Effect of Amphiphilic Silicon Quantum Dots on Foam Stability and Their Potential in Enhanced Oil Recovery

Nowadays, novel silicon quantum dots (SiQDs) are applied in various aspects of the petroleum industry, especially in enhanced oil recovery (EOR). Herein, amphiphilic silicon quantum dots (ASiQDs) were synthesized to improve the stability of the foam formed by the nonionic surfactant polyethylene glycol monoisodecyl ether (PMIE). The greater stability and oil resistance of foam stabilized by the 0.05% PMIE-0.1% ASiQD system compared to other systems (including pure PMIE systems and conventional silica nanoparticles (SiNPs)-PMIE systems) were confirmed by relative foam volume measurement, half-life measurement, Turbiscan Laboratories expert analysis, and the observation of foam morphology. Based on the dynamic surface tension and modulus measurements, the promising stability of the foam was attributed to the rigid film generated by largely adsorbed ASiQDs with tiny size and moderate hydrophobicity. the more intensive electrostatic repulsion among ASiQDs stabilized smaller foam bubbles, significantly preventing coalescence. Finally, the sandpack flooding results suggested 0.05% PMIE-0.1%ASiQD system stabilized foam could efficiently plug the high permeability pore throats and evidently enhanced the oil recovery by 21.2%. The report employed the novel ASiQDs stabilized foam to improve the flooding efficiency for EOR.