Results appear here.
Formula (API RP 9B round trip)
- Round-trip ton-miles = [Wp × D × (Ls + D) + 4 × D × (M + ½C)] ÷ 10,560,000
- Wp = buoyed weight per foot of drill pipe (lb/ft)
- D = depth (ft), Ls = average stand length (ft), M = travelling assembly weight (lb)
- C = buoyed weight of BHA minus buoyed weight of the same length of drill pipe (lb)
- Buoyancy factor = (65.5 − mud weight in ppg) ÷ 65.5
Frequently asked questions
Why track ton-miles?
Drilling line wears in proportion to the work done on it. Tracking ton-miles tells the crew when to slip and cut the line.
Does this include drilling and casing ton-miles?
No. This calculator covers a round trip. Drilling, coring, short trips and running casing are calculated with separate formulas.
Do this automatically
DrillX captures the tour sheet on the rig floor and produces daily drilling reports, lost-time analysis and 36 drilling documents in Arabic and English, offline.