Laboratory Study On The Interfacial Rheological Property Of The Dual-chemical EOR Fluid System Combined By Hydrophobical Associating Polymer (NAPs) And Surfactant (SDBs)

The enhanced oil recovery mechanisms of chemical flooding and combination chemical flooding are related to oil displacement system apparent Theological property, interfacial tension, interfacial Theological property and so on. A lot of researches show that interfacial Theological property affects displacement process and final displacement effect. In the field of EOR, the following four main aspects about interfacial Theological property have been concerning. First one is efficient and powerful testing methods of interfacial viscosity; Second one is systematic study of oil-water interfacial Theological property during chemical flooding and combination chemical flooding on the basis of reliable testing methods; Third one is to study the effect of interfacial Theological property on micro-processes and macro-results of oil displacement during chemical flooding and combination chemical flooding. Forth one is to study how to make the interfacial Theological property of oil displacement system optimal during developing recovery chemicals. In this paper, the first and second aspect has been addressed.Interfacial viscosity reflects material components and state in the interface layer, and is one of basic parameters to express interfacial Theological property. So it is of significance to measure interfacial viscosity reliably, precisely and conveniently. As a summary it was evidenced that the interfacial rheology is an efficient and powerful detection technique, which may enhance our knowledge on formation, structure, properties and behavior of interfacial layers formed in oil/water systems. Thus similar studies will probably accelerate the progress significantly not only in oil recovery but also in all areas of colloid science and technology.Up to now, many researchers have done a lot of creative studies on expressionand measuring methods of interfacial Theological property, and achieved some significant progress. Among those methods measuring interfacial viscosity, the deep channel viscous interfacial viscometer has been accepted by most of researchers because of its reliable theoretical basis and relative simple structure. Since 1980's, it has been the most important method to measure interfacial viscosity. But it couldn't be used to measure the interfacial viscosity of viscous fluids because of its defects of measuring method. Consequently, it couldn't be used to study the interfacial Theological property of chemical flooding and combination chemical flooding. All in all, the study of this area lags behind development of petroleum industry obviously, and it can't satisfy the needs of oil development with high efficiency. So on the basis of systematic analysis to structure and principle of deep channel viscous interfacial viscometer, its measurement method was modified and improved. Because of those improvements, it becomes reality to measure surface viscosity and interfacial viscosity of viscous fluids, consequently, interfacial viscosities of polymer solution and oil, and combination chemical flooding system and oil can be obtained now. Error analysis shows that measuring precision of lower liquid depth is a key factor affecting interfacial viscosity measurement. A new type of liquid depth meter was designed and employed. It greatly improved the precision of depth.By using of NAPs and SDBS, we studied surface viscosity of polymer solution, surfactant solution, and Polymer/Surfactants fluid system as well as interfacial viscosity between them and simulation oil. Results show that interfacial viscosity heavily affects by bulk viscosity , so it isn't comprehensive enough to use interfacial viscosity to describe interfacial Theological property of viscous liquid only. A dimensionless interfacial viscosity was proposed. It has been proved to be reasonable and reliable for describing the interfacial Theological property.Both interfacial viscosity and dimensionless interfacial viscosity affect by temperature, polymer concentration and salinity. The effect of NAPs concentration on dimensionless interfacia...