Page 41 - DGH_Annual_Report

India's Sedimentary Basins: Subsurface Insights 41

2.2.4 SAURASHTRA BASIN

Saurashtra is a Category II basin with sub-commercial discovered in-place, potential to be
commercially produced. The area geographically overlaps with the state(s) of Daman and Diu,
Gujarat.

Source: DGH Internal

The basin was built with Pre-Cambrian basement
overlain by Mesozoic sediments followed by
Deccan traps. A thin cover of Neogene and
Quaternary sediments occurs at the top. The
drainage of Saurashtra shows a radial pattern
from the central highland.

The source rocks maturity of Cretaceous is poor
and it remains immature in onland.
Source: DGH Internal
Sub-basalt imaging, variable basalt thickness
and sub-optimal onland seismic data are some
The basin is geologically contiguous with Kutch areas of focus for exploring Cretaceous plays.
basin and separated by the Saurashtra Arch in
the offshore part, which trends north-northwest- • Hydrocarbon prospectivity and Basin
south-southeast direction. The basin has maturity:
presence of prospective plays of Middle Jurassic In the basin, 16 plays are located within Middle
to Early Cretaceous with significant potential Jurassic-to-Early Cretaceous in Onland and
of sub-basalt Mesozoic plays. There has been a Middle Jurassic-to-Trap-to Middle Miocene in
gas discovery in Early Cretaceous reservoirs at Offshore. Petroleum system was modelled in 3D
4,500m depth, below 2,500m thick weathered where datasets were adequate and Aerial Yield
basalts. The northerly located proven Tertiary method was used where data were limited.
Plays of Kutch basin is extended into this basin.
Onland sub-basin has a total hydrocarbon
Major part of Saurashtra mainland is covered in-place of 33 MMTOE and this is entirely
with Deccan Trap basalts with thin veneer of undiscovered risked in-place. The basin has
Miocene and younger sediments, exposed along 100% of total in-place, potential to be explored
Porbandar coast. The Cenozoic sediments have and discovered.
been encountered in the wells drilled in the
offshore Saurashtra basin. In offshore, the basin Offshore sub-basin has a total hydrocarbon in-
lies north of Mumbai Offshore Basin, while the place of 267 MMTOE. This includes discovered
onland part borders with Cambay Basin on its in-place of 70 MMTOE and undiscovered risked
eastern flanks. The deeper offshore Saurashtra in-place of 197 MMTOE. The discovered in-place
borders with the Indus fan. is subject to commercial development.