New Scaling Criteria For Polymer, Emulsion And Foam Flooding Experiments

Abstract

Abstract This paper presents for the first time a set of scaling criteria JOT polymer, emulsion, and foam flooding experiments. Numerous studies dealing with the flow of polymer, emulsion and foam have been reported. These materials have been used extensively as mobility control or diverting agents in enhanced oil recovery by gas drive, steam injection, water flood or micellar floods. The rise of these blocking agents has been successful in reducing the problem of gravity override and channelling. However, in order to scale up laboratory experiment results for field application or to determine specific parameters of the process, the model has to be properly scaled (1–3). This requires a set of similarity groups governing the process. In the past, most laboratory experiments with polymer, emulsion, and foam have been performed in unsealed or partially scaled models. This is due to lack a/scaling criteria for a process with emulsion, polymer or foam. Recently there have been many new developments in the theory of emulsion and foam flow through porous media but no effort was made to find the scaling criteria in order to make the laboratory scaling results applicable to the reservoirs. Starting with governing partial differential equations, new scaling criteria have been derived for polymer, emulsion and foam experiments, using inspectional analysis. Scaling criteria have been derived also by dimensional analysis. Emphasis has been on the process itself, especially complex interactions and mass transfer between phases, interfacial tension, fractional flow, dispersion, adsorption, mechanical entrapment, slug size, polymer transport, and foam and emulsion formation and stability. A variety of scaling options are investigated and their elative merits pointed out. Situations where, by relaxing the requirement a geometric similarity, the same fluid and the same porous media can be used, are presented. It is shown that in ertain situations geometric similarity has to be relaxed in order to scale properly all the pressure-dependent properties along with dispersion. The conditions for properly scaling adsorption and mechanical blockage are pointed out. Example calculations are finally provided in order to be able to design a specific scaled model. Introduction The use of polymer, emulsion and foam has been a subject of many investigations in the petroleum industry for many years. These materials have been used as mobility control or diverting agents in different enhanced oil recovery techniques, such as gas drive, steam injection, waterflood or micellar flood(4–10). Many studies have shown that these materials may improve oil recovery by a substantial amount due to improvement in sweep efficiency. However, laboratory studies performed to-date have used unsealed or only partially scaled models. Therefore, the quantitative results obtained from polymer, emulsion, and foam flooding experiments are not applicable to the field. Unscaled models are chosen such that they represent the conditions atsome point in the field. However, their dimensions are selected on the basis of the aspect of recovery being studied and/or the physical constraints of the test equipment(2). Consequently, while unsealed models elucidate some of the mechanisms in the process, they could not be applied to predict field performance.