Company lists · Data refreshed September 2026

Top 25 Offshore drilling rig companies worldwide

RevenueBase identified 1,574 offshore drilling rig companies worldwide as of September 2026 and tracks 230,899 professional contacts across them, including 34,676 with verified work emails. The United States is the largest market and Houston the largest hub.

This list covers offshore drilling rig companies 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 20, 2026. Country and city lists for offshore drilling rig companies 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 20, 2026 86% judged on-target in blind review
1,574Companies
230,899Contacts tracked
34,676Verified emails
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The 25 largest offshore drilling rig companies worldwide

Ranked by team size
Top 25 of 1,574 offshore drilling rig companies worldwide, ranked by team size, largest first. Data refreshed Sep 20, 2026. RevenueBase Smart Search rates how each company's information relates to offshore drilling rig companies: 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
1Strong evidenceZug, SwitzerlandHQ checked Sep 20, 20261,001-5,00010,068 contacts →

Strong evidence

“Transocean is a leading international provider of offshore contract drilling services for oil and gas wells.”

Source: RevenueBase Database · checked Sep 20, 2026
2Indirect evidenceHouston, TX, United StatesHQ checked Sep 20, 202610001+5,865 contacts →

Indirect evidence

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

Source: RevenueBase Database · checked Sep 20, 2026
3Strong evidenceHouston, TX, United StatesHQ checked Sep 20, 20265,001-10,0005,601 contacts →

Strong evidence

“Noble is a leading offshore drilling contractor for the oil and gas industry.”

Source: RevenueBase Database · checked Sep 20, 2026
4Partial evidenceChuo-ku, JapanHQ checked Sep 20, 20265,001-10,0005,077 contacts →

Partial evidence

“MODEC has been a leading provider of solutions for the floating offshore oil and gas market for over 50 years.”

Source: RevenueBase Database · checked Sep 20, 2026
5Partial evidenceHouston, United StatesHQ checked Sep 20, 20261,001-5,0004,845 contacts →

Partial evidence

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

Source: RevenueBase Database · checked Sep 20, 2026
6Partial evidenceJakarta Selatan, IndonesiaHQ checked Sep 20, 20261,001-5,0003,932 contacts →

Partial 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 20, 2026
7Partial evidenceHouston, TX, United StatesHQ checked Sep 20, 20265,001-10,0003,290 contacts →

Partial evidence

“Tidewater Inc.(Tidewater) is the owner and operator of the world’s largest Offshore Support Vessel (OSV) fleet.”

Source: RevenueBase Database · checked Sep 20, 2026
8Partial evidenceAl Khobar, Saudi ArabiaHQ checked Sep 20, 20265,001-10,0003,251 contacts →

Partial evidence

“ADES is a world-leading international provider of oil and gas drilling services.”

Source: RevenueBase Database · checked Sep 20, 2026
9Indirect evidenceHouston, TX, United StatesHQ checked Sep 20, 20265,001-10,0003,173 contacts →

Indirect evidence

“We Are Valaris With decades of expertise and strategic commitment built on efficiency, capability and ingenuity, our sights are continually set toward a future built with purpose…”

Source: RevenueBase Database · checked Sep 20, 2026
10Partial evidenceBergen, NorwayHQ checked Sep 20, 20265,001-10,0002,942 contacts →

Partial evidence

“With a multi-national workforce of over 5,700 personnel, DOF is an international group of companies which owns and operates a fleet of modern offshore/subsea vessels, with an…”

Source: RevenueBase Database · checked Sep 20, 2026
11Partial evidenceDubai, United Arab EmiratesHQ checked Sep 20, 20261,001-5,0002,689 contacts →

Partial evidence

“Shelf Drilling is a wholly owned subsidiary of ADES Holding Company, a leading international oil and gas drilling services provider.”

Source: RevenueBase Database · checked Sep 20, 2026
12Partial evidenceLeiden, NetherlandsHQ checked Sep 20, 20261,001-5,0002,643 contacts →

Partial evidence

“Heerema Marine Contractors is a world-leading marine contractor in the international offshore energy industry.”

Source: RevenueBase Database · checked Sep 20, 2026
13Partial evidenceChâtel-saint-denis, SwitzerlandHQ checked Sep 20, 20261,001-5,0002,554 contacts →

Partial evidence

“Allseas is a world-leading contractor in the offshore energy market.”

Source: RevenueBase Database · checked Sep 20, 2026
14Indirect evidenceCalgary, AB, CanadaHQ checked Sep 20, 20265,001-10,0002,471 contacts →

Indirect evidence

“Precision is a leading provider of safe and High Performance, High-Value services to the oil and gas industry.”

Source: RevenueBase Database · checked Sep 20, 2026
15Indirect evidenceRio De Janeiro, BrazilHQ checked Sep 20, 20261,001-5,0002,427 contacts →

Indirect evidence

“A OCYAN atua há décadas na prestação de serviços para o setor de óleo e gás upstream, estruturando suas operações em três frentes de atuação.”

Source: RevenueBase Database · checked Sep 20, 2026
16Partial evidenceSandnes, NorwayHQ checked Sep 20, 20265,001-10,0002,373 contacts →

Partial evidence

“Archer is a company providing drilling and well services to the global energy industry.”

Source: RevenueBase Database · checked Sep 20, 2026
17Partial evidenceAl-khobar, Saudi ArabiaHQ checked Sep 20, 20261,001-5,0002,312 contacts →

Partial evidence

“Zamil Offshore Services Company has been offering diversified offshore and marine support services to the oil and gas industry since 1977.”

Source: RevenueBase Database · checked Sep 20, 2026
18Indirect evidenceHouston, TX, United StatesHQ checked Sep 20, 20265,001-10,0002,215 contacts →

Indirect evidence

“Oil States International, Inc.”

Source: RevenueBase Database · checked Sep 20, 2026
19Indirect evidenceCalgary, AB, CanadaHQ checked Sep 20, 20261,001-5,0002,176 contacts →

Indirect evidence

“Ensign Energy Services Inc.”

Source: RevenueBase Database · checked Sep 20, 2026
20Partial evidenceCairo, EgyptHQ checked Sep 20, 20265,001-10,0002,122 contacts →

Partial evidence

“EDC is one of the leading drilling contractors in Egypt and the MENA region; established in 1976 in partnership with Maersk Drilling, EDC is now 100% owned by Egyptian General…”

Source: RevenueBase Database · checked Sep 20, 2026
21Partial evidenceRio De Janeiro, BrazilHQ checked Sep 20, 20261,001-5,0002,075 contacts →

Partial evidence

“Constellation Oil Services is a drilling contractor highly differentiated due to its unique experience in deep and ultra-deepwater drilling.”

Source: RevenueBase Database · checked Sep 20, 2026
22Indirect evidenceComuna 1, ArgentinaHQ checked Sep 20, 20261,001-5,0002,064 contacts →

Indirect evidence

“Somos la mayor prestadora de servicios de perforación de la Argentina y somos líderes en la prestación de servicios asociados al mantenimiento y optimización de los pozos de…”

Source: RevenueBase Database · checked Sep 20, 2026
23Strong evidenceAl-khobar, Saudi ArabiaHQ checked Sep 20, 20265,001-10,0002,042 contacts →

Strong evidence

“We are the region’s trusted onshore and offshore oil & gas drilling company with an extensive track record of operational excellence and advanced capabilities that have enabled…”

Source: RevenueBase Database · checked Sep 20, 2026
24Partial evidenceAberdeen, United KingdomHQ checked Sep 20, 20261,001-5,0001,864 contacts →

Partial evidence

“Odfjell Drilling is an international drilling company with around 1,500 employees with operations around the world.”

Source: RevenueBase Database · checked Sep 20, 2026
25Indirect evidenceNiterói, BrazilHQ checked Sep 20, 20261,001-5,0001,847 contacts →

Indirect evidence

“O Grupo CBO é uma das maiores empresas de apoio marítimo do Brasil.”

Source: RevenueBase Database · checked Sep 20, 2026

Showing 25 of 1,574 offshore drilling rig companies worldwide

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Offshore drilling rig companies worldwide at a glance

As of Sep 20, 2026
15.0%Verified-email coverage
146.7Average contacts per company
51-200Median size (employees)
6.3%Largest-city concentration · Houston
Sep 20, 2026Page data refreshed

Companies by employee count

1-10
291
11-50
461
51-200
341
201-500
200
501-1,000
106
1,001-5,000
132
5,001-10,000
25
10001+
13

Email recency is reported on each country list linked below.

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 offshore drilling rig companies, 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
Every country. Country and city lists for offshore drilling rig companies are linked below.
What qualifies
Companies worldwide whose own description of what they do matches “offshore drilling rig companies”. 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 offshore drilling rig companies), 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 offshore drilling rig companies, 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, 34,676 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 20, 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.

Offshore drilling rig companies by location

14 lists · largest first

Every Offshore drilling rig companies list RevenueBase publishes, by country and city. Counts are matching companies in each list as of its own refresh date.

Countries

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 offshore drilling rig companies, 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 offshore drilling rig companies are there worldwide?

RevenueBase identified 1,574 offshore drilling rig companies 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?

Transocean, headquartered in Zug, tops this list with the largest team on record.

Which country has the most offshore drilling rig companies?

The United States leads with 322 companies, followed by the United Kingdom (96) and Singapore (82). Every offshore drilling rig companies list by country and city is linked on this page.

Which city has the most offshore drilling rig companies?

Houston leads with 99 headquartered companies, followed by Singapore (53) and Aberdeen (27).

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 34,676 verified decision-maker contacts tracked across these 1,574 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 20, 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.