Vasquez-Beggs Bubble Point Pressure from Solution GOR Formula
Vasquez-Beggs Bubble Point Pressure from Solution GOR calculates bubble point pressure for pvt properties workflows in phase behavior and thermodynamics.
How engineers use this formula
Use this formula when the listed inputs (R_sb, T, API, gamma_g, C_pb1, C_pb2, C_pb3) 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, p_b equals 2,500 psi.
569.1641063395102
180
35
0.8
0.0178
1.187
23.931
Inputs
R_sb
SCF/STBSolution Gas-Oil Ratio at Bubble Point
T
°FReservoir Temperature
API
APIOil API Gravity
gamma_g
fractionGas Specific Gravity
C_pb1
dimensionlessVasquez-Beggs C1 Coefficient (0.0178 if API > 30; 0.0362 if API <= 30)
C_pb2
dimensionlessVasquez-Beggs C2 Coefficient (1.1870 if API > 30; 1.0937 if API <= 30)
C_pb3
dimensionlessVasquez-Beggs C3 Coefficient (23.931 if API > 30; 25.724 if API <= 30)
Outputs
p_b
Bubble Point Pressure
R_sb
Solution Gas-Oil Ratio at Bubble Point
Source and review
reviewedVasquez and Beggs 1980 oil PVT correlations, as summarized in IHS Harmony / WellTest documentation and PIPESIM fluid-property documentation.
Source