The Origin of the Fatehgarh Formation, the Major Oil Reservoir in the Barmer Basin, Rajasthan, India
Paul M. Compton and Sujoy Mukherjee
Cairn India Ltd, Gurgaon, India
With the Mangala, Aishwariya and Bhagyam oil discoveries in 2004, Cairn established the Barmer Basin of Rajasthan as a major new hydrocarbon province. Most reserves in the basin are contained in fluvial sandstone reservoirs of the Fatehgarh Formation, of probable Paleocene age, but which may extend down into the latest Cretaceous. The Fatehgarh sandstones were mainly derived from reworking of older Mesozoic sandstones surrounding the northern end of the Barmer rift, but with some volcaniclastic input from Deccan affinity volcanic rocks within and on the margins of the rift.
The thick, quartz-rich, high porosity and high permeability Fatehgarh sandstones provide an excellent reservoir in the north of the Barmer Basin, but the increasing volcanic influence further south causes reservoir quality and net sand thickness to decrease. This paper relates how the tectonic and volcanic evolution of the northwest margin of the Indian plate has influenced the depositional trends which have resulted in formation of this world class reservoir.
Presentation GEO India Expo XXI, Noida, New Delhi, India 2008©AAPG Search and Discovery