Bio-Nanofluids Dispersed in Natural Gas Stream for Enhanced Oil Recovery

Summary Enhanced oil recovery (EOR) is one of the greatest challenges in the oil and gas industries. Hence, this work aims to improve the gas-dispersed chemical injection (DCI) EOR process based on bio- and nano-convergent technologies. Bio-nanofluid systems were selected by comparing two carrier fluids and nanoparticles using static and dynamic tests to formulate the nanofluid applied to the EOR process using natural gas. The static evaluation based on fluid-fluid and fluid-rock interactions of the bio-nanofluids showed their high capacity to promote the mobility of the residual oil by reducing the interfacial tension (IFT) from 23.34 mN·m−1 to approximately 0.05 mN·m−1 and promoting water-wettable surfaces for the systems in the presence of 50 mg·L−1 nanoparticles. This result implies that bio-fluid/rock interactions enhance the action of the bio-surfactant, which was corroborated by adsorption tests. Furthermore, during the dynamic evaluation under reservoir conditions, a significant increase in recovered oil of 20% was observed at a concentration of the bio-nanofluid dispersed in the gas stream of 1.5 bbl‧MMscf−1. According to the capillary blocking test, no restrictions were generated for the gas concentration dispersed through the porous medium.