Calculator

Horizontal & Extended-Reach Kill Sheet Additions

Two extra drillpipe pressure checkpoints for a directional or horizontal well — at kick-off point (KOP) and end of build (EOB) — read against the same ICP-to-FCP schedule as the standard kill sheet.

🚨 From Your Kill Sheet

Run the kill sheet calculator first — bring ICP, FCP, and strokes to bit over from there.

🔧 Well Path & Pump
KOP String Volume—
Strokes to KOP—
Drillpipe Pressure at KOP—
EOB String Volume—
Strokes to EOB—
Drillpipe Pressure at EOB—
This is a reference tool, not an operational authority. Real well control decisions must be made by your certified well control supervisor following your company's approved procedures.

The Formulas Used

String Volume & Strokes to a Checkpoint
Volume = Checkpoint MD × DP Capacity
Strokes = Volume ÷ Pump Output
Drillpipe Pressure at a Checkpoint
Pressure = ICP − (ICP − FCP) × (Strokes to Checkpoint ÷ Strokes to Bit)
The same straight-line ICP-to-FCP relationship the standard kill sheet's 10-step schedule uses, evaluated at KOP and EOB instead of at even stroke increments.

This page only covers the two extra checkpoints — for kill mud weight, ICP, FCP, strokes to bit, and the full 10-step pressure schedule itself, use the kill sheet calculator. For the Driller's Method and Wait-and-Weight procedures this schedule supports, see the well control reference page.

Frequently Asked Questions

Why does a directional or horizontal well need extra pressure checkpoints at all?

The standard kill sheet schedule only guarantees the drillpipe pressure at the start (ICP) and once kill mud reaches the bit (FCP) — everything between is a straight-line assumption based on strokes pumped. On a straight vertical well that's a safe approximation. On a well with a build section, the point where the string starts curving (KOP) and the point where it straightens back out (EOB) are worth checking against explicitly, since that's where crews most often catch a schedule that has drifted from what the choke operator is actually seeing.

Is the pressure at KOP and EOB calculated any differently than the rest of the schedule?

No — it uses the exact same straight-line ICP-to-FCP relationship as the standard 10-step schedule, just evaluated at the specific stroke count where the string crosses KOP or EOB instead of at even 10% increments. It's the same schedule, read at two extra points that happen to matter for a directional well.

Do KOP and EOB need to be entered as measured or vertical depth?

Both — measured depth (MD) is what actually goes into the string-volume and strokes calculation, since that's the length of pipe the kill mud has to travel through. Vertical depth (TVD) isn't used directly in this calculator but is worth having on hand, since the two diverge more and more past the KOP and that gap is exactly why this checkpoint exists in the first place.