适合大庆油田的无碱表面活性剂性能评价研究

Study on the Performance of Alkali-free Surfactant for Daqing Oilfield

随着油田不断开发,大庆油田开发对象正逐渐从一类油层向渗透率低、黏土矿物含量较高的二、三类油层转变,但逐步进入工业化推广阶段的三元复合驱中碱的存在会加剧对二、三类油层的伤害,因此弱碱化、无碱化成为了复合驱技术的发展方向。针对大庆油田二类油层油水条件,采用AFS-A和AFS-B无碱表面活性剂复合体系开展了二元复合驱室内研究。实验结果表明:这两种无碱表面活性剂复合体系均可在活性剂浓度为0.05%～0.3%(质量分数)范围内与大庆原油形成10-3mN/m数量级界面张力,但AFS-B复合体系亲水性较强,AFS-A复合体系亲油性较强,AFS-B复合体系抗吸附性能要好于AFS-A复合体系;驱油效率方面,在水驱基础上,AFS-A复合体系化学驱平均采收率为17.28%,AFS-B复合体系化学驱平均采收率为19.81%。

Along with the continuous oilfield development,the production target is changing from type Ⅰ oil layers to type Ⅱ and type Ⅲ oil layers with low permeability and high clay content.But alkali in popularizing ASP combination flooding on industrialization will bring more damage on the type Ⅱ and type Ⅲ oil layers.So sodium carbonate and alkali-free for SP flooding should be studied.According to the oil and water conditions of the type Ⅱ oil layers in Daqing oilfield,laboratory research of SP flooding is made by AFS-A and AFS-B alkali-free surfactant systems.The results indicate that ultra-low interfacial tension with 10-3mN/m order can be formed with Daqing oil for these two systems under the condition of 0.05%-0.3% of mass fraction of the surfactant.But AFS-A combined system has strong water wettability,and AFS-B combined system has strong oil wettability.AFS-B combined system has better anti-adsorptivity than AFS-B combined system.Chemical flooding by AFS-A and AFS-B combined system can enhance by 17.28% and 19.81% of average recovery efficiency than water flooding respectively.