Chemical modification of guar by different synthetic vinyl monomers for enhancing oil recovery under severe sandstone reservoir conditions

Abstract Nowadays more emphasis is given to biodegradable polymers owing to their distinct properties. Biopolymers are natural, inexpensive, available, and environmentally friendly substitutes that are planned to substitute HPAM for enhanced oil recovery (EOR). In this research, grafted guar with different vinyl monomers prepared through a free radical emulsion polymerization reaction to enhance the drawbacks of native guar gum. Structure characterization was conducted by various spectroscopic techniques including (FTIR) spectroscopy, atomic force microscope (AFM), nuclear magnetic resonance (1H NMR), and thermal analysis established by TGA analysis. Rheological characteristics were tested at severe reservoir conditions. Laboratory flooding experiments performed by sandstone packed model. It is indicated from the rheological analysis that the modified composites have more temperature resistance, salt tolerance, and improved viscosity properties than native gum. The flooding data assumed that the prepared GG-g-AM& MMA and GG-g-AM, MMA&TEVS are suitable for EOR techniques where they can withstand the severe reservoir condition and achieve a recovery factor up to (47.7%) from residual oil by using GG-g-AM& MMA and (55.5%) of residual oil by using GG-g-AM, MMA&TEVS while native guar achieves only (27.7%).