Technical
Thesaurus oil & gas
T
Tanker
A ship or vehicle used to
transport oil, refined products or liquefied gas.
Tare weight
The weight of an empty
container, e.g. a road tanker.
Task
Prior to the commencement
of the inspection Tasks may be set up which help define the work to be
performed on the structure. Tasks may be assigned per component of the
structure. Usually a task is an Event name applied to a component. e.g. A Task
might be: Perform Flooded Member detection on Member 0 100-0 I 08. Member 0
100-0 108 will be defined in the Structure hierarchcal tree and Flooded Member
is an Event, which comes pre-configured with Inspection Manager Eventing
Module.
Taut wire measuring gear
An apparatus designed for
measuring horizontal distances at sea. It is constructed so that a wire of
small diameter, one end of which is anchored on the bottom, passes around a
calibrated sheave as the ship streams along the route to be measured.
Tax paid cost
The actual cost to an oil
company of the oil it produces in a particular country (all costs incurred plus
amounts paid to the State in royalties, rentals and taxes).
TD
See total depth.
Tectonic process
A process whereby rocks or
strata are deformed by natural forces within the Earth's crust.
Telemetry
The study and technique
involved in measuring a quantity or quantities in place, transmitting this
value to a station, and there interpreting, indicating, or recording the
quantities.
Temperature gradient
The rate of increase or
decrease of temperature against depth. The rate of regular or graded ascent or
descent of temperature.
Temperature log
Recording temperature
variations down hole by the use of an electrode containing a length of platinum
wire that readily assumes the temperature of the drilling mud, gas or water in
the hole. One important use of the logging device is to determine the location
of cement in the annular space between casing and well bore after a cement job.
The curing or hardening cement gives off heat which alters the temperature
gradient in the well bore and which can be detected by the tool.
TEMPSC
Totally Enclosed Motor
Propelled Survival Craft. The primary method of escape from offshore oil and
gas facilities. Provides an enclosed safe haven for workers escaping from a
burning rig.
Tension leg platform
A semi-submersible drilling
platform held in position by multiple cables anchored to the sea floor. The
constant tension of the cables makes the platform immune to heave, pitch and
roll caused by wave action conditions that affect conventional
semi-submersibles. See semi-submersible drilling rig.
Terminal
An onshore installation
designed to receive oil and/or gas from a pipeline or from tankers; it is not a
refinery.
Terminal platform
An offshore platform from
which oil or gas is pumped ashore through a pipeline.
Tertiary era
The era of geological time
which began roughly 60 million years ago and ended roughly one million years
ago; it is in lower Tertiary formations that many oil fields have been found in
the
Tertiary recovery
Recovery of oil or gas from
a reservoir over and above that which can be obtained by primary and secondary
recovery; it generally involves using sophisticated techniques such as heating
the reservoir to reduce the viscosity of the oil.
Texas tower:
A fixed tower mounted on
the continental shelf or on a shoal used to drill and operate gas or petroleum
wells, and to provide a platform with aids to navigation and meteorological or
oceanographic instruments.
Therm
100,000 British Thermal
Units; a unit used to measure quantities of gas.
Thermal cracking
The process whereby heavy
hydrocarbon molecules are broken etc.
Thermal shock
The property of a material
to withstand rapid changes in temperature without fracture.
Thermocouple
An electrical temperature
measuring device consisting of two wires of differing metals which are joined
at the ends. When this junction is heated, the voltage produced is
proportionate to the temperature.
Thermowell
A hollow tube placed inside
a vessel in which a thermometer, or other temperature indicator, is inserted.
It is sometimes filled with mercury to ensure uniform and rapid heat
conduction.
Thief zone
A very porous formation
downhole into which drilling mud is lost. Thief zones, which also include crevices
and caverns, must be sealed off with a liner or plugged with special cements or
fibrous clogging agents before drilling can resume.
Thread protector
A device that is screwed
onto or into pipe threads to protect the threads from damage when the pipe is
not in use. Protectors may be metal or plastic.
Three-point fix method
One of the principal
methods used on inshore hydrographic surveys for establishing the position of
the survey vessel. It involves the measurement with sextants of two angles between
three known stations, the middle station being common to both angles, and
plotting the vessel's position graphically with a three-arm protractor.
Thribble
A stand of pipe made up of
three joints and handled as a unit. See stand. Compare single, double, and
fourble.
Thribble board
The name used for the
working platform of the derrick man, or monkeyboard, when it is located at a
height in the derrick equal to three lengths of pipe joined together. Compare
double board and fourble board. See monkeyboard.
Throughput
A term used to describe the
total amount of raw materials that are processed by a plant such as an oil
refinery in a given period.
Throwing chain
The act of employing a
spinning line in making a connection between two sections of pipe.
Thruster propeller
A small propeller mounted
underneath a floating structure or vessel to enable it to change or maintain
its position.
Tidal difference
Difference in time or
height of a high or low water at a subordinate station and at a reference station
for which predictions are given in the tide tables. The difference, when
applied according to sign to the prediction at the reference station, gives the
corresponding time or height for the subordinate station.
Tidal movement
The movement which includes
both the vertical rise and fall of the tide, and the horizontal flow of the
tidal currents. This movement is associated with the astronomical
tide-producing forces of the moon and sun acting upon the rotating Earth.
Tide
The periodical rise and
fall of the surface of oceans, bays etc., due principally to the gravitational
interactions between the moon, sun, and Earth.
Tide analysis
The mathematical process by
which the observed tide or tidal current is separated into basic constituents.
Tie-in
An operation in pipeline
construction in which two sections of line are connected; a loop tied into the
main line; a lateral line to a trunk line.
Tight formation
A petroleum or
water-bearing formation of relatively low porosity and permeability. See porosity
and permeability.
Time (Greenwich Mean Time or
Mean solar time at the
Time (local)
Time based upon the local
meridian as reference, as contrasted with that based upon a zone meridian, or
the meridian of
Time charter
Charterer has the use of
the vessel for a specified period. The shipowner supplies the crew and
provisions.
Toluene
Methyl benzene (C6HSCH3)
-an important organic solvent.
Ton
A long ton weighs
Tong line
A wire, manila or fibre
rope attached to a tong handle in order to exert torsion on a pipe.
Tongs
Hydraulically operated
grabs used to hold sections of pipe during screwing or unscrewing; sometimes
known as pipe tongs.
Tool joint
A heavy coupling element
for drill pipe made of special alloy steel. Tool joints have coarse, tapered
threads and seating shoulders designed to sustain the weight of the drill stem,
withstand the strain of frequent coupling and uncoupling, and provide a leak
proof seal. The male section of the joint, or the pin, is attached to one end
of a length of drill pipe, and the female section, or box, is attached to the
other end. The tool joint may be welded to the end of the pipe, or screwed on,
or both. A hard metal facing is often applied in a band around the outside of
the tool joint to enable it to resist abrasion from the walls of the borehole.
Tool string
A term used in wireline
operations which consists of rope socket, stems, jars, knuckle joints. To this
is connected the running or pulling tool with the sub-surface controls.
Toolpusher
The supervisor in charge of
the drilling rig and associated equipment.
Torque
The turning force that is
applied to a shaft or other rotary mechanism to cause it to rotate or tend to
do so. Torque is measured in foot-pounds, joules, metre-kilograms, and so
forth.
Torque converter
A connecting device between
a prime mover and the machine actuated by it. The elements that pump the fluid
in the torque converter automatically increase the output torque of the engine
to which the torque is applied, with an increase of load on the output shaft.
Torque converters are used extensively on mechanical rigs that have a compound.
See mechanical rig.
Torr
An international unit of
vacuum measurement. 760 torr = one standard atmosphere.
Total depth
The maximum depth reached
after the drilling or deepening of a well. It is usually quoted either along
hole or true vertical.
Total salinity
The total amount of salts
dissolved/contained in a specific volume of liquid (mainly water). It is
usually expressed as mg/ l or ppm.
Tour
A drilling shift
(pronounced "tower").
Town gas
The traditional type of
locally manufactured gas fuel, originally made from coal.
Toxic
The quality of substance
being poisonous.
Track plotter
A plotter used to plot the
track or course of a craft.
Tranche
A portion of the total
amount available under a loan agreement that is taken up at anyone time.
Transducer
A device which converts one
type of signal to another (e.g. electronics to acoustic and vice versa).
Transhipment
Transfer of a cargo from
one ship (or other means of transport) to another.
Transmission
The gear or chain
arrangement by which power is transmitted from the prime mover to the
drawworks, mud pump, or rotary table of a drilling rig. See prime mover.
Transparent
A term used to denote that
a price is promptly and publicly ascertainable, as for example on the IPE and
NYMEX where trading is by open outcry and prevailing prices are immediately
available on screen internationally through the Reuter Monitor, Telerate and
similar services
Transponder
A device which transmits an
acoustic signal automatically on receipt of one.
Transverse mercator grid
The grid on a chart using
the transverse mercator projection. Also see UTM.
Trap
A geological structure in
which hydrocarbons build up to form an oil or gas field.
Travelling block
The moving pulley system
used in conjunction with the (fixed) crown block for raising and lowering the
drill string, casing, etc.
Treatment plant
See processing plant.
Trend
A general term for the
direction or bearing of a geological feature of any dimension, such as layer,
vein, ore body or fold.
Triassic period
The period of geological
time which began roughly 230 million years ago and ended roughly 180 million
years ago.
Trip
The operation of hoisting
the drill stem from and returning it to the well bore. See make a trip.
Trip gas
Gas encountered in the
bottom of a well that is being drilled after pulling and re running the entire
drill string.
Tripping the bit
Removing the bit from the
hole and running it in again. (In removing the bit the drill pipe must be
pulled a stand at a time in order to reach the bit).
Tropical cyclone
A tropical low pressure
area in which winds exceed 33 knots in all quadrants.
Tropospheric scatter radio network
A communications technique
involving the scatter of short-wave radio waves from the lower part of the
atmosphere
True vertical depth
The projection of any
deviated hole or portion of it in the vertical direction. It is calculated
using the directional survey data.
Tubing
Steel pipe hung inside the
casing, often only supported by the wellhead. Oil and gas are produced to the
surface through the tubing which protects the production string of casing.
Tubing hanger
A device screwed on top of
a tubing string used to suspend the string from the wellhead and to seal the
annulus formed by the tubing and the casing.
Tubing head
A unit, attached to the
uppermost casing head or smallest casing string, which serves to suspend the
tubing and to seal the annular space between the tubing and casing.
Tubing performance
The relationship in a
producing well between the different production rates, Phase(s) produced, FTHP,
FBHP. for the specific string installed in that well.
Tungsten carbide
An extremely hard material
used in the manufacture of drill bit studs.
Turbine
A piece of equipment in
which a shaft is steadily rotated by the impact of a current of steam, air,
water or other fluid directed from jets or nozzles upon blades of a wheel.
Turbine drilling
Drilling in which the drill
string remains stationary, the bit being rotated by a downhole multi-stage
turbine powered by the drilling mud.
Turbine meter
A flow meter in which fluid
is passing a rotor and causing it to turn with an angular velocity that is
proportional to the fluid linear velocity and, therefore the volumetric flow
rate.
Turbodrill
The down hole drilling
mechanism used in turbine drilling.
Turnkey contract
A contract in which a
drilling contractor agrees to furnish all materials and labour and do all that
is required to drill and complete a well in a workman-like manner. When on
production, he “delivers" it to the owner ready to "turn the
key" and start the oil running into the tank, all for an amount specified
in the contract. Also used for engineering and production contracts.
Twist off
To twist a joint of drill
pipe in two by excessive torque applied by the rotary table. Many failures
which result in parting of the drill pipe in the well bore are erroneously
referred to by this term.
Typhoon
In the NW Pacific region, a
tropical cyclone with winds exceeding 63 knots (storm force). Also known as
hurricanes or severe tropical cyclones.