Compressibility of multiphase fluid in thermodynamic equilibrium at a given pressure p and temperature T is a simple sum of its components:
(1) | c_f(p, T) = \sum_{\alpha} s_\alpha c_\alpha |
where
s_\alpha | \alpha-phase saturation, subjected to \sum_{\alpha} s_\alpha = 1 |
---|---|
c_\alpha = c_\alpha(p, T) | \alpha-phase compressibility as function of pressure p and temperature T |
In most popular practical case of a 3-phase fluid model this will be:
(2) | c_f = c_w \, s_w + c_o \, s_o + c_g \, s_g |
where {w, \, o, \, g} mean water phase, oil phase and gas phase.
See also
[Compressibility] [Compressibility (multi-phase fluid) @model]