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Emeraude v2.60 – Doc v2.60.01 - © KAPPA 1988-2010
Guided Interpretation #3
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B03 - 10/11
In this interpretation, the slippage constraint forces the light phase to go faster than the heavy
phase on upflow. One can see in the ‘Slip velocity match’ track, that the slippage velocity
between liquid and gas (red dotted line) is positive. In the interpretation #2, with no constraint
on the slippage velocity, the red dotted line is negative which would mean that the liquid goes
faster that the gas.
B03.5 • Hybrid Genetic Algorithm (HGA)
It is possible to couple the Global Regression with a pre-processing called HGA, for ‘Hybrid
Genetic Algorithm’. This pre-processing is particularly suited at avoiding local traps or finding a
better starting point for the regression. Access to HGA is enabled in the ‘Misc’ tab of the
‘Interpretation - Settings’ panel.
When enabled, access the Global Regression through the ‘Contributions’ tab of the ‘Zone Rates’
dialog. This option shows two additional controls:
A check box to use HGA in the next run
A button to view/edit the HGA parameters.
This should normally not be changed
.
When running a Global Regression with the HGA option checked, a dialog appears to show the
HGA progress, Fig. B03.11.
Fig. B03.11 • HGA progression dialog
In this dialog, the following information is plotted/displayed:
In white, the value of the objective function corresponding to the solution before the call
(base case).
In green, the value of the objective function for the consecutive improvements in HGA.
Typical behavior
HGA is not ‘biased’ by the starting point and it will usually start with solutions having a much
higher (worse) objective functions than the base case. Also, a Genetic Algorithm improves the
solution iteratively, but unlike a classical optimization, it does not provide a systematic
improvement at each iteration. This will be translated in the plot where new points are drawn
only when there is an improvement. So the plot may seem to be halted for some time and
then start again. An automatic scaling is executed every 5 new points.