用于降压增注的双子表面活性剂合成及性能评价研究

Synthesis and research on performance and evaluation of a Gemini surfactant in technique of depressurization and stimulation of water injection

摘要:

针对低渗油田注水井注入压力高的问题，研发出一种新型表面活性剂MT-01，并且通过室内实验考察了双子表面活性剂的性能及降压增注的效果。研究表明：当双子表面活性剂在较低质量浓度为800 mg/L时，表面张力达到最低，且能有效防止粘土膨胀，能够有效降低油水界面张力，其良好的润湿能力使储层砂岩表面从亲水性向中间润湿转变。岩心驱替实验结果表明，当其质量浓度在400~1000 mg/L浓度范围下，注入2 PV双子表面活性剂降压增注效果显著，降压幅度最高可达29％，提高水相渗透率幅度最高达40％。该新型双子表面活性剂对于提高渗透油田注水井吸水能力、降低注入压力具有较好应用潜力。

Abstract:

In order to reduce high injection pressure in low permeability oilfield, MT-01 gemini surfactant has been synthesized for the test on the depressurization and injection augmenting effcct. The experimental results are as follows: when the mass concentration of MT-01 gemini surfactant is 800 mg/L, the surface tension can been decreased the lowest and can prevent the swelling of the clay, and the oil/water interfacial tension can be decreased effectively, the gemini surfactant makes the wettability of core surface change from hydrophilic to intermediate wettability. Finally, the gemini surfactant is good for improving water injection by core displacement experiments. The displacement pressure could be reduced up to 29％ and the relative permeability of the water phase could be increased up to 40％ by injecting 2 PV surfactant solutions in the range of 400~1000 mg/L. The new type gemini surfactant has a good application potential.