硫酸溶液中2-巯基苯并噻唑与氯离子的协同缓蚀作用  

Synergistic Inhibition Effect between 2-Mercaptobenzothiazole and Chloride Ion in Sulfuric Acid Solution

作　　者：刘冬梅 杨康[2,3] 石鑫 魏晓静 高多龙[1,3] 闻小虎 LIU Dong-mei;YANG Kang;SHI Xin;WEI Xiao-jing;GAO Duo-long;WEN Xiao-hu(Research Institute of Engineering Technology,Northwest Oilfield Branch Company,SINOPEC,Urumqi 830011,China;Engineering Supervision Center,Northwest Oilfield Branch Company,SINOPEC,Urumqi 830011,China;Key Laboratory of Enhanced Oil Recovery in Carbonate Fractured-vuggy Reservoirs,SINOPEC,Urumqi 830011,China)

机构地区：[1]中国石油化工股份有限公司西北油田分公司工程技术研究院,乌鲁木齐830011 [2]中国石油化工股份有限公司西北油田分公司石油工程监督中心,乌鲁木齐830011 [3]中国石油化工集团公司碳酸盐岩缝洞型油藏提高采收率重点实验室,乌鲁木齐830011

出　　处：《表面技术》2021年第7期351-357,共7页Surface Technology

摘　　要：目的提高缓蚀剂在酸溶液中的缓蚀性能。方法构建含有2-巯基苯并噻唑(MBT)以及不同浓度Cl^(–)的Fe表面溶液模型,并进行分子动力学计算。观察缓蚀剂分子在Fe表面的吸附构型,考察不同Cl^(–)值下缓蚀剂膜的致密化行为。提取缓蚀剂分子的均方位移(MSD)曲线,评价缓蚀剂膜的稳定性。计算水分子的密度分布和扩散系数,考察不同Cl^(–)值下MBT缓蚀剂膜的驱水能力和水分子的迁移能力。结果当Cl^(–)值从0增加到25时,MBT膜的厚度(0.42~1.51 nm)和致密度(占有面积0.33~1.31 nm^(2))增加,缓蚀剂分子的自扩散系数减小(从1.25×10^(-9)m^(2)/s到接近0),水分子的吸附峰强度(相对密度为72.3~33.9nm^(–3))和扩散系数(1.495×10^(-9)~0.627×10^(-9) m^(2)/s)降低。当Cl^(–)值从25增加到36时,则出现了相反的趋势。结论缓蚀剂分子与Cl^(–)之间存在协同作用,适当浓度的KCl可以提高MBT缓蚀剂在H_(2)SO_(4)溶液中的缓蚀性能。Cl^(–)值为25时,MBT缓蚀效率最高。To improve the corrosion inhibition performance of inhibitors in acid solution,we constructed mild steel(Fe)surface models containing 2-Mercaptobenzothiazole(MBT)and different concentrations of chloride ion(Cl^(–))in sulfuric acid(H_(2)SO_(4))solution,and carried out the molecular dynamics calculations.Adsorption configurations of inhibitor molecules on the metal surface were monitored to investigate the densification behavior of inhibitor film at different Cl^(–)numbers;the stability of the inhibitor film was evaluated by extracting the mean square displacement(MSD)curve of inhibitor molecules;the density distribution and diffusion coefficient of water molecules were calculated to investigate the water displacement ability of the inhibitor film and water molecule migration ability inside the inhibitor film,respectively.The results show that there is a synergistic effect between MBT and Cl-.When the Cl-number increased from 0 to 25,the thickness(0.42~1.51 nm)and densification(occupied area 1.31~0.33 nm^(2))of MBT film increased,the self-diffusion coefficient of inhibitor molecules decreased(from 1.25×10^(-9) m^(2)/s to nearly 0 m^(2)/s),the adsorption peak intensity(relative density 72.3~33.9 nm^(-3))and diffusion coefficient(1.495×10^(-9)~0.627×10^(-9) m^(2)/s)decreased.However,there is an opposite trend when the Cl-number increased from 25 to 36.Thus,there is a synergistic effect between the inhibitor molecules and Cl-,and an appropriate concentration of KCl can improve the inhibition performance of MBT in H_(2)SO_(4) solution.In our work,MBT inhibitors possess the highest inhibition efficiency when Cl-number is 25.

关 键 词：有机缓蚀剂 酸溶液 卤素离子 协同作用 分子模拟 

分 类 号：TG174.42[金属学及工艺—金属表面处理]