Prospects and Economics of Miscible -CO2 Enhanced Oil Recovery in Some Nigerian Reservoirs.

摘要

On exhausting conventional oil extraction techniques, about 2/3 of discovered reserves are usually unproduced. CO2 injection into oil reservoirs is widely accepted as an effective Enhanced Oil Recovery (EOR) technique, and has been used in the oil industry for over 40 years. In this study, incremental oil, producible by CO2-EOR from the large domestic oil reservoirs at Obagi field was calculated. The study utilized the CO2-PROPHET model to evaluate the oil database and found Obagi fit for CO2 flooding. Afterwards a Kinder Morgan Scoping economic model was used to evaluate the economic viability of the flood. With 1.2 Billion barrels initial oil in place and a residual oil saturation of 50%, the field would only have up to 17% recovery at a 100% hydrocarbon pore volume of CO2 injected. Sensitivity on the Dykstra Parsons correlation coefficient showed that increasing the parameter i.e. (increasing heterogeneity) results in no change in oil produced with time. Also, a sensitivity on viscosity showed that for the range of oil viscosities analyzed, oil production clearly decreases with increasing oil viscosity. Economic sensitivity was positive with a Present Value Profit after Tax of $149.8MM. This is equivalent to $1,623,038,950.00 after a project lifetime of 25 years.