Petromium Tools / Formula set SURGE-SWAB-001
Surge & Swab
Steady-state tripping pressure screening · open and closed-end strings · V2.0
Moving-string pressure path
Run in hole · surge · surface
Open-hole pressure context
Running in hole · surge · surface
Figure data
| Quantity | Value |
|---|---|
| Bottom surge density (ppg) | 12.286 |
| Bottom swab density (ppg) | 11.714 |
| Cased depth (ft) | 3,500 |
| Total depth (ft) | 9,000 |
Trip-speed sensitivity
Effective density versus pipe speed · unsafe regions retained
Figure data
| Pipe speed (ft/min) | Surge ECD (ppg) | Swab ECD (ppg) |
|---|---|---|
| 0 | 12 | 12 |
| 30 | 12.14 | 11.86 |
| 60 | 12.218 | 11.782 |
| 90 | 12.286 | 11.714 |
| 120 | 12.378 | 11.622 |
| 150 | 12.496 | 11.504 |
| 180 | 12.644 | 11.356 |
| 210 | 12.82 | 11.18 |
| 240 | 13.013 | 10.987 |
| 270 | 13.222 | 10.778 |
| 300 | 13.445 | 10.555 |
Entered speed
90 ft/min
Pressure magnitude
133.6 psi
Surge density
12.286 ppg
Swab density
11.714 ppg
Calculated boundary
Not reached
Review · not an approval
Pressure-window snapshot
Bottom surge density
12.286 ppg
Fracture-boundary speed
Not reached
Pore-boundary speed
238 ft/min
Search ceiling
300 ft/min
Direction review
Displayed direction
Both directions are always calculated and retained in the audit. This selector changes presentation only.
Explicit user assumptions
Steady-state trip model
End condition and rheology
Surface-to-bottom intervals
Order rows from surface to bottom. Limits are optional and are never invented by the worksheet.
Interval result
7.6 psi · Re 1,271
Surge / swab 12.049 / 11.951 ppg
Interval result
67 psi · Re 1,386
Surge / swab 12.169 / 11.831 ppg
Interval result
59.1 psi · Re 2,590
Surge / swab 12.286 / 11.714 ppg
Calculation complete
Calculation audit
Pressure magnitude
134 psi
Governing boundary
238 ft/min
Surge density
12.286 ppg
Swab density
11.714 ppg
Calculation observations
BHA in open hole: transitional flow is represented by interpolation between the published regime boundaries.
No entered fracture boundary is reached within the declared speed-search range.
Equivalent annular velocity uses the entered clinging factor 0.45 and peak-velocity factor 1.5; neither factor is selected or calibrated by the worksheet.
Steady-state single-phase screening only. Acceleration, gels, compressibility, temperature/pressure rheology, cuttings, losses, influx, free-surface movement, and dynamic pressure waves are excluded.