OGS

A gas pressure dependent intrinsic permeability model.
The model was proposed in [44] and it was further investigated in [45] .
The model takes the form of
\[\mathbf{k} = f(p_g)\, \mathbf{k}_0 = \left\{ \begin{array}{cc} (1+a_1 p_g) \mathbf{k}_0 & p_g \leq p_\text{thr} \\ (a_2 (p_g  p_\text{thr}) + 1 + a_1 p_\text{thr}) \mathbf{k}_0 & p_g > p_\text{thr} \end{array} \right.\]
where \(\mathbf{k}\) is the permeability, \(\mathbf{k}_0\) is the initial intrinsic permeability, \(p_g\) is the gas pressure, \(a_1\), \(a_2\) and \(p_\text{thr}\) are three parameters. The threshold pressure and gas pressure, \(p_g\) , \(p_\text{thr}\), are in Pascal, and the \(a_1\) and \(a_2\) are dimensionless, representing the values reported in [45], and permeabilities, \(\mathbf{k}\) and \(\mathbf{k}_0\) are in \(m^2\).
No additional info.
Used in no endtoend test cases.