Estimation of Petroleum Source Rocks Based on the Crude Oil Geochemistry in Amu Darya Basin, Northern Afghanistan

Amu Darya and Afghan-Tajik Basins in the northern Afghanistan are proven basins and considered to have the highest potential of hydrocarbons in Afghanistan. This research is concentrated on two oil elds in the Amu Darya Basin. In order to determine the origin of oils and depositional environment of source rocks in the study area, physical properties, light hydrocarbon composition, biomarkers and carbon isotopic composition of oil samples were determined. The main nding of the research shows that oils collected from the northern Afghanistan Amu Darya Basin were derived from marine organic matter deposited in reducing environment. It was confirmed by the concentration of n-alkanes and isoprenoids in the Kashkari and Angot oils. In addition, it was found that the oils were expelled from source rocks in the early oil generation stage and no sign of biodegradation was observed. Based on the geological information of the Afghan Amu Darya Basin and stable carbon isotopic composition of the saturated hydrocarbons, it was determined that the oils were generated from Jurassic carbonate source rocks.