Technical
Thesaurus oil & gas
Letter
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.
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