烷醇酰胺表面活性剂在降压增注技术中的性能与应用研究

Research on Performance and Application of Alkanolamide Surfactant in Technique of Pressure Decreasing and Injection Increasing

针对我国油田部分注水井注入压力高、注水驱替效率低的情况,进行了烷醇酰胺表面活性剂在降压增注技术中的性能与应用研究.室内完成了烷醇酰胺表面活性剂体系界面张力、界面张力稳定性能研究以及岩心驱替评价试验研究.实验结果表明,烷醇酰胺表面活性剂油水界面张力达到10-2mN/m数量级,且具有较好的界面张力稳定性,同时也验证了烷醇酰胺表面活性剂具有较强的抗盐能力和较大的吸附量.岩心驱替评价实验表明,烷醇酰胺表面活性剂对岩心的降压效果较好,降低了注入聚合物溶液压力20%以上.同时,为进一步验证表面活性剂降压增注技术的可行性,对大庆油田采油二厂的7口井进行了表面活性剂现场注入实验,取得了显著的降压增注效果,单井最长增注量达3 600 m3,单井有效期最长达130天.

Aiming at the problem of high water injection pressure and low displacement efficient in low - permeability reservoir of China, performance and applied research on decreasing injection pressure by Alkanoamide surfactant is carried out. Laboratory research on interfacial tension of Alkanoamide surfactant system and the stability have been in process. We have also proceeded core simulation experiments by surfactant. Results indicate that the interfacial tension between oil and water is below 10^-2 mN/m and the stability is satisfactory. At the same time ,it is proved that Alkanoamide surfaetant has strong adsorption capacity and salt resistance. Core simulation experiments show that Alkanolamide surfactants have a good effect of decreasing pressure on the core, reducing the injection pressure of polymer solution more than 20%. Finally, field surfactant injection test has been done at 7 wells in the No. 2 Production Plant of Daqing oilfield for further proving the feasibility of decreasing pressure and increasing injection by surfactant, a remarkable effect is obtained, injection of a single well amount to 3 600 m^3, and single well is valid for a maximum of 130 days.