Field tool · days vs depth
Plot your well's days vs depth against the plan
Paste the plan and the morning-report depths. Get the curve, plan vs actual days at every depth, days and footage per section, and your own NPT shaded. Runs in your browser.
Buy Now, $19Depth going down the page
Days from day zero across, depth increasing downward, as on the rig floor chart. Plan dashed, actual solid with a dot at each report, offset wells dotted.
Sections you define
Plan days, actual days and average rate for each hole section. A boundary crossed between two reports is placed on the straight line between them.
ft or m, offsets mixed
Switch the display unit and every table, axis and download follows. An offset well entered in metres is converted and labelled with the unit it came in.
Your NPT, shaded
Type your own NPT periods and they are shaded on the chart. Overlapping entries are joined before they are added up. Nothing is shaded that you did not enter.
CSV and SVG export
Readings, sections, chart points and your NPT as CSV, and the chart as an SVG you can drop into a report. A JSON backup restores everything.
Works on the rig
Runs in your browser with nothing uploaded. Install it on a phone or laptop and it opens with no signal.
From the built-in example (ft):
| Section | Plan days | Actual days | Actual minus plan, days | Average rate (ft/day) | Your NPT days |
|---|---|---|---|---|---|
| Surface 0 to 2,000 | 2.00 | 2.67 | 0.67 | 750.0 | 0.00 |
| Intermediate 2,000 to 7,500 | 7.00 | 6.83 | -0.17 | 804.9 | 0.50 |
| Production 7,500 to 10,000 | 7.00 | 5.70 | -1.30 | 438.6 | 2.00 |
How the numbers are worked out
Actual minus plan = the day of the reading minus the day the plan first reaches the same depth. A negative number means the reading came before the plan's day for that depth.
Between plan points the plan is a straight line, and where the plan holds at one depth the plan day for that depth is the day the plan first reaches it. A reading deeper than the plan's last depth has no plan day; nothing is extended past your plan. A section boundary reached between two reports is placed by straight-line interpolation between those two readings. Average rate is the section's depth over its days, including holds and your NPT, which is shown beside it.
The page works with depth and time only. Every number is one you can check by hand from your own entries.
From Oil Rigs Now: tools for drilling engineers, superintendents, company men and operations geologists.
$19 one-time
- Plan, morning-report depths, sections, offset wells and your NPT periods
- Days vs depth chart with depth increasing downward
- Actual minus plan days at every reading; days and average rate per section
- CSV and SVG downloads and a JSON backup you can restore
- Light and dark themes, offline use, installable on phone or desktop
No refunds. All sales are final.