Technical
Thesaurus oil & gas
P
Packed columns
A distillation or
absorption tower which is filled with small objects, called packing, to effect
an intimate contact between rising vapours.
Packer
A mechanical device
containing a rubber packing element which can be expanded against the well bore
or casing to isolate the annular sections above and below the element.
Packer fluid
Any tough, pliable material
-rubber or fibre -used to fill a chamber or "gland" around a moving
rod or valve stem to prevent the escape of gas or liquid; any yielding material
used to effect a pressure-tight joint. Packing is held in place and compressed
against a moving part by a "follower", an adjustable element of the
packing gland.
Palaeozoic era
The era of geological time
(comprising the Cambrian, Ordovician, Silurian, Devonian, Carboniferous and
Permian Periods) which began roughly 600 million years ago and ended roughly
230 million years ago.
Paper barrels
Crude oil or products
traded on the forward or similar markets which are closed out by subsequent
sale or settlement without physical or 'wet' delivery.
Paraffin
A name given in the
Paraffins
The simplest homologous
series of hydrocarbons containing no unsaturated carbon-to-carbon bonds; also
known as the alkanes.
Paraxylene
An aromatic compound used
in the manufacture of polyester fibres.
Party chief
The industry expression for
the manager of a survey team.
Pay sand
The producing formation,
often one that is not even sandstone. It is also called pay zone, and
production zone.
Pay zone
The stratum of rock in
which oil and/or gas is found.
PDVSA
Petroleos de Venezuela S.A.
PEMEX
Petroleos Mexicana
Pentane
The saturated hydrocarbon
(alkane) with five carbon atoms in its molecule (CSH 12); the fifth member of
the paraffin series -a liquid under normal conditions.
Perforate
To pierce the casing wall
and cement to provide holes through which formation fluids may enter, or to
provide holes in the casing so that materials may be introduced into the
annulus between the casing and the wall of the borehole. Perforating is
accomplished by lowering into the well a perforating gun, or perforator, that
fires electrically detonated bullets or shaped charges from the surface. See
gun perforator.
Perforating gun
See gun perforator.
Permeability
A measure of the capacity
of a rock or stratum to allow water or other fluids such as oil to pass through
it.
Permian period
The period of geological
time which began roughly 280 million years ago and ended roughly 230 million
years ago.
Persuader
An oversize tool for a
small job; an extension added to the handle of a wrench to increase the
leverage.
Petrochemical
An intermediate chemical
derived from petroleum, hydrocarbon liquids or natural gas, e.g. ethylene,
propylene, benzene, toluene and xylene.
Petrol
See motor spirit.
Petroleum
A generic name for
hydrocarbons including crude oil, natural gas liquids, natural gas and their
products.
Petroleum engineer
The engineer who is
responsible for the overall strategy of oil and gas drilling and production
operations for a particular field.
Petrosulphur compounds
Hydrocarbon chemicals which
include sulphur in their molecules, e.g. mercaptans.
pH
A measure of the acidity or
alkalinity of a solution which is a function of the hydrogen-ion-concentration.
The pH scale is a logarithmic scale and ranges from 0, which represents a
strong acid, to 14, which represents a strong alkali. A neutral solution, which
is neither acidic nor alkali, and pure water, has a pH value of 7.
Photovoltaic (Electricity from sun)
Photovoltaic technology
allows for the direct tranformation of solar energy into electric energy.
Photovoltaic systems have been installed all over the world giving more than
500 MWp power in order to provide locally generated energy to isolated users
and communities and to produce power for the distribution grids. Interest in
photovoltaics lies in the following characteristics: widespread availability of
the solar source, total modularity (from a few watts up to megawatts), high level
of reliability, low maintenance requirements. Solar energy can be converted
into electricity not only by means of photovoltaic systems, but also using
thermodynamic technology. By concentrating radiation with mirrors, high
temperatures can be reached and steam can be generated to produce energy with
traditional turbo-generators. All over the world there are a dozen plants
giving a total installed power of 360 MW.
Photovoltaic peak power stations
Photovoltaic power stations
are electric power stations which are highly modular (100-300 kWp modular
units) and easy to integrate in Medium Voltage distribution networks. Entirely
automated and remote controlled, they have very low maintenance costs and make
it also possible to reinforce the weak points of the grid, improving
reliability and quality of service during peak hours.
Photovoltaic rooftops
Photovoltaic systems
integrated into residential and industrial constructions (photovoltaic
rooftops) can range in size from a few kilowatts to hundreds of kilowatts, and
are connected to the distribution electricity grid. They produce energy to
satisfy local electricity power requirements and use the network as backing, by
absorbing energy when it is lacking or supplying it in case of surplus. This
application is characterised by the following features: production of energy
close to the load, use of marginal surface areas, possibility of replacing
conventional building elements with photovoltaic modules.
Pig
A piece of equipment that
is inserted into a pipeline and is carried along by the flow of oil or gas;
used to clean or monitor the internal condition of the pipeline or to mark an
interface between two different products.
Piling
Steel piles driven into the
sea-bed to anchor fixed steel structures such as production and drilling
platforms.
Pilot
A small flame in the flare
section to control the burning of gas. There are three pilots in each flare
system, and they are alight continuously. The pilots will ignite gas that is
sent through to be flared.
Pin
The male section of the
tool joint. See tool joint.
Pin end
Externally threaded pipe
end which screws into a box or female end.
Pinch-out trap
A trap where a bed or
reservoir rock gets progressively thinner as it nears an impervious area and
eventually disappears.
An acoustic pulse signal
projected by an underwater transducer.
Pinger
A device which produces a
short pulse of relatively low energy sound for acoustic work.
Pipe hook
A steel hook used in
handling drill pipes.
Pipe laying barge
See lay barge.
Pipe rack
A structure on which
sections of piping or casing may be stored.
Pipe ram
A sealing component for a
blowout preventer that closes the annular space between the pipe and the
blowout preventer or wellhead. See annular space and blowout preventer.
Pipe tongs
See tongs.
Pipeline
A pipe through which oil,
its products, or gas is pumped between two points, either offshore or onshore.
Pit
An unroofed sump or tank
for holding liquids such as drilling mud.
PIW
Petroleum Intelligence
Weekly
Plant unit
A major piece of equipment
within a plant section or possibly a plant train, e.g. sulfinol unit.
Plastic
A generic term for a range
of high-molecular-weight polymers that can be used to produce artefacts.
Plastic resins
See engineering plastic
resins.
Plastic viscosity
The plastic viscosity is a
measure of the internal resistance to fluid flow attributable to the amount,
type and size of solids present in a given fluid.
Plastomer
A molecule or combination
of molecules that can form the basis of a polymer or plastic.
Plate column
A distillation column
consisting of a number of equally spaced, perforated, horizontal plates which
may be used in place of a packed column.
Plateau level
The level of peak
production reached by an oil or gas field; it is always followed by declining
levels of production.
Platform
An offshore structure from
which development wells are drilled. See drilling platform, production
platform.
Platform equipment
The equipment installed on
a production or drilling platform (drilling equipment, processing equipment,
power plant, accommodation modules, etc.).
Platform sample
A sample of hydrocarbon,
water, corrosion, etc., collected on the production platform.
Plugging a well
When a well is abandoned
for any reason, either temporarily or permanently, it must be sealed off to
ensure that no escape of any kind can occur. This sealing off is generally
accomplished by insertion of a plug of cement. Also called plugging.
Pneumatic control
The control and monitoring
of automated or remote processing plant by means of compressed air.
Polished rod
A smooth brass or steel rod
that works through the stuffing box or packing gland of a pumping well; it is
the uppermost section of the string of sucker rods, attached to the walking
beam of the pumping jack.
Polyacrylamides
A class of resins which
swell when water is added to them.
Polyethylene (polythene)
A polymer formed by joining
ethylene molecules together; one of the most important plastics.
Polymer
A complex compound formed
by the polymerisation of one or more monomers.
Polymerisation
The process whereby simple
units containing one or more molecules are joined together to form complex
molecules.
Polyphenylene sulphide
An engineering plastic with
excellent resistance to most chemicals.
Polypropylene
A polymer formed by joining
propylene molecules together; an important plastic.
Pontoon
A hollow buoyancy tank used
to support a semi-submersible rig, barge or other structure.
Porcupine
A cylindrical steel drum
with steel bristles protruding from its surface; pipe-cleaning pig for swabbing
a sediment laden pipeline.
Pore
An opening or space within
a rock or mass of rocks, usually small and often filled with some fluid (as
water, oil, gas, or all three). Compare vug.
Pore pressure
The natural internal
pressure in a formation.
Porosity
A measure of the amount of
free space or voids in a rock; generally expressed as a percentage of the total
volume.
Positioning
Practise used to compute
coordinate locations; a static process (i.e. instantaneous position fixing even
in a moving craft). Methods include radio positioning (surface), acoustic
positioning (underwater). There is unavoidable overlap between navigation and
positioning, both of which use similar systems offshore (navigation uses radio
positioning while positioning sensors uses ship's gyro).
Positive choke
A choke in which the
orifice size must be changed to change the rate of flow through the choke. See
choke and orifice.
Positive displacement pump
A pump that displaces or
moves a measured volume of liquid on each stroke or revolution; a pump with no
significant slippage; a piston, plunger or rotary pump.
Possible reserves
Undeveloped oil and/or gas
reserves which best judgement indicates might eventually be recoverable from
undrilled or untested structures.
Post completion
After setting the tubing
string for the purpose of continuous production from a well.
Potable water
Water that is fit for human
consumption (e.g. drinking).
Potential
The production possibility
of a well.
Potential (optimum)
The rate at which the well
can produce with the optimum completion equipment installed.
Potential (present)
The rate at which the well
can produce with the present completion equipment installed.
Power tong
An air or
hydraulically-powered mechanism for making up and breaking out joints of drill
pipe, casing or tubing.
Precipitate
An insoluble substance
formed in a solution by a chemical reaction; it sinks to the bottom of a vessel
as a sediment.
Precision emphemeris
The emphemeris which
describe the orbit of a navigational satellite precisely. They are of higher
precision than the broadcast emphemeris but not available in real time
Preheater
A type of heat exchanger in
which a cold liquid or gas being fed to a process is preheated utilising one of
the hot liquids or gases leaving the process, or by steam.
Prepayment
The repayment to the bank
of a specific amount of debt under a loan agreement before the scheduled time.
Pressure
The force of one body
acting on another by weight or the application of power. Measured as force per
unit area, e.g. pounds per square inch (psi).
Pressure drop
The decrease in pressure
due to friction which occurs when a liquid or gas passes through a pipe, vessel
or other piece of equipment.
Pressure equipment
Vessels, piping and other
equipment specially designed to operate under pressure. Excessive pressure
relief is provided by safety relief valves, or bursting discs.
Pressure gauges
Devices for the measurement
of pressure.
Pressure gradient
A scale of pressure
differences in which there is a uniform variation of pressure from point to
point. For example, the pressure gradient of a column of water is about 0.433
psi/ft of vertical elevation (9.794 kPa/m). The normal pressure gradient in a
well is equivalent to the pressure exerted at any given depth by a column of 10
per cent salt water extending from that depth to the surface (i.e., 0.465
psi/ft or 10.518 kPa/m).
Pressure relief valve
A valve that opens at a
preset pressure to relieve excessive pressures within a vessel or line; also
called a relief valve, safety valve, or pop valve.
Pressure surge
A sudden, usually
short-duration increase in pressure. When pipe or casing is run into a hole too
rapidly, and increase in the hydrostatic pressure results, which may be great
enough to create lost circulation. Pressure surges can also occur when starting
up pumps or compressors or when opening or closing valves.
Preventer
Shortened form of blowout
preventer. See blowout preventer.
Primary cementing
The cementing operation
that takes place immediately after the casing has been run into the hole; used
to provide a protective sheath around the casing, to segregate the producing
formation, and to prevent the migration of undesirable fluids. See secondary
cementing and squeeze cementing.
Primary migration
Nearly all sedimentary
rocks contain a small percentage of organic materials from which petroleum
could be formed. As pressure from overlying layers compacts these 'source'
rocks, the oil or gas droplets are squeezed out and joined together to form
globules large enough to flow under pressure.
Primary recovery
Recovery of oil or gas from
a reservoir purely by using the natural pressure in the reservoir to force the
oil or gas out.
Prime mover
An internal-combustion
engine that is the source of power for a drilling rig in oilwell drilling.
Priming
Reference a boiler, a
violent, spasmodic action resulting in the throwing of slugs of water over with
the steam; reference a pump, preliminary filling of the pump with liquid
vapours, hence eliminating the tendency to become vapour locked.
Principal
The original sum borrowed
on the basis of which interest is calculated. See loan capital, interest.
Probable reserves
Undeveloped oil and/or gas
reserves considered to be recoverable from penetrated formations but lacking
information to be classified as proven reserves.
Process engineering
That branch of engineering
which deals with industrial processes, particularly the production of
petrochemicals and their products.
Processing
In the context of survey,
refers to navigation (producing charts), analogue work (conditioning raw
signal), or digital work (producing sections from raw data, onboard or ashore).
Processing plant
Special plant installed on
a production platform or at a pipeline terminal to separate gas, oil and water
from a mixture containing some or all of these components. Also called
treatment or separation plant.
Producing horizon
Rock from which oil or gas
is produced.
Production
1. The phase of the
petroleum industry that deals with bringing the well fluids to the surface and
separating them and with storing, gauging, and otherwise preparing the product
for the pipeline. 2. The amount of oil or gas produced in a given period.
Production drilling
Drilling of wells in order
to bring a field into production.
Production licence
A licence to produce oil or
gas in a particular area issued to a company by the governing State.
Production phase
The phase in the life of a
field in which oil or gas is produced.
Production platform
A platform from which
development wells are drilled and which carries all the associated processing
plant and other equipment needed to maintain a field in production.
Production string
See production tubing.
Production test
A test conducted in a well
to assess its production potential through measurements of pressures and fluid
volumes produced during various specified time intervals.
Production trains
Series of separating and
processing facilities on a platform and in a plant for a stream of
hydrocarbons.
Production tubing
The pipe in a production
well through which oil or gas flows from the reservoir to the surface. Also
known as the production string.
Production well
A well used to remove oil
or gas from a reservoir.
Profile
Analogue sub sea-bed record
(metres to tens of metres penetration).
Project life
The length of time a
project is estimated to last.
Projection (lambert conformal conic)
A conformal projection of
the conical type on which all geographic meridians are represented by straight
lines which meet in a common point outside the limits of the map, and the
geographic parallels are represented by a series of arcs or circles having this
common point for a centre. Meridians and parallels intersect at right angles,
and angles on the Earth are correctly represented on the projection. This
projection may have one or two standard parallels along which the scale is held
exact.
Projection (mercator)
A conformal projection of
the cylindrical type. The Equator is represented by a straight line true to
scale; the geographic meridians are represented by a straight line
perpendicular to the line representing the Equator; they are spaced according
to their distance apart at the Equator. The geographic parallels are
represented by a second system of straight lines perpendicular to the family of
lines representing the meridians, and therefore parallel with the Equator.
Conformality is achieved by mathematical analysis, the spacing of the parallels
being increased with the increasing distance from the Equator to conform with
the expanding scale along the parallels resulting from the meridians being
represented by parallel lines. Since rhumb lines appear as straight lines and
directions can be measured directly, this projection is widely used in
navigation.
Propagation:
Transmission of signals
from radio or sonic devices. Velocity of p -For radio waves, somewhere near the
velocity of sound in air. P Factor - Factor to use on signal values due
generally to minor variations in the transmission conditions at that time.
Propane
The saturated hydrocarbon
(alkane) with three carbon atoms in its molecule (C3H8); the third member of
the paraffin series -a gas under normal conditions.
Propene (propylene)
The member of the alkene
series containing three carbon atoms, two of which are connected by a double
(unsaturated) bond (C3H6); an important raw material in the chemical and
plastics industries.
Proppant
See propping agent.
Propping agent
A granular substance (as
sand grains, aluminium pellets, or other material) carried in suspension by the
fracturing fluid that serves to keep the cracks open when the fracturing fluid
is withdrawn after a fracture treatment.
Prospect
Geological structure that
can be hydrocarbon bearing; interpreted from a number of techniques, one of the
more important being mapping of seismic data.
Proven field
An oil and/or gas field
whose physical extent and estimated reserves have been determined.
Proven reserves
Those reserves proved to a
high degree of certainty by reason of actual depletion, successful testing or,
in certain cases, adequate core analyses or quantitative log interpretation.
They are defined really by reasonable geological interpretation of structures
and known continuity of oil or gas saturated reservoir rock. If reliable
correlations can be made between two wells then the intervening area may also
be regarded as proven.
PSI
Abbreviation for pounds per
square inch. See pressure.
Pull one green
To pull a drill bit from
the hole before it is worn out; to pull a bit before it is necessary.
Pulling tubing
The operation of removing
the tubing from a well.
Pump duplex
A double acting, two
cylinder, constant displacement, reciprocating piston or plunger pump.
Pump pressure
Fluid pressure arising from
the action of the pump.
Pump simplex
A one cylinder steam pump
used in refineries and processing plants. Simplex pumps are simple,
direct-acting pumps with the steam piston connected directly to the pump's
fluid plunger.
Pump triplex
A single acting, three
cylinder, constant displacement, reciprocating plunger pump.
Pumps
Mechanical devices to
transport liquids or gases from one vessel to another along pipelines. There are
a wide variety of pumps of three, general types: reciprocating, gear and
centrifugal. The choice depends on the height to which the liquid is to be
pumped (delivery head), quantity and nature of the liquid (viscosity, corrosive
nature, etc.) and availability of prime movers (electric motors, turbines,
etc.)
Purchases in place
Estimate of Security
Exchange Commission (USA) reserves purchased in the ground from another party.
Purging
Cleansing of processing
equipment, or pipelines. Vessels must be purged of noxious gases by sweeping
them with air before removing man ways or entering them for cleaning or
inspection. Pipelines must be purged of material, e.g. water, before they are
placed into service to carry crude oil or natural gas.