, overlain by the thick Tertiary sediments comprising of Paleocene 14. BENGAL-PURNEA BASIN DGH Internal DGH Archive The offshore part of basin has 2/3rd potential lying in Middle Miocene play and six gas discoveries are contemplated for development. Occurrence of channelised deposits associated to subtle structures in the east-central area may be significant exploration targets. Bengal basin is currently under active exploration stage. Some biogenic gas shows are reported from the Tertiary stratigraphic interval ranging from the oldest sediments of Paleogene to the youngest sediments of Miocene-Pliocene complex, geographically distributed majorly over offshore areas with strati-structural entrapment conditions. The basin, like other east coast basins of India, is also a peri-cratonic, rift/extensional- passive margin basin, with number of individual Gondwana rift grabens in the onland part and a