A Well Test Interpretation Anomaly

[rahim_der]

The interpretation of the extended build-up of an isochronal test run on a gas-condensate producing well gave what appears to me to be anomalous results. The model that gave the best match was a radial composite reservoir coupled with a changing WBS (Hegeman) and a rate-dependent skin.
Here are the results that seem to be off:
Total Skin: 62.5 (So = 11.5)
k avg: 554 md, inconsistent with core permeability (about 35 md) and with results of WTA performed on nearby wells (same reservoir) which gave permeabilities of about 25 md.
Can non-Darcy skin be as high as 51 ? (last flow rate before BU: 12 MMscf/day)
Here's a screenshot of the match.

[link Point to another website Only the registered members can access]

[i-anuar]

just wondering do you have partial penetration? then first zero slope may be related to the perforated interval and second zero slope corresponding to the whole production interval thickness?
just a version to check really...