Sensitivity of Steam Displacement Predictions to Three-Phase Relative Permeability Models

Placeholder Show Content

Abstract/Contents

Abstract
Users of thermal simulators usually provide data in terms of two sets of two phase relative permeability functions: (1) krow and krw, in a water-oil system, and (2) krog and krg in an oil-gas system. Within the thermal simulator two-phase relative permeabilities are used to predict effective permeability of each phase when all three phases are flowing simultaneously in a block. The most frequently used models for making these predictions are due to Stone (Model I and Model II) and their modifications. The literature does not provide clear guidance on the selection of a relative permeability model for a given problem. This paper presents theoretical and numerical analyses of three-phase relative permeability models for steamflood problems. The analysis shows that relatively high krw and krg (from two-phase data ) lead to higher kro from Model I than Model II, and the reverse is true when krw and krg are relatively low. The differences in predicted kro by the two models are greatest in the range of low oil saturations.Three sets of data have been selected from the literature that have been previously used for the modelling of steamfloods. Data Sets 1, 2 and 3 are characterized by moderate, low and high values of krw and krg, respectively. The oil relative permeability (kro) predicted for Data Set 1 by the Stone's two models is about the same. As expected from our theoretical analysis, Stone's two models yield quite different kro's for Data Sets 2 and 3. However, oil production predictions with Model I and Model II for Data Set 3 are not too different, but these two models show significant differences in the simulation results for Data Set 2. Investigation of saturation profiles near production and injection wells show that low krw and krg values (Data Set 2) tend to drive saturations into the range where Stone's two models give different results, and high krw and krg values (Data Set 3) tend to keep saturations in the range where the two models give similar results.Simulation results show that saturation changes caused by the steam vaporization and condensation process play an important role in determining conditions for the flow of water phase. The results of this study should be of value in selecting three-phase relative permeability models for steamflood simulations.

Description

Type of resource text
Date created June 1987

Creators/Contributors

Author Sato, Kozo
Primary advisor Aziz, Khalid
Degree granting institution Stanford University, Department of Petroleum Engineering

Subjects

Subject School of Earth Energy & Environmental Sciences
Genre Thesis

Bibliographic information

Access conditions

Use and reproduction
User agrees that, where applicable, content will not be used to identify or to otherwise infringe the privacy or confidentiality rights of individuals. Content distributed via the Stanford Digital Repository may be subject to additional license and use restrictions applied by the depositor.

Preferred citation

Preferred Citation
Sato, Kozo. (1987). Sensitivity of Steam Displacement Predictions to Three-Phase Relative Permeability Models. Stanford Digital Repository. Available at: https://purl.stanford.edu/sx620jd0104

Collection

Master's Theses, Doerr School of Sustainability

View other items in this collection in SearchWorks

Contact information

Also listed in

Loading usage metrics...