Evaluating the application of foam injection as an enhanced oil recovery in unconsolidated sand

In the Niger Delta, low oil recovery rates less than 30% results mainly due to oil production problems such as water coning, wax deposition and high gas/oil ratios. Meanwhile, the remaining oil becomes a good candidate for EOR methods such as CO2 injection, polymer and foam injection, in-situ combustion and steam injection. But as it stands, the practice of these known methods of enhanced oil recovery is scarce in the Nigeria’s Oil and Gas industry. However, this project is aimed at evaluating the application of foam injection as an enhanced oil recovery method in sandstone reservoir and exploring possible improvement of oil production in the Niger Delta. The project was carried out using two cases. In Case 1, a synthetic model built with static modeling software, later imported to dynamic modeling software and simulated to mimic foam injection process while in Case 2 a real life model with an aquifer fully populated with the necessary reservoir and fluid properties and production history. From the results obtained in Case 1, production indices, field oil recovery, etc. were compared with gas flooding process. For foam flooding, a significant increase in oil recovery as compared to gas flooding and reduction in gas oil ratio and gas produced were observed while in Case 2, field oil recovery, oil production rate, cumulative oil production, gas oil ratio and water cut were compared and significant increase oil recovery using foam flooding, and reduced field water cut was also observed. The economic viability of the project in both cases was also investigated using some economic indicators. Improved displacement efficiency resulting into increased recoverable reserves, and subsequently increased total field oil production has been achieved by foam injection.   Key words: Chemical, foam, enhanced oil recovery, modeling, oil production.