Ecrin v4.20 - Doc v4.20.01 - © KAPPA 1988-2011
Rubis Guided Session #4
• Rub
GS04 - 11/14
Fig. B02.7 • Comparing analytical and linear numerical models
A few remarks can be drawn from this comparison:
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As noted before, the analytical model is unable to reproduce the production period
pressure trend visible on the pressure data because its model is infinite acting: quite
clearly the reservoir average pressure is maintained.
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On the other hand, the numerical linear model (based on the sector contour) exhibits
dropping derivative on the log log which characterizes a closed system. In fact, it is
clearly visible that the sector is only a region of the whole reservoir.
The sector that has been dragged from Rubis is appropriate for near-well conditions and
intermediate (permeability, first boundaries) interpretation, for instance it can be an essential
tool, by its diagnosis tool, for the diagnosis and the analysis of more complex cases like
fractured well, non homogeneous formation or not totally sealing fault. Nevertheless it cannot
replace the full history match built in Rubis – unless the sector is built from the complete
reservoir.
Let us now go back to the Rubis sector analysis, and change the well skin value from 0.3 to 0
– the value obtained in the linear models (edit the perforations of the Prod 1 well, as you
would do in Rubis). Then, visit the Settings dialog again and exit with OK to enable the
Simulate button. Click on Simulate and wait until the new model is completed:
1...,387,388,389,390,391,392,393,394,395,396 398,399,400,401,402,403,404,405,406,407,...485