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Ecrin v4.12 - Doc v4.12.02 - © KAPPA 1988-2009
Saphir Guided Session #1
• Sa
pGS01 - 7/12
be done automatically, i. e. without the intervention of the two
To invoke automatic extraction you hold down the shift key while clicking on the icon
The extraction process can also
dialogs in Figure C01.1. In that case it is always the last extractable period in the history that
is extracted.
.
e icon
ely
finite acting radial flow and wellbore storage. If Saphir can find these regimes it will make
the match by setting the white horizontal dotted line on the stabilization of the derivative and
the unit slope white dotted line on the early time data as seen in Figure C01.2. The lines are
connected and can be moved to any other position by you (click and drag with mouse) in the
event that the automatic match is not satisfactory.
D01 • Modeling
Once the match is satisfactory the process changes to diagnostic mode. The diagnostic phase
includes the search for all flow regimes that may be present in the response of the extracted
period. This allows the interpreter to choose the most appropriate model that includes all the
flow regimes identified. Then th
run the model and obtain the
match which again will yield the results.
he response of this extracted flow period is straight forward with a long period of infinite
small amount of wellbore storage to start with. Small wellbore storage
was expected as this is a DST with downhole shut-in.
The most appropriate model to use in this analysis would be a model that takes this into
account, hence the use of the homogeneous model with wellbore storage and skin in an infinite
system.
Click on the Model icon
The red flash on th indicates that the extraction is in automatic mode.
At the extraction Saphir makes an automatic match. Stabilization is sought in the derivative,
as well as a unit slope straight line at early time in both the derivative and the delta P. This
corresponds to the two most common flow regimes seen in pressure transient analysis, nam
in
e next natural process is to
T
acting radial flow and a
. This will open the Model dialog where the combination of
wellbore, well, reservoir and boundary models may be selected. The default model parameters
are displayed in the dialog and you can modify them manually. The default values of C
(wellbore storage coefficient) and kh (permeability thickness product) are deduced from the
original automatic match made by Saphir. Keep the default values as seen in Figure D01.1.