Five stands short of a barrel is not a rounding error. It is the well telling you it is swabbing, and on a paper trip sheet that signal is buried in a column of numbers nobody totals until the trip is over. This runs the tally stand by stand, names the direction the discrepancy is running in, and says the word influx while there is still time to space out and flow check.
One-time purchase. No subscription. No account. Works offline on the rig floor.
No single stand looks wrong. A tenth of a barrel light, then two tenths, then three. It is only the running total that screams, and the paper sheet has no running total — it has a column you add up at the end of the trip, which is after the point where it mattered.
Dry or wet displacement, pipe or collars, the constant nobody can quite remember at three in the morning. Get the per-stand figure wrong once and every row after it is measured against the wrong target, so the sheet reads clean while the hole quietly takes the wrong volume.
Taking less than theoretical means something is filling that space for you. Taking more means you are losing it to the formation. Same column of numbers, opposite responses, and a tired hand reading a paper form is the only thing standing between the two.
Whatever you write it on ends up attached to the IADC report. A sheet that lives on a clipboard gets wet, gets lost, and gets rewritten from memory at the end of tour.
You enter the trip tank reading. That is the only thing you type per stand. The app already knows the theoretical fill because it worked it out from your hole size, pipe and collar dimensions and stand length, and it shows you that arithmetic in full — capacity, dry and closed-end displacement, annular capacity, all to six decimals with the formula printed beside each one.
Then every row carries its own theoretical cumulative, actual cumulative, per-stand difference and cumulative difference, so you can check any line against your own figures. A driller does not trust a number he cannot check, so nothing is hidden behind a verdict.
Hole size, casing or open-hole ID, pipe OD and ID, collar OD, ID and length, stand length and mud weight. It computes every capacity and displacement on the standard 1029.4 constant and shows the working.
Tripping out or tripping in, dry or wet. The sign convention flips with it and the app says on screen which mode is live, so a gain and a fill never get read as the same thing.
One number per row, plus a note if you want one. Theoretical, actual, per-stand and cumulative difference appear immediately, with the row colour-coded against your tolerance.
CSV for the morning report, and a print layout that comes off clean on a sheet of A4 so it can be signed and filed with the IADC report.
This is a volumetric trip sheet, not a well control simulator. It compares the mud you actually put in or took back against the volume the steel displaced, on the standard field-unit formulas, and flags the difference. It does not model swab and surge pressures, temperature or compressibility effects, ballooning, or the behaviour of the well after an influx is detected — the moment it flags a discrepancy the response belongs to your well control procedures and the person in charge, not to a phone. A worked example ships inside it, so before you put it on a live trip you can load a full ten-stand sheet on a 5-7/8" hole with 4-1/2" pipe and check the arithmetic against your own.
Built by people who have worked the lease. Oil Rigs Now has been making tools for oilfield professionals since 2011 — field-first, offline-first, and priced so a driller can expense it without asking anyone.
Everything stays on your device. Nothing is uploaded, no account is created, and the sheet keeps working when the rig has no bars.