Sour Gas PVT Properties
Spreadsheet
34 rows x 4 columns
| A | B | C | D | |
|---|---|---|---|---|
| 1 | Sour Gas PVT Properties | |||
| 2 | Gas Composition | |||
| 3 | Gas Specific Gravity | 0.75 | dimensionless | |
| 4 | H2S Mole Fraction | 0.1 | fraction | |
| 5 | CO2 Mole Fraction | 0.05 | fraction | |
| 6 | Temperature | 200 | degF | |
| 7 | ||||
| 8 | Pseudo-Critical Comparison | Sweet | Sour | Difference |
| 9 | Ppc (psia) | 656.525 | 618.6296526 | 37.89534738 |
| 10 | Tpc (degR) | 389.7 | 368.9645573 | 20.73544267 |
| 11 | ||||
| 12 | Pressure Sweep (Sour) | |||
| 13 | P (psia) | Ppr | Tpr | Z |
| 14 | 500 | 0.808238011 | 1.788789701 | 0.9582508316 |
| 15 | 1000 | 1.616476022 | 1.788789701 | 0.924323699 |
| 16 | 2000 | 3.232952044 | 1.788789701 | 0.8908298696 |
| 17 | 3000 | 4.849428066 | 1.788789701 | 0.9074113749 |
| 18 | 4000 | 6.465904088 | 1.788789701 | 0.9600876156 |
| 19 | 5000 | 8.08238011 | 1.788789701 | 1.033027614 |
| 20 | ||||
| 21 | Gas Properties (Sour) | |||
| 22 | P (psia) | Bg (rcf/scf) | ρg (g/cc) | μg (cP) |
| 23 | 500 | 0.03577023482 | 0.02565439927 | 0.01338981886 |
| 24 | 1000 | 0.01725188994 | 0.05319207862 | 0.01435938456 |
| 25 | 2000 | 0.008313374894 | 0.1103840375 | 0.01720155206 |
| 26 | 3000 | 0.005645410868 | 0.1625504161 | 0.02085462058 |
| 27 | 4000 | 0.004479849942 | 0.2048425501 | 0.02473824377 |
| 28 | 5000 | 0.003856155311 | 0.2379737879 | 0.028498568 |
| 29 | ||||
| 30 | Z-Factor Comparison | |||
| 31 | P (psia) | Z sweet | Z sour | Error (%) |
| 32 | 1000 | 0.910406509 | 0.924323699 | -1.505661927 |
| 33 | 3000 | 0.8713662435 | 0.9074113749 | -3.972303227 |
| 34 | 5000 | 0.9944048424 | 1.033027614 | -3.738793737 |
Description
Calculate gas PVT properties for sour gas (containing H2S and CO2) using Wichert-Aziz pseudo-critical corrections. Compare sweet vs sour pseudo-critical properties and show how acid gas content affects Z-factor, Bg, density, and viscosity across a pressure range.
Key insight: Ignoring acid gas corrections overestimates pseudo-critical properties and produces incorrect Z-factors — especially dangerous for high H2S content where the error can exceed 10%.
Workflow
- Inputs: Gas gravity, H2S and CO2 mole fractions, temperature
- Step 1: Compute sweet and sour pseudo-critical properties (Standing + Wichert-Aziz)
- Step 2: Calculate pseudo-reduced properties at each pressure
- Step 3: Compute Z-factor (DAK) and downstream properties (Bg, ρg, μg)
- Output: Pressure-dependent gas property table with sour corrections applied
How to use this blueprint
- In Excel, go to the Petroleum Office ribbon tab and click Blueprint Manager
- Search for Sour Gas PVT Properties
- Click on the blueprint to preview the spreadsheet template
- Click Insert to place it into your worksheet. Modify the input values to match your data.