Study On The Interaction Of Functional Polymer And Surfactant Vesicles

After conventional waterflooding processes the residual oil in the reservoir remains as a discontinuous phase in the form of oil drops trapped by capillary forces and is likely to be around 70% of the original oil in place. In view of the world-wide shortage of oil, as far as possible to enhance the recovery of oilfields has become a major task of the current oil exploitation. Chemical Flooding has proved to be effective in reducing the oil residual saturation after water flooding. Polyacrylamide (PAM) is one of the most widely used polymers in Chemical Flooding. However, there are many defects in its practical application, such as low temperature resistance, poor salt tolerance, and easy to oxidative degradation. Therefore, the selective research of good heat-tolerant and salt-resistant surfactant-functional polymer system that can reduce the interfacial tension and mobility ratio between oil and water phases has been made.Since the performance of surfactant will be greatly improved after gathered into vesicles, a compounded system of functional polyacrylamide polymer and surfactant vesicles was prepared. The rheologic behavior and emulsification properties of compounded system and pure functional polymer solution were researched, and the solution behavior and aggregated structure were studied by fluorescence and scanning electron microscope. The results showed that: The rheologic properties and emulsification abilities of compounded system has been great upgraded. The apparent viscosity could be controlled by adjusting the content of vesicles. In vesicle-functional polymer system, the type of emulsion changed into oil-in-water, however, it is water-in-oil in traditional surfactant-functional polymer system, the fluidity of emulsion has been improved greatly. The aggregated structure of functional polymer is like a network construction and certain relationship between the rheology and such network has been proved. However, the aggregated structure of compounded system is very different. When the concentration is high, the aggregated structure is like the gels'. In all cases, the viscosity of the functional polymer solution decreases with the addition of salt or the increase of temperature. However, the compounded system was less affected by temperature increasing, owing to the hydrophobically associating becoming more closer.In a word, the rheologic and emulsification properties of the vesicle-functional polymer compounded system can exceed some applied surfactant-functional polymer system. The results provide useful information for the future design and development of the complex flooding formulation technologies.