The 5 biggest offshore drilling companies

By Administrator on Apr 02 in Offshore Drilling. 2 Comments

If you check the Forbes list, you will see, that some of the richest companies in the world are such, because of their oil and gas business. But that’s not always the case. Once very profitable, this business can turn to a burden when the prices of the black gold are going down.

Although during the oil price drop the offshore drilling business didn’t look like a profitable endeavor there are companies that are injecting billions into their fleets. Companies, which despite the situation are increasing their market share.

Here we are going to have a look over the 5 biggest offshore drilling companies in the world. These are the companies with the largest fleets that are operating worldwide.

So let’s start our list from the bottom:


Shelf Drilling Holdings, Ltd.

This 2012 established company poses a fleet with 31 jack-up drilling rigs.

The vessels of the company with headquarters in Dubai are mainly operating in African and Asian waters and around the Arabian Peninsula.

Here the choice of this drilling operator is to keep a portfolio of only jack-up rigs.

Because Shelf Drilling has only jack-up rigs in the fleet, the service they can provide is limited. With their vessels, their operational limits are up to 375 feet of water depth.

But despite the limitations of their abilities, the jack-up rigs are with lower operational costs, which makes them a great option in times when the industry is on hold, and the clients are cutting their drilling budgets.



We can follow the roots of this offshore giant back to the very first start of the offshore drilling.

In 1953 “The Offshore Company” is created by Southern Natural Gas Company. The company goes into history with the launching of the Rig 51(the first mobile jack-up rig, in the Gulf of Mexico.) in 1954. In 1982 the company is changed to Sonat Offshore Drilling Inc.

 1992 is year when the giant acquires the Norwegian group Transocean ASA for US$1.5 billion and soon the name is changed to Transocean Offshore-the company we know it today.

At the moment, the company that survived the financial hit taken by the Deepwater Horizon disaster owns a fleet of 37 drilling rigs. 27 of them are ultra-deepwater and the rest 10 are harsh environment rigs.



Registered on 10th of May 2005 in Bermuda, Seadrill is a company founded by John Fredriksen (Norwegian-born Cypriot oil tanker and shipping billionaire businessman).

Since its establishment, Seadrill acquires many other offshore drilling companies.

In September 2006, the company acquired a controlling share of Smedvig.

In 2007, the company acquired Eastern Drilling.

In May 2010, Scorpion Offshore is acquired.

In June 2013, the company acquired a majority interest in Sevan Drilling.

Currently, Seadrill operates its own fleet of 35 drilling rigs and manages 18 rigs on behalf of its partners.

In the company’s portfolio, you can find ultra-deepwater floaters, harsh environment floaters, and high specification jack-ups, which makes it one of the most diverse in the industry.



China Oilfield Services (COSL) is a Chinese state-owned company founded in 2001, with headquarters in Beijing.

Except the areas of Southeast Asia, the Middle East, and Central Asia the company is operating in Europe through its wholly-owned subsidiary COSL Drilling Europe AS, with headquarters in Norway.

The Norwegian branch is a result of the acquisition of Norway’s Awilco Offshore ASA for 2.51 billion U.S. dollars back in 2008.

Currently, the company is possessing an impressive fleet of 44 drilling rigs consisting of jack-ups and semi-submersible floaters.

With this fleet, the company is managing to step stable on the drilling market even at unfavorable times for the oil and gas industry.



Now the first place is for the boldly first company of the offshore drilling market.

Valaris is a company with a long history, even if that history was written by a company with a different name.

The company was established in 1975 in Texas by the name Blocker Energy and quickly became a major player on the market. In 1987 the company with already more than 50 rigs, change its name to Energy Service Company (Ensco).

In 1990 Ensco adds additional 19 rigs with the acquisition of Penrod.

In May 2011 Pride International is acquired.

In 2017 Ensco completes the acquisition of Atwood Oceanics.

2019 is the year when ENSCO merged with Rowan and changed its name to Valaris plc.

Valaris is in possession of an impressive fleet of 74 rigs, consisted of 50 offshore jack-up rigs, 16 drillships, and 8 semi-submersible drilling rigs.



Shawn 1 year ago

I used to work for Rowan, it was a great company, but once Ensco took over, we became just numbers for them.


James 1 year ago

Yes,Ensco is the worst drilling contractor I’ve ever worked for!!!


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