Reference
Say what you mean.
Our industry runs on abbreviations that make perfect sense on a rig floor and none at all anywhere else. Here is every term used on this site, in plain language.
AFE
Authority for expenditure. The document by which an operator approves the money for a well or a change to one.
Annular velocity
The speed at which drilling fluid travels back up the space between the drill pipe and the hole wall. Too slow and cuttings settle out instead of coming to surface.
Barrier
Anything that stops formation fluid reaching the surface. A well is drilled with two independent, tested barriers at all times.
BHA
Bottom hole assembly. The collection of bit, steering tool, measurement tools and heavy pipe at the bottom of the string.
BOP
Blowout preventer. The stack of valves that closes the well in. Function-tested every fourteen days, pressure-tested every twenty-one.
Cantilever jackup
A jackup rig whose drill floor slides out on a beam over an existing platform, so it can drill or work over wells it is not sitting on.
Casing point
The depth at which drilling stops and a casing string is run and cemented. Moving it is a programme deviation.
Cement bond log
An acoustic log that tells you how well the cement is bonded to the casing and the formation. Xtragate runs one on every production string.
Choke
An adjustable restriction used to hold backpressure on the well, either while killing a kick or continuously on a managed-pressure well.
Day rate
The daily fee paid for the rig and its crew, whether it is drilling, tripping or waiting on weather.
Dogleg severity
How sharply the wellbore is turning, in degrees per hundred feet. High DLS makes casing and completions hard to run.
DP-2
A dynamic positioning class. A DP-2 vessel can hold station on thrusters after any single equipment failure.
ECD
Equivalent circulating density. The pressure the formation feels while you are circulating, expressed as a mud weight.
EUR
Estimated ultimate recovery. How much a well is expected to produce over its whole life.
Geosteering
Steering the wellbore in real time against the log rather than against the pre-drill plan, to stay inside the target rock.
Hookload
The weight hanging in the derrick. Compared live against the torque-and-drag model as an early warning of hole problems.
Ironhand
Xtragate's robotic pipe-handling concept, in which no person is on the drill floor at any point in the well. Currently a land test stand only.
Jackup
A mobile offshore unit that floats to location and then jacks its hull up out of the water on three legs.
Kick
An unplanned influx of formation fluid into the wellbore. Detected on flow-out and pit gain, and killed on a circulated kill sheet.
Kick tolerance
How large an influx the well can take and still be killed without breaking down the shoe.
LWD / MWD
Logging and measurement while drilling. Sensors in the BHA reporting formation and directional data on the way up the pipe.
MAASP
Maximum allowable annular surface pressure. The most you can hold on the annulus before the weakest exposed formation fractures.
MPD
Managed pressure drilling. A closed circulating system with a rotating control device and automated choke, used where the pressure margin is narrow.
Non-productive time
Any rig time that is not making hole or doing planned work. Xtragate's figure since start-up is 1.9%.
Pad drilling
Drilling several wells from one surface location, with the rig walking between slots rather than being rigged down.
POB
Personnel on board. The headcount at a location at any moment, tracked live for muster and for bed capacity.
Rate of penetration
How fast the bit is making hole, in feet per hour. Meaningless on its own without cost per foot beside it.
Rotary steerable
A steering tool that deflects the bit while the whole string keeps rotating, giving smoother hole than a sliding motor.
Semi-submersible
A floating drilling unit supported by submerged pontoons, held in place either by mooring lines or by dynamic positioning.
SIDPP
Shut-in drill pipe pressure. The number that tells you how much extra mud weight a kill requires.
Spud
To begin drilling a well.
Stop-work authority
The right of any person on a location to halt an operation they believe is unsafe, without needing to justify it first. Unconditional at Xtragate.
Tripping
Pulling the drill string out of the hole or running it back in. Historically the most injury-prone operation on a rig, which is why it is automated.
TRIR
Total recordable incident rate, per 200,000 hours worked. Xtragate's figure since start-up is 0.00.
TVD
True vertical depth. The straight-line depth below the rig floor, as opposed to measured depth along the wellbore.
WITSML
The industry standard for streaming well data between a rig and everybody who needs to see it.
Workover
Re-entering an existing well to repair, stimulate or recomplete it.
How we take work.
Xtragate does not tender publicly and does not accept unsolicited enquiries. Programmes come to us through operators we already work for.