India's Hydrocarbon Outlook – 2022-2023

83 DGH: 3 DECADES OF UNLOCKING INDIA'S HYDROCARBON POTENTIAL Spiti-Zankskar is a Category III basin and it has an area of 32,000 sq. km. which is entirely onland. In the basin, 2 plays are present within Paleozoic and Mesozoic. The basin is situated within north-northwestern Himalayan Mountains along northern margin of India. The Basin exposes about 11,000 metre of Paleozoic, Mesozoic and a part of Lower Tertiary sediments. The basin is sparsely explored with inadequate geoscientific data and the elements of petroleum system in the basin are speculative. The basin is bounded in the north by Indus Tsangpo Suture Zone (ITSZ). The metamorphic basement of central crystalline complex, exposed to the south of the basin forms the floor for sedimentary sequence. The south-eastern limit of the basin is limited up to India's international boundary with China. The basin comprises of sedimentary sequence of Precambrian to Eocene age. The Paleozoic and Mesozoic Plays of the Potwar Basin of Pakistan are considered close analogues. These plays have four assessment units identified based on geological rationales. Prospectivity The Spiti-Zankskar basin has a total hydrocarbon inplace of 11 MMTOE, which is entirely undiscovered and potential for intense exploration. The basin has been assessed for the first time. During 2017 Hydrocarbon Resource Assessment Study, Aerial Yield method has been used on analogy of Kohat Potwar Basin (Pakistan). The basin has envisaged 11,000m sedimentary thickness. Geological map and GM data (1,077 stations) are used in the study. Seismic data is not available. Gravity data are of goodqualitywhile theMagneticdataandReports are of fair quality but the Geochemical data is poor. The data reliability is good. Inadequate geoscientific data leads to adopting areal yield method to assess the hydrocarbon resources. No subsurface information is available. The basin is highly deformed. Results may be reviewed as and when new sets of data are available. 21. SPITI-ZANKSKAR BASIN DGH Internal DGH Archive