# Drilling Calculator for Rigs — Well Control, Kill Sheet, Mud

> Well Control, Kill Sheet, Mud (iPhone/iPad app by Aneesh Pradeep.)

- Source: https://appshunter.io/ios/app/drilling-calculator-for-rigs/id6785307917 (this page in markdown: same URL + `.md`)
- Developer: [Aneesh Pradeep](https://appshunter.io/developer/1836157821)
- Category: Utilities, Productivity
- Price: $1.99
- Age rating: 4+
- Requires: iOS 18.6 · 5 MB
- Languages: American English
- Released: 2026-07-06
- Data updated: 2026-08-17
- User reviews in markdown: https://appshunter.io/ios/app/drilling-calculator-for-rigs/id6785307917/reviews.md

## What is Drilling Calculator for Rigs?

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/


## Version history (last 2 releases)

### 4 — 2026-07-23

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

### 1.0 — 2026-07-06

No release notes.

## More apps by Aneesh Pradeep

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- [HIKE.SH - Hike and Trail Log](https://appshunter.io/ios/app/hikesh-hike-and-trail-log/id6758045678)
- [Terminal File Manager Advanced](https://appshunter.io/ios/app/terminal-file-manager-advanced/id6758665420)
- [Expense Tracker AI : SpendIQ](https://appshunter.io/ios/app/expense-tracker-ai-spendiq/id6758729622)

All apps by Aneesh Pradeep: https://appshunter.io/developer/1836157821

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*Data collected daily from the US App Store and indexed by [AppsHunter](https://appshunter.io/). User reviews are verbatim App Store reviews. Ratings, prices and chart positions refresh continuously; this snapshot is from 2026-08-17.*