Reservoir EngineeringPVT Properties
Two-Phase Formation Volume Factor Formula
Two-Phase Formation Volume Factor calculates two-phase formation volume factor for pvt properties workflows in reservoir engineering.
How engineers use this formula
Use this formula when the listed inputs (B_o, B_g, R_soi, R_so) 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_t equals 2.2 bbl/STB.
B_obbl/STB
1.2
B_gbbl/SCF
0.005
R_soiSCF/STB
800
R_soSCF/STB
600
Inputs
B_o
bbl/STBOil Formation Volume Factor
B_g
bbl/SCFGas Formation Volume Factor
R_soi
SCF/STBInitial Solution Gas-Oil Ratio
R_so
SCF/STBCurrent Solution Gas-Oil Ratio
Outputs
B_t
bbl/STB
Two-Phase Formation Volume Factor
B_o
bbl/STB
Oil Formation Volume Factor
B_g
bbl/SCF
Gas Formation Volume Factor
R_soi
SCF/STB
Initial Solution Gas-Oil Ratio
R_so
SCF/STB
Current Solution Gas-Oil Ratio
Source and review
reviewedPetroWiki. Two-phase formation volume factor.
Source