Drilling Calculator for Rigs

About this app

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/

- Bug fixes and performance improvements. - No ads for a cleaner experience. - Enhanced app stability and reliability. - General improvements and optimizations.

Momentum comes from crawler snapshots for the tracked storefront. “Viral growth signal” means unusually fast recent rating gains; it is an indicator, not download data.

1. First observed Aug 8, 2026 · 5:34 PM $1.99