Six calculators a field engineer actually reaches for — running live in your browser, free, no sign-up. Each one shows the formula and the standard behind it, so you can see exactly where the number comes from. Measured, not guessed.
Enter the basket stroke and speed to get the G-force the deck is actually developing. Most decks target 4–8 G; below that, conveyance and screen life suffer.
in
rpm
0 G
G-force developed at the basket
—
Formula & reference
G = RPM² × stroke(in) ÷ 70,400
(stroke = total throw; mm ÷ 25.4 → in)
Standard vibratory-screen relation; target 4–8 G typical for linear-motion shakers per OEM/API RP 13C practice. Confirm the OEM rating for your specific deck.
Mass-balance dilution relation (API RP 13C / SPE solids-control practice). Whole-mud dilution then needs weight-up — see the barite calculator. Equipment removal is always cheaper than dilution.
API 13B weight-up relation, barite SG 4.2 → 35.0 ppg. W in ppg. Volume gain dilutes other properties — re-check rheology and chemistry after weight-up.
Desanders and desilters are designed around a feed head — not just a pressure. Enter manifold pressure and mud weight to see the head you're actually feeding. Target ≈ 75 ft.
psi
ppg
0 ft
feed head delivered to the cones
—
Formula & reference
Head(ft) = P(psi) ÷ (0.052 × MW(ppg))
Target operating head ≈ 75 ft (desander & desilter)
Hydrocyclones are head-driven devices; OEMs specify ~75 ft of feed head for correct cut. Too low → poor separation; too high → premature cone wear. Verify against your cone OEM curve.
Fluid velocity in a transfer line or in the annulus. Annular velocity must beat cuttings slip velocity to lift solids; transfer lines have their own erosion/settling windows.
Standard field hydraulics relations. Annular velocity must exceed cuttings slip velocity (commonly ~100–120 ft/min minimum) for effective hole cleaning; slip velocity itself depends on rheology and cutting size.
Pick an API screen designation to see its separation cut-point and what it removes — and where you start losing barite. Finer than ~API 200 begins taking weighting material out.
75 µm
approximate D100 separation cut-point
—
API No.
Cut-point
Removes
API 40
420 µm
Coarse — gravel/large cuttings
API 60
250 µm
Coarse sand
API 80
180 µm
Medium sand
API 100
150 µm
Medium sand
API 120
125 µm
Fine sand
API 140
106 µm
Fine sand
API 170
90 µm
Very fine sand
API 200
75 µm
Coarse silt / barite-friendly
API 230
63 µm
Silt
API 270
53 µm
Fine silt
API 325
45 µm
Fine silt — barite recovery limit
Formula & reference
API RP 13C screen designation ↔ d100 separation potential (microns).
Barite median ≈ 10–75 µm → screens finer than ~API 200 start removing barite.
API RP 13C (ISO 13501) screen labelling. Cut-points are nominal separation potentials; actual performance depends on G-force, conveyance, mud rheology and screen condition.
These calculators are field aids for quick checks and decisions, not a substitute for a full engineering review. Results depend on the inputs you give and on assumptions noted under each tool. For anything load-bearing — a weight-up programme, a dilution plan, a hydrocyclone or shaker set-up on a live well — have it validated against your actual fluid, equipment and well conditions.
Numbers point one way — your rig may be another
These tools tell you what the formulas say. A field evaluation tells you what your shakers, hydrocyclones, centrifuge and mud system are actually doing — and what to change. That's the engineering.
