Study On Mechanism Of Using Enhanced Liquid To Improve Development Effect In Water Flooding Sandstone Reservoirs

At present, most oil fields inland have come into the late-mid-exploitation phase, and water flooding effect was poor, water cut increased rapidly, and the recovery of crude oil was very low in the development. As the most widely applied measure to improve water flooding reservoir development effect, enhanced liquid can reduce water cut or restrain the water cut from increasing in oil field development and improve reservoir recovery. It is applicable to almost all water flooding reservoir types. Based on previous studies on enhanced liquid mechanism and remaining oil distribution characteristics, this paper have detailedly studied of mechanism of using enhanced liquid to improve water flooding development effect in sandstone reservoirs.This paper have made microscopic heterogeneity experimental models, and studied a reasonable displacement rate, a reasonable enhanced liquid quantity and a reasonable enhanced liquid time by changing the displacement rate, enhanced liquid quantity and enhanced liquid time using different microscopic heterogeneity experimental models. Based on previous microscopic remaining oil distribution characteristics in experiments and water displacing oil physical simulation processes, combined with theoretical studies, this paper have analysed the influence of reservoir rock wettability, microscopic heterogeneity and crude oil properties to microscopic remaining oil distribution, analysed the experimental phenomena and results, and ultimately determined the microscopic mechanism of using enhanced liquid to improve water flooding development effect in sandstone reservoirs.This paper have used Eclipse reservoir simulation software to establish the ideal models, and studied a reasonable displacement rate, a reasonable enhanced liquid quantity and a reasonable enhanced liquid time by formulate different development modes using different crude oil viscosity and macroscopic heterogeneity ideal models. Based on previous macroscopic remaining oil distribution characteristics in practices and reservoir numerical simulation processes, this paper have analysed the influence of macroscopic heterogeneity, crude oil properties, well pattern, injection-production system and fractures to macroscopic remaining oil distribution, analysed the numerical simulation caculations, and ultimately determined the macroscopic mechanism of using enhanced liquid to improve water flooding development effect in sandstone reservoirs.Based on the experiment, numerical simulation and mechanism studies, this paper have analysed main factors influencing enhanced liquid development effect, and summarized reservoir types and geological conditions suitable for enhanced liquid developing.