Sources, Methodology and Corrections Policy

Principles

Primary sources first. For law and regulation we read the statute, the gazetted regulation or the regulator's own guideline. For crude quality we read assays published by producers. For trade we prefer official statistics from both exporter and importer.
Every figure is attributed and dated. Numbered citations lead to a source list showing the publisher, publication date, the date we retrieved it, and the kind of evidence it is.
We do not fill gaps. If no citable figure exists, the cell is blank or marked "not published".
Disagreement is shown, not hidden. Where reputable sources differ, we present them side by side and explain why.
Our own reasoning is labelled. Phrases such as "in our reading", "in our assessment" and "our arithmetic" mark interpretation or calculation that is ours rather than the source's.

Evidence labels

Label	Meaning
Official	The issuer's own document: a statute, an NNPC contract template, an OPEC bulletin, an ICC statement.
Regulatory	A gazetted regulation, guideline, register or data release from a regulator.
Government	Statistics or statements from a government body, such as the EIA or a ministry.
Company-reported	Information published by a company about its own assets, assays or transactions. Reliable for what it is, but self-reported.
Industry	Price-reporting agencies, research institutes and specialist trade publications.
Legal commentary	Commentary by a law firm on an instrument we have also read ourselves where possible.
Secondary source	General press, including press reports that relay official statistics we could not open directly.
Unverified	Reported but not confirmed by us. Used sparingly and always flagged.

Regulatory content carries a second label distinguishing Law / regulation from Commercial procedure, Industry practice and Unverified claim — because one seller's procedure is not the law.

Derived figures

Barrels per tonne. We calculate specific gravity from API gravity using SG = 141.5 ÷ (API + 131.5),¹ convert to density using 999.016 kg/m³ for water at 60 °F, and apply 6.2898 barrels per cubic metre.² The result is labelled "derived" wherever it appears. As a cross-check, OPEC's published factor for Nigeria is 7.394 barrels per tonne,³ which corresponds to a gravity close to Bonny Light's.

Cargo arithmetic — for example the number of cargoes a stream can support each month — is simple division of cited figures and is marked as our arithmetic.

Known limitations

Several assays are old (Forcados 2014, Bonga 2015 alongside 2025). We show the assay date prominently.
The regulator's production data are by stream, not by export cargo, and recent months are provisional.
Nigerian trade statistics record the declared destination, by value. Hub ports and transhipment distort them.
Some official Nigerian statistics were accessible to us only through press reports; these are labelled secondary.
Keyword and search-demand research that shaped this site used observed search suggestions and results, not paid keyword-volume data; we make no claims about search volumes.

Review and updates

Each page shows the date it was last reviewed. Regulatory and market pages are reviewed when the underlying instrument, data release or ownership changes, and at least quarterly. Assay values are updated when a producer publishes a new assay.

Corrections

If you believe something here is wrong, out of date or unfairly characterised, email info@nigeriacrudeoilmerchant.com with the page address and, if possible, a source. We correct confirmed errors promptly and update the review date. We describe patterns of fraud, never named private companies or individuals; if you believe any passage could be read as referring to you, please tell us.

Not advice

This website provides general information. It is not legal, tax, financial or investment advice, and it is not an offer to sell crude oil. See the disclaimer.