Perforating Design Calculator
Calculate shot density, penetration depth, and flow efficiency for well completions
Perforating Parameters
Enter gun and formation properties
Shot Density Guidelines
- Low perm (<10 md): 12+ SPF
- Medium perm (10-100 md): 6-12 SPF
- High perm (>100 md): 4-6 SPF
- Gravel pack: 12-18 SPF
Perforating Results
Enter parameters and click Calculate
Typical Gun Performance
| Gun Size | Max SPF | API Pen (in) | Hole Dia (in) |
|---|---|---|---|
| 2-1/8" | 6 | 8-12 | 0.25-0.30 |
| 3-3/8" | 6 | 15-20 | 0.35-0.45 |
| 4-1/2" | 12 | 25-35 | 0.40-0.55 |
| 7" | 27 | 35-45 | 0.60-0.80 |
Formula Reference
Formation Penetration Estimate
L_form = L_api x (UCS_concrete / UCS_formation)^0.5
Typical UCS_concrete = 6,000 psi
Sandstone: 2,000 - 8,000 psi
Limestone: 5,000 - 20,000 psi
Flow Efficiency (Karakas-Tariq)
PR = (ln(re/rw) + S) / (ln(re/rw) + Sp)
Where:
Sp = Perforation skin
S = Formation skin
re = Drainage radius
rw = Wellbore radius