文章基本信息

标题：The effect of N-ethyl-N-hydroxyethyl perfluorooctanoamide on wettability alteration of shale reservoir
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作者：Yongfei Li ; Yanling Wang ; Kun Wang 等
期刊名称：Scientific Reports
电子版ISSN：2045-2322
出版年度：2018
卷号：8
期号：1
页码：6941
DOI：10.1038/s41598-018-25100-9
语种：English
出版社：Springer Nature
摘要：The wettability of the formation is critical for the flow back of the fracturing fluid and can further affect the gas production. So it is very necessary to study the wettability of shale reservoir. Here, a novel fluorocarbon surfactant, N-ethyl-N-hydroxyethyl perfluorooctanoamide, was synthesized and characterized by different methods. the contact angles of water and n-decane on the shale increased from 36° and 0° to 121° and 105°, respectively, after treated by N-ethyl-N-hydroxyethyl perfluorooctanoamide (0.5 wt.%). The surface free energy reduced from 72 mN/m to 7.4 mN/m. The results agreed with that of imbibition and capillary tube rise test. Additionally, the analysis of scanning electron microscope (SEM) and energy dispersive spectroscopy (EDS) showed that the roughness of shale surface remarkably increased. These results fully proved that the shale wettability is changed to super gas-wetting. Besides, the thermal analysis revealed that the novel fluorocarbon surfactant has good thermal stability. This indicates that it can be better applied to reservoir modifications at higher temperatures.