Abstract The presence of indigenous microorganisms in the petroleum reservoirs with the capability of biosurfactants production implies the existence of significant amounts of biosurfactants dissolved in the reservoir crude oil. The extraction of these biosurfactants to the aqueous phase can be considered as a promising microbial enhanced oil recovery process in a lower cost without the common limitations and risks related to the microbial systems. Ethylenediamine (EDA) was used to extract the crude oil dissolved biosurfactants (as anionic surfactants) of a crude oil sample to the aqueous phase and form a cat-ionic surfactant complex. The biosurfactant was isolated from the crude oil and preliminarily characterized which was capable of reducing the surface tension to 48 mN/m. Various concentrations of EDA were utilized to extract the crude oil biosurfactants and their effectiveness on the oil recovery was studied in a glass micro-model. Results indicated that an incremental 22 % oil production was obtained by flooding the 10 mM EDA solution. The incremental oil production was related to the formation of the cat-ionic complex surfactant which believed to cause a significant IFT reduction and simultaneously, have a higher efficiency in the wettability alteration than the anionic biosurfactants. It can be concluded that the extraction of the indigenous biosurfactant content of the crude oil and their interaction by EDA can be considered as a low-cost low-risk potential to the enhanced oil recovery processes.

中文翻译：

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本地原油溶解生物表面活性剂的提取及其在提高石油采收率方面的潜力

摘要 具有生物表面活性剂生产能力的油藏中固有微生物的存在意味着存在大量溶解在油藏原油中的生物表面活性剂。将这些生物表面活性剂提取到水相中可以被认为是一种有前景的微生物强化采油工艺，成本较低，没有与微生物系统相关的常见限制和风险。乙二胺 (EDA) 用于将原油样品中溶解在原油中的生物表面活性剂（作为阴离子表面活性剂）萃取到水相中并形成阳离子表面活性剂复合物。生物表面活性剂从原油中分离出来并初步表征，能够将表面张力降低到48 mN/m。使用不同浓度的 EDA 来提取原油生物表面活性剂，并在玻璃微模型中研究了它们对石油采收率的有效性。结果表明，通过注入 10 mM EDA 溶液获得了 22% 的增量油产量。增加的石油产量与阳离子复合表面活性剂的形成有关，该表面活性剂被认为会导致 IFT 显着降低，同时在润湿性改变方面比阴离子生物表面活性剂具有更高的效率。可以得出结论，通过 EDA 提取原油的原生生物表面活性剂含量及其相互作用可以被认为是提高石油采收率过程的低成本低风险潜力。结果表明，通过注入 10 mM EDA 溶液获得了 22% 的增量油产量。增加的石油产量与阳离子复合表面活性剂的形成有关，该表面活性剂被认为会导致 IFT 显着降低，同时在润湿性改变方面比阴离子生物表面活性剂具有更高的效率。可以得出结论，通过 EDA 提取原油的原生生物表面活性剂含量及其相互作用可以被认为是提高石油采收率过程的低成本低风险潜力。结果表明，通过注入 10 mM EDA 溶液获得了 22% 的增量油产量。增加的石油产量与阳离子复合表面活性剂的形成有关，该表面活性剂被认为会导致 IFT 显着降低，同时在润湿性改变方面比阴离子生物表面活性剂具有更高的效率。可以得出结论，通过 EDA 提取原油的原生生物表面活性剂含量及其相互作用可以被认为是提高石油采收率过程的低成本低风险潜力。在润湿性改变方面比阴离子生物表面活性剂具有更高的效率。可以得出结论，通过 EDA 提取原油的原生生物表面活性剂含量及其相互作用可以被认为是提高石油采收率过程的低成本低风险潜力。在润湿性改变方面比阴离子生物表面活性剂具有更高的效率。可以得出结论，通过 EDA 提取原油的原生生物表面活性剂含量及其相互作用可以被认为是提高石油采收率过程的低成本低风险潜力。