The Structural and Stratigraphic Evolution of the Barmer Basin, Rajasthan
Eleanor J. Rowley, Sudhir Mathur, Srinivas Mokashi, and Biswanath Ghosh
Exploration, Cairn India, Gurgaon, India
Over 20 hydrocarbon discoveries have been made in the Barmer Basin since the late 1990s, including the giant Mangala Field in 2004, the largest onshore oil field discovery in India since 1985. As a result the Barmer Basin has been established as a major hydrocarbon province in India.
The Barmer Basin is a Tertiary rift basin forming a northerly extension to the Cambay Basin. The basin is oriented along a NNW-SSE axis, with a secondary set of faults orientated NE-SW. Both fault trends are interpreted to be inherited from existing Precambrian basement fabrics. The basin is a prolific hydrocarbon province with over 3.6 BBbbls STOIIP discovered to date predominantly in the Fatehgarh Formation, a Palaeocene fluvial sandstone. Additional reserves have also been discovered in younger Barmer Hill, Dharvi Dungar and Thumbli formations, as well as in pre-rift volcanics.
Recent work integrating all well and seismic data across the basin has led to the development of a sequence stratigraphic framework identifying a number of distinct sequences that correspond to predominantly fluvial, lacrustine and marginal marine depositional environments. Excellent control from extensive coring and field outcrops has provided confidence in the interpretation. Examples of the types of depositional environments encountered in the basin will be illustrated using field outcrops, core and seismic facies analysis.
A number of modern and ancient lacrustine rift systems can act as good analogues for the depositional environments and potential play types of the Barmer Basin. These systems include the Cambay Basin and East African Rift and will be compared with the Barmer Basin.
Presentation GEO India Expo XXI, Noida, New Delhi, India 2008©AAPG Search and Discovery