Valko - McCain bubble point pressure correlation

Brief

Valco - McCain correlation is ...

Math & Physics

$P_{bp} = e^{2.498 + 0.713 z + 0.0075 z^2}$

where:

$z1 = -4.814074834 + 0.7480913 log(R_{sb}) + 0.1743556 log^2(R_{sb}) - 0.0206 log^3(R_{sb})$

$z2 = 1.27 - 0.0449 Y_{oil_API}+ 0.000436 Y^2_{oil_API} - 0.00000476 Y^3_{oil_API}$

$z3 = 4.51 - 10.84 \times SG_{g} + 8.39 \times SG^2_{g} - 2.34 \times SG^3_{g}$

$z4 = -7.2254661 + 0.043155 \times T - 8.5548e-5 \times T^2 + 6.00696e-8 \times T^3$

$z = z1 + z2 + z3 + z4$

Nomenclature

$P$ = pressure, MPA

$P_{bp}$ = bubble point pressure, MPA

$R_s$ = oil gas ration, m3/m3

$SG_g$ = gas specific gravity, dimensionless

$T$ = temperature, °R

$Y_{oil_API}$ = oil API gravity, dimensionless