India's Hydrocarbon Outlook – 2022-2023

40 DGH: 3 DECADES OF UNLOCKING INDIA'S HYDROCARBON POTENTIAL Assam Shelf is a Category I basin, implying that the basin has significant commercial discovered inplace. The basin has an area of 56,000 sq. km. which is entirely onland. In the basin, 8 plays are present within Basement and Tertiary. The AssamShelf basin is a petroliferous province, characterized primarily by siliciclastic deposits of shelf margin, situated to the north-east region of Indian peninsula, falling mostly within the state of Assam. The Assam Shelf basin is still under active exploration stage. Commercial hydrocarbon occurrences, besides Basement is spread over different stratigraphic intervals ranging from the oldest sediments of Paleocene (Tura) to the youngest sedimentsof Pliocene (Girujan). Several oil and gas fields have been discovered within structural, stratigraphic and strati-structural entrapment conditions. Assam Shelf basin is a peri-cratonic, passive margin basin, with the signature of compressional tectonics as a result of Himalayan orogeny. The basin hosts thick pile of Tertiary sediments, ranging from Paleocene to Recent which overlies Basement consisting of Granitic and Metamorphic complex. Gondwana sediments are exposed in the western extremity bank of Brahmaputra river. The hydrocarbon accumulations often indicate charging from multiple source sequences. Prospectivity The Assam Shelf basin has a total hydrocarbon inplace of 2,705 MMTOE, out of which 1,827 MMTOE has been discovered and it includes both commercial and sub-commercial inplace. The remaining, 878 MMTOE, nearly 32% of total inplace is potential to be explored and discovered. The basin has been assessed earlier during 1995- 96 study along with 14 other basins. During 2017 Hydrocarbon Resource Assessment Study, 3D PSM approach has been used due to availability of adequate datasets. The 2017 resource reassessment study has incorporated 2,723 LKM of 2D seismic data, 10,995 SKM of 3D seismic data, 275 drilled well information. The basin is highly explored with good seismic coverage. Geochemical, 2D/3D seismic, well data and reports are excellent while gravity data is good 3. ASSAM SHELF BASIN DGH Internal DGH Archive of Garo Hills, consisting of gritty sandstones, carbonaceous shale and lenticles of coals. The basin unconformably extends up to the northern