Abstract
With the declines in oil discoveries during the last decades, it is believed that Enhanced Oil Recovery (EOR)technologies will play a key role to meet the energy demand in years to come. Different processes have been designed to improve displacement efficiency by reducing residual oil saturation. However, polymer flooding was designed to improve sweep efficiency by improving the mobility ratio. In Nigeria, EOR materials and technologies are virtually imported, making them limited and expensive to use. This study is aimed at designing and constructing an efficient locally made core flooding apparatus, to carry out EOR experiments (flooding) and also to investigate the suitability of using locally sourced polysaccharide, potato starch in place of xanthan gum in polymer flooding, considering cost and concentration. The core flooding laboratory equipment was personally designed and fabricated to carry out the experiments at room temperature and pressure. Six core samples (P1 – P3; X1 – X3) with sand particle size of 425um were used and saturated with brine of concentration 10,000ppm and 1wt% salinity while heavy crude of API 18.21 was flooded through each sample. After water flooding, potato starch and xanthan gum prepared at 2,000ppm,4000ppm and 6000ppm concentration were flooded for tertiary recovery. The result showed that xanthan gum gave better recovery than potato starch but at concentration of 6000ppm, potato starch gave a recovery of 28.57% which is close to that of xanthan gum (30.56% recovery). Also, in respect to cost, xanthan gum cost ₦9,000 for 0.227 kg and an estimate of ₦40,000 for 1kg while potato starch cost ₦2,000 for 0.227kg and ₦9,000 for 1 kg, making xanthan gum more expensive than potato starch. This shows that potato starch, which is a cheaper polymer agent, gives better recovery at higher concentrations, hence can be applied in the oil and gas industry when more research is carried out on it for better improvement.