@wikipedia
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The explicit form of physical correlations is given by following analytical formula: | Jc | P_{cow} (s_w) = \frac{ (\sigma \cos \theta) _{ow} } { \sqrt \frac{k}{\phi}} \; J_{cow}(s_w) |
ccog} (s_g) = \frac{ (\sigma \cos \theta) |
^-1og} } { \sqrt \frac{k}{\phi}} \ |
, P_{c} (s)
where | oil-water surface tension | | oil-gas surface tension | | oil-gas contact angle | | oil-gas contact angle | | absolute permeability to air | | porosity | | some function of water saturation | | some function of gas saturation |
The functions and are called Leverett J-functions. They are individual to every certain rock type, just like relative permeability curves. There are many correlations for Leverett J-functions and the most popular is Brooks-Corey correlation: | LaTeX Math Block |
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| J_{cow}(s_w) = a \ ( s_{wn} )^{-1 / \lambda} |
where | LaTeX Math Inline |
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| body | s_{wn} = \frac {s_w - s_{wс}}{1-s_{wс}} |
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– normalised water saturation, – critical water saturation, – model parameters which are set for laboratory data on capillary pressure and/or on resistivity water saturation during SHF. Model parameter is related to the the size of the pore size distribution.The most popular value is 2 but it can vary to smaller or higher values.
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See also
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Petroleum Industry / Upstream / Subsurface E&P Disciplines / Petrophysics / Capillary pressure / Capillary pressure @model
