Numerical Model Limitations

While numerical models can be useful in the well performance analysis process, there are some important limitations that must be recognized:

• Currently numerical models in Harmony do not simulate changes in oil and gas composition.
• Numerical modeling calculations are more time consuming than analytical model calculations. You may notice that the primary advantage of analytical models is their near instantaneous calculation speed. The numerical models run much slower, depending on how many grid cells are included in the model.
• Although the numerical engine is robust, there are several cases that will cause the execution of the model to fail (this is true of any gridded simulator.) This usually happens when the model shortens its timesteps too much, such as when there are rapid operational changes in rate or pressure. These issues can usually be overcome by smoothing the data and eliminating dramatic shifts in rate and/or pressure.