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Dynamic Data Analysis – v5.12.01 - © KAPPA 1988-2017
Chapte
r 6 – W ell models -p176/743
The figure below illustrates the loglog match of the well behavior before and after a fracture
stimulation job. The model matches the whole history of the test sequence including the
fracture treatment.
Fig. 6.C.5 – Changing well loglog match
Fig. 6.C.6 – Changing well history match
6.C.3
Time dependent skin
When the well is cleaning up one will see a decrease of skin with time. Conversely a well may
get progressively damaged during its producing life, hence an increase of the skin factor.
These effects may be modeled by allowing the mechanical skin to vary over the well life. This
may actually be combined with a rate dependent component, though solving for both may
often be an under-specified problem.
In Saphir, time dependent skin is just a subset of the changing well model where each status
is assigned a skin. The figure below illustrates a well that is cleaning up matched with a
constant and changing skin model.
Fig. 6.C.7 – Well cleaning up