| Revision | Date | Change and reason |
|---|---|---|
| 1 | 2026-10-19 | Added the sourced WAR methodology limits so day counts carry their coverage, boundary and basis caveats. Published numerical results are retained. |
| 2 | 2026-10-21 | Restored the decision link and added the annual regulatory source so the declared basis and reporting cadence can be checked. Published numerical results are retained. |
Drilling days = spud date → total-depth date. Completion days =
total-depth date → last completion activity. Medians are the headline figure
(robust to the sidetracks and recompletions whose WAR milestones coincide on a
single day); means are shown alongside. Total D&C is the summed drilling +
completion days per lease; rolled up to developments (Cascade+Chinook, Jack+St Malo)
it reconciles to the World Oil April 2026 article benchmark
on the matched developments. The deepest borehole in the set is North Platte well 608074032001 at 37,743 ft measured / 35,115 ft TVD.
| Field | Wells | Total D&C | Drill (med) | Drill (mean) | Compl (med) | Compl (mean) | Water depth (ft) |
|---|---|---|---|---|---|---|---|
| St Malo | 65 | 5,696 | 26 | 35.3 | 14 | 52.3 | 6,820 |
| Big Foot | 38 | 3,033 | 12 | 31.8 | 19 | 48.1 | 5,190 |
| Shenandoah | 23 | 1,989 | 38 | 53.8 | 15 | 32.7 | 5,840 |
| Stones | 22 | 2,602 | 70 | 66.2 | 48 | 52.0 | 9,525 |
| Anchor | 15 | 1,825 | 51 | 54.7 | 34 | 66.9 | 5,080 |
| North Platte | 14 | 971 | 46 | 48.2 | 24 | 21.1 | 5,840 |
| Cascade | 9 | 1,694 | 71 | 98.7 | 60 | 89.6 | 8,200 |
| Julia | 9 | 1,687 | 96 | 89.1 | 96 | 98.3 | 7,335 |
| Jack | 8 | 1,117 | 58 | 81.5 | 36 | 58.1 | 7,240 |
| Kaskida | 7 | 841 | 37 | 79.4 | 46 | 40.7 | 5,860 |
| Chinook | 5 | 773 | 28 | 63.4 | 27 | 91.2 | 8,900 |
| Tiber | 2 | 250 | 107 | 107.0 | 18 | 18.0 | 4,130 |
Each well's milestones come from its BSEE Well Activity Reports: the spud date, the total-depth date, and the last recorded completion activity. Drilling and completion days are the calendar spans between them. Records where a milestone is missing or the span is zero (33 wells show zero drilling days, 31 show zero completion days — typically sidetracks or recompletions that open and finish an interval the same day) are kept in the population and reported as-is rather than dropped or estimated, which is why the mean sits well above the median for several fields.
Figures are computed deterministically from one frozen, committed
reference workbook,
docs/…/FDAS_V30/drilling_and_completion_days.xlsx,
itself derived from public BSEE Well Activity Reports under the V30 drilling/
completion-days methodology. The page is regenerated by
scripts/completion/build_completion_report.py — same workbook
in, byte-identical HTML out.
Weekly boundary quantization: 30 CFR 250.743(a) requires weekly WARs for the region covered by that paragraph, Sunday (12 a.m.) through Saturday (11:59 p.m.). Periods are no longer than seven days; first and last periods may be shorter. When activity transitions are inferred only from weekly status rows, a per-well count is quantized at each boundary by up to one reporting week. This is an inference from the cadence, not a measured error bound on every report date; daily narratives or more frequent reports can refine the boundaries.
Coverage floor: the repository records reports submitted since April 2004 (Makefile, comment above the data target, attributed to issue 1066). This is reported, not confirmed from an agency page; the bulk-file start date remains unconfirmed from the BSEE Raw Data and eWell WAR Field Definitions pages examined here. Historical completeness, including coverage of earlier paper reports, is not established. Missing historical reports shall not be interpreted as zero days.
Depth basis: legacy Days/10K ratios are per 10,000 ft and use measured depth (MD), MAX_BH_TOTAL_MD, minus water depth as drilled footage below the mudline, with the denominator bounded below in the code. The learning-series ratios are per 1,000 ft and instead use true vertical depth (TVD), MAX_WELL_BORE_TVD. MD and TVD are not interchangeable; these D&C surfaces display counts and geometry and do not calculate a new dry-hole ratio. Code locators: scripts/extract_all_well_data.py, the footage calculation; packages/worldenergydata-bsee/src/worldenergydata/lower_tertiary/drilling_learning.py, _clean; and bsee.analysis.drilling_intensity.DEPTH_COLUMNS.
Publisher-declared basis: no definition was found in the sources cited here (30 CFR 250.743, BSEE Raw Data and eWell WAR Field Definitions). Existing figures retain their legacy calendar and WAR-union arithmetic. Milestone basis is the default: drilling days = total-depth date minus spud date; completion days = every reported day from total depth onward, all activity codes, with unreported gaps left out. The activity-code breakdown, milestone basis and interim rule are retained side by side, including suspended and temporarily abandoned time kept separate in the activity-code breakdown and combined figures derived from the granular ones. The decision requires confirmation across the wider well population once the weekly records are obtained, before any published figure is replaced. This note replaces no figure and infers no additional code meanings. Decision: #1064 decision
Sanity reference: the public publisher-deposited abstract of SPE-87117-MS, Deepwater Success Through Predictable and Distinctive Drilling and Completion Performance, paragraph 4, reports 20–23 days per 10,000 ft for its deepwater examples. The abstract does not establish MD versus TVD or comparability to the legacy figures here. The band is a plausibility reference, not an acceptance threshold; no per-well ratio is reproduced or asserted by this note. Record: https://api.crossref.org/works/10.2118/87117-MS
Sources examined 2026-10-21: