Geochemical Characterization and Classification of Crude Oils from Eastern Lake Albert Basin, Western Uganda

This study aimed at characterizing and classifying crude oils with the view of inferring source rock characteristics from the chemistry of oils and thus inferring the hydrocarbon resource potential. The use of Gas Chromatographic-Flame Ionization Detector traces (GC-FID) in indicating Kibiro, Nzizi2 Murram Pit, Runga, and Sonso is heavily biodegraded oil seep samples and Mputa-1, Mputa-3, Mputa-4, Waraga-1, and Nzizi-2 oil samples are non-degraded oils. From the Ternary diagram, Mputa-1, Mputa-3, Mputa-4, Waraga-1, and Nzizi-2 oils belong to Paraffinic oils while Kibiro and Nzizi-2 Murram Pit oil seeps are classified as Paraffinic-napthenic oils, and Runga and Sonso oil seeps belong to Napthenic oils. The plots of Moretane/Hopane vs Ts/Tm, 20S/(20S + 20R) for C27 sterane vs 22S/(22S + 22R) for C31-homohopane, and saturates, aromatics and NSO + Asph and ratios of αββ/(αββ + ααα) for C29-sterane and Ts/(Ts + Tm) show that the studied oil seep and oil samples originated from mature source rock which has tendency to yield significant amount of hydrocarbon. A plot of DBT/Phen vs NH/Hop, diasteranes/Steranes vs dH/29Ts and ratios of CPI, DBT/Phen, Pr/Ph suggests that oil and seep samples are derived from shale source rock which yields significant quantity of hydrocarbons.