Efficiency Research Of Flooding Systems To Intermediate Wettability Oil Reservoir In Laboratory

In this paper, the characteristics of hydroxyl sulfo betaine surfactant SL12, carboxyl betaine surfactant SL14 and heavy aklyl benzenes sulfonate surfactant SA has been conducted the systemic research. Result show that:The SL betaine series surfactant may form the ultra lower interfacial tension of 10^-3mN/m magnitude in wide concentration range under nonalkali condition.This series surfactant has the good heat resistant performance, this series surfactant can achieve the ultra lowe interfacial tension between oil and water interface in 45℃～80℃ scope.The SL betaine series surfactant has strong ability to anti-salty and divalent ion,it can bear salinity ability to surpass 100000mg/L and bear the divalent ion ability also to achieve 1500mg/L.The right amount sodium phosphate is joined in the SL betaine series surfactant solution to take the sacrifice medicinal preparation which can faster the speed to achieve the most lower interfacial tension and the balance interfacial tension in water-oil interface and the suitabl concentration sodium phosphate could reduce the water-oil interfacial tention.The independent system of heavy aklyl benzenes sulfonate surfactant SA is unable to reach the ultra lower interfacial tention of 10^-3mN/m magnitude,joining the right amount strong alkali in the system , the water-oil interfaicial tension could reach ultra low, optimum alkali content would increase along with the increasing surfactant. In the foundation that the interfacial characteristics of SL betaine series surfactant and the heavy aklyl benzenes sulfonate surfactant SA were researched, aimed at the intermediate wettability models the surfactant flooding above and the highly concentrated polymer solution system to were carried on physical modeling experimental study with emphasis.Appraisal of effect were carried on to above flooding system. The result of research show that: Physical analogue experiments were carried on in view of the homogeneous and heterogeneous models.The SL betaine surfactant compound flooding system have strong ability to enhancing the recovery, the recovery enhanced about 25%(OOIP). The SA strong alkali ternary compound flooding system has the equivalent recovery compared with the SL series surfactant sodium phosphate flooding system. Under the condition of polymer relative molecular mass and suitable concentration, the highly concentrated polymer solution flooding has the good driving efficiency similarly, its recovery could enhance above 20%.