文献类型：期刊文献

英文题名：Synergistic Effect of Salt and Anionic Surfactants on Interfacial Tension Reduction: Insights from Molecular Dynamics Simulations

作者：Lin, Yutong[1,2];Tang, Weiqiang[1];Xiao, Peiwen[3,4];Ma, Jule[1,2];Han, Xue[3,4];Xu, Xiaofei[1,2];Luo, Jianhui[3,4];Zhao, Shuangliang[1,5,6]

机构：[1]East China Univ Sci & Technol, State Key Lab Chem Engn, Shanghai 200237, Peoples R China;[2]East China Univ Sci & Technol, Sch Chem Engn, Shanghai 200237, Peoples R China;[3]PetroChina, Res Inst Petr Explorat & Dev RIPED, Beijing 100083, Peoples R China;[4]CNPC, Key Lab Nano Chem KLNC, Beijing 100083, Peoples R China;[5]Guangxi Univ, Guangxi Key Lab Petrochem Resource Proc & Proc In, Nanning 530004, Peoples R China;[6]Guangxi Univ, Sch Chem & Chem Engn, Nanning 530004, Peoples R China

年份：2023

卷号：39

期号：35

起止页码：12392

外文期刊名：LANGMUIR

收录：;EI(收录号：20233614696410);WOS:【SCI-EXPANDED(收录号:WOS:001063592600001)】；

基金：This work is supported by the National Natural Science Foundation of China (Nos. 22178072 and 22108070), the Young Elite Scientists Sponsorship Program in CAST (No. 2022QNRC001), and the PetroChina Scientific Research and Technology Development Project (No. 2018A-0907).

语种：英文

外文关键词：Hydrogen bonds - Molecular dynamics - Molecules - Oxygen - Petroleum reservoir engineering - Petroleum reservoirs - Saline water - Sulfur compounds

摘要：Surfactants are commonly utilized in chemical flooding processes alongside salt to effectively decrease interfacial tension (IFT). However, the underlying microscopic mechanism for the synergistic effect of salt and surfactants on oil displacement remains ambiguous. Herein, the structure and properties of the interface between water and n-dodecane are studied by means of molecular dynamics simulations, considering three types of anionic surfactants and two types of salts. As the salt concentration (? (salt)) increases, the IFT first decreases to a minimum value, followed by a subsequent increase to higher values. The salt ions reduce the IFT only at low ? (salt) due to the salt screening effect and ion bridging effect, both of which contribute to a decrease in the nearest head-to-head distance of surfactants. By incorporating salt doping, the IFTs can be reduced by at most 5%. Notably, the IFTs of different surfactants are mainly determined by the hydrogen bond interactions between oxygen atoms in the headgroup and water molecules. The presence of a greater number of oxygen atoms corresponds to lower IFT values. Specifically, for alkyl ethoxylate sulfate, the ethoxy groups play a crucial role in reducing the IFTs. This study provides valuable insights into formulating anionic surfactants that are applicable to oil recovery processes in petroleum reservoirs using saline water.