Normalised Normalised dimensionless difference between the actual drawdown wellbore pressure difference between the sandface bottomhole pressure (BHP)
and a model of a full-entry vertical well with homogeneous reservoir and non-damaged near-reservoir zone and the sandface reservoir pressure :\displaystyle p({\bf r}, t) |_{r = r_w} |
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at the well-reservoir contact. LaTeX Math Block |
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S_G = \frac{2 \pi \sigma}{q_t} \left([ p_{wf}(t) - p*_{wf}(t) \right)({\bf r}, t) |_{r = r_w} \right] |
where
It characterises the pressure drop at well-reservoir contact due to well-reservoir contact geometry.
The geometrical skin is negative for fractured wells and slanted.
It also negative for horizontal wells when lateral permeability is not much lower than vertical.
The geometrical skin is positive for limited entry wells.
For the fractured vertical well the geometrical skin-factor
is related to Fracture half-length as: LaTeX Math Block |
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S_G = - \ln \left(\frac{X_f}{2\, r_w} \right) |
See Also
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Petroleum Industry / Upstream / Subsurface E&P Disciplines / Well Testing / Pressure Testing
[ Well & Reservoir Surveillance ] [ Skin-factor (total) ] [ Skin-factor (mechanical) ]