Beggs and Robinson Oil Viscosity correlation

Brief

Beggs - Robinson is an empirical correlation for the oil viscosity published in 1975 .

Math & Physics

Dead oil viscosity:

$\mu_{od} = 10^x-1$

where:

$x = T^{-1.163} \times e^{(13.108-6.591/SG_{o})}$

Saturated oil viscosity:

$\mu_{os} = A \mu_{od}^B$

where:

$A = 10.715\ (R_s + 100)^{-0.515}$

$B = 5.44\ (R_s + 150)^{-0.338}$

Undersaturated oil viscosity:

$\mu_{o} = \mu_{os} (P/P_b)^m$

where:

$m = 2.6\ P^{1.187}\ e^{(-11.513-8.98 \times 10^{-5}\ P)}$

Nomenclature

$A$ = coefficient

$B$ = coefficient

$m$ = coefficient

$P$ = pressure, psia

$R_s$ = solution gas-oil ratio, scf/stb

$SG_o$ = oil specific gravity, dimensionless

$T$ = temperature, °F

$x$ = coefficient

$\mu$ = viscosity, cP

Subscripts

b - bubble point
od - dead oil
os - saturated oil
o - undersaturated oil