By popular demand here is a run-down of a few common offshore terminologies and slang.
Oil rigs and platforms - they are really two different items. Generally a 'rig' is mobile and does the exploratory drilling.
Rigs are either semi-submersible (big square floaters basically) like this...
... Jack-up rigs (which stand on legs and jack themselves out the water) and drill-ships (often large ships with a hole cut in the middle and converted to drilling).
Platforms (also known as 'Jackets') are the permanent structures (like Piper Alpha etc) which take over the drilling process once oil/gas is found. Platforms have varying functions, drilling, processing, accomodation etc and are often joined by walkways to form a '
Complex'.
This photo shows a platform with a jack-up drilling rig behind it...
Notice the 'clarity' of the water - this is the Bombay 'High' field - perhaps
the most challenging place you'll ever work - no vis and tides running faster than Intercity!
Up the side of any platform/jacket you'll find vertical pipes that extend from the sea-floor, these are called '
Risers' and they carry all manner of stuff; oil, gas, water and have varying sizes from 4" to over 32". Risers are held in place at varying depths down the platform face by
riser clamps which can either be installed during jacket fabrication or later on by... you, the diver. The thinner the riser the more clamps there are securing it. At the very bottom of the riser you'll find the
'J' tube which turns the vertical riser into the horizontal of a pipeline.
Platforms as you can see above look like a latticework of pipes and they have their own names. At the corners there are the
Legs (jackets may have more than 4 legs - thats an eight-legger in the photo). All the lesser structural pipes/tubulars are called
Members and there are
Horinzontal members (that form box shapes) and
Horizontal Diagonal members (which join corners and form diamond shapes). On the vertical face of a jacket there are horizontals at each
Level and these
levels have diagonal members joining them -
Vertical Diagonal Members or VDM's. The point at which members meet is called a '
Node' and there are 'K' nodes and 'X' nodes which refer to their shape.
The diver is grit-blasting an 'X' node for weld inspection. Two VDM's originating from the horinzontal member form a 'V' shape and there is a mirror image beneath the horizontal.
Platforms are larger at their base than at the top - sloping inwards like a pyramid does except not so pronounced. This 'slope' is called the jacket/platform '
Batter' (not to be confused with a cod fillets batter or a Mars Bars if you're a Jock). Batter angles vary from jkt to jkt ie, 1:6.8, 1:8, 1:10 etc and some jackets have a face with no batter ie, 100% vertical.
The first deck level on a platform is called the
'Spider Deck' and the area between the spider deck and the 'oggin is called the
'Splash Zone'. The next deck above the s/deck is the
'Cellar Deck', here and above is the gubbins of the platform which doesn't concern us here. Around the jkt legs you'll see bundles of small diameter pipes (2"-ish) running into the water - these are
'Grout Pipes' (can be seen behind the diver above - held by brackets to the inside of the leg) and they're your friend! When the tide is running like stink, theres no vis, your umbilical weighs a ton and the platform leg is 2.5 metres wide with bugger-all to hold-on to... find a grout pipe - happiness. They are often the only thing handy to tie anything off to and it don't matter if they get a bit bent 'cos once the platform is installed gt/pipes are defunct.
Anodes - these are big lumps of zinc and something-or-other which are welded to the platform to help protect it from the electrolitic action of seawater (in above photo, 3 metres behind the diver on horinzontal). You'll find them dotted over the members and you'll know they are there 'cos they will foul your umbilical. Somtimes we have to remove them to install clamps and stuff on a member and then we re-install or
'Retro-fit' the anode close to where it was removed. You may also get to install
'Bracelett Anodes' on a platform where the original ones are depleted.
Right, on to vessels. A
DSV is a Diving Support Vessel as seen here...
My place of work.
Very often they will have one or two holes in their hulls (like the drill ship) for bell or ROV (Rarely Operative Vehicle) launching. This hole is the
Moonpool. Although the correct term for a Bell is an SDC (work it out yourselves) it is always known as a
Bell as a chamber (DDC) is always known as a 'pot' or the 'bin' - never 'tins'! Whether on a saturation project or air diving work a DSV will generally work (dive) 24/7, Xmas, New Year, your birthday (though you'll get a cake from the cooks) and even your divorce anniversary - you can have a cake for that too.
Around the dive system. Doors to chambers are either 'doors' or 'hatches' and are held shut by locking handles called '
dogs'. The short (sometimes long) cylindrical space before a hatch is a '
trunking' and the hole in the bottom of a bell is known as 'trunking' or 'trunk'.
Well, thats me just about run out of ideas for the present but I'll add more as they come to me. However, someone asked me recently about pigs and was it true that we kept them offshore? Yes, we do keep pigs offshore, they are used as plugs to clean debris etc from the inside of pipelines. You choose a pig of the correct size for the pipeline (must be a tight fit), push it inside, seal the end of the pipeline and put pressure behind it. This forces the pig down the pipeline dragging or rather collecting debris as it continues to the other end of the line (which may be several miles) where it is finally caught in... the 'pig-catcher' of course!
Berko
PS; I doubt any of this information will be given by schools so someone owes me a grand so far at least!