Phase Behavior and ThermodynamicsPVT Properties

Glaso Solution Gas-Oil Ratio from Saturated Oil FVF Formula

R_s=\frac{B_o^*-0.968T}{(\gamma_g/\gamma_o)^{0.526}}

Glaso Solution Gas-Oil Ratio from Saturated Oil FVF calculates solution gas-oil ratio for pvt properties workflows in phase behavior and thermodynamics.

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How engineers use this formula

Use this formula when the listed inputs (B_o, gamma_g, gamma_o, T) are known and the assumptions behind the cited pvt properties relationship match the engineering case being checked.

Assumptions

Input values are representative for the well, reservoir, fluid, or equipment case being evaluated.
The declared units match the field-unit constants used in the formula.
The cited formula applies to the selected petroleum engineering workflow.

Limitations

The calculation does not replace a full engineering model or operating procedure.
Accuracy depends on the source correlation, assumptions, input quality, and unit consistency.

Common mistakes

Mixing unit systems without converting the inputs.
Using default example values as field recommendations.
Applying the formula outside the source assumptions.

Default example

Using the default inputs, R_s equals 600 SCF/STB.

B_oRB/STB

1.3210909284519903

gamma_gfraction

0.8

gamma_ofraction

0.85

Tdeg F

180

Inputs

B_o

RB/STB

Saturated Oil Formation Volume Factor

gamma_g

fraction

Gas Specific Gravity

gamma_o

fraction

Stock-Tank Oil Specific Gravity

T

deg F

Reservoir Temperature

Outputs

R_s

SCF/STB

Solution Gas-Oil Ratio

A_glaso_fvf

dimensionless

Glaso Saturated Oil FVF Logarithmic Exponent

x_glaso_fvf

dimensionless

Glaso FVF Correlating-Parameter Logarithm

B_o_star

dimensionless

Glaso Oil Formation Volume Factor Correlating Parameter

B_o

RB/STB

Saturated Oil Formation Volume Factor

Source and review

reviewed

Oil Formation Volume Factor (Bo) Correlations, Glaso, O., Petroleum Office

Glaso, O. 1980. Generalized Pressure-Volume-Temperature Correlations, Journal of Petroleum Technology, SPE-8016-PA; Petroleum Office oil FVF correlations.

Source