Company lists · Data refreshed September 2026

Top 25 Upstream oil and gas operators worldwide

RevenueBase identified 1,237 upstream oil and gas operators worldwide as of September 2026 and tracks 252,809 professional contacts across them, including 63,696 with verified work emails and 0 with mobile numbers. The United States is the largest market and Houston the largest hub.

This list covers upstream oil and gas operators worldwide, matched on what each company actually does as described in its own words. Ranked by team size, largest first. Every row shows the company's own description, its RevenueBase Smart Search rating, and when it was last checked. Data refreshed September 19, 2026. Country and city lists for upstream oil and gas operators follow the table.

Published by RevenueBase, a B2B data infrastructure company. This list was built with RevenueBase Smart Search, the natural-language company search RevenueBase customers use to build their own targeted lists and unlock verified emails and direct dials at the companies on them. How these lists are built and judged.

How to read this list HQ checked on every row RevenueBase Smart Search rating on every row Refreshed Sep 19, 2026 86% judged on-target in blind review
1,237Companies
252,809Contacts tracked
63,696Verified emails
0Mobile numbers
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The 25 largest upstream oil and gas operators worldwide

Ranked by team size
Top 25 of 1,237 upstream oil and gas operators worldwide, ranked by team size, largest first. Data refreshed Sep 19, 2026. RevenueBase Smart Search rates how each company's information relates to upstream oil and gas operators: strong evidence (its own description names it), partial (names part of it), indirect (matched on the rest of its profile rather than the description shown). Click a contact count to view that company's people.
#CompanyRevenueBase Smart SearchHeadquartersEmployeesContacts
1Indirect evidenceHouston, TX, United StatesHQ checked Sep 19, 202610001+60,138 contacts →

Indirect evidence

“Our greatest resource is our people.”

Source: RevenueBase Database · checked Sep 19, 2026
2Indirect evidenceHouston, TX, United StatesHQ checked Sep 19, 202610001+53,380 contacts →

Indirect evidence

“We collaborate and engineer solutions to maximize asset value for our customers.”

Source: RevenueBase Database · checked Sep 19, 2026
3Indirect evidenceHouston, TX, United StatesHQ checked Sep 19, 202610001+5,865 contacts →

Indirect evidence

“Nabors Industries is a leading provider of advanced technology for the energy industry.”

Source: RevenueBase Database · checked Sep 19, 2026
4Strong evidenceHouston, TX, United StatesHQ checked Sep 19, 2026n/a5,489 contacts →

Strong evidence

“We are an independent oil and natural gas acquisition, exploitation and exploration company.”

Source: RevenueBase Database · checked Sep 19, 2026
5Strong evidenceHouston, United StatesHQ checked Sep 19, 20261,001-5,0004,845 contacts →

Strong evidence

“Seadrill is setting the standard in deepwater oil and gas drilling.”

Source: RevenueBase Database · checked Sep 19, 2026
6Indirect evidenceHouston, TX, United StatesHQ checked Sep 19, 20261,001-5,0004,346 contacts →

Indirect evidence

“EOG Resources, Inc.”

Source: RevenueBase Database · checked Sep 19, 2026
7Strong evidenceJakarta Selatan, IndonesiaHQ checked Sep 19, 20261,001-5,0003,932 contacts →

Strong evidence

“We are the one and only national company that possesses combined competencies in oil & gas services: seismic, drilling and oilfield.”

Source: RevenueBase Database · checked Sep 19, 2026
8Indirect evidenceHouston, United StatesHQ checked Sep 19, 20265,001-10,0003,683 contacts →

Indirect evidence

“National Energy Services Reunited Corp.(NESR) was founded in 2017 as one of the largest national oilfield services providers in the MENA and Asia Pacific regions and was the first…”

Source: RevenueBase Database · checked Sep 19, 2026
9Strong evidenceHouston, TX, United StatesHQ checked Sep 19, 2026n/a3,514 contacts →

Strong evidence

“Murphy Oil Corporation is a global independent oil and natural gas exploration and production company.”

Source: RevenueBase Database · checked Sep 19, 2026
10Strong evidenceThe Woodlands, TX, United StatesHQ checked Sep 19, 20261,001-5,0003,460 contacts →

Strong evidence

“Anadarko is among the world’s largest independent oil and natural gas exploration and production companies, with corporate offices in The Woodlands, Texas.”

Source: RevenueBase Database · checked Sep 19, 2026
11Indirect evidenceHouston, TX, United StatesHQ checked Sep 19, 20261,001-5,0002,755 contacts →

Indirect evidence

“Headquartered in Houston, Texas, Key Energy Services provides a wide array of leading edge energy production solutions and services.”

Source: RevenueBase Database · checked Sep 19, 2026
12Strong evidenceHouston, TX, United StatesHQ checked Sep 19, 202610001+2,317 contacts →

Strong evidence

“Patterson-UTI is a leading provider of drilling and completion services to oil and natural gas exploration and production companies in the United States and other select…”

Source: RevenueBase Database · checked Sep 19, 2026
13Indirect evidenceDhahran, Saudi ArabiaHQ checked Sep 19, 20265,001-10,0002,250 contacts →

Indirect evidence

“TAQA is an international company that offers leading well solutions for the energy industry and is creating value and opportunity for all its stakeholders.”

Source: RevenueBase Database · checked Sep 19, 2026
14Indirect evidenceDubai, United Arab EmiratesHQ checked Sep 19, 20261,001-5,0002,249 contacts →

Indirect evidence

“OiLSERV is a provider of an expanding range of oilfield services, including well logging, well testing, production enhancement, drilling services, surface production management…”

Source: RevenueBase Database · checked Sep 19, 2026
15Partial evidenceHouston, TX, United StatesHQ checked Sep 19, 20265,001-10,0002,215 contacts →

Partial evidence

Oil States International, Inc.”

Source: RevenueBase Database · checked Sep 19, 2026
16Indirect evidenceCalgary, AB, CanadaHQ checked Sep 19, 20261,001-5,0002,176 contacts →

Indirect evidence

“Ensign Energy Services Inc.”

Source: RevenueBase Database · checked Sep 19, 2026
17Strong evidenceDenver, CO, United StatesHQ checked Sep 19, 2026501-1,0002,176 contacts →

Strong evidence

“SM Energy Company is an independent energy company focused on the exploration, exploitation, development, acquisition, and production of natural gas and crude oil in the United…”

Source: RevenueBase Database · checked Sep 19, 2026
18Strong evidenceMidland, TX, United StatesHQ checked Sep 19, 20261,001-5,0002,093 contacts →

Strong evidence

“XTO Energy Inc, a subsidiary of Exxon Mobil Corporation, is a leading natural gas and oil producer in the U.S.”

Source: RevenueBase Database · checked Sep 19, 2026
19Strong evidenceHouston, TX, United StatesHQ checked Sep 19, 20261,001-5,0001,938 contacts →

Strong evidence

“For oil & gas exploration and production companies worldwide, Superior Energy Services is an oilfield products and services company with global reach, financial stability and…”

Source: RevenueBase Database · checked Sep 19, 2026
20Indirect evidenceHouston, TX, United StatesHQ checked Sep 19, 20261,001-5,0001,803 contacts →

Indirect evidence

“Hilcorp Energy Company was founded in 1989 with the vision of being the premier independent energy company in America.”

Source: RevenueBase Database · checked Sep 19, 2026
21Strong evidenceCalgary, AB, CanadaHQ checked Sep 19, 20261,001-5,0001,690 contacts →

Strong evidence

“Encana is a leading North American energy producer that is focused on growing its strong portfolio of diverse resource plays producing natural gas, oil and natural gas liquids.”

Source: RevenueBase Database · checked Sep 19, 2026
22Indirect evidenceDubai, United Arab EmiratesHQ checked Sep 19, 20261,001-5,0001,685 contacts →

Indirect evidence

“Every year, drilling teams make decisions worth millions of dollars on incomplete information.”

Source: RevenueBase Database · checked Sep 19, 2026
23Indirect evidenceJakarta, IndonesiaHQ checked Sep 19, 20261,001-5,0001,647 contacts →

Indirect evidence

“PT Pertamina Hulu Rokan (PHR) is a subsidiary of PT Pertamina Hulu Energi (PHE)”

Source: RevenueBase Database · checked Sep 19, 2026
24Indirect evidenceJakarta Selatan, IndonesiaHQ checked Sep 19, 202610001+1,537 contacts →

Indirect evidence

“PT Pertamina Hulu Energi (PHE) merupakan anak perusahaan PT Pertamina (Persero).”

Source: RevenueBase Database · checked Sep 19, 2026
25Partial evidenceHouston, TX, United StatesHQ checked Sep 19, 20261,001-5,0001,500 contacts →

Partial evidence

“With over 70 offices in more than 50 countries located in major oil-producing provinces, Core Laboratories provides services to the world's major, national, and independent oil…”

Source: RevenueBase Database · checked Sep 19, 2026

Showing 25 of 1,237 upstream oil and gas operators worldwide

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Upstream oil and gas operators worldwide at a glance

As of Sep 19, 2026
25.2%Verified-email coverage
204.4Average contacts per company
11-50Median size (employees)
14.8%Largest-city concentration · Houston
Sep 19, 2026Page data refreshed

Companies by employee count

1-10
433
11-50
396
51-200
213
201-500
71
501-1,000
32
1,001-5,000
62
5,001-10,000
13
10001+
13

How this list was built

Company categories are rarely black and white. RevenueBase reads each company's own description of its business to decide whether it belongs among upstream oil and gas operators, so some rows will be adjacent to the category rather than pure plays. The description and RevenueBase Smart Search rating on every row are there so you can check each match yourself.

Source
The RevenueBase company graph: 60 million companies and 398.9 million professional contacts resolved from primary sources, queried with RevenueBase Smart Search, the natural-language company search available to every RevenueBase user.
Coverage
8 countries, largest first: the United States, Canada, the United Kingdom, Nigeria, Indonesia, the United Arab Emirates, India, Brazil. Country and city lists for upstream oil and gas operators are linked below.
What qualifies
Companies worldwide whose own description of what they do matches “upstream oil and gas operators”. Matching reads each company's description, not its industry code or its name.
RevenueBase Smart Search
RevenueBase Smart Search is how this list is assembled and how each row is rated. RevenueBase's data engine and AI assess a company's LinkedIn profile, information supplied directly by the company, its website and other publicly available information, then relate it to a category defined in a user's own words. Each row is rated strong evidence (its own description names upstream oil and gas operators), partial evidence (it names part of the category) or indirect evidence (the description shown names none of it and the match rests on the rest of the company's profile). The description supporting each rating is quoted on the row.
What we exclude
Companies whose own description does not clearly place them among upstream oil and gas operators, and records with no verified work email.
Match quality
In blind human judging of this matching method, 86% of matched companies were on target. Expect roughly 1 in 7 rows to be adjacent to the category rather than a pure play. Every row shows the company's own description and its RevenueBase Smart Search rating so you can judge each match yourself. Read the full methodology: how the lists are built, how the judging worked, and what the figure means.
Ranking
Team size, largest first: companies are ordered by the number of professionals RevenueBase tracks at each one. Employee ranges shown are reported bands, for context.
Verification
Every listed company carries at least one verified work email, 63,696 across the full list. Contacts re-verify on a rolling cadence, and each contact's own verification date is shown inside RevenueBase.
Refresh
This page's figures were pulled from the company graph on September 19, 2026. Lists refresh periodically as the graph is re-checked.
Corrections
Wrong category, wrong headquarters, or a company that has closed? Use “Report an issue” on any row. Reports go to the RevenueBase Data Team and feed back into the company graph.

Upstream oil and gas operators by location

14 lists · largest first

Every Upstream oil and gas operators list RevenueBase publishes, by country and city. Counts are matching companies in each list as of its own refresh date.

Countries

Cities

Frequently asked

What is RevenueBase Smart Search?

RevenueBase Smart Search is how RevenueBase decides which companies belong on this list and how strongly each one fits. Its data engine and AI assess a company's LinkedIn profile, information supplied directly by the company, its website and other publicly available information, then relate it to the category the list is about. Each row is rated strong evidence when the company's own description names upstream oil and gas operators, partial evidence when it names part of the category, and indirect evidence when the description shown names none of it and the match rests on the rest of the company's profile.

How many upstream oil and gas operators are there worldwide?

RevenueBase identified 1,237 upstream oil and gas operators worldwide as of September 2026, matched on each company's own description of what it does rather than its industry code.

What is the largest company on this list?

Chevron, headquartered in Houston, tops this list with the largest team on record.

Which country has the most upstream oil and gas operators?

The United States leads with 890 companies, followed by Canada (80) and the United Kingdom (63). Every upstream oil and gas operators list by country and city is linked on this page.

Which city has the most upstream oil and gas operators?

Houston leads with 183 headquartered companies, followed by Dallas (58) and Calgary (51).

How do I get contact information for these companies?

A free RevenueBase account lets you run this exact search and work the top results, verified emails and direct dials included. Upgrading unlocks all 63,696 verified decision-maker contacts tracked across these 1,237 companies.

How current is this list?

The list refreshes periodically as the company graph is re-checked. This page's figures were pulled on September 19, 2026.

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About this data

RevenueBase is a B2B data infrastructure company. Its company graph covers 60 million companies and 398.9 million professional contacts, with emails verified on a rolling cadence rather than scraped once and left to decay. These company lists are generated directly from that graph with RevenueBase Smart Search, the same natural-language company search every RevenueBase user has: describe a market in plain words, get the companies that match, and add verified emails and direct dials for the people at them. It is the same data that powers RevenueBase's B2B data products, and a free account includes 500 credits to start. How these lists are built and judged.