Gas Reservoir p/z Analysis
Spreadsheet
30 rows x 4 columns
| A | B | C | D | |
|---|---|---|---|---|
| 1 | Gas Reservoir p/z Analysis | |||
| 2 | Initial Conditions | |||
| 3 | Initial Pressure (Pi) | 4500 | psia | |
| 4 | Initial Z-factor (Zi) | 0.92 | - | |
| 5 | Initial p/z | 4891.304348 | psi | |
| 6 | Abandonment Pressure | 500 | psia | |
| 7 | Z at Abandonment | 0.98 | - | |
| 8 | _1E9 | 1000000000 | (scf/Bscf conversion) | |
| 9 | Production History | |||
| 10 | Time (years) | Pressure (psia) | Z-factor | Gp (Bscf) |
| 11 | 0 | 4500 | 0.92 | 0 |
| 12 | 1 | 4200 | 0.925 | 5.5 |
| 13 | 2 | 3900 | 0.935 | 11.2 |
| 14 | 3 | 3600 | 0.945 | 17 |
| 15 | 4 | 3300 | 0.955 | 22.5 |
| 16 | 5 | 3000 | 0.965 | 28 |
| 17 | ||||
| 18 | p/z Analysis | |||
| 19 | Time (years) | p/z (psi) | OGIP Estimate (Bscf) | RF (fraction) |
| 20 | 0 | 4891.304348 | - | 0 |
| 21 | 1 | 4540.540541 | 76.6959799 | 0.07171171171 |
| 22 | 2 | 4171.122995 | 76.06779661 | 0.1472370766 |
| 23 | 3 | 3809.52381 | 76.86602871 | 0.2211640212 |
| 24 | 4 | 3455.497382 | 76.64982164 | 0.2935427574 |
| 25 | 5 | 3108.80829 | 76.83412322 | 0.3644214162 |
| 26 | ||||
| 27 | Summary | |||
| 28 | OGIP (average) | 76.62275002 | Bscf | |
| 29 | Ultimate RF | 0.89569161 | fraction | |
| 30 | Recoverable Reserves | 68.63035432 | Bscf |
Description
Perform p/z analysis for gas reservoirs to estimate OGIP (Original Gas in Place). The p/z vs Gp plot is linear for volumetric depletion, with x-intercept = OGIP.
Method:
- Plot p/z vs cumulative production (Gp)
- Extrapolate line to p/z = 0 to find OGIP
- Slope indicates reservoir behavior
How to use this blueprint
- In Excel, go to the Petroleum Office ribbon tab and click Blueprint Manager
- Search for Gas Reservoir p/z Analysis
- 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.