Research On Displacement Efficiency Of Alkalescent ASP System In Class? Layers Of Block A

At present,ASP flooding has entered the stage of industrial application in Daqing Oilfield,and can be divided into strong alkali ASP flooding and weak alkali ASP flooding according to the type of alkali.Although ASP flooding technology has entered the stage of industrial application in Daqing Oilfield,a series of problems are becoming more and more serious.For example,strong alkali in ASP flooding is easy to react with minerals in formation,forming serious alkali scale,causing damage to reservoirs,and seriously hindering the normal production of subsequent wells.Therefore,weak alkali ASP flooding came into people's vision gradually.Due to the differences of geological conditions and sedimentary facies in different blocks,the formulations of weak alkali ASP flooding suitable for second-class reservoirs are also different.Through a large number of literature research,combined with the geological characteristics of Block A,indoor physical simulation experiments are carried out to analyze the displacement effect of weak alkali ASP flooding for type ? reservoirs,which has important theoretical significance and application value for improving the technology of weak alkali ASP flooding in the exploitation of type ? reservoirs.The results show that the viscosity of weak alkali ternary system decreases with the increase of alkali concentration,first decreases and then increases with the increase of surfactant concentration;the higher the temperature and the longer the storage time,the lower the viscosity;when the alkali concentration is between 1.0% and 1.4%,and the surfactant concentration is between 0.3% and 0.4%,the weak alkali ternary system meets the ultra-low interfacial tension;core permeability and resistance coefficient It is inversely proportional to the residual resistance coefficient;the smaller the alkali concentration in weak alkali ternary system,the larger the resistance coefficient and residual resistance coefficient;by contrast,the effect of weak alkali ternary flooding is better than that of polymer flooding.Increasing the alkali concentration and surfactant concentration in weak alkali ternary system and increasing the size of main slug can effectively improve the oil displacement effect of weak alkali ternary system.