IOR/EOR Research Institute, Enhanced Oil Recovery (EOR) Research Center, Shiraz University, Shiraz, Iran.
Department of Petroleum Engineering, Faculty of Petroleum, Gas, and Petrochemical Engineering, Persian Gulf University, Bushehr, Iran.
Sci Rep. 2024 May 18;14(1):11408. doi: 10.1038/s41598-024-62255-0.
In the enhanced oil recovery (EOR) process, interfacial tension (IFT) has become a crucial factor because of its impact on the recovery of residual oil. The use of surfactants and biosurfactants can reduce IFT and enhance oil recovery by decreasing it. Asphaltene in crude oil has the structural ability to act as a surface-active material. In microbial-enhanced oil recovery (MEOR), biosurfactant production, even in small amounts, is a significant mechanism that reduces IFT. This study aimed to investigate fluid/fluid interaction by combining low biosurfactant values and low-salinity water using NaCl, MgCl, and CaCl salts at concentrations of 0, 1000, and 5000 ppm, along with Geobacillus stearothermophilus. By evaluating the IFT, this study investigated different percentages of 0, 1, and 5 wt.% of varying asphaltene with aqueous bulk containing low-salinity water and its combination with bacteria. The results indicated G. Stearothermophilus led to the formation of biosurfactants, resulting in a reduction in IFT for both acidic and basic asphaltene. Moreover, the interaction between asphaltene and G. Stearothermophilus with higher asphaltene percentages showed a decrease in IFT under both acidic and basic conditions. Additionally, the study found that the interaction between acidic asphaltene and G. stearothermophilus, in the presence of CaCl, NaCl, and MgCl salts, resulted in a higher formation of biosurfactants and intrinsic surfactants at the interface of the two phases, in contrast to the interaction involving basic asphaltene. These findings emphasize the dependence of the interactions between asphaltene and G. Stearothermophilus, salt, and bacteria on the specific type and concentration of asphaltene.
在强化采油（EOR）过程中，界面张力（IFT）已成为一个关键因素，因为它会影响残余油的回收。表面活性剂和生物表面活性剂的使用可以通过降低界面张力来提高采收率。原油中的沥青质具有作为表面活性物质的结构能力。在微生物强化采油（MEOR）中，即使生物表面活性剂的产量很少，也是降低界面张力的重要机制。本研究旨在通过结合低生物表面活性剂值和低盐度水（使用 NaCl、MgCl 和 CaCl 盐，浓度分别为 0、1000 和 5000 ppm），以及嗜热脂肪芽孢杆菌（Geobacillus stearothermophilus），来研究流体/流体的相互作用。通过评估界面张力，本研究考察了不同浓度（0、1000 和 5000 ppm）的 NaCl、MgCl 和 CaCl 盐与低矿化度水以及含有低矿化度水的水相混合物中不同百分比（0、1 和 5 wt.%）的沥青质与细菌之间的相互作用。结果表明，嗜热脂肪芽孢杆菌形成了生物表面活性剂，导致酸性和碱性沥青质的界面张力降低。此外，对于高沥青质百分比，在酸性和碱性条件下，沥青质与嗜热脂肪芽孢杆菌之间的相互作用都导致界面张力降低。此外，该研究发现，在 CaCl、NaCl 和 MgCl 盐存在的情况下，酸性沥青质与嗜热脂肪芽孢杆菌之间的相互作用会导致两相界面处形成更多的生物表面活性剂和本征表面活性剂，而碱性沥青质的相互作用则相反。这些发现强调了沥青质与嗜热脂肪芽孢杆菌、盐和细菌之间的相互作用取决于沥青质的具体类型和浓度。
