Phase Behavior and ThermodynamicsFluid Properties
Live Oil Density from Formation Volume Factor Formula
Live Oil Density from Formation Volume Factor calculates live oil density for fluid properties workflows in phase behavior and thermodynamics.
How engineers use this formula
Use this formula when the listed inputs (rho_o_st, R_s, gamma_g, B_o) are known and the assumptions behind the cited fluid 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, rho_o equals 47.320505 lb/ft^3.
rho_o_stlb/ft^3
53.03063063063063
R_sSCF/STB
600
gamma_gdimensionless
0.75
B_obbl/STB
1.25
Inputs
rho_o_st
lb/ft^3Stock-Tank Oil Density
R_s
SCF/STBSolution Gas-Oil Ratio
gamma_g
dimensionlessGas Specific Gravity
B_o
bbl/STBOil Formation Volume Factor
Outputs
rho_o
lb/ft^3
Live Oil Density
rho_o_st
lb/ft^3
Stock-Tank Oil Density
R_s
SCF/STB
Solution Gas-Oil Ratio
gamma_g
dimensionless
Gas Specific Gravity
B_o
bbl/STB
Oil Formation Volume Factor
Source and review
reviewedScienceDirect Topics. Fluid Phase Behavior for Conventional and Unconventional Oil and Gas Reservoirs, Eq. 1.54.
Source