|The Offshore Hydrocarbon Potential of India’s Andaman Islands|
|Exploration Hot Spots|
1Spectrum Geo Ltd, 2Hornet Geoconsulting Ltd
This paper is based on the recent reprocessing and interpretation of approximately 10,600 line kilometres of reprocessed 2D offshore seismic data extending across an area of some 245,000 square kilometres of the Indian waters of the Andaman Sea; an area defined on the USGS worldwide basins map as part of the Andaman Sea Basin.
The Andaman Sea lies to the southeast of the Bay of Bengal and forms part of an Island Arc System which extends 1200 Km from Myanmar in the North to Indonesia in the South.
The seismic data used is from five different surveys of 1982 to 2001 vintage and was reprocessed by Spectrum Geo Ltd in 2009/10 under an agreement with Directorate General of Hydrocarbons (DGH) India. The seismic dataset extends over the fore-arc basin, volcanic arc and back-arc basin areas of the
The Indian part of the Andaman Sea Basin is considered frontier in nature with only 13 wells drilled in the project area east of the Andaman Islands, all targeting the shallow water part of the fore-arc basin and most of them close to the Andaman Islands. Of these wells, the first drilled well (AN-01-1) discovered gas in Miocene limestone. The discovery proves the presence of active hydrocarbon systems with generating hydrocarbon source, reservoir and seal horizons as well as migration & trapping mechanisms. However, the vast majority of the basin (especially the deep water) remains unexplored.
Interpretation of the reprocessed data has shown that the Andaman Sea Basin contains all the elements for successful hydrocarbon exploration as it has identified potential source, reservoir (carbonates and clastics) and seal intervals as well as structural and stratigraphic trapping geometries. Direct Hydrocarbon Indicators (DHI’s) are observed which include gas clouds, bright and flat spots, seabed pock marks, vent mounds and also Bottom Simulating Reflectors (BSR’s) indicating the presence of Gas Hydrates.
The exploration focus is now turning to this frontier area, with the recent award of further exploration licences in the Andaman region. The reprocessed seismic data will provide explorationists with vital regional structural and stratigraphic insight to de-risk an area which is hoped to provide future high impact hydrocarbons.
The authors are pleased to thank DGH,