How We Research Company Profiles
Every profile on Houston Oil Companies is built from public sources. This page explains where the figures come from, what they mean, and how companies that have been acquired are handled. Company facts were last checked on October 23, 2026.
Where the figures come from
- Revenue is total revenue as reported for the company's latest full fiscal year, taken from its annual report (Form 10-K for US-listed companies) or its year-end earnings release. The fiscal year is shown next to the figure.
- Employees is the headcount the company itself reports, usually in the human capital section of its annual report, as of the date shown on the profile.
- Status, headquarters and leadership come from company press releases, investor relations pages and SEC filings. For acquisitions, we use the announcement that the deal closed.
- Private companies show a figure only when the company publishes one. Otherwise the field is left blank rather than estimated.
Each profile lists the documents behind its figures under Sources and shows the date its facts were last checked.
What we don't cite
Wikipedia, data aggregators and staffing-site estimates can point to a document, but a figure is published only when it can be linked to the company's own filing or announcement, or to a major news report.
Acquired and merged companies
When a company is acquired, its profile stays online as a history page. It is marked with the buyer and the closing date, shows the last figures the company reported as an independent business, and links to the buyer's profile. Acquired companies are left out of rankings such as the largest oil and gas companies in Houston. A company that has shut down entirely is removed and its address redirects to its sector page.
US units of global companies
Some of Houston's biggest energy employers are the US arms of companies headquartered abroad, which do not report separate US results. Their profiles show the parent company's figures, labeled as such, and are not ranked against companies headquartered here.
The rest of each profile
The overview, history and operations sections summarize each company's own descriptions and the public record for readers who are new to the company. They are not investment research. Figures change, so check the linked filing before relying on a number.
Independence
No company pays to be listed, featured or described more favorably. The site is supported by advertising.
Corrections
To report an error, use the contact page and include a link to the source.