Model cuttings movement in annular flow with confidence. Choose slip models and apply corrections easily. Export results for reports, audits, and field decisions today.
| Time | Hole/Pipe (in) | Flow (gpm) | Mud (ppg) | Cut Size | Incl (°) | Model | CTR (%) | Status |
|---|---|---|---|---|---|---|---|---|
| No saved calculations yet. | ||||||||
| Hole ID (in) | Pipe OD (in) | Flow (gpm) | Mud (ppg) | PV / YP | Cut Size | Incl (°) | Model | CTR (%) | Status |
|---|---|---|---|---|---|---|---|---|---|
| 8.5 | 5.0 | 450 | 10.5 | 25 / 15 | 0.20 in | 0 | General | ~70 | Excellent |
| 12.25 | 5.5 | 500 | 11.8 | 30 / 20 | 6 mm | 30 | General | ~55 | Good |
| 6.125 | 4.0 | 220 | 9.8 | 18 / 10 | 0.12 in | 60 | Stokes | ~35 | Marginal |
Cuttings transport improves as annular velocity rises. The calculator converts flow and annular area into velocity, so small diameter changes can shift results sharply. For example, reducing pipe OD increases annular area less than increasing hole ID, so velocity may fall even with the same pump rate. Many drilling programs track 120–200 ft/min in vertical intervals, then reassess in high-angle sections. Monitor both geometry inputs and pump rate together.
Plastic viscosity and yield point influence apparent viscosity through a shear-rate estimate. Higher apparent viscosity lowers predicted slip velocity and generally raises the transport ratio. However, very high PV can increase circulating pressures and ECD, so improvements should be balanced against hydraulic limits. Use measured PV and YP from the active system for best consistency. Update inputs after each mud treatment or dilution cycle.
Larger or denser cuttings settle faster and demand more lift. The tool accepts cuttings size in inches or millimeters and converts internally for stable calculations. If density is close to fluid density, slip becomes small and transport improves. When using the general drag option, the calculation iterates drag to handle a wider Reynolds-number range. Stokes is best reserved for small particles and low-Re laminar settling.
Inclination reduces effective lifting because gravity acts against upward transport in deviated sections. A rotation factor can represent improved agitation and bed breakup, while an eccentricity factor can adjust for off-center pipe behavior. These are optional because their influence is field dependent. Apply them only when you can justify a calibrated factor. Record which factors were applied when exporting results for traceability.
CTR represents the fraction of effective annular velocity available after slip. Values above 70% suggest strong cleaning, 55–70% is typically good, and below 40% signals risk of beds and packoff. Pair CTR with torque, drag, and cuttings returns to validate the trend. Use the target CTR feature to estimate the pump rate needed to reach a chosen threshold, then evaluate whether that rate is operationally feasible. Document assumptions, then rerun scenarios during changing drilling conditions.
It estimates how much of the effective annular velocity remains after subtracting cuttings slip velocity. Higher values indicate better lifting capacity and reduced bed formation risk, assuming the inputs reflect current geometry, flow, and mud properties.
Use the general drag option for most field cases because it adapts across a wider settling regime. Use the laminar option only when particles are small and Reynolds number is expected to be low.
In deviated holes, gravity promotes settling and bed development. The inclination factor lowers effective lifting velocity to reflect this challenge. It is a simplified correction, so calibrate it against observed cuttings returns and downhole conditions.
It is a directional estimate based on the same slip model and correction factors you selected. Treat it as a planning number, then validate with hydraulics, pressure limits, ECD, and surface trends before changing pump rates.
Annular velocity and cuttings size typically dominate, followed by mud density and viscosity. Small geometry changes can shift velocity strongly, so verify hole and pipe sizes, then update PV and YP from the latest mud report.
Yes. Download the current result or the saved history as CSV, and generate a PDF from the on-page buttons. Keep the same assumptions and factors across runs to maintain consistent comparisons between intervals.
Important Note: All the Calculators listed in this site are for educational purpose only and we do not guarentee the accuracy of results. Please do consult with other sources as well.