# Valco - McCain correlation

## Contents

### Brief

Valco - McCain is an empirical correlation for the bubble point pressure published in 2003 [1].

### Math & Physics

$P_{bp} = e^{2.498 + 0.713 \alpha + 0.0075 \alpha^2}$[1]

where:

A0 = -4.814074834
A1 = 0.7480913 A2 = 0.1743556
A3 = 0.0206

$\alpha1 = A_0+ A_1 log(R_{sb}) + A_2 log^2(R_{sb}) - A_3 log^3(R_{sb})$

B0 = 1.27
B1 = 0.0449
B2 = 4.36e-4
B3 = 4.76e-6

$\alpha2 = B_0 - B_1 Y_{oil_API}+ B_2 Y^2_{oil_API} - B_3 Y^3_{oil_API}$

C0 = 4.51
C1 = 10.84
C2 = 8.39
C3 = 2.34

$\alpha3 = C_0 - C_1 SG_{g} + C_2 SG^2_{g} - C_3 SG^3_{g}$

D0 = -7.2254661
D1 = 0.043155
D2 = 8.55e-5
D3 = 6.00696e-8

$\alpha4 = D_0 + D_1 T - D_2 T^2 + D_4 T^3$
$\alpha = \alpha1 + \alpha2 + \alpha3 + \alpha4$

### Nomenclature

$A_0..A_{3}$ = coefficients
$B_0..B_{3}$ = coefficients
$C_0..C_{3}$ = coefficients
$D_0..D_{4}$ = coefficients
$P$ = 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

### References

1. Valkó, P. P.; McCain, W.D. (2003). . J. Pet. Sci. Eng. 37 (3–4): 153-169.