Ray Debanjan, Jangid Lavisha, Joshi Dinesh, Prakash Shubham, Ojha Keka, Manor Ofer, Mandal Ajay
Enhanced Oil Recovery & Carbon Utilization and Storage Laboratory, Department of Petroleum Engineering, Indian Institute of Technology (Indian School of Mines), Dhanbad 826 004, India.
Wolfson Department of Chemical Engineering, Technion-Israel Institute of Technology, Haifa 3200003, Israel.
ACS Omega. 2024 Dec 6;9(50):50024-50040. doi: 10.1021/acsomega.4c09829. eCollection 2024 Dec 17.
This research explores the development of engineered oil-water microemulsions stabilized by a synergistic combination of polymer and surfactant to enhance stability and interfacial properties for improved enhanced oil recovery (EOR). Conventional surfactant-stabilized emulsions often suffer from phase instability and limited wettability alteration during water flooding and chemical injection, hindering the EOR efficiency. In contrast, our formulations incorporating polymers significantly increase the emulsion viscosity and resilience to temperature fluctuations, resulting in enhanced phase stability. Experimental investigations reveal that while the water-microemulsion interfacial tension (IFT) increases with salinity, the oil-microemulsion IFT decreases substantially, achieving an optimal IFT of 4.43 × 10 mN/m at balanced salinity levels. The microemulsions exhibit remarkable stability across varying temperatures, successfully transitioning between Winsor type II and III phases, which is critical for effective EOR applications. Notably, the addition of polymers enhances the viscosity of the surfactant-stabilized emulsion from 50 mPa·s at a shear rate of 10 s to 300 mPa·s, significantly improving emulsion stability, as confirmed by measured zeta potential values of -31.1 mV for the surfactant system and -33.2 mV for the polymer-augmented surfactant system. These enhancements contribute to improved sweep efficiency during the oil recovery processes. Furthermore, the microemulsions effectively alter the sandstone wettability from oil-wet to water-wet, promoting better oil displacement. Core flooding experiments demonstrate that injecting one pore volume of the polymer-augmented surfactant-stabilized microemulsion results in an additional 20.58% oil recovery compared with conventional water flooding.
本研究探索了由聚合物和表面活性剂协同组合稳定的工程化油水微乳液的开发，以增强稳定性和界面性质，从而改善强化采油（EOR）效果。传统的表面活性剂稳定乳液在水驱和化学注入过程中常常存在相不稳定和润湿性改变有限的问题，阻碍了EOR效率。相比之下，我们加入聚合物的配方显著提高了乳液粘度和对温度波动的弹性，从而增强了相稳定性。实验研究表明，虽然水-微乳液界面张力（IFT）随盐度增加而升高，但油-微乳液IFT大幅降低，在平衡盐度水平下达到了4.43×10 mN/m的最佳IFT。微乳液在不同温度下均表现出显著的稳定性，成功地在Winsor II型和III型相之间转变，这对有效的EOR应用至关重要。值得注意的是，聚合物的加入使表面活性剂稳定乳液在剪切速率为10 s时的粘度从50 mPa·s提高到300 mPa·s，显著改善了乳液稳定性，表面活性剂体系的测量zeta电位值为-31.1 mV，聚合物增强表面活性剂体系的测量zeta电位值为-33.2 mV，证实了这一点。这些改进有助于提高采油过程中的波及效率。此外，微乳液有效地将砂岩润湿性从油湿改变为水湿，促进了更好的驱油效果。岩心驱替实验表明，注入一孔隙体积的聚合物增强表面活性剂稳定微乳液比传统水驱多采收20.58%的原油。
