甜菜碱型两性表面活性剂在高温高矿化度油藏条件下砂岩表面的吸附规律

Adsorption of betaine amphoteric surfactants on sandstone surface under reservoir conditions of high temperature and high salinity

利用紫外分光光度法测定了甜菜碱型两性离子表面活性剂在3种不同砂岩表面的吸附量,研究了甜菜碱型两性离子表面活性剂在胜利油藏环境下的吸附等温线,分别从吸附热力学和吸附动力学角度考察了两性离子表面活性剂在砂岩表面上的吸附规律,并对两性离子表面活性剂在石英砂、净砂、油砂表面吸附规律进行对比。结果表明,甜菜碱型两性离子表面活性剂在砂岩表面吸附符合Langmuir吸附规律,在石英砂上的吸附量最多,净砂次之,在油砂上的吸附量最少。温度由60~70℃的焓变小于温度为70~80℃的焓变,随温度升高影响趋势逐渐变小。Elovich方程能更好的描述吸附量随时间的变化关系。

UV spectrophotometry was used to determine adsorption of betaine zwitterionic surfactant on three types of sandstone surface. Adsorption isotherms with betaine zwitterionic surfactant under Shengli reservoir were studied,and enthalpies of adsorption were calculated. Adsorption of betaine zwitterionic surfactant on the surface of quartz sand,net sand and oil sand was studied in terms of kinetics and thermodynamics. Adsorption of betaine zwitterionic surfactant obeyed the Langmuir equation with adsorption amount：quartz sand＆gt;net sand＆gt;oil sand. Enthalpy change at 60-70℃ was less than enthalpy change at 70-80℃,becoming smaller with increasing temperature. The kinetic results showed that change of adsorption capacity with time could be described by the Elovich equation.