abstract
- Copyright 2016, Society of Petroleum Engineers.An integrated methodology is presented for development of a comprehensive empirical foam model based on tailored laboratory tests and representative numerical simulations that encompass processes of foam generation, coalescence, shear thinning along with rheological characteristics and flow regimes. Multitude of steady state and unsteady state laboratory experiments of foam floods in a vertical column of sandpack with and without oil at different surfactant concentrations and at varied gas-surfactant solution injection rates are designed, conducted and analyzed. The logic and basis for the conduct of each of these experiments are provided. Test results from experiments in the presence of oil provide information on the oil-induced foamlamella coalescence functions. Unsteady state experiments are conducted to characterize foam generation and foam dry-out phenomena, while steady state experiments capture the effects of foam quality, foam velocity and surfactant concentration. Process-based numerical simulations of these experimental results are combined with analytical solutions of foam flow equations to provide a methodology for comprehensive foam model. Simulations of unsteady state foam flow experiments with and without oil saturation quantify the foam generation and coalescence function parameters. A procedure is presented to fully model the effect of surfactant concentration on foam strength and quantify all concentration function parameters, and in particular, epsurf. The combination of sound mathematical principles of governing foam flow equations and numerical simulation techniques is shown to be the key for uniquely defining the empirical foam model parameters and for preserving consistency with simulations of foam flow processes.