污水配制二元复合驱驱油体系优化研究

Optimization of the binary flooding systems prepared with sewage

将石油磺酸盐与甜菜碱两种表面活性剂进行复配,设计合成了污水配制的表面活性剂/聚合物二元驱油体系;考察了复配体系的界面张力、乳化性能、抗盐性能和驱油效率,并对表面活性剂/聚合物二元驱油体系注入参数进行了优化。实验结果表明,石油磺酸盐与甜菜碱质量比为5∶5时,体系的界面张力、乳化性能及驱油效率均高于单一表面活性剂;在一定盐质量浓度范围内,复配体系显示出良好的抗盐性能。三管并联岩心驱替实验结果表明,聚合物含量及用量不变的条件下,梯次降低表面活性剂含量的注入方式提高采收率幅度最高,采收率可达14.35%,比恒定表面活性剂含量注入方式的采收率高3.65百分点。在表面活性剂注入方式不变的条件下,梯次增加聚合物含量注入方式的采收率为15.79%,比恒定聚合物含量注入方式的采收率高5.09百分点。现场试验结果表明,梯次降低表面活性剂含量及梯次增加聚合物含量的注入方式可有效提高砾岩油藏二元驱的采收率。

According to the theory of surfactant addition,combined with the performance characteristics of petroleum sulfonate and beet-alkali,a surfactants/polymers binary flooding system was designed and synthesized.The interfacial tension,emulsification performance,salt resistance and oil displacement efficiency of the compound system were investigated,and the injection parameters of the binary flooding system were optimized.The results show that the interfacial tension,emulsifying performance and oil displacement efficiency of the compound surfactant are higher than that of single surfactant when the mass ratio of petroleum sulfonate to beet-alkali is 5∶5.The compound surfactant shows good salt resistance in a certain range of salt concentration.The results of three parallel pipes experiment show that,under the condition of constant polymer content and dosage,the oil recovery of decreasing surfactant content in echelon is the highest with 14.35%and 3.65 percentage points higher than that of single content injection.Under the condition of the same surfactant injection mode,the oil recovery of increasing polymer content in echelon is 15.79%,which is 5.09 percentage points more than that of single content injection.The field test results show that the injection mode of“decreasing surfactant content in echelon and increasing polymer content in echelon”can effectively improve oil recovery of the binary flooding in conglomerate reservoir.