Crude Cut № 002 · tutorial · five questions, one Access file
Every evaluation shop has one: a .accdb — a Microsoft Access database that only ARIES itself will open. Before anyone opens it, there is a first question worth asking the file directly: what is actually in here? We pointed Claude at a demo evaluation — 20 producing oil wells, five operator groups, three states — plus the two files that ship beside it in every deal, the oneliner Excel and the Reserves & Economics PDF. Then we asked five questions: four about what is actually in the file, then the one everyone wants to ask first. Each tab below is one question: the prompt as typed, the answer as returned. Setup is one line: brew install mdb-tools.
Question one · the manifest
Here's an ARIES database. Before I open it: what's in it, and what's actually populated? — plus the file path
Claude lists the tables with mdb-tables, counts every one, and sorts them by what ARIES itself says they are. The file is a 5.7 MB ARIES 2017.1 database: one DBS, one project (YE26_NON-OP, a transported project), one scenario (2026Q3), effective 08/2026. Of 60 tables, 28 hold rows and 91% of all rows are daily production. The per-property tier is where a deal lives, and it is thin: five of nineteen tables populated — the master, the economics lines, saved fits, monthly and daily history. Every run-output table is empty. The PV10 on the PDF cover exists only in the exports; the database holds inputs and history, not results.
Table manifest · every table in the file · rows in each · hover for what it holds
populated empty run output · empty
RESULT: per-property tables populated — AC_PROPERTY 20 · AC_ECONOMIC 590 · AC_FCST 128 · AC_PRODUCT 961 · AC_DAILY 29,580. Empty: ONELINE, ECOSUM, MONTHLY, DETAIL (the run results), OWNER, WELL, TEST, NOTE, RESERVES, PZFCST, RATIO. Instructions: 9 scenario lines, 112 side-file lines holding five price decks (two of them unreferenced), one lookup table (Oklahoma taxes).
Question two · the case
What's on each well? Which master fields are filled, and which economics sections does each case carry?
The master row is what export tools see; the economics case is what ARIES actually ran. On the master, 37 of 50 fields are filled on every well — API, operator, county and state, basin, zone, lateral length, TVD, spud and first-production dates, WI, NRI, asset group. All 20 are horizontal, active, oil-major, booked 1PDP: Midland 12, Delaware 6, Oklahoma 2; laterals 4,438–15,306 ft; first production 12/2021–02/2024. Coordinates are blank on the four NM and OK wells, frac date on eight, and the prior-cumulative fields on all twenty. The economics carry one qualifier, 2026Q3, and the same skeleton on every case: 3 settings lines, 10–11 forecast, 4–5 price, 7–10 expense, 1–2 ownership, 2–3 investment. The exceptions are the story — four wells carry reversions, two carry capital, two route Oklahoma taxes through a lookup.
AC_PROPERTY · 50 fields · how many wells have each one filled
AC_ECONOMIC · lines by section · qualifier 2026Q3 · 20 cases
RESULT: §2 SHRINK · BTU · ELOSS §4 START ×3 · OIL · GAS · WTR · NGL/GAS · CUMS §5 SIDEFILE + differentials §6 OPC/T · OPC/OIL · OPC/GAS · OPC/WTR · STX · ATX §7 NET §8 SALV · ABDN. AC_OWNER is empty and the master's PRIOR_* cums are blank — the ownership lives only in the §7 NET lines and the cumulatives only in §4 CUMS. Hold that for Q4.
Question three · the history
What production history and forecasts are in here? Check the tables against each other.
ARIES keeps two histories. The monthly table is what the declines regress on: 961 rows of oil, gas and water, no days-on, and one month (10/2025) missing on 18 of 20 wells. Beside it sits a daily table nobody mentioned — 29,580 rows carrying tubing and casing pressure on most days and choke on half — that covers the missing month and runs 18 days past the monthly. Rolled up, the two agree within 1% on 838 of 960 well-months. The other 122 are where to look. October 2024 is booked as a near-shut-in on ten wells in the monthly table while the daily table has them producing normally. The four ConocoPhillips wells run 10–18% under the daily for 17 months straight. One Kale well double-counts February 2024 through a leap-day duplicate row, and the two Kale wells have their May 2025 volumes swapped. The saved fits in AC_FCST are 2022 vintage on 16 wells; the forecast that ran is inline in §4, anchored 01/2025.
History coverage by asset group · monthly vs daily table · months where the two disagree on oil by >10%
monthly table daily table monthly ≠ daily, oil >10% missing month · hover a group
RESULT: cum oil, daily minus monthly — DREADNAUGHT +4.1% · BURTON +4.1% · SHOOTER +0.7% · HORTON +0.0% · KALE −1.8% · portfolio +1.75% (91,330 bbl). 10/2024 on the ten flagged wells: monthly 10,909 bbl, daily 62,467. One §4 forecast line, verbatim — OIL 3382.780 X B/M 7.000000 EXP B/0.9500 24.322066 — 3,382.78 bbl/month start, hyperbolic b = 0.95, 24.3%/yr initial decline, to a 7%/yr exponential tail, 30 bbl/month floor. The 2022 fits in AC_FCST started at 69–85%/yr.
Question four · the audit
Cross-check the database against the oneliner Excel and the R&E PDF. Does everything tie?
A deal hands you three versions of the same economics: the database, the oneliner, the PDF. Q1 showed the database holds no run results, so the headline tie-out is between the two exports: summing the oneliner's 20 rows against the PDF's grand-total page, every headline number ties to the penny. Then the catch: the property master's NRI column — the one a quick Excel pull would grab — disagrees with the interests the economics actually ran on 7 of 20 wells, including four where it is off by a factor of 180. The interests that matter live in the ownership section of the economics, reversions and all — not in the metadata.
Tie-out · sum of oneliner rows vs R&E PDF grand total (p.12)
| Measure | Oneliner Σ | R&E PDF | Verdict |
|---|---|---|---|
| Net oil, MBbl | 90.092 | 90.092 | ✓ ties |
| Net gas, MMcf | 205.565 | 205.565 | ✓ ties |
| Net revenue, M$ | 6,905.530 | 6,905.530 | ✓ ties |
| Undisc. net cash flow, M$ | 3,578.307 | 3,578.307 | ✓ ties |
| Net PV10, M$ | 2,254.809 | 2,254.808 | ✓ ties |
Master-table NRI vs the interest the economics ran · the 7 disagreements
| Well | Master NRI | Ran (§7 NET) | Off by |
|---|---|---|---|
| Shooter McGavin B 2625LS · SM Energy | 28.116% | 0.156% | × 180.7 |
| Shooter McGavin B 2626LS · SM Energy | 28.116% | 0.156% | × 180.7 |
| Shooter McGavin B 2646WA · SM Energy | 28.116% | 0.156% | × 180.7 |
| Shooter McGavin B 2647WA · SM Energy | 28.116% | 0.156% | × 180.7 |
| Kale 26-18-6 2HO · BCE-Mach III † | 48.241% | 21.094% | × 2.3 |
| Burton Flat 621H · Devon † | 2.690% | 3.086% | × 0.87 |
| Burton Flat 622H · Devon † | 2.723% | 3.125% | × 0.87 |
† carries a reversion — the ran interest steps down later (Kale: to 12.66% after 3,652.8 M$ cum on stream 747), which no single master-table number can represent.
RESULT: ANYONE WHO PULLED THE NRI COLUMN INTO A SPREADSHEET VALUED THE SM ENERGY WELLS 180× TOO HIGH. The economics live in section 7, not the metadata.
Question five · the valuation, tied together
Now value it. What is the portfolio worth as the seller ran it, and which groups carry the value?
This is the question everyone asks first, and the four tabs before it are why the answer can be trusted. As run — scenario 2026Q3, the 06/30/26 strip, effective 08/2026 — the twenty wells carry 2,254.8 M$ of net PV10 on 90.1 MBbl of net oil. Count and value disagree: the four ConocoPhillips wells are 20% of the wells and 62% of the value; the eight APA wells are 40% of the wells and under 4%. The spread runs 57× per well, and it follows the section 7 interest, not the rock. Every input behind the number was located on the way here: the results themselves are not in the database, the interests are in section 7, the forecast is in section 4 and was fit on a monthly history that a second table disputes, and the two exports tie to each other five for five.
Net PV10 by asset group · M$ (thousands) · hover for share of wells vs share of value
What the number stands on · where each input lives in the file · the tab that checked it
| Input | Where it lives | Seen in |
|---|---|---|
| The PV10 itself | Not in the database — every run-output table is empty. It comes from the oneliner export (20 rows × 49 columns), which ties to the PDF. | Q1 · Q4 |
| Interests | §7 NET lines — WI, net oil, net gas, with reversion steps on 4 wells. Not the master NRI column, which is wrong on 7 of 20. | Q2 · Q4 |
| Forecast | §4 8-word expressions, anchored 01/2025, qualifier 2026Q3. The saved fits in AC_FCST are 2022 vintage and unused. | Q2 · Q3 |
| History it was fit on | AC_PRODUCT monthly — 10/2025 missing on 18 wells. The daily table carries 1.75% more cumulative oil. | Q3 |
| Prices | AR_SIDEFILE — the 06/30/26 strip (AE_MSTRIP_260630) plus Waha and TX/OK gas differentials; two decks in the file are unreferenced. | Q1 · Q2 |
| Costs & taxes | §6 — 8,000–15,000 $/month fixed, per-unit opex on oil, gas and water, severance and ad valorem; Oklahoma taxes via ARLOOKUP. | Q2 |
| Cross-check | Oneliner Σ vs PDF grand total — net oil, net gas, revenue, cash flow, PV10 — 5 of 5 tie. | Q4 ✓ |
RESULT: DREADNAUGHT 1,400.7 · BURTON 665.1 · HORTON 86.1 · KALE 78.3 · SHOOTER 24.6 M$ — total 2,254.8 M$; per well 350.2 → 6.1 M$. Had the master NRI column been used, the SM Energy wells' net revenue would be 180× what ran — 11,931 M$ against 66 M$ — more than the entire portfolio's 6,905.5 M$ of net revenue. The metadata error is bigger than the deal.
Run this on your own database
This page ran on a demo file, but the moves are the same on any ARIES database: one brew install mdb-tools, then the five prompts above, verbatim, in a Claude session pointed at your .accdb. The full recipe — prompts, the commands underneath, and what to check — ships with this cut.
crudecode.devThe files: a demo ARIES evaluation — alchemist energy-20260721.accdb (5.7 MB, exported 07/21/2026), its oneliner Excel (20 rows × 49 columns), and its Reserves & Economics PDF (12 pages, DBS "DEMO", scenario 2026Q3, effective 08/2026). The wells and operators are real and public record; the ownership interests and economics are demonstration constructs. Tools: mdb-tools (Homebrew) to read the .accdb, openpyxl for the Excel; every number on this page comes out of one extraction script shipped with the cut.
The manifest (Q1): mdb-tables for the list, mdb-count per table. Tiers are ours, derived from ARIES's own registry (ARSYSTBL): tables it parents on the master (PARENT = M) are per-property data; other registered tables are economics instructions; unregistered tables are housekeeping (projects, graphs, filters, units, locks). "Run output" = AC_ONELINE, AC_ECOSUM, AC_MONTHLY, AC_DETAIL — the tables ARIES writes results into.
The case (Q2): a master field counts as filled when it is non-blank after mdb-export; partial counts are wells with the field blank. Economics lines are AC_ECONOMIC rows grouped by SECTION; the section names are ARIES's. "Same skeleton" = keyword set per section is identical across cases except the exceptions named. The scenario table routes every section to qualifier 2026Q3 (section 4 also lists a fallback qualifier, ALCHEMIST, which has no lines).
The history (Q3): monthly = AC_PRODUCT, keyed by P_DATE month; daily = AC_DAILY summed to the same well-month by D_DATE. A well-month "ties" when oil differs by ≤1% (or ≤0.5 bbl); ">10%" is on the larger of the two. The chart marks a group-month when any well in the group is >10% off. Coverage lines are first→last row per group; the notch is the month with no monthly row. The leap-day duplicate is two AC_PRODUCT rows for one well dated 02/28/24 and 02/29/24 with identical volumes. Forecast: AC_FCST rows by QUALIFIER; the live forecast is the §4 8-word expressions (initial rate, units, limit, method, b, secant-effective annual decline) with a START line per phase.
The audit (Q4): headline tie-out = sums of the oneliner's 20 rows vs the PDF grand-total page (p.12); net revenue compares against the PDF's TOTAL NET REVENUE row (its metrics block prints the oil-only figure, 5,767.620, on the same page). Interests ran = AC_ECONOMIC section 7 NET lines (words: WI%, net oil %, net gas %; ditto lines are reversion steps). Master NRI = AC_PROPERTY.NRI × 100. Disagreement threshold 0.005 pp; 13 of 20 wells tie.
The valuation (Q5): per-well PV10, net volumes and net revenue from the oneliner export, grouped by its ASSET_GROUP column; group PV10 totals cross-checked against the PDF's per-group pages (Horton p.1, Kale p.3, Dreadnaught p.5, Burton p.7, Shooter p.9) — all five tie. PV10 = discounted cash flow at 10%, M$ = thousands of dollars; shares are of the 2,254.8 M$ total. The "had the master NRI been used" figure is the Shooter group's net revenue (66.025 M$) scaled by 180.7, the ratio of master NRI to the interest that ran — a linear scaling of revenue, not a rerun; costs sit on the working interest and would not scale with it.
What we'd push back on ourselves: this is a demo database, and both catches — the 180× metadata mismatch and the two histories disagreeing — may well be planted. But they are exactly the classes of error this workflow exists to catch in real books, where the master table drifts from the economics across quarters of revisions and a daily feed and an allocated monthly feed stop agreeing. We do not know which history is right; the daily table has the more plausible October 2024, but "more plausible" is not evidence — the state filings for these public wells would settle it, and a connected session can run that check. Our tier labels are a reading of ARSYSTBL, not ARIES documentation. And we keyed the PDF values in by hand from the printed report, page references given.