DeGolyer and MacNaughton is a petroleum consulting firm formed in 1936 and headquartered at 5001 Spring Valley Road, Suite 800 East, Dallas, Texas. Its overview page states that it employs more than 180 petroleum professionals, including engineers, geologists, geophysicists, petrophysicists, statisticians and economists who speak more than 30 languages between them. The firm publishes no general e-mail address on its website; enquiries go through an online contact form, with telephone and fax numbers given for each office.
Origins in reservoir evaluation
The firm was founded by Everette Lee DeGolyer and Lewis MacNaughton in response to a specific industry problem. By the 1930s open-flow production had created chronic oversupply, forcing US producers into proration and a search for better reservoir engineering, while banks lending against underground oil reserves needed independent assessments they could rely on. DeGolyer had been a pioneer of geophysical exploration since 1919, had served as president of Amerada Petroleum Corporation and retired in 1932 at the age of 46; MacNaughton, a geologist he had hired in 1928, joined him to create what the firm describes as the first petroleum consulting organisation offering services internationally. The industry's DeGolyer Distinguished Service Medal is named in his honour. The company now describes a history of almost 90 years.
Technical service lines
The practice is published as a set of named service lines:
- Reserves assessments and economic evaluations
- Prospective, contingent and unconventional resources assessments
- Competent person's reports for international filings
- Reservoir simulation and engineering analysis
- Petrophysical, geophysical and geological studies
- Economic modelling
- CO2 storage studies, geothermal resources and critical minerals
- Environmental, social and corporate governance support
Reserves reporting and regulatory reference
Because reserves statements feed into securities filings, the firm keeps a reference library on US Securities and Exchange Commission practice: guidance documents for reserves reporting and a collection of SEC comment letters. It also publishes price series used in evaluations, covering the Henry Hub natural gas spot price in US dollars per million British thermal units and the Brent and West Texas Intermediate crude benchmarks in US dollars per barrel. The Twenty First Century Petroleum Statistics compilation and downloadable brochures make up the rest of the public reference material.
Offices and organisation
Alongside Dallas, the firm lists offices in New Delhi, India, in Algiers, Algeria and in Kazakhstan, and its website is published in English, Spanish, French, Portuguese, Russian, Kazakh, Arabic and simplified Chinese. Technical staff are grouped into divisions covering North America, Europe and Africa, Central Europe and Asia, and Asia Pacific and Latin America, and a geographic experience section records where the firm has worked. Clients include oil and gas companies, financial institutions and government agencies.
Recent activity
The news page carries a 2 June 2026 item on an interview with John W. Wallace, the firm's chairman and chief executive, recorded at the Baku Energy Forum, discussing Azerbaijan's hydrocarbon potential alongside geothermal, critical minerals and offshore opportunities. Other 2026 material includes a reserves report on enhanced geothermal systems prepared for Fervo Energy, which the firm describes as a first for the sector, and articles on carbon capture, utilisation and storage. A separate ESG and greenhouse gas publication sets out how the firm supports emissions-related reporting alongside its conventional reserves work. The site also advertises staff vacancies, reflecting continued hiring across its technical divisions.