Wichert-Aziz Sour Gas Pseudo-Critical Correction Formula
Wichert-Aziz Sour Gas Pseudo-Critical Correction calculates corrected pseudo-critical temperature for gas properties workflows in phase behavior and thermodynamics.
How engineers use this formula
Use this formula when the listed inputs (T_pc_star, P_pc_star, y_CO2, y_H2S) are known and the assumptions behind the cited gas 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, T_pc_corr equals 349.264557 °R.
370
670
0.05
0.10
Inputs
T_pc_star
°RUncorrected Pseudo-Critical Temperature
P_pc_star
psiaUncorrected Pseudo-Critical Pressure
y_CO2
fractionCarbon Dioxide Mole Fraction
y_H2S
fractionHydrogen Sulfide Mole Fraction
Outputs
T_pc_corr
Corrected Pseudo-Critical Temperature
P_pc_corr
Corrected Pseudo-Critical Pressure
Source and review
reviewedWichert, E. and Aziz, K. 1971. Compressibility factor of sour natural gases, Canadian Journal of Chemical Engineering 49:267-273.
Source