# C7+ Fraction Concentration (For Gas Condensates)

The heptane-plus fractions composition of original reservoir gas can be estimated using the initial producing gas/condensate ratio. Also when the well-stream gas composition data are not available, the C7+ fraction can be estimated using well-stream gas specific gravity.

The relationship between the composition of heptanes plus in percent and initial producing gas/condensate ratio is a power function.

References: Tools To Manage Gas/Condensate Reservoirs; Novel Fluid-Property Correlations on the Basis of Commonly Available Field Data, Ovalle, A. P., Lenn, C. P., & McCain, W. D. (2007) Two-Phase Compressibility Factors for Retrograde Gases, D. G. Rayes; L. D. Piper; W. D. McCain, Jr.; S. W. Poston

### Correlations

- 1-Rayes et al
- 2-Ovalle et al

### Input Parameters

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

Well Stream Specific Gravity | 0.85 | SG | |||||

Producing Gas/Condensate Ratio | 120000 | SCF/STB | This is the value at reservoir pressures above dew point. | ||||

CALCULATE | |||||||

## Results | |||||||

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

1-Rayes et al | 11.898 | % | |||||

2-Ovalle et al | 0.582 | % |