Development And Evaluation Of Oil-displacement System With Ultra-low Interfacial Tension

At present, the alkali-surfactant-polymer (ASP)lfooding is a effective tertiaryrecovery technology。But the difficulties in dealing with the produced liquid and theformation damage brought by ASP lfooding caused a large extent limit to the ASPflooding industrialization.The voice of Surfactant-polymer (SP)lfooding withoutalkali is more and more loud. However, the polymer/surfactant lfooding oil systemcan reduce the adverse effect of alkali on oil displacement eiffciency and theequipment, but also can improve the interfacial tension between oil and water. So thesurfactant has put forward higher requirements.This paper respectively used different carbon chain alkyl tertiary amine reactwith3-C1-2hydroxy propyl sulfonic acid sodium chloride，to obtain the final productof Alkyl-Hydroxyl-Sulfobetaines(Twelve Alkyl-Hydroxyl-Sulfobetaines, FourteenAlkyl-Hydroxyl-Sulfobetaines, Sixteen Alkyl-Hydroxyl-Sulfobetaines). And analysedthe product with infrared spectrum. Through the evaluation ofAlkyl-Hydroxyl-Sulfobetaines interfacial tension, showed that in the absence of alkalicondition, the interfacial tension decreased with the decreasing surfactantconcentration, and decreased with the increase of salinity.Betaine type amphotericsurfactant with very low concentration could reduce the interfacial tension to a ultralow level.Screened by polymer concentration, temperature, salinity of the compositesystem, obtained the oil displacement system which corresponded with super lowinterfacial tension:2000ppm polymer+300ppm sixteen Alkyl-Hydroxyl-Sulfobetaines.Finally, through the indoor experiment and numerical simulation technology,proved the necessity and feasibility of the two element composite test.And providedthe direction of new technology ideas and research for tertiary recovery，alsoprovided technical support for oilfield stable production plan.