ppor
¶
- Group 1 - IPOROS
- Group 2 - JA, JB, JC, POR1, POR2, POR3, POR4
Input Variable | Format | Description |
---|---|---|
IPOROS | integer | Model type:
IPOROS = 1, aquifer compressibility model
IPOROS = -1, specific storage model (use
only for isothermal conditions)
IPOROS = -2, Gangi model (not available for
air-water-heat conditions)
|
Model (1): IPOROS = 1, | Aquifer compressibility
\(\phi = \phi_0 + \alpha_a(P-P_0)\) where
\(\alpha_a\) = aquifer compressibility (MPa-1),
\(\phi_0\) = initial porosity,
\(P_0\) = initial pressure (MPa)
|
|
POR1 | real | Aquifer compressibility \(\alpha (MPa^{-1})\) |
Model (-1): IPOROS = -1, | Specific storage
\(S_s = \rho(\alpha_a + \phi \beta)\) where
\(\rho\) = liquid density (kg/m3),
\(g\) = gravity,
\(\alpha_a\) = aquifer compressibility (MPa-1),
\(\phi\) = porosity,
\(\beta\) = liquid compressibility (MPa-1)
|
|
POR1 | real | Specific storage \(S_S (m^{-1})\) |
Model (-2): IPOROS = -2, | Gangi model with calculation of initial permeability
and porosity.
\(\phi = \phi_0 \left[ 1 - \left(\frac{P_c}{P_x}\right)^m \right]\)
and \(P_c = \sigma - P - \alpha E(T-T_0)\)
where
\(\phi_0\) = initial porosity,
\(m\) = Gangi exponent,
\(P_x\) = fitted parameter (MPa)
Note: for the Gangi model the permeability is varied by
\(k = k_0 \left(\frac{\phi}{\phi_0}\right)^3\)
|
|
POR1 | real | Exponent \(m\) in Gangi bed of nails model. |
POR2 | real | \(P_x\) parameter (MPa) in Gangi equation. |
POR3 | real | \(\sigma\) in-situ stress (MPa). |
POR4 | real | \((\sigma E)\) The product of the coefficient
of thermal expansion for the rock and the Young’s
modulus (MPa/C).
Note: For isothermal simulations the thermal term does not apply.
|
In the following example of ppor, aquifer compressibility is modeled. All nodes in the model are assigned a compressibility of 1.e-2 MPa-1.
ppor | |||
1 | |||
1 | 0 | 0 | 1.e-2 |
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