Company lists · Data refreshed September 2026

Top 25 Offshore decommissioning companies worldwide

Name: Offshore decommissioning companies worldwide
Creator: RevenueBase
License: https://creativecommons.org/licenses/by/4.0/

Compiled by the RevenueBase Data Team Data refreshed Sep 20, 2026 385 companies tracked

RevenueBase identified 385 offshore decommissioning companies worldwide as of September 2026 and tracks 33,716 professional contacts across them, including 7,916 with verified work emails. The United Kingdom is the largest market and Houston the largest hub.

This list covers offshore decommissioning 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 decommissioning 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

385Companies

33,716Contacts tracked

7,916Verified emails

Explore this list → Free signup · no credit card · 500 free credits

The 25 largest offshore decommissioning companies worldwide

Ranked by team size

Top 25 of 385 offshore decommissioning 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 decommissioning 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.
#	Company	RevenueBase Smart Search	Headquarters	Employees	Contacts
1	Deme Group	Partial evidence	Beveren-kruibeke-zwijndrecht, BelgiumHQ checked Sep 20, 2026	5,001-10,000	4,395 contacts →
	Partial evidence “DEME (Euronext Brussels: DEME) is a leading contractor in the fields of offshore energy, dredging and marine infrastructure, and environmental remediation.” Source: RevenueBase Database · checked Sep 20, 2026
2	DOF	Partial evidence	Bergen, NorwayHQ checked Sep 20, 2026	5,001-10,000	2,942 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
3	Allseas	Partial evidence	Châtel-saint-denis, SwitzerlandHQ checked Sep 20, 2026	1,001-5,000	2,554 contacts →
	Partial evidence “Allseas is a world-leading contractor in the offshore energy market.” Source: RevenueBase Database · checked Sep 20, 2026
4	OCYAN	Indirect evidence	Rio De Janeiro, BrazilHQ checked Sep 20, 2026	1,001-5,000	2,427 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
5	Helix Energy Solutions Group	Partial evidence	Houston, TX, United StatesHQ checked Sep 20, 2026	1,001-5,000	1,706 contacts →
	Partial evidence “Helix Energy Solutions, headquartered in Houston, Texas, is an international offshore energy services company that provides specialty services to the offshore energy industry…” Source: RevenueBase Database · checked Sep 20, 2026
6	Rawabi Vallianz Offshore Services	Partial evidence	Al Khobar, Saudi ArabiaHQ checked Sep 20, 2026	1,001-5,000	1,664 contacts →
	Partial 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 20, 2026
7	Deepocean	Indirect evidence	Oslo, NorwayHQ checked Sep 20, 2026	1,001-5,000	1,375 contacts →
	Indirect evidence “DeepOcean is a technology-driven, independent solution provider in the ocean space.” Source: RevenueBase Database · checked Sep 20, 2026
8	CCC Underwater Engineering S.A.L	Indirect evidence	Abu Dhabi, United Arab EmiratesHQ checked Sep 20, 2026	201-500	1,279 contacts →
	Indirect evidence “(Underwater Engineering) S.A.L was established in 1976.” Source: RevenueBase Database · checked Sep 20, 2026
9	Vantage Drilling	Partial evidence	Hamilton, BermudaHQ checked Sep 20, 2026	501-1,000	1,001 contacts →
	Partial evidence “Vantage is an international offshore drilling contractor, formed in 2007, which markets, operates and manages modern, high specification drilling rigs.” Source: RevenueBase Database · checked Sep 20, 2026
10	Altera Infrastructure	Partial evidence	Aberdeenshire, United KingdomHQ checked Sep 20, 2026	501-1,000	955 contacts →
	Partial evidence “Altera Infrastructure is a leading global energy infrastructure services group focused on the ownership and operation of offshore energy assets.” Source: RevenueBase Database · checked Sep 20, 2026
11	GO Offshore	Partial evidence	West Perth, AustraliaHQ checked Sep 20, 2026	201-500	576 contacts →
	Partial evidence “GO OFFSHORE is an international energy services company, specialising in marine services to the offshore industry.” Source: RevenueBase Database · checked Sep 20, 2026
12	Boskalis Subsea Services	Partial evidence	Aberdeen, United KingdomHQ checked Sep 20, 2026	201-500	516 contacts →
	Partial evidence “Boskalis Subsea Services is a world-leading provider of specialist subsea solutions for the offshore energy industry, seamlessly integrating services to deliver optimum results.” Source: RevenueBase Database · checked Sep 20, 2026
13	Island Offshore	Partial evidence	Ulsteinvik, NorwayHQ checked Sep 20, 2026	501-1,000	501 contacts →
	Partial evidence “Island Offshore - The Island Offshore Group is a leading provider of services to the offshore industry ranging from Platform Supply, Walk-to-work and Anchor Handling to Advanced…” Source: RevenueBase Database · checked Sep 20, 2026
14	Reach Subsea	Partial evidence	Haugesund, NorwayHQ checked Sep 20, 2026	201-500	454 contacts →
	Partial evidence “Reach Subsea ASA (“Reach Subsea”, “Reach” or “the Group”) is a prominent offshore contractor that offer high quality solutions and technology to clients in need of ocean data and…” Source: RevenueBase Database · checked Sep 20, 2026
15	N-Sea Group	Indirect evidence	Dordrecht, NetherlandsHQ checked Sep 20, 2026	201-500	364 contacts →
	Indirect evidence “N-Sea is an end-to-end subsea services provider.” Source: RevenueBase Database · checked Sep 20, 2026
16	Eidesvik Offshore ASA	Partial evidence	Langevag, NorwayHQ checked Sep 20, 2026	501-1,000	308 contacts →
	Partial evidence “Offshore Shipping Company.” Source: RevenueBase Database · checked Sep 20, 2026
17	Executive Offshore	Partial evidence	SingaporeHQ checked Sep 20, 2026	n/a	259 contacts →
	Partial evidence “Executive Offshore owns, operates and commercially manages high specification offshore vessels.” Source: RevenueBase Database · checked Sep 20, 2026
18	Akofs Offshore	Partial evidence	Oslo, NorwayHQ checked Sep 20, 2026	201-500	233 contacts →
	Partial evidence “AKOFS Offshore is a global provider of vessel based subsea well construction and intervention services to the oil and gas industry.” Source: RevenueBase Database · checked Sep 20, 2026
19	Omega Subsea	Partial evidence	Bergen, NorwayHQ checked Sep 20, 2026	201-500	209 contacts →
	Partial evidence “Omega Subsea delivers ROV, survey, engineering, and subsea project services to the global offshore industry.” Source: RevenueBase Database · checked Sep 20, 2026
20	Dynamic Drilling & Services	Partial evidence	New Delhi, IndiaHQ checked Sep 20, 2026	201-500	206 contacts →
	Partial evidence “Dynamic Drilling, is an Indian Offshore Oil and Gas Drilling Company incorporated under the Indian Companies act 1956 with an objective to carry out business in the field of…” Source: RevenueBase Database · checked Sep 20, 2026
21	Alam Maritim Resources Berhad	Indirect evidence	United StatesHQ checked Sep 20, 2026	51-200	194 contacts →
	Indirect evidence Source: RevenueBase Database · checked Sep 20, 2026
22	Acteon	Partial evidence	Norwich, United KingdomHQ checked Sep 20, 2026	1,001-5,000	192 contacts →
	Partial evidence “Acteon delivers data-driven, engineering-led solutions across the lifecycle of offshore energy infrastructure.” Source: RevenueBase Database · checked Sep 20, 2026
23	Fontis Energy	Partial evidence	Ciudad Del Carmen, MexicoHQ checked Sep 20, 2026	501-1,000	189 contacts →
	Partial evidence “Fontis Energy (formerly known as Seamex) is an offshore drilling contractor with a fleet of five high-specification jack-up rigs.” Source: RevenueBase Database · checked Sep 20, 2026
24	HF Offshore	Strong evidence	Ciudad Del Carmen, MexicoHQ checked Sep 20, 2026	51-200	171 contacts →
	Strong evidence “HF OFFSHORE offers a wide range of maritime services in the field of marine, transportation, installation, decommissioning, salvage and deep-sea technologies with location in…” Source: RevenueBase Database · checked Sep 20, 2026
25	Petrodec	Strong evidence	Spicalaan 13 2132 Jg Hoofddorp the Netherlands, NetherlandsHQ checked Sep 20, 2026	51-200	168 contacts →
	Strong evidence “Petrodec is a responsible offshore contractor, ready to deliver safe, efficient and innovative decommissioning or re-use solutions.” Source: RevenueBase Database · checked Sep 20, 2026

RevenueBase Smart Search

RevenueBase Smart Search assesses information from a company’s LinkedIn profile, information supplied directly by the company, its website, and other publicly available sources. It uses that information to rate how closely the company relates to this list’s category: offshore decommissioning companies. Every row carries its rating and the description the rating was read from, so each one can be checked rather than taken on trust.

Strong evidence: The company's own public description of its business names offshore decommissioning companies.
Partial evidence: Its own public description names part of offshore decommissioning companies, so it works in or next to the category without describing itself that way.
Indirect evidence: The description shown does not name offshore decommissioning companies. The match rests on the rest of the company's public profile rather than the one sentence quoted here, so this is the rating to check first.

RevenueBase Smart Search is how these lists are built: RevenueBase's data engine and AI assemble the companies that match a category defined in a user's own words, so a list can be about what companies actually do rather than about whichever industry code they were filed under.

Showing 25 of 385 offshore decommissioning companies worldwide

See the full list, filter by size, metro and specialty, and get verified emails and direct dials for all 7,916 reachable decision-makers.

Free signup · no credit card

View the full list →

Offshore decommissioning companies worldwide at a glance

As of Sep 20, 2026

23.5%Verified-email coverage

87.6Average contacts per company

11-50Median size (employees)

4.4%Largest-city concentration · Houston

Sep 20, 2026Page data refreshed

Companies by employee count

1-10

115

11-50

109

51-200

201-500

501-1,000

1,001-5,000

5,001-10,000

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 decommissioning 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 decommissioning companies are linked below.
What qualifies: Companies worldwide whose own description of what they do matches “offshore decommissioning 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 decommissioning 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 decommissioning 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, 7,916 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 decommissioning companies by location

7 lists · largest first

Every Offshore decommissioning 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 decommissioning 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 decommissioning companies are there worldwide?

RevenueBase identified 385 offshore decommissioning 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?

Deme Group, headquartered in Beveren-Kruibeke-Zwijndrecht, tops this list with the largest team on record.

Which country has the most offshore decommissioning companies?

The United Kingdom leads with 62 companies, followed by the United States (55) and Nigeria (50). Every offshore decommissioning companies list by country and city is linked on this page.

Which city has the most offshore decommissioning companies?

Houston leads with 17 headquartered companies, followed by Singapore (16) and Aberdeen (11).

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 7,916 verified decision-maker contacts tracked across these 385 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.

Ready to reach these companies? Verified emails and direct dials for all 385 offshore decommissioning companies worldwide. Start with a free account, no credit card.

Download this list →

Related lists

Browse the directory

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.