Bio-polymers and bio-surfactants have attracted increasing attention for their application in chemical enhanced oil recovery (EOR) due to the environmental concerns of synthetic chemical agents. Here, a ternary compound system consisted of carboxylic cellulose nanofibrils (CCNF), ethoxylated phytosterol (BPS), and n-pentanol was constructed. The rheological property and interfacial activity of the compound system and the effects of each component at high temperature (80 °C) was investigated systematically. The ternary compound system exhibited excellent performance in thickening, IFT reduction (<10⁻² mN m⁻¹), emulsification, and better salt tolerance. CBP, the ternary system of CCNF (2000 mg L⁻¹), BPS (2000 mg L⁻¹), and n-pentanol (5000 mg L⁻¹), greatly enhanced the oil recovery (24.3%) in the core flooding tests by its high displacement efficiency and sweep enlargement, which was demonstrated directly in the visual micromodel flooding. As an eco-friendly system with remarkable performance, the compound system of CBP shows great application potential in EOR.

中文翻译：

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一种新型羧基纤维素纳米纤丝-乙氧基化植物甾醇-醇环保体系在提高采收率中的应用研究

由于合成化学试剂的环境问题，生物聚合物和生物表面活性剂因其在化学提高采收率 (EOR) 中的应用而受到越来越多的关注。在这里，构建了由羧基纤维素纳米纤维 (CCNF)、乙氧基化植物甾醇 (BPS) 和正戊醇组成的三元复合体系。系统研究了复合体系的流变性能和界面活性以及各组分在高温（80℃）下的影响。三元复合体系在增稠、降低IFT（<10 ^-2 mN m ^-1）、乳化和更好的耐盐性方面表现出优异的性能。CBP，CCNF (2000 mg L ^-1 )、BPS (2000 mg L ^-1) 和正戊醇 (5000 mg L ^-1 )，通过其高驱替效率和波及扩大，在岩心驱油测试中大大提高了石油采收率（24.3%），这在可视化微观模型驱油中得到了直接证明。CBP复合体系作为一种性能卓越的环保体系，在提高采收率方面显示出巨大的应用潜力。