碱、聚合物对表面活性剂吸附影响分析

摘要

The adsorption of surfactant on oil reservoir, is the interaction between surfactant and chemical substances on sandstone surface. In ASP compound system solution, effect of alkali on the adsorption of surfactant is great, after adding alkali, adsorbed surface active agent on sandstone surface decreases, and the adsorption capacity decline range is proportional to the concentration of alkali. The experimental results show that alkali addition can make the clay minerals' adsorption capacity for anionic surface active agent reduce by 70% to 80%, and sandstone reservoirs' adsorption capacity reduce by 10%~40%. Polymer has less effect on surfactant adsorption, numerical simulation results show that the adsorption quantity is reduced by 15%~30%. This is because the polymer hydrolysis in the surface active agent solution to form molecular group with negative charge, which inhibits the sandstone's adsorption effect for surface active agent; In addition, after adding polymer, the compound system thickens, resulting in lower solution diffusion rate to decrease the swept volume, thus weakening the effect of surface active agent adsorption.%油藏对表面活性剂的吸附作用，是砂岩表面化学物质与表面活性剂间相互作用的结果。ASP 复配体系溶液中，碱对表活剂的吸附影响较大，在表活剂溶液中加入碱后，砂岩对表活剂的吸附量下降，且吸附量下降幅度与碱浓度成正比。实验结果表明，碱可以使粘土矿物对阴离子表面活性剂吸附量降低70%~80%，而油藏砂岩对表活剂吸附量可降低10%~40%。聚合物对表活剂的吸附影响较小，数值模拟结果表明吸附量降低15%~30%。这是由于聚合物在表活剂溶液中水解后，部分分子团带有负电荷，这就抑制了砂岩对表活剂的吸附作用；另外，加入聚合物后，复配体系溶液变稠，使得溶液扩散速率降低，减小波及体积，进而削弱表活剂吸附效果。