Drilling Calculator for Rigs

Hydrostatic, kill sheet, MAASP and mud-weight window in seconds. Your active well pre-fills every calc, with an AI co-pilot grounded in your numbers. Field or SI.

DERRICK is a fast, accurate drilling and well-control calculator for the rig floor. Set up your well once and every calculator pre-fills from it, so you only change what is different today. Built for drilling engineers, toolpushers, company men, mud engineers, and students who need the right number under pressure.

• Your active well pre-fills every calculation. Less typing, fewer mistakes.
• Tap show your work on any result to see the formula with your exact numbers.
• Works fully on device. No account, no sign-in, no tracking.
• Field or SI units on every input and result.
• iPhone and iPad, with a purpose-built two-pane layout on iPad.

CALCULATORS

• Pressure and gradient: hydrostatic pressure, equivalent mud weight, equivalent circulating density, bottomhole pressure.
• Well control: kill mud weight, formation pressure, MAASP, LOT and FIT to EMW, kick tolerance, gas expansion.
• Hydraulics: pump output, annular velocity, strokes and lag, bit hydraulics.
• Volumes and capacities: pipe and hole capacity, annular capacity, pipe displacement, slug volumes.
• Mud and tubulars: weight up with barite, buoyancy factor, trip margin, and more.

MUD WEIGHT WINDOW

• See pore pressure, mud weight, ECD and fracture across the whole hole.
• Tap or drag the chart to read every value and your margins at any depth.

KILL SHEET

• Enter shut-in pressures and get kill mud weight, ICP, FCP and a step schedule.
• Automatic gas influx indication from the casing to drillpipe differential.

AI CO-PILOT

• Ask questions grounded in your active well and get clear, field-ready answers.
• Explain any calculation, interpret a kick, or draft an end of tour handover.
• Decision support only. It always defers to written procedure and the on-site supervisor.

HISTORY AND EXPORT

• Save any result to your well log with a note, then filter and search the log.
• See your activity heatmap and export clean reports.

Unlimited wells, the full history, export and reports, unlimited AI, and specialist modules like casing design.

PRIVACY

• Your wells and calculations stay on your device. No analytics, no ads, no tracking.

SAFETY

• DERRICK assists calculation. It does not replace your company well-control procedures, the well program, or the judgment of the on-site supervisor. Always verify independently before acting.

Terms of Use: https://www.apple.com/legal/internet-services/itunes/dev/stdeula/