# McCain Oil Formation Volume Factor equation

## McCain Oil Formation Volume Factor equation

McCain equation is determined from material balance equation based on the definition of the oil formation volume factor[1].

McCain Oil Formation Volume Factor equation in the PVT Software

## Math & Physics

$B_o = \frac{\rho_{STO}+1.22117\ R_s\ SG_g}{\rho_{oR}}$[2]

## Example. Calculation of the oil formation volume factor

Example source [3]

### Input data

$R_s$ = 53.24 sm3/sm3 at P = 10 MPa
$SG_o$ = 0.85 or 35 API
$SG_g$ = 0.75
$\rho_{oR}$ = 749 kg/m3 at P = 10 MPa

Calculate oil formation oil factor at p = 10 MPa?

### Solution

$B_o$ = 1.199 rm3/sm3

The solution is available in the online PVT calculator software model at www.pengtools.com

## Application range

$2.35 \le R_s \le 322$
$0.754 \le SG_o \le 0.989$
$0.555 \le SG_g \le 1.245$
$21.1 \le T, C \le 160$

## Nomenclature

$B_o$ = oil formation volume factor, rm3/sm3
$R_s$ = solution gas-oil ratio, sm3/sm3
$SG_g$ = gas specific gravity, dimensionless
$SG_o$ = oil specific gravity, dimensionless
$\rho_{oR}$ = oil density at reservoir conditions, kg/m3
$\rho_{STO} = SG_o \times 1000$ = stock tank oil density, kg/m3

## References

1. McCain, W.D. Jr. (1990). Properties of Petroleum Fluids (2 ed.). Oklahoma: PennWell Corp. ISBN 978-0878143351.
2. Afanasyev, Vitaliy; Moskvin, Igor; Wolcott, Ken; McCain, W.D. (2004). "Practical PVT Calculations for black oils". YUKOS publication.
3. Wolcott, Don (2009). . Houston: Energy Tribune Publishing Inc.