新型弱碱表面活性剂在三次采油中的应用

Application of new surfactant for weak alkali in enhanced oil recovery

以α-烯烃为初始原料,经过烷基化,再经磺化、中和研制出了组分相对单一、结构合理的新型弱碱烷基苯磺酸盐表面活性剂。室内评价结果表明,该表面活性剂具有良好的界面活性,配制的复合体系在较宽的表面活性剂浓度和碱浓度范围可与原油形成10-3mN/m数量级的超低界面张力。同时,该表面活性剂对大庆油田不同区块、不同油层的油水条件表现出了很强的适应性。另外,由于表面活性剂组成较为单一,可大大降低表面活性剂在地层中因吸附滞留而产生的色谱分离效应。室内天然岩心驱油实验表明,三元复合体系平均驱油效率可比水驱提高约20%。所开展的小井距三元复合驱矿场试验,取得了比水驱提高采收率24.66%的显著效果,为三元复合驱技术在大庆油田的工业化推广,特别是在二类油层的应用奠定了坚实基础。

Alkyl benzene sulfonate surfactant with single-component and reasonable construct is prepared by the alkylation of olefin, sulfonation and neutralization. The property evaluation indicates that the ASP system can reduce the oil-water interfacial tension （IFF）to/below 10^-3mN/m within wide concentration range of surfactant and alkali. The study also shows that the surfactant can be applied to reservoirs in Daqing different blocks. In addition, the corresponding ASP system can dramatically eliminate chromatographic fractionation effect due to the singleness in surfactant composition. The laboratory core flooding experiment demonstrates that the ASP flooding can enhance about 20% more original oil in place（OOIP） than water flooding. The small well-spacing ASP flooding field test which is conducted in October 2004, now displays a significant oil production and water-cut drop response and its oil recovery amounts to 24.66 percent more （OOIP） than water displacement. Consequently, the ASP technology using single-component surfactant is hopeful to be applied in an industrialization scale in the reservoirs characterized by their higher clay mineral content and lower permeability.