50 US Oil & Gas Companies (Verified 2026)

If you sell equipment, software, or services into the energy sector — or you recruit for it — you don't need another “top 10 oil companies” listicle. You need a working list: who's actually still operating, how big they are, and how to reach a specific person once you've picked your targets.

This is that list. Fifty US oil & gas companies — operators, refiners, pipeline operators, and oilfield service firms — each one re-verified as operating in September 2026, each linked to the email pattern its addresses follow.

What “verified” means here

Every company below was checked and kept up to date as of September 2026.

Removed every company that was acquired, merged, or shut down — Pioneer Natural Resources, Hess, Marathon Oil, Anadarko, Noble Energy, and a dozen others are gone from this list because they're gone from the industry.
Corrected rebrands to current names and domains (Apache → APA Corporation, Liberty Oilfield Services → Liberty Energy, World Fuel Services → World Kinect, and similar).
Kept company size figures labeled as approximate — treat them as ballpark.

We don't publish anyone's email address. The last column links to each company's publicly observable email patternfrom MailPattern's dataset of 2.2 million verified patterns — so you can reach the person you already know you want, instead of guessing.

The list

#	Company	Founded	Employees (approx.)	Email pattern
1	SLB	1926	10,001+	pattern
2	Chevron	1879	10,001+	pattern
3	ExxonMobil	1999	10,001+	pattern
4	Halliburton	1919	10,001+	pattern
5	NOV	1841	10,001+	pattern
6	ConocoPhillips	2012	10,001+	pattern
7	Occidental Petroleum	—	10,001+	pattern
8	CB&I	1889	10,001+	pattern
9	McDermott	1923	10,001+	pattern
10	Phillips 66	2012	10,001+	pattern
11	Oceaneering	—	10,001+	pattern
12	Marathon Petroleum	2014	10,001+	pattern
13	Tenaris	2002	10,001+	pattern
14	Valero	1980	10,001+	pattern
15	Kinder Morgan	1997	10,001+	pattern
16	Williams	1908	5,001–10,000	pattern
17	Nabors Industries	1952	10,001+	pattern
18	Enterprise Products	1968	5,001–10,000	pattern
19	Devon Energy	1971	1,001–5,000	pattern
20	APA Corporation (Apache)	1954	5,001–10,000	pattern
21	Baker Hughes	—	10,001+	pattern
22	MRC Global	1921	1,001–5,000	pattern
23	EOG Resources	1999	1,001–5,000	pattern
24	CITGO	1983	1,001–5,000	pattern
25	Energy Transfer	1995	10,001+	pattern
26	W&T Offshore	1983	201–500	pattern
27	Murphy Oil	1950	501–1,000	pattern
28	John Crane	1917	5,001–10,000	pattern
29	Helmerich & Payne (H&P)	1920	5,001–10,000	pattern
30	AmeriGas	1959	5,001–10,000	pattern
31	Flint Hills Resources	2002	1,001–5,000	pattern
32	ONEOK	1906	1,001–5,000	pattern
33	Key Energy Services	1977	1,001–5,000	pattern
34	Motiva Enterprises	1998	1,001–5,000	pattern
35	Gilbarco Veeder-Root	1865	1,001–5,000	pattern
36	World Kinect	1985	5,001–10,000	pattern
37	S&B Engineers and Constructors	1967	5,001–10,000	pattern
38	Oil States International	—	5,001–10,000	pattern
39	Plains All American	1989	1,001–5,000	pattern
40	T.D. Williamson	1920	1,001–5,000	pattern
41	ENTRUST Solutions Group	2001	1,001–5,000	pattern
42	Superior Energy Services	—	5,001–10,000	pattern
43	Just Energy	1997	1,001–5,000	pattern
44	Suburban Propane	1928	1,001–5,000	pattern
45	Targa Resources	2005	1,001–5,000	pattern
46	PAC	1999	201–500	pattern
47	Cheniere Energy	—	1,001–5,000	pattern
48	Strike	2003	5,001–10,000	pattern
49	Hilcorp	1989	1,001–5,000	pattern
50	AmSpec	1986	1,001–5,000	pattern

How to use this list

Pick your targets. The company names link to their websites; filter by size and segment however your sales motion works.
Click the pattern link for any company. You'll see the email format that company uses (for example, first.last@domain.com), how much evidence backs it, and when it was last verified. If the evidence is thin, the page says so — treat it as a hint, not a guarantee.
Look up a specific person free. Enter any name + company on the MailPattern homepage — no sign-up, and the result comes with mail-server verification. Have your own list of prospects? The bulk lookup takes a CSV; 200 rows a month are free.

FAQ

How do I find someone's email at an oil company?

Enter their name and the company's domain into MailPattern's free lookup. You'll get the address the company's pattern predicts plus mail-server verification — or an honest “we don't know” when the evidence isn't there, instead of a guess.

What's the most common email format at oil & gas companies?

It varies company by company, which is exactly why we link each company above to its own pattern page instead of giving one generic answer. Large enterprises usually standardize on one format for most staff — but “usually” is how bounce rates happen. Check the specific company; it takes five seconds.

Is this list current?

Yes — every company was re-verified as operating in September 2026, and companies absorbed by acquisition were removed (this sector consolidated heavily in recent years). Employee counts are approximate; company status is the part we re-verified. Founding years are founding years.

Why is my company missing / listed wrong?

The list is a ranked slice of a large dataset, not a directory of everyone. If we got something wrong, tell us: contact@mailpattern.tech.

Company data verified September 2026. MailPattern's email-pattern dataset covers 2.2M patterns across 1.68M domains. We never publish individual email addresses.

50 US oil & gas companies, verified for 2026 — and the email format each one uses