Technical
Thesaurus oil & gas
Letter
V
Vacuum
A system is under vacuum when
its pressure is below that of the surrounding atmosphere. The lower the pressure,
the higher the vacuum.
Valves
Devices to control or regulate
the flow of liquids or gases through pipes. The main types are diaphragm,
gate, globe, butterfly, check, ball, plus and relief.
Vapour
Substance in a gaseous state.
V-belt
A belt with a trapezoidal
cross section that is made to run in sheaves, or pulleys, with grooves of
corresponding shape. See belt.
V-door
The opening in the derrick
opposite the drawworks used for bringing in drill pipe and casing from the
nearby pipe racks.
Velocimeter
An instrument used for the
"in situ" measurement of the speed of sound in the sea and other
natural waters.
Velocipede
Instrument using a probe lowered
to the sea-bed and used to calibrate echo sounders; may be called TDS or CTD
dip as it measures temperature, depth and salinity (or conductivity); in most
waters (less than
Velocity
1. Of sound in sea water (velocipede).
2. Seismic velocities, also
acoustic (two way time).
Vent losses
Acid gas which is being vented.
Venturi meter
An instrument for measuring
the volume of flowing gases and liquids. It consists of two parts -the tube
through which the fluid flows and a set of indicators which show the pressures,
rate of flow or quantity discharged. The tube, in the shape of an elongated
hour glass, is flanged into a pipeline carrying the fluid. The effect of the
tube is to increase the velocity and decrease the pressure at the point where
the tube's diameter is reduced. The relationship between the line pressure
and the narrow "waist" of the tube is used in computing the rate
of flow.
Very large crude carrier (VLCC)
A large ocean-going tanker
of over 200,000 metric tonnes deadweight used to transport crude oil from
its source to a transhipment storage facility or direct to a refinery.
Vibrocorer
Soil sampling device lowered
to the sea-bed and using hammering action to penetrate, produces cores up
to five to
Viscosity
A measure of the resistance
that a fluid makes to motion or flow; it usually decreases as the temperature
rises.
Viscosity index improver
A compound added to lubricating
oils to maintain their viscosity at high temperature.
VLCC
Very Large Crude Carriers
Voyage charter
The shipowner hires his vessel,
subject to various conditions, for the carriage of cargo for a single voyage.
V-sec
The viability (yes/no) which
indicates whether reserves can be calculated from the actual company reserves.
Vug
A cavity in a rock.