Workover and well servicing
Kill fluid density and volume, tubing and annulus volumes, circulation time, tubing weight in fluid and hook load, stuck point depth from pipe stretch.
14 calculators
Well killing
Volumes and circulation
Tubing volume, annulus volume down to the tubing shoe, casing volume from the shoe to the bottom, total fluid volume, the kill fluid volume and the reserve required by the rules.
V_t = π/4 · d_i² · L; V_a = π/4 · (D² − d_o²) · LFull circulation time through the tubing, the time for fluid to rise from the tubing shoe to surface in direct and reverse circulation, and the upward velocities in the annulus and in the tubing.
V_t = π/4 · d_i² · L; V_a = π/4 · (D² − d_o²) · LTubing and stuck pipe
Length of the free pipe above the stuck point from the stretch measured for an increase in pull — an estimate of where tubing or drill pipe is stuck.
L = E · A · ΔL / ΔFStretch of a freely hanging string from an axial pull, from its own weight in fluid and from a temperature change, and the thermal force in a string fixed at both ends (e.g. on a packer).
A = π/4 · (D² − (D − 2t)²)Volume of a spotting fluid (oil, water or acid) that covers the stuck zone in the annulus with a reserve inside the pipe, the displacement volume, and the drop in bottomhole pressure caused by the lighter pill.
V_a = π/4 · (D² − d_o²) · h · (1 + k)Other areas
Pressure of a column of drilling or kill fluid at a true vertical depth, and its gradient (equivalent density).
P = ρ · g · HFrom DrillingHow much weighting material (barite, hematite, calcium carbonate), water or another fluid to add to bring the mud to the required density, and the final volume.
V_a = V_1 · (ρ_2 − ρ_1) / (ρ_a − ρ_2)From DrillingOutput per stroke and flow rate of a single-acting triplex or quintuplex pump from the liner size, stroke length, pump speed and volumetric efficiency.
q = z · π/4 · D² · S · ηFrom DrillingInternal volume per metre and for the whole string, metal (open-end) and closed-end displacement — for the trip sheet: hole fill when pulling and returns when running in.
C = π/4 · d²From DrillingVolume per metre and over an interval of the annulus between the hole (or casing) and the pipe.
C_a = π/4 · (D² − d²)From DrillingString weight in air and in mud (buoyancy factor) for one or two pipe sections, and the hook load including the travelling block and top drive.
k_b = 1 − ρ / ρ_sFrom DrillingFast-line and dead-line tension, derrick load and the rope breaking strength needed to lift the string on n lines, allowing for the efficiency of the block and tackle.
F_f = W / (n · E); F_d = W / nFrom DrillingSlurry volume for a plug of a given length, the slurry height with the pipe in the hole, the spacer volume behind the cement that balances the columns, and the displacement volume.
V_c = π/4 · D² · L · (1 + k)From DrillingResults 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.