【作者】 苟聪博； 吴海荣； 李哲； 高凯； 杨蒙； 袁永杰； 康万利； 侯吉瑞；

【Author】 Congbo Gou;Hairong Wu;Zhe Li;Kai Gao;Meng Yang;Yongjie Yuan;Wanli Kang;Jirui Hou;Unconventional Petroleum Research Institute, China University of Petroleum (Beijing);School of petroleum engineering, China University of Petroleum (East China);

【机构】 中国石油大学(北京)非常油气科学技术研究院； 中国石油大学(华东)石油工程学院；

【摘要】 乳状液的稳定性在化学驱油中起着至关重要的作用,通过改善宏观波及系数和微观驱油效率,表面活性剂的乳化作用可以显著地提高原油采收率。因此,本文利用烷基糖苷(APG)和氧化胺(OAE)之间的协同增效作用,构建了一种协同增强乳状液稳定性的表面活性剂复配体系。通过测量乳状液的析水率、液滴尺寸分布、表/界面张力、稳定性分析、流变性质及微观驱替等。探究了APG/OAE复配体系粒径分布、界面行为,协同稳定乳状液的机理以及提高采收率效果。结果表明:当总质量浓度为0.5wt%,APG与OAE的质量比为7:3时,乳状液的粒径最小且分布集中,表/界面张力最低。同时,体系乳化能力最强,乳状液表现出最好的稳定性。此外,流变测量结果表明,乳状液具有更高的粘度及粘弹性。这是由于APG分子中羟基的存在使其显负电性,OAE水溶液中部分分子去质子化成阳离子。因此,在静电引力的作用下,APG与OAE分子在油-水界面上的排布更加致密,乳状液稳定性增强。同时,由于两种表面活性剂分子形成分子间氢键,也有利于界面膜的强度。最后,通过微观可视化实验,表明APG与OAE的复配体系能够有效地乳化捕获并携带残余油,从而达到提高采收率的目的。这些优异的性能使该表面活性剂复配体系成为化学驱提高采收率(EOR)过程中一种经济有效的选择。更多还原

【Abstract】 Emulsion stability plays a crucial role in chemical flooding. Hence, emulsification effect can dramatically enhance oil recovery by improving macroscopic sweep efficiency and microscopic displacement efficiency. In this study, a newly-designed hybrid surfactants system, including alkyl polyglucoside(APG) and amine oxide(OAE), was formulated to synergistically stabilize O/W emulsion for EOR. By performing the measurements of dewatering ratio, droplet size distribution, surface/interfacial tension, stability analysis, rheological properties and microscopic displacement experiment. The compound surfactants stabilized emulsions droplet distribution, interfacial behavior, synergistically stabilize emulsion mechanism and EOR result were investigated. The results suggest that emulsion droplet size reaches the smallest, surface/interfacial tension the minimum, and emulsion the most stable, when the total mass concentration is 0.5 wt% and the mass ratio of APG and OAE is 7:3. Additionally, rheological measurement results demonstrate that the hybrid system shows higher viscosity and favorable viscoelasticity than sole ones. This can be attributed that the presence of hydroxyl group in APG makes it electronegative and some molecules in the OAE aqueous solution are deprotonated into cations. Thus, the oil-water interfacial membrane is more compact under electrostatic attraction. Simultaneously, the formation intermolecular hydrogen bond between APG and OAE molecules can also benefit to improvement of interfacial film strength. Ultimately, the microscopic flooding experiment was conducted by microscopic model, which indicates that the established blended system can effectively emulsify by trapping and carrying the residual oil to enhance oil recovery(EOR). These excellent performances enable the compound surfactant system to become an effective alternative in the chemical flooding process for EOR.更多还原