延长油田降压增注用地层水与表面活性剂作用研究

Study on the effect of formation water and surfactant for depressurization and injection in Yanchang Oilfield

通过提高SO浓度的方法对延长油田地层水进行改性,分析了地层水与十六烷基三甲基溴化铵(CTAB)复配的效果。通过接触角、界面张力(IFT)、Zeta电位和自吸试验考察了地层水与CTAB的协同作用。试验结果表明:地层水中SO浓度的增加会增强岩石的润湿性能,使岩石变得更加亲水。随着界面CTAB单体数目的增加,界面张力降低。地层水与阳离子表面活性剂复配表现出更强的渗吸作用,与接触角、Zeta电位和界面张力试验结果完全一致。延长油田改性地层水与阳离子表面活性剂的复配具有较好的协同效应。

The formation water of Yanchang Oilfield is modified by increasing the concentration of SO,and the effect of mixing formation water with cetyltrimethylammonium bromide(CTAB)is analyzed.The synergistic effect of formation water and CTAB is investigated by contact angle,interfacial tension(IFT),Zeta potential and self-absorption tests.The test results show that the increase of SOconcentration in formation water can enhance the wettability of rocks and make them more hydrophilic.With the increase of the number of interfacial CTAB monomers,the interfacial tension decreases.The combination of formation water and cationic surfactant shows stronger imbibition,which is completely consistent with the test results of contact angle,Zeta potential and interfacial tension.The combination of modified formation water and cationic surfactant in Yanchang Oilfield has a good synergistic effect.