Leverett J-function explained
In petroleum engineering, the Leverett J-function is a dimensionless function of water saturation describing the capillary pressure,[1]
}where
is the water saturation measured as a fraction,
is the
capillary pressure (in
pascal),
is the
permeability (measured in
m²),
is the
porosity (0-1),
is the
surface tension (in N/m) and
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
is a characteristic length of the capillaries' radii.
This function is also widely used in modeling two-phase flow of proton-exchange membrane fuel cells.[2] A large degree of hydration is needed for good proton conductivity while large liquid water saturation in pores of catalyst layer or diffusion media will impede gas transport in the cathode.
J-function in analyzing capillary pressure data is analogous with TEM-function[3] [4] in analyzing relative permeability data.
See also
External links
- http://www.ux.uis.no/~s-skj/ResTek1-v03/Notater/Tamu.Lecture.Notes/Capillary.Pressure/Lecture_16.ppt
- http://perminc.com/resources/fundamentals-of-fluid-flow-in-porous-media/chapter-2-the-porous-medium/multi-phase-saturated-rock-properties/averaging-capillary-pressure-data-leverett-j-function/
- Leverett J-Function in Multiphase Saturated Rocks
Notes and References
- M.C. Leverett. Capillary behaviour in porous solids. Transactions of the AIME. 142. 159–172. 1941.
- J. M. LaManna, J. V. Bothe Jr., F. Y. Zhang, and M. M. Mench, J. Power Sources 271, 180 (2014).
- 10.1016/j.petrol.2019.04.044. New technique of True Effective Mobility (TEM-Function) in dynamic rock typing: Reduction of uncertainties in relative permeability data for reservoir simulation. 2019. Mirzaei-Paiaman. Abouzar. Saboorian-Jooybari. Hadi. Chen. Zhangxin. Ostadhassan. Mehdi. Journal of Petroleum Science and Engineering. 179. 210–227. 149962022 .
- 10.1016/j.ptlrs.2020.06.003. A new framework for selection of representative samples for special core analysis. 2020. Mirzaei-Paiaman. Abouzar. Asadolahpour. Seyed Reza. Saboorian-Jooybari. Hadi. Chen. Zhangxin. Ostadhassan. Mehdi. Petroleum Research. 5. 3. 210–226. free.