Geo-microbial Studies for Hydrocarbon Exploration in Sediment Samples from Southern Part of Gulf of Mannar,Kerala-Konkan Offshore Basin

摘要

Geo-microbial prospecting for hydrocarbons is an exploration method based on the seepage of light gaseous hydrocarbons from oil/gas reservoirs towards the surface and their utilization by hydrocarbon-oxidizing bacteria. The detection of anomalous populations of hydrocarbon-oxidizing bacteria in the surface soil or sediment helps to evaluate the prospects for hydrocarbon exploration. Geo-microbial prospecting studies have been carried out for hydrocarbon exploration in sediment samples from southern part of Gulf of Mannar,Kerala-Konkan Offshore Basin; the Propane oxidizing bacteria (POB) range from 0.2×10~2 to 6.5×10~4 cfu/gm. The bacterial concentration distribution maps shows two microbial blooms of high concentration of Propane oxidizers in the northeastern and southwestern parts of the studied area. In the present study the propane oxidizing bacteria were found to be between 10~3 to 10~4 cfu/gm of sediment sample,which is significant and thereby substantiates the seepage of lighter hydrocarbon accumulations from the subsurface. Based on the microbial prospecting results the Kerala-Konkan Offshore Basin study area appears to be positive prospects for hydrocarbon exploration.