Small deviations variations of ambient formation pressure
from initial pressure formation lead to
the exponential changes in
porositypermeability:
| LaTeX Math Block |
|---|
|
k=k_0 \, e^{n_k \cdot c_r (p-p_0)} |
where
| formation compressibility |
| LaTeX Math Inline |
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| body | n_k = \frac{\ln (k/k_0)}{\ln(\phi/\phi_0)} |
|---|
|
| power degree of permeability-porosity correlation |
| formation permeability at reference pressure |
(usually picked up at initial reservoir |
| formation porosity at reference pressure |
= )i | reference pressure, usually picked up at initial formation pressure |
nk = \frac{\ln (k/k_0)}{\ln(\phi/\phi_0)}power degree of permeability-porosity correlation
The substantial reduction of formation pressure leads to shrinking a lot of numerous pore throats and massive reduction in permeability deviating from exponential.
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