In many practical cases the pore compressibility can be considered as independent on reservoir pressure variation: .

But in case the reservoir pressure is changing substantially one may need to account for the effect it takes on pore compressibility.

The model usually relates pore compressibility  to a given pressure   and initial pore compressibility  at initial formation pressure .



Name/AuthorScope
\displaystyle c_\phi(p) = c_{\phi i} \cdot \frac{ \ln \left( \frac{ p_n }{p_{\rm max}} \right)  }{ \ln \left( \frac{p_{ni}}{p_{\rm max}} \right)  }
p_n = p_{\rm min} + 1.75 \cdot \phi^{0.51} \cdot (p_{\rm max} - p) 
p_{ni} = p_{\rm min} + 1.75 \cdot \phi^{0.51} \cdot (p_{\rm max} - p_i)




Dobrynin



Sandstone

Wide pressure range: pmin = 1 MPa < p < pmax = 200 MPa


See also

Petroleum Industry / Upstream / Subsurface E&P Disciplines / Petrophysics / Geomechanical Rock Modelling / Pore compressibility


Pore Compressibility.xls