Preliminary hydrocarbon analysis of crude oils from Umutu/Bomu fields, south west Niger Delta Nigeria

Abstract

Seven different crude oil samples were collected from two oil fields in the Niger Delta Nigeria. The bulk properties of these crude oils which include API gravity, reid vapour pressure; kinematic viscosity, dynamic viscosity, moisture, gum content and cloud point were analysed. Aliphatic biomarkers were used as supporting tool to deduce the geochemical characteristics such as thermal maturity, depositional environments, source of organic matter and extent of biodegradation. Results show that API° gravity ranged from 29.00° to 85.00°, specific gravity 0.65 to 0.88, 3.00 to 9.00, reid vapour pressure 3.00 to 9.00 kPa, kinematic viscosity 0.90 to 10.10 cSt, dynamic viscosity 0.70 to 8.90 cP, moisture content 0.13% to 26.00%, gum content 6.27 to 45.84 mg/L, cloud point 3.00 to 12.00 °C, pour point −7.00 to 4.00 °C and flash point <30.00 °C. Distribution of n-alkanes (Pr/Ph, and isoprenoide/n-alkanes ratios) reflects that the oil samples originated mainly from terrestrial organic sources deposited in an oxic paleoenvironment.