P. Lemouzy, 1999. "Evaluation of Multiple Geostatistical Models Using Scaling-Up with Coarse Grids: A Practical Study", Reservoir Characterization—Recent Advances, Richard A. Schatzinger, John F. Jordan
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In the field delineation phase, the uncertainty in hydrocarbon reservoir descriptions is large. In order to quickly examine the impact of this uncertainty on production performance, it is necessary to evaluate a large number of descriptions in relation to possible production methods (well spacing, injection rate, etc.). The method of using coarse scaled-up models was first proposed by Ballin et al. Unlike other methods (connectivity analysis, tracer simulations), it considers parameters such as thermodynamic behavior of the fluids, well management, etc.
This paper presents a detailed review of scaling-up issues, along with applications of the coarse scaling-up method to various water-injection cases, as well as to a depletion case of an oil reservoir in the presence of aquifer coning.
The need for correct scaling-up of wellbore and near-wellbore parameters is emphasized and is far more important than correct scaling-up far from wells. I present methods to accurately represent fluid volumes in coarse models. I propose simple methods to scale-up the relative permeabilities, and methods to efficiently correct for numerical artifacts.
I obtained good results for water injection. The coarse scaling-up method allows the performance of sensitivity analyses on model parameters in a much lower computer time than comprehensive simulations. Models repre-senting extreme behaviors can be easily distinguished.
For the depletion of an oil reservoir in the presence of aquifer coning, however, the method is not as promising. It is my opinion that further research is required for scaling-up close to the wells.