Company lists · Data refreshed September 2026

Top 25 Drill ship operators worldwide

RevenueBase identified 906 drill ship operators worldwide as of September 2026 and tracks 166,564 professional contacts across them, including 23,991 with verified work emails. The United States is the largest market and Houston the largest hub.

This list covers drill ship 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 drill ship 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
906Companies
166,564Contacts tracked
23,991Verified emails
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The 25 largest drill ship operators worldwide

Ranked by team size
Top 25 of 906 drill ship operators worldwide, ranked by team size, largest first. Data refreshed Sep 19, 2026. RevenueBase Smart Search rates how each company's information relates to drill ship 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 evidenceZug, SwitzerlandHQ checked Sep 19, 20261,001-5,00010,068 contacts →

Indirect evidence

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

Source: RevenueBase Database · checked Sep 19, 2026
2Indirect 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
3Indirect evidenceHouston, TX, United StatesHQ checked Sep 19, 20265,001-10,0005,601 contacts →

Indirect evidence

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

Source: RevenueBase Database · checked Sep 19, 2026
4Indirect evidenceHouston, United StatesHQ checked Sep 19, 20261,001-5,0004,845 contacts →

Indirect evidence

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

Source: RevenueBase Database · checked Sep 19, 2026
5Partial evidenceHouston, TX, United StatesHQ checked Sep 19, 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 19, 2026
6Indirect evidenceAl Khobar, Saudi ArabiaHQ checked Sep 19, 20265,001-10,0003,251 contacts →

Indirect evidence

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

Source: RevenueBase Database · checked Sep 19, 2026
7Indirect evidenceHouston, TX, United StatesHQ checked Sep 19, 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 19, 2026
8Indirect evidenceBergen, NorwayHQ checked Sep 19, 20265,001-10,0002,942 contacts →

Indirect 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 19, 2026
9Indirect evidenceDubai, United Arab EmiratesHQ checked Sep 19, 20261,001-5,0002,689 contacts →

Indirect 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 19, 2026
10Indirect evidenceChâtel-saint-denis, SwitzerlandHQ checked Sep 19, 20261,001-5,0002,554 contacts →

Indirect evidence

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

Source: RevenueBase Database · checked Sep 19, 2026
11Indirect evidenceCalgary, AB, CanadaHQ checked Sep 19, 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 19, 2026
12Indirect evidenceSandnes, NorwayHQ checked Sep 19, 20265,001-10,0002,373 contacts →

Indirect evidence

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

Source: RevenueBase Database · checked Sep 19, 2026
13Indirect evidenceAngra Dos Reis, BrazilHQ checked Sep 19, 20265,001-10,0002,370 contacts →

Indirect evidence

“Empresa multinacional na área de construção e reparos de navios e plataformas.”

Source: RevenueBase Database · checked Sep 19, 2026
14Indirect evidenceAl-khobar, Saudi ArabiaHQ checked Sep 19, 20261,001-5,0002,312 contacts →

Indirect 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 19, 2026
15Indirect evidenceCairo, EgyptHQ checked Sep 19, 20265,001-10,0002,122 contacts →

Indirect 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 19, 2026
16Indirect evidenceRio De Janeiro, BrazilHQ checked Sep 19, 20261,001-5,0002,075 contacts →

Indirect 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 19, 2026
17Indirect evidenceComuna 1, ArgentinaHQ checked Sep 19, 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 19, 2026
18Indirect evidenceAl-khobar, Saudi ArabiaHQ checked Sep 19, 20265,001-10,0002,042 contacts →

Indirect 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 19, 2026
19Indirect evidenceAberdeen, United KingdomHQ checked Sep 19, 20261,001-5,0001,864 contacts →

Indirect evidence

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

Source: RevenueBase Database · checked Sep 19, 2026
20Indirect evidenceNiterói, BrazilHQ checked Sep 19, 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 19, 2026
21Indirect evidenceLondon, United KingdomHQ checked Sep 19, 20261,001-5,0001,699 contacts →

Indirect evidence

“Borr Drilling Limited is an offshore shallow-water drilling contractor providing worldwide offshore drilling services to the oil and gas industry.”

Source: RevenueBase Database · checked Sep 19, 2026
22Indirect evidenceAl Khobar, Saudi ArabiaHQ checked Sep 19, 20261,001-5,0001,664 contacts →

Indirect evidence

“With an extensive fleet of over 200 vessels worldwide, Rawabi Vallianz Offshore Services leverages Rawabi’s expertise to ensure exceptional quality and on-time delivery.”

Source: RevenueBase Database · checked Sep 19, 2026
23Indirect evidenceSkudeneshavn, NorwayHQ checked Sep 19, 20261,001-5,0001,625 contacts →

Indirect evidence

“Solstad is a company with more than 60 years of experience within various shipping segments, and is currently one of the leading provider of specialized offshore tonnage to the…”

Source: RevenueBase Database · checked Sep 19, 2026
24Indirect evidenceCovington, LA, United StatesHQ checked Sep 19, 20261,001-5,0001,418 contacts →

Indirect evidence

“Hornbeck Offshore Services, Inc.”

Source: RevenueBase Database · checked Sep 19, 2026
25Indirect evidenceUnited StatesHQ checked Sep 19, 20261,001-5,0001,402 contacts →

Indirect evidence

“Somos uma empresa focada em oferecer soluções em Perfuração Offshore, com expertise e excelência em afretamento e operação de sondas para águas ultraprofundas.”

Source: RevenueBase Database · checked Sep 19, 2026

Showing 25 of 906 drill ship operators worldwide

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Drill ship operators worldwide at a glance

As of Sep 19, 2026
14.4%Verified-email coverage
183.8Average contacts per company
51-200Median size (employees)
5.0%Largest-city concentration · Houston
Sep 19, 2026Page data refreshed

Companies by employee count

1-10
157
11-50
235
51-200
210
201-500
129
501-1,000
65
1,001-5,000
83
5,001-10,000
17
10001+
8

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 drill ship 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
Every country. Country and city lists for drill ship operators are linked below.
What qualifies
Companies worldwide whose own description of what they do matches “drill ship 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 drill ship 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 drill ship 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, 23,991 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.

Drill ship operators by location

8 lists · largest first

Every Drill ship operators 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 drill ship 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 drill ship operators are there worldwide?

RevenueBase identified 906 drill ship 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?

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

Which country has the most drill ship operators?

The United States leads with 148 companies, followed by Norway (47) and India (45). Every drill ship operators list by country and city is linked on this page.

Which city has the most drill ship operators?

Houston leads with 45 headquartered companies, followed by Singapore (38) and Dubai (17).

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 23,991 verified decision-maker contacts tracked across these 906 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.