Among the 76 priority geologic provinces identified for the World Energy Assessment Project of the U.S. Geological Survey is the Bombay geologic province (province 8043), which is an oil-prone area, both onshore and offshore. The Bombay geologic province is bounded on the north by the Nagar-Parkar Ridge, on the east by the Precambrian Vindhyan Plateau and Deccan Syncline, on the south by the Vengurla Arch and on the west by the 2,000-m bathymetric contour. The area includes the outer shelf of western India, much of which is referred to as the Bombay Shelf; Bombay High; Dahanu, Panna, and Surat Depressions; Cambay and Narmada Deltas; Cambay and Kutch Grabens; and Saurashtra or Kathiaw Peninsula.

Structurally, the province consists of a deformed and rifted portion of the western Indian plate passive margin. Significant features include the uplifted structures of the Bombay High and Saurashtra Peninsula, failed rifts forming the Kutch and Cambay Grabens, and the Narmada-Domodar Graben or lineament.

Within the Bombay geologic province, a composite total petroleum system (TPS), the Eocene-Miocene Composite TPS (804301), was identified. For the purposes of oil and gas assessment, the TPS was further subdivided into two assessment units (AU), the Eocene-Miocene Bombay Shelf AU (80430101) and the Eocene-Miocene Cambay Deltaic AU (80430102). The Eocene-Miocene Bombay Shelf AU is an oil-prone assessment unit located offshore along the west coast of India. A pericratonic basin, it is characterized by extensive carbonate-platform shelf development during middle Eocene to middle Miocene time. The carbonates reached their maximum areal extent in the late Oligocene, covering much of the shelf from the Indus River Delta, south to the Vengurla Arch . The Eocene-Miocene Cambay Deltaic AU is also an oil-prone composite assessment unit, located both onshore and offshore along the west coast of India. The prospective area consists of the Cambay Graben created during Late Cretaceous failed rifting and a delta extending southwest from the graben toward the Bombay Shelf.