Isothermal Gas Compressibility (Cg)
Gas compressibility, or isothermal gas compressibility, is also called the coefficient of isothermal compressibility of gas. It is defined as the relative change in the volume of the gas with respect to the change in pressure at constant temperature.
At low pressures, gas compressibility is very high, which means that the gas can expand significantly to occupy a large volume at low pressure. This property is responsible for the high recovery factor from volumetric dry gas reservoirs.
Reference: Equations of State and PVT Analysis, Tarek Ahmed
Correlations
- 1-Hall-Yarborough
- 2-Dranchuk-Abou Kassem
Input Parameters
| Name | Input Value - Unit | Converted Value | Validity | Link to Calculation Page | |||
|---|---|---|---|---|---|---|---|
| Temperature | 610 | °R | |||||
| Pressure | 2100 | psi | |||||
| Compressibility Factor (Z-Factor) More Details | 0.88 | - | Gas Compressibility Factor (Z-Factor) | ||||
| 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-Hall-Yarborough | 0.0006 | 1/psi | |||||
| 2-Dranchuk-Abou Kassem | 0.000521 | 1/psi | |||||