Characterization of petroleum oil seepage using modern spectroscopic techniques: in case of Were Ilu-Legeheda, Ethiopia

Abstract

The sedimentary regions of Ethiopia cover a significant portion of the country and comprise five distinct sedimentary basins; namely, Ogaden, Abay, Mekele, Gambela and Southern Rift Basins. The Blue Nile basin is a North West-South East trending branch of the Ogaden intra continental rift basin. The presence of an oil seepage at Were Ilu and Legeheda points to the presence of an active petroleum system. The main aim of this study was to characterize the chemical nature of the seepage oil leaked out from the hard basalt rock of Mechela river. Seepage oil samples were analyzed using ultraviolet (UV), infrared (IR), and nuclear magnetic resonance (NMR) spectroscopic methods. All the chemical analysis obtained from UV, IR and NMR showed that high contents of saturated hydrocarbons were found in the petroleum collected from the stated areas, which is the principal criterion for identification of pure petroleum oil.