Offshore oil and gas installations: an introduction.

Not everybody following oil and gas websites and blogs does so because they are an expert in oil matters.  Some follow sites like this to find a way into the industry, and some do so to stay current or to find out a little more.

As a point of fact, most people who work in the industry are specialised in one or two particular areas. My own particular speciality is concerned with the wells, what goes on down there, and well construction.  But even offshore engineers and specialists working on wells are broken down into multiple disciplines, so complex can they be.  So, for insiders and outsiders alike, an overview of the offshore industry will always be an opportunity to expand knowledge.

Let’s begin with rig types:

Production platform

Nexen’s Buzzard Platform, east of Aberdeen

The production platform will employ a core crew of mechanical, electrical, and instrumentation technicians to perform maintenance on all the process equipment and will have a command structure ranging from trades through Team Leaders, and upwards to the OIM (Offshore Installation Manager). The general route into this offshore function will normally require full trade certificates, unless in the catering or logistics side, but I would wager that catering and logistics crews also require experience in their areas of responsibility, such as ex-forces personnel.

Platforms can sometimes have integrated drilling facilities if there was a forseen requirement for it at the time of commissioning, but if you look a little closer at the photograph of the Buzzard Platform, above, then you’ll see the derrick poking up actually belongs to a separate jack-up platform, which is explained very conveniently next…



The name gives away what this type of installation is capable of.  A jack-up drilling rig is a floating barge, and is generally towed to a position at sea or next to a platform before the legs are lowered to the seabed and the platform itself is ‘jacked up’ to a working height.  The drilling rig is then extended out on a cantilever to be positioned exactly above a well or planned well before drilling or well workover activities are carried out.  That drilling operation may happen directly through a slot on an existing platform, as is what appears to be happening in the photograph above.  This is a true ‘rig’, in the sense that its purpose is for drilling.  Jack-ups have a limited working water depth, constrained by how far down the legs can reach to contact the sea bed.  As such, they are useful only in relatively shallow waters.

Again, catering and logistics crews are ever present, but that’s where the similarity ends.  A drilling rig will have their maintenance trades, but the scope of work diversifies from a mostly process based role on a platform to a role specialised in repairing and maintaining drilling rig specific equipment.

The command structure is also significantly different.  Entry level positions on drilling rigs are twofold; roustabouts and deck crew.  Both can be demanding in the sense that there’s plenty to learn, and both can and will lead to promotion through the ranks.  Each and every Driller or Tool-pusher offshore will have been a roustabout, and that leads to a vey formalised command structure, much like the military.

The general structure can vary, but normally reads out like this:

  • Roustabout
  • Roughneck
  • Derrickman
  • Assistant driller
  • Driller
  • Day / night Toolpusher

Aside from this, the rig will have a Barge Master / Engineer, and an OIM.  These positions will most likely be filled with people that emerged through the same structure.

Company Men, often confused as the ‘man in command’ on the rig, are in fact representatives from the company that the drilling rig is drilling for, and are external to the drilling structure.  Their role is to ensure the rig is carrying out operations to the satisfaction of the company who pays for the rig to be there.



The clue is in the name again.  A semi-submersible, such as the Maersk Discoverer pictured above, is a floating drilling platform capable of operating in ultra deep water due to no need to either contact or tie itself to the seabed.  Some semi-submersibles are self-propelled and some have to be towed to location, but all will have thrusters to position themselves over the subsea well.

The command structure is broadly similar to a jack-up drilling rig but obviously brings different challenges as the heave of the sea has to be compensated for during drilling or completion activities. Accommodation, like a jack-up, tends to be much smaller than a platform due to space restrictions, but some of the newer semi-subs and jack-ups are reasonably well kitted out to make your stay a little more bearable, depending on what company owns the rig and what country it was designed to work in.  For example, an oil company or drilling company may design a luxurious accomodation module for a rig initially built to operate in European or American waters; single man cabins, televisions, phones, wi-fi in your room, and an equal time rotation or better. The same company may then specify in the middle east or far east for four man cabins, two public telephones you may need to buy a pre-paid card for, a communal television room, and a rotation that is closer to three months on and one month off.  Is it wrong?


Getting there


If you’re a very nervous flier, or get sea sick on a rowing boat, then perhaps a land based job would be more to your liking.  Visiting offshore rigs and platforms will in most cases require a helicopter trip to get there, although some regions shuttle via boats.  Actually, sometimes even in European waters during extended foggy conditions it becomes necessary to get back to land by boat, which involves being lifted by crane from the platform to the boat, so include a head for heights alongside flying and sailing.  I’ve done the platform to boat transfer (Billy Pugh) many times in several countries, and it’s best described as exhilarating to avoid disconserting the uninitiated.  In areas such as the North Sea, sea states are normally too poor for boat transfers, but fog brings calm seas and vice-versa in that particular oil playground, so it does happen on occasion, even in the harshest of sea areas.

By helicopter, the standard again varies across regions.  Stories of helicopters in Africa having steel plates fitted to the bottom to fend off pot-shots from disgruntled locals have been told.  In warmer climes such as the middle east it wouldn’t be abnormal to be handed a sorry looking life jacket and to climb in with locals in their flip-flops.  The European region is mostly much more structured, flying robust Sikorsky S92’s or the deeply unpopular Super Puma EC225 that was rebranded the Airbus / Eurocopter Ec225 following too many accidents.

Whether it is openly admitted or not, concern is visible on every passenger’s face each time they don their survival suit to board, but tension is more often than not masked by joviality, and that’s the way I like it.




  1. Hi I’m a marine engineer and looking to join a rig is there any phone numbers out there I can ring to get me started I have been in the marine industry all my life and looking to move up in the world


    1. Hi David,

      There are so many companies out there that to offer a few phone numbers probably wouldn’t be too helpful. My advice is to do a lot of research and prepare a top quality CV that draws on your marine experience.

      For links to offshore companies, directly to their careers pages, have a read at this article and the links at the bottom of the page:


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