Well volumes & circulation time
Annular and string volumes section by section, then the strokes and the minutes to bottoms-up and to a full circulation.
Drilling
MAASP & fracture gradient from LOT / FIT
Turn a leak-off or integrity test into a fracture gradient, a maximum allowable mud weight and the surface pressure the shoe will take.
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How it is calculated
- Formation strength at the shoe = 0.052 × test mud weight × shoe TVD + surface test pressure.
- Fracture gradient = strength / shoe TVD; equivalent mud weight = gradient / 0.052.
- MAASP = (maximum allowable MW − current MW) × 0.052 × shoe TVD, with the allowable MW reduced by whatever safety margin you set.
- Kick tolerance is expressed as the equivalent mud weight at total depth that the shoe can still support.
Standards it speaks
Where this stops being true
The test measures the weakest point exposed at the time it was run, which is usually just below the shoe but not always — an unseen weak bed deeper in the open hole will fail first and this number will not warn you. Leak-off also changes after the hole has been open for days, and ballooning formations give a leak-off that is partly elastic and partly real. Re-test rather than re-use an old number on a long open-hole section.
The capability that automates this
- DR-02Early Kick Detection & Well ControlA kick is formation fluid entering the wellbore. Left unchecked it becomes a blowout. This watches eleven sensor streams and warns the crew minutes earlier than pit-volume alarms do.
- DR-04Wellbore Stability PredictionPredicts the mud weight window that keeps the hole open — not too light and it caves, not too heavy and it fractures.
Related tools
ECD & bottom-hole circulating pressure
Annular pressure loss, flow regime and the equivalent circulating density the formation actually sees while the pumps are running.
Bit hydraulics & nozzle selection
Total flow area, nozzle pressure drop, HSI and jet impact force — plus the nozzle size that would put the optimum share of pump pressure at the bit.
Directional survey — minimum curvature
Paste MD, inclination and azimuth and get TVD, northings, eastings, dogleg severity, vertical section and closure — with the well path drawn.