PROPERTIES OF BLACK OILS - Petroleum Reservoir Fluid Property Correlations - page 105

Beggs and Robinson used approximately one-half of the data
described in table 3-22 in preparation of their correlation equations. 43
Hanafy et al. used approximately one-half of the table 3-22 data in
preparing their correlation equations. 44 The other researchers apparently
did not use any of these data.
Equations (3.23a)-(3.23e) are recommended for use at reservoir
pressures equal to bubblepoint pressure with R sb substituted for R s in
equations (3.23d) and (3.23e). 45

Evaluation of proposed correlation equations for reservoir
oil viscosities at reservoir pressures equal to and less than
bubblepoint pressure
Statistics of the data set used to evaluate reservoir oil viscosity
correlation equations for reservoir pressures equal to and less than
bubblepoint pressures are given in table 3-24.

Table 3-24. Statistics of data set used to evaluate reservoir oil viscosity correlation equations
at reservoir pressures equal to and less than bubblepoint pressures (1,123 lines of data from 184
reservoir fluid studies with worldwide origins)
Laboratory measurement Minimum Median Mean Maximum

Bubblepoint pressure, p b , psia 120.7 1,669.7 1,809.0 5,311.7

Pressure, p , psia 41.7 1,114.7 1,288.2 5,311.7

Reservoir temperature, T R , ºF 107.0 193.0 197.4 320.0

Stock-tank oil gravity, API , ºAPI 15.8 35.0 34.3 57.7

Separator gas specific gravity, γ gSP 0.6506 0.8579 0.8908 1.3033

Solution gas-oil ratio at p b , R sb , scf/STB 12.3 378.0 349.6 1,534.0

Reservoir oil density, ρ oR , lb/cu ft 34.27 46.32 46.48 57.42

Reservoir oil viscosity, μ oR , cp 0.167 0.728 4.2 157.6

Solution gas-oil ratio, R s , scf/STB 4.0 287.0 456.8 1,534.0

An evaluation of the published correlation equations for reservoir
oil viscosities at reservoir pressures equal to and less than bubblepoint
pressures is shown in table 3-25.
Beggs and Robinson and Kartoatmodjo and Schmidt used essentially
all of the data described in table 3-24 in preparation of their correlation
equations. 46 It is not known if the other researchers had access to
these data.