Leverett J-function

In petroleum engineering, the Leverett J-function is a dimensionless function of water saturation describing the capillary pressure,^[1]

J(S_{w})={\frac {p_{c}(S_{w}){\sqrt {k/\phi }}}{\gamma \cos \theta }}

where $S_{w}$ is the water saturation measured as a fraction, $p_{c}$ is the capillary pressure (in pascal), $k$ is the permeability (measured in m²), $\phi$ is the porosity (0-1), $\gamma$ is the surface tension (in N/m) and $\theta$ is the contact angle. The function is important in that it is constant for a given saturation within a reservoir, thus relating reservoir properties for neighboring beds.

The Leverett J-function is an attempt at extrapolating capillary pressure data for a given rock to rocks that are similar but with differing permeability, porosity and wetting properties. It assumes that the porous rock can be modelled as a bundle of non-connecting capillary tubes, where the factor ${\sqrt {k/\phi }}$ is a characteristic length of the capillaries' radii.

References

↑ M.C. Leverett (1941). "Capillary behaviour in porous solids". Transactions of the AIME (142): 159–172.

External links

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Leverett J-function

See also

References

External links