Petroleum System Analysis of the Barmer Basin, India: A Case Study

Abstract

The Barmer Basin is a late Cretaceous to early Tertiary intra-cratonic rift basin located in the western part of Rajasthan, north western India. Sediment thickness exceeds 6 kilometres in the main rift depocenters and overlies Proterozoic basement. The main phase of exploration in this basin began in 2000 and seismic data were acquired over most of the basin, around 100 exploration and appraisal wells drilled to date. In addition, a large amount of data has been collected on source rocks, oils, heat flow measurements and rock properties in both wells and from outcrop sections. These data have been incorporated into a detailed petroleum systems analysis to understand the hydrocarbon generation and charge prediction. An integrated methodology was adopted for construction of a robust regional petroleum system model which incorporates a set of gross depositional environment (GDE) maps for the main source unit (Barmer Hill Formation), the major reservoirs (Fatehgarh, Dharvi Dungar and Thumbli formations) and both intraformational and regional seals. The amount of Himalayan orogeny related uplift/erosion was calibrated to apatite fission track and vitrinite reflectance data. A regional 3D basin model with appropriate thermal scalars was constructed by using the calibrated 1D models across the basin. Measured kerogen kinetics was used to improve the source rock model. The regional 3D migration model derived from this specific kinetics was calibrated to the known distribution of discoveries, charge volumes and hydrocarbon shows in the basin. Source rock characteristics indicate that the northern Barmer Basin is dominated by oil-prone lacustrine source facies whilst the southern Barmer Basin contains both oil- and gas prone facies. The use of measured source kinetics in the 3D model has provided critical insights to the spatio-temporal generation and distribution of migrated hydrocarbons which is being used to high rank remaining prospective areas in the basin.

AAPG Datapages/Search and Discovery Article #90194 © 2014 International Conference & Exhibition, Istanbul, Turkey, September 14-17, 2014