Log-log plot of unit-rate drawdown pressure
and pressure
log-derivative (see Fig. 1 – Fig. 2 for example).
The pressure log-derivative
provides a zoomed insight into the pressure diffusion character at different times which helps identifying the diffusion model behind the pressure evolution.
See PTA Type Library for a wide range of typical PTA Diagnostic Plots.
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| Image Added |
Fig. 1. PTA Diagnostic Plot for vertical well in single-layer homogeneous reservoir without boundaries. Pressure is in blue and log-derivative is in red. | Fig. 2. PTA Diagnostic Plot for vertical well in single-layer homogeneous reservoir without boundaries. Pressure is in blue and log-derivative is in red. |
