Page 220 - KAPPA - Ecrin v4.30 tutorials

Ecrin v4.20 - Doc v4.20.01 - © KAPPA 1988-2011 Saphir Guided Session #8 • SapGS08- 8/11
From the shape of the semi-log derivative, we can identify a late pseudo-radial flow (unit
slope). No clear pseudo-linear flow (1/2-slope) is present here. Hit the specialized line button
, select ‘Radial FR’ and set a graphical line onto the late (left part) semi-log data for putting
into evidence the radial flow regime. We will remove the vertical lines corresponding to the
start and end of the pseudo linear flow regime, as it cannot be detected here. Click on and
uncheck start and end of linear flow, only one vertical line remains corresponding to the start
of the radial flow regime. Click next on to move this line toward the start of the pseudo-
radial trend:
Fig. B02.5 • Pseudo-radial flow regime identification
Now that the flow regimes have been identified, click on plot type and select ‘Radial FR’
(we will not use ‘Linear FL’ as no clear linear flow regime has been detected). The plot has
changed to the plot of pressure versus radial flow function in Cartesian coordinates.
On this plot a straight line fit of the data in the radial flow regime time interval will give the
reservoir pressure (and far-field mobility in the case of pseudo-radial flow).
Use the zoom on the horizontal axis button to focus on data around the picked start of
pseudo-radial flow (recall here that time increases from right to left).
Click on the line button , select ‘Regression’ and set the two points for the linear regression
(one on the left of the first data point and the second at the position of the dashed vertical
line). The regression line appears and the reservoir pressure (10959 psia) is automatically
updated based on the intercept of this line with the pressure axis.