Experimental Investigation of Ultrasound-Assisted Weak-Acid Hydrolysis of Crystalline Starch Nanoparticles for Chemical Enhanced Oil Recovery

Ascorbic acid was used to synthesize crystalline starch nanoparticles (CSNP) for the first time. The CSNP was isolated and the influence of the process variables on the physical properties, recovery yield and crystallinity were studied. Rheology of crystalline starch nanofluid (CSNF) was compared with cassava starch (CS) solution and xanthan. Interfacial tension (IFT) of CSNF was studied at various concentration and temperatures. Influence of concentration, temperature, salinity and their interaction with ultrasound were investigated. Sessile drop contact angle method was used to determine the wettability proficiency of CSNF on an initially oil-wet sandstone core. To justify the finding highlighted above, CSNF and CS solution were applied for EOR purposes at reservoir condition. The approaches were efficient in generating sphere-shaped and elongated nanoparticles (50 nm mean diameter) and higher yield of 39%. Increase in concentration, surface area and temperature of CS and CSNF increased viscosity in comparison to decline in viscosity as the temperature increases for xanthan. Increased concentration, salinity and temperature rise of CSNF decreased IFT and altered the wettability of the sandstone core. CSNF increased the oil recovery by 23% and was effective at high temperature high pressure reservoir conditions. The energy consumption and cost estimation has demonstrated that the methods and polymeric nanofluid are cost-effective than traditional methods and products.