Beggs and Robinson correlation

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Brief

Beggs and Robinson is an empirical correlation for the oil viscosity published in 1975 [1].


Oil viscosity in the PVT Tool

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 (P < Pb):

\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 (P > Pb):

\mu_{o} =  \mu_{os} (P/P_b)^m [2]

where:

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

Discussion

Application range

Description of the Data Used[1]:

  20 \le R_s \le 2,070
  0.75 \le SG_o \le 0.96
  0 \le P \le 5250
  70 \le T \le 295

Number of oil systems = 600
Number of dead oil observations = 460
Number of live oil observations = 2,073

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

References

  1. 1.0 1.1 Beggs, H. D.; Robinson, J. R. (September 1975). "Estimating the Viscosity of Crude Oil Systems"Free registration required. Journal of Petroleum Technology. 27(09) (SPE-5434-PA). 
  2. Vazquez, M.; Beggs, H.D. (1980). "Correlations for Fluid Physical Property Prediction."Free registration required. Society of Petroleum Engineers (SPE-6719-PA).