Numerical simulation of steam-chemical oil recovery processes require high temperature multiphase rock-fluid properties such as relative permeabilities and capillary numbers. These parameters are needed to predict and evaluate oil recovery performance and efficiency. Experiments in both Berea sandstone and sandpacks have been conducted to measure relative permeabilities of high and low tension oil-water mixtures at elevated temperatures. A new mathematical model consisting of sets of empirical correlations based on experimental data have been developed for relating endpoint relative permeabilities to both residual and mobile oil-water saturations and capillary numbers to residual oil-water saturations.
The tests were run over a wide range of temperature, 72 to 400F, and overburden pressure range of 500 to 1000 psia. It is our belief that this model is new for the range of temperature and pressure of steam oil recovery processes with chemical additives. Predictive results made with empirical correlations are in good agreement with experimental results.
Several studies have been undertaken to investigate and describe the mechanisms of multiphase flow in the porous media. Generally, the characterization of multiphase flow in porous media is in terms of rock-fluid properties consisting of the relative permeability, which exhibits the flow characteristics, and the capillary pressure, which depicts the static characteristics. These combined rock-fluid properties are used for describing and quantifying the mechanisms of multiphase flow in the porous media. The relative permeability and capillary pressure characteristics reflect the composite effect of pore geometry, wettability, fluid distribution and saturation history. The effects of temperature and interfacial tension on these composite parameters may modify the regular characteristics of relative permeability and capillary pressure. With the increasing interest in the concurrent injection of chemicals with steam, an understanding and modeling of the combined effects of temperature and interfacial tension on relative permeability and capillary pressure characteristics is required for simulating steam-chemical recovery processes.
Several experimental studies have been conducted on the individual effects of temperature and interfacial tension on residual saturations, relative permeabilities and capillary pressures. An excellent literature review on these topics is provided by several investigators. In this study, we present the summary of the literature survey as follows: