BEI ENERGETIQUE ET PROCEDE
STUDY OF SAGD PROCESS

 
Achievements I

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Software

To perform our work, we used STARS©, a dynamical reservoir simulator, which can take into account the thermal conditions, the reservoir rocktype and also the production forecast.This software, developed by CMG, is rather simple to use, and can provide very interesting results, such as comparing a 10 years production forecast, while using steam only or steam & solvent for example.

Achievements

For the first draft, we considered a Black-oil model (3 components: water, light & heavy oil & 3 phases: aqueous, oleic & gaseous), with a simple reservoir modeling (symmetric & 2D, isotropic, porosity 0.3, permeability 1000 mD). Our mesh was static and Cartesian mesh (50 x 1 x 30). Moreover, we took into account two wells:

 

  • one steam injector (30 bar, 260° C, quality 0.8) in 50 x 1 x 25
  • one oil producer in 50 x 1 x 30

We can see on the graph above the reservoir pressure, as well as the wells position (bottom right corner)

We observed the temperature & saturation profiles after a 45 days simulation, and the forecasted oil and gas production within a two year simulation.[2]

This first graphic presents half the steam chamber after 45 days. We can clearly see the temperature increase in the reservoir, which will lead to lower the oil viscosity, and to decrease the oil saturation, set up at 1.00 at the beginning of the run. (see graphics below)

We can also take a look at the forecasted oil & gas production. It is clear that the peak oil has been reached on that example (the cumulative oil is looming to its asymptote), which means that fewer and fewer oil will be produced, and gas, dissolve in the oleic phase, will be more and more abundant. This type of curves is typical of a mature field (such as those found in the North Sea), in which oil will be more and more sparse.

This first simulation provided us some useful