Binary Complex Chemical Flooding System And Poly Table Interaction

Alkaline-surfactant-polymer (ASP) flooding is a potential enhanced oil recovery (EOR) technology that is more powerful than the previous polymer flooding. Since its proposal in the mid 1980s, ASP flooding has attracted widespread-attentions around the world.However, severe scaling and emulsification may occur in the produced water of the ASP process. In order to overcome these drawbacks, and continuously investigate the further applications of chemical flooding in Shengli Oilfield, we have developed an alkali-free surfactant-polymer (SP) flooding system. Because of the complicated chemical components in the SP system, the successful oil recovery crucially depends on the interaction between chemicals in bulk phase, and between chemical and crude oil or sands. This thesis focuses on the study of the interaction of surfactants and polymers in the system and crude oil by means of experimental and theoretical methods, such as dynamic interfacial tension, dynamic light scattering, and molecular simulation.The main research works and essential conclusions are shown below:(1) The oil/water interfacial activity and oil-phase adaptability of the sulfonate SP flooding system have been studied. The results show that the composition and molecular arrangement of oil/water interface is the key factor of the interfacial tension, no matter what ingredients are in the oil and surfactant bulk phases.(2) The dynamic behavior, including diffusion and adsorption, of the flooding system surfactants on oil/water interface has been investigated. The effects of additives, salinity, and temperature on the diffusion coefficient of surfactants have been studied as well. The experiments exhibit a significant synergism between nonionic and sulfonate anionic surfactants. These two types of surfactants coadsorb on oil/water interface, dramatically decreasing the interfacial tension and shortening the time to reach equilibrium. It has been found that the synergism phenomenon is associated with the molecular structure of both surfactants and crude oil. Therefore, it is desirable to choose the suitable auxiliary nonionic surfactant matching with the primary sulfonate anionic surfactant in the flooding system, which displays the characteristics of quick diffusion and absorption for anionic surfactants as...