Experimental Investigation of the Suitability of Afzelia africana and Colocasian esculenta as Alternative to Hydroxyethyl cellulose in Enhanced Oil Recovery

Abstract

Polymer flooding is a chemical enhanced oil recovery where polymer is injected into the reservoir to recover oil that remained in the reservoir after the primary and secondary recovery mechanisms, improves oil recovery by reducing the water mobility ratio and increases the viscosity of the displacing fluids for sweep displacement efficiency of the reservoir. Synthetic polymers are widely used chemical enhanced oil recovery. However, there is a big concern about the high cost of these polymers which can result to high cost of oil production and environmental concerns due to the toxic nature of these polymers. Hence, there is need to source for local polymers that can be environmentally friendly, less expensive and can serve as a mobility control agent in enhanced oil recovery. In this study, experimental analysis was carried out to improve hydrocarbon productivity using local polymers such as Afzelia Africana, Colocasian esculenta and compared with synthetic polymer Hydroxyethyl cellulose. Characterization (FTIR and SEM) of these polymers were carried out to determine the functional groups and the morphology. Rheological behavior of these polymers was investigated. Core-flooding experiment was conducted on the local polymers and the synthetic polymer to examine the potential of these polymers in enhanced oil recovery. The results of the study showed that the samples contained hydroxyl group (OH), carboxyl group (COOH), and amine (NH3) based on the functional groups. The scanning electron microscopy test showed that the samples are mesoporous and crystalline in nature. The rheology test results showed that the samples exhibit shear thinning behavior and a non-Newtonian fluid. The core-flooding experiment showed that Afzelia Africana had oil recovery of 8.4%, 14.4% and 17.6%. More so, Colocasian esculenta had oil recovery of 6.8%, 14.0% and 17.2% while the synthetic polymer had oil recovery of 9.6%, 14.8% and 19.2% for different polymer concentrations of 0.2wt%, 0.3wt% and 0.4wt% respectively. The results from this study showed that the local polymers compared favorably with the synthetic polymer in enhanced oil recovery.