阴离子表面活性剂在油砂和净砂表面的吸附规律

ABSORPTION OF ANIONIC SURFACTANT ON THE SURFACE OF SANDSTONE BEFORE AND AFTER SOLVENT EXTRACTION

为了更加真实地了解表面活性剂在地层岩石表面的吸附状况 ,对比研究了阴离子表面活性剂ABS在抽提清洗前、后地层岩心表面的吸附情况。实验表明 ,阴离子表面活性剂ABS在抽提清洗前、后砂岩 (分别称为油砂和净砂 )表面的吸附有很大程度的不同。与净砂相比 ,ABS在油砂表面达到平衡吸附的时间较长 ,饱和吸附量约降低2 1%。ABS在油砂和净砂表面的吸附等温线均呈典型的“S”型 ,但在油砂表面的吸附量在出现最大值后又大幅度下降。NaCl的存在将增加ABS在油砂和净砂表面的吸附量 ,而碱则减少其吸附量。

In order to acquire comprehensive knowledge of surfactant reservoir absorption on sandstone, the absorption status of anionic surfactant (ABS, alkylbennyl sulfonate) on sandstone cleaned up by solvent extraction and on oil contaminated sandstone washed only by water was comparably studied. The experimental results indicate that the absorbabilities on the surfaces of above two kinds of sandstones are quite different. The absorption equilibrium may be established more quickly. The absorption of surfactants capacity on cleaned sandstone is greater than that on oil contaminated sandstone. Their absorption isothermal curves displied as S mode. The absorption capacity on the surface of oil contaminated sandstone decreases greatly when the surfactant concentration exceeds the critical micelle concentration. The addition of electrolyte (NaCl) can increase the absorption capacity of surfactant, but the alkali (Na 2CO 3) has a converse effectiveness.