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Phase Behavior and ThermodynamicsPVT Properties

Glaso Saturated Oil Formation Volume Factor Formula

Bo=1+106.58511+2.91329log10(Bo)0.27683[log10(Bo)]2B_o=1+10^{-6.58511+2.91329\log_{10}(B_o^*)-0.27683[\log_{10}(B_o^*)]^2}

Glaso Saturated Oil Formation Volume Factor calculates saturated oil formation volume factor 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 (R_s, 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, B_o equals 1.321091 RB/STB.

R_sSCF/STB

600

gamma_gfraction

0.8

gamma_ofraction

0.85

T°F

180

Inputs

R_s

SCF/STB

Solution Gas-Oil Ratio

gamma_g

fraction

Gas Specific Gravity

gamma_o

fraction

Stock-Tank Oil Specific Gravity

T

°F

Reservoir Temperature

Outputs

B_o

RB/STB

Saturated Oil Formation Volume Factor

B_o_star

dimensionless

Glaso Oil Formation Volume Factor Correlating Parameter

A_glaso_fvf

dimensionless

Glaso Saturated Oil FVF Logarithmic Exponent

Source and review

reviewed

Glaso, O. 1980. Generalized Pressure-Volume-Temperature Correlations, Journal of Petroleum Technology, SPE-8016-PA.

Source

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