Geologic Controls from the Occurrence of Gas Hydrates in the Indian Continental Margin: Results of the Indian National Gas Hydrate Program (NGHP) Expedition 01

Timothy S. Collett
US Geological Survey, Denver, CO

The Indian National Gas Hydrate Program (NGHP) Expedition 01 was designed to study the gas hydrate occurrences both spatially and temporally off the Indian Peninsula and along the Andaman convergent margin with special emphasis on understand the geologic and geochemical controls on the occurrence of gas hydrate in these two diverse settings. During NGHP Expedition 01, dedicated gas hydrate coring, drilling, and logging operations were conducted from the 28th April, 2006 to the 19th August, 2006. During its 113.5-day voyage, the JOIDES Resolution cored or drilled 39 holes at 21 sites (1 site in Kerala-Konkan, 15 sites in Krishna-Godavari, 4 sites in Mahanadi and one site in Andaman deep offshore areas), penetrated more than 9,250 meters of section and recovered nearly 2,850 meters of core with ~78% recovery. Twelve holes were logged with logging-while-drilling tools and an additional 13 holes were wireline logged. NGHP Expedition 01 established the presence of gas hydrates in Krishna-Godavari, Mahanadi and Andaman basins. The expedition discovered and closely examined one of the richest gas hydrate accumulations yet documented (Site 10 in the Krishna-Godavari basin), documented the thickest and deepest gas hydrate stability zone yet known (Site 17 in Andaman Sea), and established the existence of a fully-developed gas hydrate system in the Mahanadi basin (Site 19). In addition to the work accomplished on board, the science team also collected an unprecedented number of samples and data for analysis by an international team of experts in microbiology, sedimentology, geochemistry, and numerous other disciplines. A final synthesis of the project technical findings is expected to be published in 2008.

AAPG Search and Discovery Article #90078©2008 AAPG Annual Convention, San Antonio, Texas