Gas condensate
Gas condensate: light hydrocarbon fractions entrained in gas production which condense into liquid when brought to the surface. Changes in reservoir pressures as result of production may cause it to condense in the reservoir, when much of it may become irrecoverable.
Phase diagram
The phase diagram for gas condensate shows that as we move to higher and higher representations of lighter components, the phase envelope contracts and the critical point continues to move counter-clockwise.
The reservoir initial pressure and temperature (point 1) are to the right of the critical point, indicating that this is a gas. As the pressure reduced, we now hit the dew point line rather than the bubble point line. As pressure continues to drop we observe the retrograde condensation phenomenon.
Characteristics
| Reservoir state | gas |
| Initial GOR | between 3300 and 50,000 scf/STB |
| Producing GOR | increases when reservoir pressure drops below dew point |
| Initial STO (McCain) | greater than 40o API, increases when Pres less than dew point |
| Color | usually light color, orange, green, or nearly colorless |
| C7+ Mole Fraction | less than 12.5% |