# Gas Compressibility Factor (Z-Factor)

The compressibility factor (Z) corrects for deviation from the ideal gas law. The compressibility factor is calculated using an equation of state or industry correlation.

For an ideal gas, the value of Z is 1 at all states. For real gases, Z is a function of the state.

Reference: Natural Gas Measurement Handbook, James E. Gallagher

### Correlations

- 1-Papay
- 2-HALL-YARBOROUGH
- 3-Dranchuk-Abu Kassem
- 4-Heidaryan
- 5-Brill-Beggs

### Input Parameters

Name | Input Value - Unit | Converted Value | Validity | Link to Calculation Page | |||
---|---|---|---|---|---|---|---|

Temperature | 619.67 | °R | |||||

Pressure | 3500 | psi | |||||

Average Surface Gas Specific Gravity | 0.7 | SG | |||||

Pseudo Properties Calculation Method | 2 | ||||||

Pseudo Critical Properties Correction Method | 2 | ||||||

N2 Content | 0 | % | |||||

CO2 Content | 5 | % | |||||

H2S Content | 10 | % | |||||

CALCULATE | |||||||

## Results | |||||||

Correlation | Calculated Value | Warnings | Remarks | ||||

1-Papay | 0.843 | - | This is a direct method to calculate Z-Factor | ||||

2-HALL-YARBOROUGH | 0.832 | - | For pseudo critical pressure (Ppr) range from 0.2 to 25 For pseudo critical temperature (Tpr) range from 1.0 to 3 | ||||

3-Dranchuk-Abu Kassem | 0.833 | - | For pseudo critical pressure (Ppr) range from 0.2 to 15 For pseudo critical temperature (Tpr) range from 1.0 to 3 | ||||

4-Heidaryan | 0.852 | - | This is a direct method to calculate Z-Factor For pseudo critical pressure (Ppr) range from 0.2 to 15 For pseudo critical temperature (Tpr) range from 1.2 to 3 | ||||

5-Brill-Beggs | 0.825 | - |