Performance assessment of a novel bio-based polymer for enhanced oil recovery in high salinity sandstone reservoirs

Polymer flooding is arguably the oldest chemical oil recovery method. The use of natural polymers in enhanced oil recovery process has gained wide acceptance due to their excellent viscosity, high resistance to challenging reservoir conditions ranging from increased salinities, temperatures and divalent cations. In recent times, research into the efficiency of green natural polymers is gaining attention as an eco-friendly, readily available and cost-effective option. In this study, the displacement efficiency of Abelmoschus esculentus as a natural polymer in recovering heavy crude from sandstone reservoirs was examined and a simulation model was built to replicate the laboratory model. Abelmoschus esculentus was cleaned, sun-dried, and grinded into powder form and enclosed in an airtight bag. The various phases were analyzed to ascertain the fluid-fluid compatibility and consistency. Polymer rheological studies was conducted at varied temperatures. Core flooding at optimum polymer concentration was considered in an oil-wet sandstone core under reservoir conditions. Results showed that the solubility of the fluids is a function of temperature. Furthermore, polymer viscosity showed a direct relationship to the polymer concentration and temperature. Polymer flooding resulted in additional recovery of 16.26 % oil initially in place (OIIP), thus affirming the efficiency of this natural polymer in recovering heavy oil. However, a viscosity enhancer is required for improved performance. The simulation model was built, and the recovery factors of both models was successfully matched.