Kill Sheet Calculator
A kill sheet is the worksheet a rig crew fills out after shutting in on a kick to work out kill mud weight, circulating pressures, and the drillpipe pressure step-down schedule needed to safely regain control of the well. Use this after shutting in on a kick to calculate kill mud weight, circulating pressures, strokes, and the full drillpipe pressure step-down schedule — the same core math taught in IWCF and IADC well control certification.
Reviewed for accuracy by Jabin Travis, IADC WellSharp-certified driller.
Requires the well to already be shut in with SIDPP recorded. See the shut-in procedure if you haven't done this yet.
| Step | Cumulative Strokes | Drillpipe Pressure |
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The Formulas Used
What Is Slow Circulating Pressure?
SCR (sometimes SPR) is the standpipe pressure recorded at a reduced, standardized pump rate — measured routinely during normal operations specifically so it's available if a kick occurs. Without a current SCR reading, ICP and FCP can't be calculated accurately, which is why crews record it every shift as standard practice.
For the full step-by-step shut-in procedure and the difference between the Driller's Method and Wait-and-Weight, see the well control reference page. For string and annular capacities on your own pipe sizes, the drilling formulas cheat sheet has the capacity formula written out. On a directional or horizontal well, the horizontal kill sheet additions extend this same schedule with two more checkpoints at kick-off point and end of build. Once a kill mud weight is chosen, check it against the shoe on the MAMW calculator, work out the barite needed to actually reach it on the barite required calculator, and re-check pump pressure at the reduced kill rate with the pump pressure adjustment calculator if SCR was recorded at a different stroke rate.
Frequently Asked Questions
What is a drillpipe pressure schedule and why do I need one?
It is the standpipe pressure to hold at each stage of pumping kill mud down the string, stepping from ICP down to FCP as heavier mud replaces the original mud in the drill string. Holding a schedule rather than jumping straight to FCP keeps bottomhole pressure constant while the density inside the pipe is changing — skip it and you either underbalance or overbalance the well partway through the kill.
Why does the schedule step down in strokes, not time?
Because the variable that matters is how much of the string has been displaced by kill mud, and that tracks pump strokes directly, not the clock. Pump rate changes, but the volume per stroke does not, so strokes-to-bit is the reliable reference for where the kill-weight mud front actually is.
Why do I need both drill string and annular volume?
Strokes to bit uses only the drill string capacity, because that is what has to be displaced before kill mud reaches bit. Bottoms-up strokes uses annular volume, because that is what has to be pumped afterward to bring the original mud and any influx back to surface. Total circulation is both together — the full round trip.
What happens if I get pump output wrong?
Every strokes-based number on this page scales directly off it — strokes to bit, bottoms-up, total circulation, and every step in the pressure schedule. A pump output that is off by 5% shifts the whole schedule by roughly the same amount, which is why measured pump output beats a nameplate figure.