Phase Behavior and ThermodynamicsPVT Properties
Van der Waals Covolume from Critical Properties Formula
Van der Waals Covolume from Critical Properties calculates van der waals covolume parameter for pvt properties workflows in phase behavior and thermodynamics.
How engineers use this formula
Use this formula when the listed inputs (R, T_c, P_c) 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_vdw equals 0.689831 ft^3/lbmol.
Rpsi*ft^3/(lbmol*R)
10.7316
T_cR
343
P_cpsi
667
Inputs
R
psi*ft^3/(lbmol*R)Gas Constant
T_c
RCritical Temperature
P_c
psiCritical Pressure
Outputs
b_vdw
ft^3/lbmol
van der Waals Covolume Parameter
R
psi*ft^3/(lbmol*R)
Gas Constant
T_c
R
Critical Temperature
P_c
psi
Critical Pressure
Source and review
reviewedEngineering LibreTexts, Phase Relations in Reservoir Engineering, Section 7.04: The van der Waals Equation.
Source