Sustainable Enhanced Oil Recovery Using NaOH Pretreated Sugarcane Bagasse Polymer

Abstract The growing demand for cost effective and environmentally sustainable enhanced oil recovery methods has created interest in alternative polymer sources beyond conventional synthetic chemicals. This study presents a novel application of sugarcane bagasse, an abundant agricultural waste in the Niger Delta, as a natural polymer for enhanced oil recovery, with emphasis on improving polymer performance through alkaline pretreatment. The work advances the concept of converting locally available biomass into a functional EOR agent capable of improving oil displacement efficiency. Raw and NaOH pretreated sugarcane bagasse polymer solutions were prepared, characterized, and evaluated through laboratory scale experiments. The physical and rheological properties of encapsulated core plugs were determined, including bulk volume, pore volume, porosity, permeability, viscosity, density, and cumulative oil recovery at varying polymer concentrations. Fourier Transform Infrared analysis identified key functional groups such as hydroxyl, carbonyl, and ether bonds, which contribute to the hydrophilic behavior of the polymer and its interaction with brine and crude oil. NaOH pretreatment enhanced these interactions by removing lignin and exposing additional active sites, leading to improved viscosity and increased alkalinity. Core flooding experiments conducted at a brine salinity of 10,000 ppm demonstrated superior performance of the pretreated sugarcane bagasse polymer, achieving a maximum cumulative oil recovery of 88.67%, compared to 85% for the raw sample. The results confirm that sugarcane bagasse is an effective and locally sourced polymer for enhanced oil recovery. This study highlights its potential for field application while offering a sustainable pathway for transforming agricultural waste into a valuable material for oilfield operations.