India's Hydrocarbon Outlook – 2022-2023

52 DGH: 3 DECADES OF UNLOCKING INDIA'S HYDROCARBON POTENTIAL Saurashtra is a Category II basin, implying that the basin has sub-commercial discovered inplace, which needs to be adequately appraised and developed for commercial production. The basin has an area of 194,114 sq. km. with 75,076 sq. km. onland area, 42,617 sq. km. shallow water area and 76,421 sq. km. deepwater area. In the basin, 16 plays are identified within Mid Jurassic- to-Early Cretaceous in Onland and Mid Jurassic- to-Trap-to-Mid Miocene in Offshore. The basin is geologically contiguous with Kutch basin and separated by the Saurashtra Arch in the offshore part, which trends north- northwest-south-southeast direction. The basin has presence of prospective plays of Middle Jurassic to Early Cretaceous with significant potential of sub-basalt Mesozoic plays. There has been a gas discovery in Early Cretaceous reservoirs at 4,500m depth, below 2,500m thick weathered basalts. The northerly located proven Tertiary Plays of Kutch basin is extended into this basin. Major part of Saurashtra mainland is covered with Deccan Trap basalts with thin veneer of Miocene and younger sediments, exposed along Porbandar coast. The Cenozoic sediments have been encountered in the wells drilled in the offshore Saurashtra basin and expected to be The granitic basement has been encountered in well Dhanduka-1 near to the western margin fault. Also, basalt/dolerite dykes and sills are frequently present in the sandstone beds of Wadhwan and Dhrangadhra formations in these two wells. Interplay of three major Pre- Cambrian tectonic trends of western India, Dharwar (NNW-SSE), Aravalli-Delhi (NE-SW) and Satpura (ENE-WSW) controlled the tectonic style of the Saurashtra basin. The Saurashtra horst is the uplifted part of a west-southwest- plunging basement arch which divide the western continental margin into a northern Kutch-Saurashtra shelf and a southern Mumbai- Kerala shelf. The geological history of the basin indicates that the basinwas formed by sequential reactivation primordial faults. Regional uplift took place during the Late Cretaceous and was 8. SAURASHTRA BASIN DGH Internal DGH Archive present below the Deccan trap basalts in the offshore. Thus, in onland part of Saurashtra basin, Mesozoic strata are only present. In offshore, the basin lies north of commercially proven Mumbai Offshore Basin, while the onland part borders with the commercially proven Cambay Basin on its eastern flanks. The deeper offshore Saurashtra borders with the Indus fan. Two wells have been drilled in the onland part of the basin viz., Lodhika-1 and Dhandhuka-1.