中国石油大学学报（自然科学版）2023，Vol.47Issue(6)：87-94,8.DOI:10.3969/j.issn.1673-5005.2023.06.010
基于减阻纳米流体岩心的润湿性反转表征
Characterization of wettability alteration of rock cores treated with drag reducing nanofluids
摘要
Abstract
Core wettability alteration is one of the key mechanisms for reducing drag using nanofluids,so it is very important to find a nondestructive and fast method to test the alteration of wettability.In this study,using a nuclear magnetic resonance(NMR)technique,a method for rapid wettability alteration testing of rock cores was proposed and investigated.The relation-ship between T2 cut-off value and wettability,and the influence of nanofluid HNF Ⅱ on wettability of cores were studied,and the effect and mechanism of resistance reduction were also examined.The results show that there is a linear relationship be-tween the T2 cut-off value and the core contact angle,in which both increase with the weakening of hydrophilicity.In the cores after nanofluid displacement,the water phase permeability increases by 33％to 72％,and the surface contact angles in-crease by 79％,103％,110％and 114％,with the corresponding T2 cut-off values increase by 17％,33％,54％and 116％,respectively.The T2 cut-off value of the core is consistent with the change trend of wettability and permeability,and the increase of contact angle is strongly correlated with the increase of T2 cut-off value(the correlation coefficient is 0.94).Nanofluid HNF Ⅱ can make the core conversion from hydrophilicity to hydrophobicity.It can increase the relaxation time,prolong the T2 cut-off value,weaken the gravity attraction of the pore wall to water,and thus decrease the water flow resist-ance.The T2 cut-off value is intrinsically consistent with wettability,providing a theoretical basis for the rapid testing method of core wettability alteration.关键词
纳米流体HNF Ⅱ/减阻/岩心润湿性/核磁共振技术/T2截止值Key words
nanofluid HNF Ⅱ/drag reduction/core wettability/NMR/T2 cut-off value分类
能源科技引用本文复制引用
顾春元,徐冬星,刘松林,庞东山,薛佩雨,潘谦宏..基于减阻纳米流体岩心的润湿性反转表征[J].中国石油大学学报（自然科学版）,2023,47(6):87-94,8.基金项目
国家自然科学基金项目(51274136) （51274136）
上海市重点学科建设项目(S30106) （S30106）
