#World Oil April 2026 — per-well D&C days listing

One row per wellbore behind the field-level D&C reconciliation matrix in the validation page, section 3 — the "listing" requested in the QA/QC review so each development's total can be audited bore by bore against the article's Table 1.

#Definitions and basis

• Source: canonical extractor output drilling_and_completion_days_v21_kc.csv (V50 = wed basis, BSEE WAR vintage 2026-02-19): 253 wellbores across 26 leases, 11 developments.
• Drilling days = rig-days from spud to total depth (TD). Completion days = rig-days after TD — this includes later recompletion and well-servicing rig time, the accounting behaviour tracked in #846.
• Producer markers come from the OGOR-A well benchmark (56 producing wells across the seven core LT fields); its calendar-day columns are never used here.
• Sidetrack bores are identified by a non-zero API12 suffix (last two digits).

#Summary vs the article

Producer scope differs between the two counts: wed 56 spans the seven core LT fields including Big Foot (8) but has no markers for Buckskin; the article's 52 excludes Big Foot and includes Buckskin (4). A dash means no marker, which is a true zero for the pre-production developments (Kaskida, North Platte, Tiber) and a coverage gap for Buckskin.

The drilling / completion split is the first troubleshooting lever the article's Table 1 cannot provide: the deltas above (Jack St Malo +119, Shenandoah +24, Buckskin +52) trace to late-arriving well data and open-ended post-TD completion accounting — never to a change in any bore's drilling days. The vintage diff below proves it.

#Drilling-days resolution (frozen V30 → wed)

Per-bore diff of the frozen V30 workbook against the wed extract (committed as data/dc_vintage_diff.csv), answering whether drilling days are stable across data vintages:

• Drilling days changed on 0 of 253 bores. Once a bore reaches TD, its drilling-day count never moves — every bore populated in both vintages carries identical drilling days.
• 7 bores are late data, not reclassification: they sat in the frozen V30 workbook as zero-day placeholder rows (no spud/TD) and now carry real WAR days. These account for every apparent "drilling delta".
• Completion days are open-ended: 5 long-TD'd bores accrued additional post-TD servicing days (+104 days) with zero drilling movement — the #846 accounting behaviour.
• 36 bores exist only in wed: all 25 Buckskin bores (the recovered development) and 11 zero-day sidetrack stubs (Anchor, North Platte).

#Late-data bores (zero-day placeholders in frozen V30, real days now)

#Servicing accrual on long-TD'd bores (drilling unchanged)

Implication for the matrix: every difference against the article decomposes into (a) wells whose WAR data arrived after the article's extract and (b) open-ended post-TD completion accrual. Drilling days need no accounting decision — they are final as printed. The only open choice is the completion-day boundary rule (#846): where post-TD rig time stops counting as completion and becomes well servicing.

#Per-development listings

#Anchor — 17 bores · 821 drilling + 1,004 completion = 1,825 D&C days

#Buckskin — 25 bores · 1,043 drilling + 1,013 completion = 2,056 D&C days

Producer markers are unavailable for Buckskin (the OGOR-A benchmark covers the seven core LT fields; the article counts 4 producers).

#Cascade Chinook — 14 bores · 1,205 drilling + 1,262 completion = 2,467 D&C days

#Jack St Malo — 73 bores · 3,065 drilling + 3,982 completion = 7,047 D&C days

Bores split across two leases: Jack (8 bores, 1,117 D&C days) and St Malo (65 bores, 5,930 D&C days). The +119-day delta vs the article is tracked as issue #846; the two flagged bores below carry the entire +234-day frozen-vs-candidate difference.

#Julia — 9 bores · 802 drilling + 885 completion = 1,687 D&C days

#Kaskida — 7 bores · 556 drilling + 285 completion = 841 D&C days

#North Platte — 23 bores · 675 drilling + 296 completion = 971 D&C days

#Shenandoah — 23 bores · 1,363 drilling + 1,007 completion = 2,370 D&C days

#Stones — 22 bores · 1,457 drilling + 1,168 completion = 2,625 D&C days

+20 of these completion days accrued after the article's Nov-2025 cutoff as post-TD servicing on three wells (TD 2018–2022) — see validation section 3.1.

#Tiber — 2 bores · 214 drilling + 36 completion = 250 D&C days

#Big Foot — 38 bores · 1,235 drilling + 2,030 completion = 3,265 D&C days

+33 of these completion days accrued after the article's Nov-2025 cutoff as post-TD servicing on one well (TD 2020) — see validation section 3.1.

#Provenance

Generated by scripts/lower_tertiary/build_wo_per_well_dc.py from the committed canonical extractor output; totals are pinned to the validation-page matrix by tests/unit/lower_tertiary/test_wo_per_well_dc.py.

#WAR methodology limits

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:

• eCFR, Office of the Federal Register, 30 CFR 250.743(a): https://www.ecfr.gov/current/title-30/chapter-II/subchapter-B/part-250/subpart-G/subject-group-ECFRa4d25de54b283e6/section-250.743
• Official annual CFR, 2025 edition, 30 CFR 250.743(a): https://www.govinfo.gov/content/pkg/CFR-2025-title30-vol2/xml/CFR-2025-title30-vol2-sec250-743.xml
• BSEE Raw Data, eWell Submissions WAR row: https://www.data.bsee.gov/Main/RawData.aspx
• BSEE eWell WAR Online Query Field Definitions: https://www.data.bsee.gov/Well/eWellWAR/FieldDefinitions.aspx