Application of lignin polymeric nanofluid as a chemical enhanced oil recovery agent at reservoir condition

Abstract

Surfactant flooding constitutes part of the relevant enhanced oil recovery (EOR) technologies desirable for Malaysian oilfields. However, the high cost of synthetic surfactant production, high toxicity, susceptibility to high salinity reservoir condition, high adsorption rate and the strict regulation laid by government agencies in different countries has limited the growth of synthetic surfactant market in the post Covid-19 era. To solve this problem, the non-petroleum-based (biomass) surfactant can be used to replace the petroleum-based surfactant. Therefore, in this study lignin polymeric nanofluid (LPNF) was synthesized from sago bark using the method of ultrasonic assisted nanoprecipitation for EOR application. Besides, the surface morphology, functional groups, purity, structure and thermal stability of the lignin nanoparticles was determined using transmission electron microscopy, Fourier transform infrared spectroscopy, high pressure liquid chromatography, nuclear magnetic resonance and thermogravimetric analysis, respectively. The interfacial tension (IFT) of the formulated LPNF at oil-water interface was determined via a Kruss tensiometer. Thereafter, the ability of LPNF to alter the wettability of oil wet sandstone core was determined using a drop shape analyzer. TEM results indicate that lignin nanoparticles of size range 10-23 nm were produced. The zeta potential of -34 mV shows long-term stability of the nanofluid. The LPNF altered the wettability of the sandstone core from oil wet (133.3°) to water wet (10.2°), decreased IFT thereby indicating high propensity to increasing oil recovery at reservoir condition.