Drilling cost per metre
Cost per metre of a bit run: the bit cost plus the rig time (rotating, connections, trip), divided by the footage; rate of penetration and cost of the run.
C = (C_b + C_r · (t_r + t_c + t_t) / 24) / ΔHv_m = ΔH / t_rEnter money in any currency — the result is in the same currency. Pull the bit when the running cost per metre stops falling. When comparing bits, use the trip time for the same depth.
Source: Bourgeois et al., Applied Drilling Engineering (SPE, 1986), ch. 1: the drilling cost equation
Inputs
You can change a field's unit: the value is converted to the formula's units automatically.
Rig plus the services paid by time.
Unit converter for this formulaTime · Length · Velocity
- s1
- min0.0166667
- h0.000277778
- d1.15741·10⁻⁵
- yr3.17098·10⁻⁸
A day is 24 h, a year 365 days.
- C_ft — Cost per foot–KZT/ft
- v_m — Rate of penetration–
- C_run — Cost of the run–KZT
Results are engineering estimates from standard formulas; for design decisions check them against the codes, project documents and specialists' calculations. The formulas carried over from the original set are unchanged, and their errors are described in the notes.