Every number checked. Here is what that means.

1. Why we audit

An engineer who learns a wrong constant, a wrong equation or a wrong keyed answer carries it into real work. Technical training content goes wrong in predictable ways: a quiz key that disagrees with its own explanation, simulator code that drifts from the prose beside it, a correction made in one place and not another, two modules giving opposite guidance on the same case. None of these is caught by reading for plausibility. They are caught by recomputation and cross-checking, so that is how WellProd content is assured.

2. What is checked

1. Full read. Every topic page is read in full by a petroleum-engineering reviewer. Nothing is sampled.
2. Recomputation. Every worked example is recomputed numerically from the inputs stated on the page, and the working is kept.
3. Quiz keys. The keyed answer to every formative question is extracted from the page code and checked against the explanation printed beneath it.
4. Simulators. The code of each interactive simulator is compared with the equation it claims to implement, including units and constants.
5. Cross-checks. Values repeated across modules (well parameters, correlations, constants) are compared, because a correction made in one place and not another is a defect in itself.

3. How findings are graded

Findings are graded by consequence, not by effort to fix:

• Critical. An engineer would carry the error into real work: a wrong equation, constant or keyed answer.
• Major. A wrong worked-example number, or a direct self-contradiction within a page.
• Minor. Imprecision, rounding, notation drift.

4. What happens with findings

Critical and major findings are corrected corpus-wide: when a value is corrected, every instance of it across the courses is corrected in the same change, and each correction is verified against the live page before it is applied. Where a correction would change the conclusion of a case study, that is an engineering judgement and is reserved for the author rather than rewritten by an editor. Minor findings are worked through in turn.

The checks are kept as scripts with the content and are re-run when content changes, so the assurance does not decay as the programme grows.

5. Status

A full audit of the eleven courses was completed in September 2026 and its findings were worked through the same month. Ten courses are audited in full; the audit of Course 09, Perforating Design, is in progress, and this statement is re-issued when it completes or when a content release changes a result.

6. Sources and provenance

The content cites public sources: SPE papers, API recommended practices and standard texts. Well data in the problems are illustrative and are not drawn from any operator's records.

7. Available on request

Prospective buyers can ask for the detail behind this statement, under a short confidentiality note:

• The per-course audit reports, with every finding, its grade and its correction
• The audit counts by course and by grade
• The remediation tracker and the list of decisions reserved for the author
• A fuller provenance note on sources

Ask any training provider for the equivalent. If it does not exist, ask why. Request ours through the contact page.