Synthesis and performance analysis of novel SiO2 Janus nanoparticles for enhancing gas foam injection in oil reservoirs

Gas foam injection offers a viable solution to challenges faced in oil reservoirs, yet ensuring optimal foamability and stability remains a pivotal hurdle in practical field operations. This study presents a novel synthesis procedure to create silica (SiO₂) Janus nanoparticles (JNPs) and examines their potential to enhance gas foam stability for enhanced oil recovery (EOR) applications. Two variations of SiO₂ JNPs were synthesized via a masking procedure, employing oleic acid and ascorbic acid within a Pickering emulsion, marking a pioneering approach. These nanoparticles underwent comprehensive analysis for a deeper understanding. The investigation sought to unravel the mechanisms behind these JNPs' performance in the foam injection process, probing various operational parameters such as JNP type, concentration, and gas medium (air, CO₂, and CH₄) impact on surface tension reduction, foamability, and stability through static tests. Results uncovered remarkable efficiency in SiO₂-oleic acid JNPs, showcasing a substantial edge in reducing surface tension compared to bare SiO₂ nanoparticles. Specifically, at a concentration of 15,000 ppm, SiO₂-oleic acid JNPs demonstrated a 25 mN/m greater reduction in surface tension than bare SiO₂ within a CH₄ medium. Notably, while the gas type had limited influence on surface tension under standard pressure, the synthesized JNPs showed superior foam stabilization in air compared to CO₂ and CH₄ environments. SiO₂-oleic JNPs exhibited outstanding foamability, stabilizing 80% of the foam generator cell's height and remaining stable for 122 min during the EOR process. Conversely, ascorbic acid-SiO₂-oleic acid JNPs displayed elevated foamability but reduced stability compared to SiO₂-oleic acid JNPs. Despite achieving full height in the foam generator cell, stability was limited to 26 min in the CO₂ medium.