用于三次采油的新型弱碱表面活性剂

以α-烯烃为初始原料,经过烷基化及磺化、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,这种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有很强的适应性.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%.小井距三元复合驱矿场试验结果表明,三元复合驱比水驱提高采收率24.66%.这种表面活性剂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基础.

New-type weak alkali surfactant applied to tertiary oil recovery

The alkyl benzene sulfornate surfactant with single-component and reasonable structure was prepared by the processes of alkylation，sulfonation and neutralization ofα-olefin. Laboratory evaluation indicates that alkaline- surfactant-polymer (ASP) system can reduce oil-water interfacial tension (IFT) to below 10^-3 mN/m within a wide concentration range of surfactant and alkali. This kind of surfactant is favorable to different reservoirs of different blocks in Daqing Oilfield. The corresponding ASP system can greatly eliminate the chromatographic fractionation effect due to the singleness of surfactant composition. The core experiment in laboratory demonstrates that the ASP flooding can enhance original oil in place (OOIP) more than water flooding by 20%. The field test of ASP flooding in the reservoirs with small well-spacing pattern shows that it displays a response of significant oil production and water-cut drop. The OOIP of ASP flooding has enhanced by 24.66% more than that of water displacement. The ASP flooding technology using single-component surfactant is hopeful to be applied in an industrialization scale of reservoirs with higher content of clay mineral and lower permeability.