Drilling Calculator for Rigs
Well Control, Kill Sheet, Mud
Free · In‑App Purchases · Designed for iPad. Not verified for macOS.
Mud weight and your margins to pore and fracture on the cover screen. Hydrostatic, kill sheet, MAASP and the window, pre-filled from your active well. No Ads. Local Data
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/
Ratings & Reviews
- This app hasn’t received enough ratings or reviews to display an overview.
HOME SCREEN WIDGET
- Active well mud weight at a glance
- Margin to pore and fracture
- Highlights a thin margin
- Flags a well you have not updated in days
- Small and medium sizes
TODAY'S NUMBERS, FASTER
- Update depth and mud weight straight from the dashboard
- No need to open the full well editor
- Warning when a well has not been updated in days
- A blank field never resets a well to zero
SAFETY
- Dashboard flags a thin margin to pore or fracture
- Warning when a gradient profile has fracture at or below pore
- Calculators reject text, infinity and overflowing numbers
- A result that cannot be computed shows a dash, never a wrong number
CALCULATORS
- Pin the tools you run every tour to the top
- Run Again reopens a saved result with today's well numbers
- Undo a save for a few seconds after it lands in the log
- Tool descriptions no longer cut off mid sentence
- Category chips no longer clipped
WELLS
- Import a pore and fracture gradient profile from CSV
- Comma, semicolon and tab separated files all work
- Header row optional
- Quoted values and thousands separators handled
- Skipped rows are reported, never dropped silently
- Warns when pore and fracture columns look swapped
SIRI AND SHORTCUTS
- Ask for your active well status by voice
- Open Derrick on a chosen screen
- derrick:// links now open the right screen
IPAD
- Sidebar returns correctly when you rotate
- Portrait no longer covers the dashboard
- Keyboard shortcuts are now named in the command menu
- Onboarding centred instead of pinned to one corner
HISTORY
- Notes save when you leave the screen
- Unit system shown on every saved result
- Exports state which unit system the figures are in
- Just now instead of a cryptic timestamp
SUBSCRIPTION
- Every plan visible on one screen
- View All Plans in Settings at any time, subscribed or not
- Current plan marked, switch plans in one tap
- Restore Purchases gives clear on-screen feedback
- Real prices for your region, never a placeholder
THROUGHOUT
- The app is now called Derrick
- Plain button names across every screen
- Large text sizes no longer clip pricing or legal text
Subscriptions
The developer, Aneesh Pradeep, indicated that the app’s privacy practices may include handling of data as described below. For more information, see the developer’s privacy policy .
Data Not Collected
The developer does not collect any data from this app.
Accessibility
The developer has not yet indicated which accessibility features this app supports. Learn More
Information
- Seller
- Aneesh Pradeep
- Size
- 7.5 MB
- Category
- Utilities
- Compatibility
Requires iOS 18.6 or later.
- iPhone
Requires iOS 18.6 or later. - iPad
Requires iPadOS 18.6 or later. - Mac
Requires macOS 15.6 or later and a Mac with Apple M1 chip or later. - Apple Vision
Requires visionOS 2.6 or later.
- iPhone
- Languages
- English
- Age Rating
4+
- 4+
- In-App Purchases
Yes
- DERRICK Pro — Annual $49.99
- DERRICK Pro — Monthly $6.99
- Copyright
- © Aneesh Pradeep