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Dynamic Data Analysis – v5.12.01 - © KAPPA 1988-2017
Chapte
r 2 – T heory- p40/743
2.H.2.c
Permeability
The figure below presents the response with all default parameters except the permeability.
Values for k are 2, 5, 10, 20 and 50 mD.
Storage and IARF: The derivative responses have the same shape but they are translated
along the wellbore storage line of unit slope. When the permeability is higher, the reservoir
reacts faster and deviates earlier from pure wellbore storage. The level of stabilization of the
derivative, i.e. the slope of the semilog plot, is inversely proportional to k. For this reason the
responses diverge on the semilog plot, the different slopes being inversely proportional to k.
PSS: At late time all derivative signals merge to a single unit slope. This is linked to the fact
that permeability has no effect on the material balance equation.
Fig. 2.H.7 – Influence of the reservoir permeability, loglog plot
Fig. 2.H.8 – Influence of the reservoir permeability, semilog and history plot