Foam Assisted WAG, Snorre Revisit with New Foam Screening Model

This study deals with simulation model of Foam Assisted Water Alternating Gas (FAWAG) method that had been implemented to two Norwegian Reservoirs. Being studied on number of pilot projects, the method proved successful, but Field Scale simulation was never understood properly. New phenomenological foam model was tested with sensitivity analysis on foam properties to provide a guideline for the history matching process (GOR alteration) of FAWAG Pilot of Snorre Field (Statoil).

The aim was to check the authenticity of presented new foam model in commercial software whether it is implementable on a complex geological model for quick feasibility studies, either for onward practical pilot or as justification for more detailed technical study.

The simulation showed that Foam model is applicable. The mismatch between history and actual GOR in some periods of injection is due to the complexity of the fluid flows control inside reservoir. The way; how specific properties control the time of gas arrival and values of GOR are described. The analyses of the improvements in the injection schedule are shown.

With increasing number of CO2 and FAWAG methods in preparation worldwide, the use of the simulation contributes to more precise planning of the schedule of water and gas injection, prediction of the injection results and evaluation of the method efficiency. The testing of the surfactant properties allows making grounded choice of surfactant to use. The analysis of the history match gives insight in the physics of in-situ processes.

Detailed Qualitative analysis is presented for foam modeling against the FAWAG historical data that provides sharp idea of the behavior of Foam model for different foam factors, which in turn provides reasons for the unpredictable foam behavior in WFB Project and serve as quick reference for future general foam pilot simulations at field scale.