Technical Thesaurus oil & gas
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
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.