Microscopic Displacement Mechanism Of S/SP/ASP Driving Residual Oil

In this thesis, based on the review and research on the mechanism of chemical flooding, themechanism of S/SP/ASP driving the residual oil was researched.Firstly, to both simplified and emulational core, the process of dynamic state in surfactantflooding was recorded according to the microscopic displacement. The mechanism of start-upand movement of residual oil was analyzed, as well as the effect of interfacial tension to therecovery. Besides, the thesis has studied the distribution of residual oil after surfactant flooding.Secondly, the displacement mechanism of SP flooding to the residual oil after waterflooding was studied, especially the difference of surfactant flooding and SP flooding in theprocess and mechanism. The effect of viscoelastic behavior and interfacial tension to therecovery was also studied. Compare of SP flooding and ASP flooding was done in thedisplacement mechanism and the distribution of the residual oil.The above investigations have revealed the displacement mechanism of S/SP/ASP in theporous media and obtained the rule of movement and start-up, especially the function of theemulsion and oil filament. Besides, the effect of interfacial tension, HPAM concentration andmolecular weight to the recovery was analyzed. The result of experiments show that the systemwhich has higher viscoelastic behavior combined lower interfacial tension can obtain the highestrecovery. To the SP flooding, it is necessary that interfacial tension is reduced enough low if wewant to enhance the higher recovery. HPAM of bigger molecular weight should be selected inthe SP flooding in the condition that the inject pressure is permitted. According to themicroscopic experiment, we find that the recovery of SP flooding is higher than ASP flooding inthe same interfacial tension condition.