Offshore oil glossary
The jargon you hear on your first hitch and quietly look up that night. Plain definitions, sourced to the IADC Lexicon and SLB's Energy Glossary wherever a real citation exists.
Key facts
- Terms defined
- 18
- Primary sources
- IADC Lexicon and SLB Energy Glossary
- Terms with no single citable source
- 9 -- given as standard industry usage, not invented
- Checked
- 2026-09-08
Checked 2026-09-08. Where a term has a real, citable source -- the IADC Lexicon (International Association of Drilling Contractors) or SLB's (Schlumberger's) Energy Glossary, both established industry references -- it's linked inline. Where it doesn't, that's said plainly rather than a source being invented.
The one-page jargon sheet
The compiled artifact for this cluster: every term below in one printable table, alphabetical.
| Term | What it means |
|---|---|
| Back-to-back | Running two crews on alternating rotations so a role stays continuously staffed offshore: one crew works its hitch while the other is off, then they swap. It's the structural reason offshore rotations run as fixed patterns like 21/21 instead of a normal work week -- see /rotations/. |
| Derrick | The tower-like structure over the drill floor that supports the crown blocks and the drillstring -- usually pyramidal in shape, built for a strong strength-to-weight ratio (SLB Energy Glossary). |
| DP (dynamic positioning) | A system that automatically holds a vessel's position and heading using its own thrusters instead of anchors or mooring lines. Formally, a DP vessel "automatically maintains its position and/or heading (fixed location, relative location or predetermined track) by means of thruster force" (IADC Lexicon, sourced to IMO MSC.1/Circ.1580). Used on mobile drilling units and specialist offshore support vessels rather than Newfoundland's own production platforms, which are fixed (Hibernia, Hebron) or moored (Terra Nova, SeaRose). |
| Drill floor | The stable working platform directly under the derrick, "surrounding the slip setting area, that provides support for employees during drilling operations" (IADC Lexicon) -- where roughnecks actually make and break pipe connections. |
| Flotel | A floating hotel -- an accommodation vessel or barge moored near a platform to house extra workers during a construction project or a major maintenance campaign, when an installation's own permanent quarters aren't enough. |
| FPSO | Floating Production, Storage, and Offloading vessel: "a ship-shaped or purpose-built facility" that gathers, processes, and stores fluids from subsea wells before offloading the oil to shuttle tankers (SLB Energy Glossary). Terra Nova and SeaRose, off Newfoundland, are both FPSOs -- see /platforms/. |
| GBS (gravity-base structure) | A large concrete platform base built to sit on the seafloor and stay in place by its own weight and ballast, rather than being piled or anchored down -- the design used at Hibernia and Hebron specifically because a GBS's mass and concrete construction can absorb an iceberg impact that a lighter structure couldn't. See /platforms/ for how Hibernia's and Hebron's GBS designs actually work. |
| Helideck | A purpose-built helicopter landing platform on an offshore installation (IADC Lexicon, sourced to the IMO's 2009 MODU Code) -- the only way crew and cargo move to and from a producing platform or FPSO off Newfoundland, since there's no dock out on the Grand Banks. |
| Hitch | The block of consecutive days worked offshore before flying home for time off -- 21 or 28 days on Newfoundland's platforms. Used as a noun ("this hitch") and loosely as a verb ("hitching out"). See /rotations/ for how 21/21 and 28/28 actually work. |
| Lifeboat / TEMPSC | TEMPSC stands for Totally Enclosed Motor Propelled Survival Craft -- the enclosed, davit-launched lifeboats used for a full platform evacuation, built to protect occupants from fire, cold, and heavy seas during launch and stand-off. Standard international maritime safety terminology (from SOLAS-derived rules), not specific to Canadian offshore installations. |
| Mud (drilling fluid) | The fluid circulated down the drill string and back up while drilling -- it cools and lubricates the bit, carries rock cuttings to surface, and helps control downhole pressure. Water-based mud specifically is "any water-based fluid composed of fresh water, naturally occurring clays, drilled solids and additives for fluid loss control, viscosity, thinning, pH control, weight control, etc." (IADC Lexicon). |
| Muster | To report immediately to your assigned emergency assembly point (muster station) when an alarm sounds, for a roll call and further instruction. Standard maritime and offshore safety terminology -- the exact muster procedure for a given platform is set by that operator's own emergency response plan, not summarized here. |
| POB (persons on board) | The total headcount of everyone physically on an installation at a given moment -- production crew, contractors, visitors, everyone -- tracked continuously because it's the number that has to be accounted for in any muster or evacuation. |
| Roughneck | A floor hand -- "a member of the drilling crew who works under the direction of the driller to make or break connections as drillpipe is tripped in or out of the hole" (SLB Energy Glossary). The IADC Lexicon's formal equivalent term is "Floorman," sourced to API RP 54, which lists roughneck, rotary helper, and driller's helper as alternate titles for the same role. |
| Roustabout | "Any unskilled manual laborer on the rigsite" -- loading and unloading, general cleaning, maintenance, and construction work, freeing up skilled tradespeople to do skilled work (SLB Energy Glossary). It's typically the easiest offshore role to land with no prior experience -- see /jobs/. |
| Topsides | The equipment and structures mounted above the waterline on a platform or FPSO -- process modules, drilling equipment, living quarters, the helideck -- sitting on top of the GBS or vessel hull that actually keeps the installation in place. When people talk about a platform's topsides being fabricated separately (often at a yard like Bull Arm) and later mated to its base, this is what they mean -- see /unions/ for how that fabrication work is staffed. |
| TR (temporary refuge) | A fire- and blast-protected area of a platform designed to protect personnel for a set period during an emergency while the situation is assessed and evacuation is prepared -- "the facilities provided for monitoring and control of the incident and protecting personnel prior to evacuation" (IADC Lexicon). |
| Weather window | A forecast period of acceptable wind and sea conditions in which a specific operation -- a helicopter flight, a supply-boat transfer, a crane lift -- can safely go ahead. Fog and weather off Newfoundland are a real operational factor; see /rotations/ for how that affects hitch scheduling and flight delays. |
Sources
- IADC Lexicon -- Oil and Gas Drilling Glossary (International Association of Drilling Contractors) — accessed 2026-09-08. Source for Floorman/roughneck, Temporary Refuge (TR), Drill Floor, Helideck, water-based drilling mud, and DP Vessel/System/Operation -- each entry cites its own underlying regulation or standard (API RP 54, IMO 2009 MODU Code, IMO MSC.1/Circ.1580, ISO 13702).
- SLB (Schlumberger) Energy Glossary — accessed 2026-09-08. Source for derrick, roughneck, roustabout, and FPSO.
Frequently asked questions
What's the difference between BST and HUET, versus HUEBA?
BST (Basic Survival Training) is the full 5-day course; HUET (Helicopter Underwater Escape Training) is bundled inside it; HUEBA is the specific compressed-air breathing apparatus used during the Canadian HUET simulator drill. See /tickets/ for the full breakdown, sourced to the offshore Code of Practice.
What is a roughneck, exactly, and how is it different from a roustabout?
A roughneck (formally "floorman" in the IADC Lexicon, sourced to API RP 54) is a drill crew member who works the drill floor itself, making and breaking pipe connections under the driller's direction. A roustabout is unskilled, entry-level rig-site labour -- general cleaning, loading, and maintenance -- that doesn't require prior drilling experience (SLB Energy Glossary). Roustabout is typically the easier role to land with no offshore background; roughneck is a step up on the drill crew.
What's the difference between a GBS and an FPSO?
A GBS (gravity-base structure) is a fixed concrete platform base that sits permanently on the seafloor under its own weight -- Hibernia and Hebron use this design, largely to resist iceberg impact. An FPSO (floating production, storage, and offloading vessel) is a ship-shaped or purpose-built floating facility that processes and stores oil before offloading it to tankers -- Terra Nova and SeaRose are both FPSOs (SLB Energy Glossary defines FPSO; see /platforms/ for how each Newfoundland installation is actually built).
What does TR mean, and is it the same as a muster station?
TR stands for temporary refuge -- per the IADC Lexicon, "the facilities provided for monitoring and control of the incident and protecting personnel prior to evacuation." In practice a platform's muster stations are typically located within or adjacent to its temporary refuge, so the terms overlap in everyday use, but TR is the broader safety-engineering term for the protected area itself.
Related guides
Off-shift entertainment
Some workers use off-shift downtime for regulated online gambling. If you do, only use operators registered in your own province -- see the regulated options by province, or pick your province below.
Regulated online gambling in Canada is province by province. Only operators registered for your own province are ever shown -- pick your province below to see what's actually available to you.
Off-shift only. Never gamble on company networks or devices. Please play responsibly. Gambling should be entertainment, not income.