Petroleum System Analysis of the Ganga Basin, Northern India - A Systematic Approach for Exploring the Frontier Basin Hydrocarbon Potential

Bodapati N. Naidu, John A. Clayburn, and Jim Russell
Exploration, Cairn India Ltd, Gurgaon, India

The increasing demand for petroleum products in India will enforce exploration activity to expand into frontier areas such as the Ganga basin in Northern India. Only 12 wells have been drilled and mostly on poor seismic or even no seismic data. However, hydrocarbon shows in some of the drilled wells and gas seeps in different parts of the basin are indications that hydrocarbon generation and migration have taken place.

The source rock characteristics of the Proterozoic and the Lower Paleozoic sequences from some of the drilled wells support the petroliferous nature of the basin in geological history. Siliclastic and carbonate reservoirs have been identified in drilled wells. Two major depositional hiatuses have been recognized and identifying the exact timing of generation, migration and entrapment is a significant challenge for exploration activities because of these major unconformities.

Two end member scenario models of hydrocarbon generation and migration were created using 2D seismic and Apatite Fission Track data. These models suggest that the timing of the generation and migration seems to be appropriate for hydrocarbon entrapment. Structural and stratigraphic traps have been identified on existing seismic data. Despite hydrocarbon shows and moderate reservoir quality, undrilled Tertiary age plays and structures have also been identified in the basin. This huge basin remains essentially under explored despite indications of the existence of several petroleum systems.

Presentation GEO India Expo XXI, Noida, New Delhi, India 2008©AAPG Search and Discovery