The Experiment Research On The Formulation And Performance Evaluation Of Spontaneous Emulsification Flooding System

Water drive reservoir of Shengli oilfield has generally reached extra high water cut period.Uneven displacement caused by reservoir heterogeneity has major influence on the development of water drive reservoir.Deep displacement is the important mean to realize balanced reservoir displacement.At present,deep displacement focuses on the adjustment for macro heterogeneity.But in the extra high water cut period,the distribution of remaining oil is more scattered.The occurrence mode of remaining oil has priority to multi pass.In order to improve the effect of water drive,micro displacement must be conducted on the basis of macro adjustment.Under the geological condition of the Shengli oilfields,this paper screens out and optimizes a spontaneous emulsification oil displacement system and evaluate the system in terms of interfacial tension,oil sands performance and suction performance.Meanwhile this paper conducts studies on indoor physical simulation flooding.The studies show that when experimental temperature is 80?,surfactant system can emulsify crude oil under slight external force without achieving ultra-low interfacial tension.If oil is cleaned out from the oil sand,the particle size of droplets is averaged 15?m and the droplets have the obvious phenomenon of coalescence and bridging under the microscope.The experiment of indoor physical simulation flooding shows that if the water drive cover 98% of the system oil revovery efficiency can still be enhanced substantially,rising over 20%.