High technical and financial risks are involved in exploring and exploiting new fields; hence, greater focus has placed on the development of environmentally friendly, cost-effective, and enhanced oil recovery (EOR) options for existing fields. For reservoirs producing high-density crudes and those with high interfacial tensions, water flooding is usually less effective due to density differences—hence the advent of polymer and surfactant flooding. For cost-effective and eco-friendly EOR solutions, a biopolymer and a surfactant synthesized from Jatropha seeds are used in this study to determine their effectiveness in increasing the oil recovery during core flooding analysis. The experiment involved an initial water flooding that served as the base cases of three weight percentages of polymers and polymeric surfactant solutions. The results for the polymer flooding of 1 wt%, 1.5 wt%, and 2 wt% showed an incremental oil recovery in comparison to water flooding of 16.8%, 17%, and 26%, while the polymeric surfactant mixtures of 5 wt% of surfactant and 1 wt%, 1.5 wt%, and 2 wt% of a polymer recorded 16.5%, 22.3%, and 28.8%, and 10 wt% of surfactant and 1 wt%, 1.5 wt%, and 2 wt% of a polymer recorded incremental oil recoveries of 20%, 32.9%, and 38.8%, respectively.

Oil recoveries from medium and heavy oil reservoirs under natural recovery production are small because of the high viscosity of the oil. Normal water flooding procedures are usually ineffective, as the injected water bypasses much of the oil because of its high mobility. Thermal flooding processes are desirable but have many disadvantages from costs, effects on the environment, and loss of lighter hydrocarbons. Chemical flooding options, such as bio-polymer flooding options, are attractive, as they are environmentally friendly and relatively cheap to deploy and help to increase the viscosity of the injecting fluid, thereby reducing its mobility and increasing its oil recovery. The downside to polymer flooding includes reservoir temperature, salinity, molecular weight, and composition. Six weight percentages of two polymers (xanthan gum, XG, and gum arabic, GA) are dissolved in water, and their viscosity is measured in the laboratory. These viscosities are incorporated with correlations in the Eclipse software to create models with different polymer concentrations of (0.1% wt., 0.2% wt., 0.3% wt., 0.4% wt., 0.5% wt., and 1% wt.). A base case of natural recovery and water injection was simulated to produce an oil recovery of 5.9% and 30.8%, respectively, while at 0.1% wt. and 1% wt., respectively, oil recoveries of 38.8% and 45.7% (for GA) and 48.1% and 49.8% (for XG) are estimated. At 5% and 10% saline conditions, a drop in oil recovery of (4.6% and 5.3%) is estimated during GA flooding and (1.2% and 1.7%) for XG flooding at 1% wt., respectively. XG exhibits higher oil recoveries compared to GA at the same % wt., while oil recoveries during GA floodings are more negatively affected by higher saline concentrations.

Polymers increase the macroscopic efficiency of the flooding process and increase crude oil recovery. The viscosity of 3 polymers xanthan, guar, and Arabic gums is measured in the lab and experimented with as EOR options. Xanthan and guar gum polymers are measured in weight percentages of 0.1, 0.2, 0.2, 0.4, 0.5, and 1, while gum Arabic is measured in 0.4, 0.5, 1, 5, 10, and 15 weight percentages. The viscosity experiments showed that gum Arabic had the lowest viscosity at 15% wt. Xanthan gum and guar gum had significantly higher viscosities than gum Arabic at corresponding weight percentages. At the same weight of 0.5%, xanthan, guar, and Arabic gums recorded a 63%, 53%, and 46% oil recovery, respectively. Due to the limitations surrounding core flooding experiments such as human error, equipment failure, and measurement of oil recoveries, it is necessary to validate the results obtained with other methods such as reservoir simulation. A reservoir model is built (using Eclipse) and incorporated with polymer and viscosity functions measured in the lab to validate results from the core flooding experiments. Peak oil recovery of 9.96%, 9.95%, and 9.90% was recorded for xanthan, guar, and Arabic gum, respectively, at a weight percentage of 0.5% weight. Also, increasing the wt% of injected polymers increases oil recovery. Results also indicate that the trend of oil recoveries during core flooding follows that observed during reservoir simulation and oil production increased as percentage weight increased for all the polymer cases considered.