Study on Influencing Factors of Alkali ASP Formulation

Formulation of system directly affects technical and economic effect of ASP flooding. It is necessary to clarify the influence of different factors on concentrations of chemical agents and performance of system, and optimize formulations according to specific characteristics of blocks. The result shows that surfactant concentration loses 40–80% after the interaction between crude oil and ASP system. The higher the asphaltene content in crude oil, the greater the decrease in surfactant concentration. Clay mineral in oil sand is another influencing factor that causes the loss of surfactant about 43–64%. Surfactant concentration should be adjusted according to the characteristics of crude oil and sand mineral content in specific area. Crude oil and sand have small difference on NaOH concentration. Because injected sewage contains HCO3−, NaOH concentration in ASP system will reduce 0.2%, NaOH concentration should be determined by sewage quality, crude oil and sand in specific block. According to physical simulation flooding experiments, there is an optimum polymer concentration in same permeability condition to get the highest recovery. Optimal principle of polymer concentration is reasonable matching of the permeability and the viscosity of ASP system. Design of strong alkali ASP system formula will provide important technical support for preparation of the best driving program.