packer n: a piece of downhole equipment that consists of a sealing
device, a holding or setting device, and an inside passage for fluids.
packer fluid n: a liquid, usually salt water or oil,
but sometimes mud, used in a well when a packer is between the tubing and the
casing. Packer fluid must be heavy enough to shut off the pressure of the
formation being produced, and should not stiffen or settle out of suspension
over long periods of time, and must be non-corrosive.
packer squeeze method n: a squeeze cementing method
in which a packer is set to form a seal between the working string (the pipe
down which cement is pumped) and the casing. Another packer or a cement plug
is set below the point to be squeeze-cemented. By setting packers, the squeeze
point is isolated from the rest of the well.
packing n: 1. a material used in a cylinder on
rotating shafts of an engine or pump in the stuffing box of a valve, or
between flange joints to maintain a leak proof seal. 2. the specially
fabricated filling in packed fractionation columns and absorbers.
packing assembly n: the arrangement of the downhole
tools used in running and setting a packer.
packing elements n pl: the set of dense rubber,
washer-shaped pieces encircling a packer, which are designed to expand against
casing or formation face to seal off the annulus.
pack-off n: a device with an elastomer packing
element that depends on pressure below the packing to effect a seal in the
annulus. Used primarily to run or pull pipe under low or moderate pressures.
Also called a stripper.
pack off v: to place a packer in the wellbore and
activate it so that it forms a seal between the tubing and the casing.
paraffin n: a saturated aliphatic hydrocarbon having
the formula CnH2n+2 (for example, methane, CH4;
ethane, C2H6). Heavier paraffin hydrocarbons (for
example, C18H38) form a waxlike substance that is called
paraffin. These heavier paraffins often accumulate on the walls of tubing and
other production equipment, restricting or stopping the flow of the desirable
paraffin scraper n: a tube with guides around it to
keep it centered in the hole, and a cylindrical piece with blades attached.
Spaces between the blades allow drilling fluid to pass through and carry away
parallel strings n pl: in a multiple completion, the
arrangement of a separate tubing string for each zone produced, with all zones
isolated by packers.
parted rods n pl: sucker rods that have been broken
and separated in a pumping well because of corrosion, improper loading,
damaged rods, and so forth.
PDC bit n: a special type of diamond drilling bit
that does not use roller cones.
penetration rate n: see rate of penetration.
perforate v: to pierce the casing wall and cement of
a wellbore 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.
perforated completion n: 1. a well completion method
in which the producing zone or zones are cased through, cemented, and
perforated to allow fluid flow into the wellbore. 2. a well completed by this
perforated liner n: a liner that has had holes shot
in it by a perforating gun.
perforated pipe n: sections of pipe (such as casing,
liner, and tail pipe) in which holes or slots have been cut before it is set.
perforating gun n: a device fitted with shaped
charges or bullets that is lowered to the desired depth in a well and fired to
create penetrating holes in casing, cement, and formation.
perforation n: a hole made in the casing, cement,
and formation through which formation fluids enter a wellbore. Usually several
perforations are made at a time.
perforation depth control log (PDC log) n: a special
type of nuclear log that measures the depth of each casing collar. Knowing the
depth of the collars makes it easy to determine the exact depth of the
formation to be perforated by correlating casing-collar depth with formation
perforator n: see perforating gun.
permanent packer n: a nonretrievable type of packer
that must be drilled or milled out for removal.
permeability n: 1. a measure of the ease with which
a fluid flows through the connecting pore spaces of a formation or cement. The
unit of measurement is the millidarcy. 2. fluid conductivity of a porous
medium. 3. ability of a fluid to flow within the interconnected pore network
of a porous medium.
petroleum n: a substance occurring naturally in the
earth in solid, liquid, or gaseous state and composed mainly of mixtures of
chemical compounds of carbon and hydrogen, with or without other nonmetallic
elements such as sulfur, oxygen, and nitrogen. In some cases, especially in
the measurement of oil and gas, petroleum refers only to oil—a liquid
hydrocarbon—and does not include natural gas or gas liquids such as propane
pilot n: a rodlike or tubelike extension below a
downhole tool, such as a mill, that serves to guide the tool into or over
another downhole tool or fish.
pilot bit n: a bit placed on a special device that
serves to guide the device into an already existing hole that is to be opened
(made larger in diameter). The pilot bit merely guides, or pilots, the cutters
on the hole opener into the existing hole so that the hole-opening cutters can
enlarge the hole to the desired size.
pilot mill n: a special mill that has a heavy
tubular extension below it called a pilot or stinger. The pilot, smaller in
diameter than the mill, is designed to go inside drill pipe or tubing that is
lost in the hole. It guides the mill to the top of the pipe and centers it,
thus preventing the mill from by-passing the pipe. Also called a piloted mill.
pinch points n: the sections where body parts or
other materials may be pinched.
ramp and pipe on rack n: an angled ramp for dragging drill pipe,
casing and other materials up to the drilling floor or bringing such equipment
pick up v: 1. to use the drawworks to lift the bit (or other tool) off
bottom by raising the drill stem. 2. to use an air hoist to lift a tool, a
joint of drill pipe, or other piece of equipment.
pin n: 1. the male threaded section of a tool joint. 2. on a bit, the
threaded bit shank.
pipe n: a long, hollow cylinder, usually steel, through which fluids
are conducted. Oilfield tubular goods are casing (including liners), drill
pipe, tubing, or line pipe.
racks n pl: horizontal supports for tubular goods.
pipe racker n: 1. (obsolete) a worker who places
pipe to one side in the derrick. 2. a pneumatic or hydraulic device used to
mechanize the rig floor.
pipe ram n: a sealing component for a blowout preventer that closes the
annular space between the pipe and the blowout preventer or wellhead.
pipe ram preventer n: a blowout preventer that uses pipe rams as the
closing elements. See pipe ram.
pipe tongs n pl: see tongs.
pipe upset n: that part of the pipe that has an
abrupt increase of dimension.
pipe wiper n: a flexible disk-shaped device, usually made of rubber,
with a hole in the center through which drill pipe or tubing passes. It is
used to wipe off mud, oil, or other liquid from the pipe as it is pulled from
pit level n: height of drilling mud in the mud tanks, or pits.
pit-level indicator n: one of a series of devices that continuously
monitor the level of the drilling mud in the mud tanks. The indicator usually
consists of float devices in the mud tanks that sense the mud level and
transmit data to a recording and alarm device (a pit-volume recorder) mounted
near the driller’s position on the rig floor. If the mud level drops too low
or rises too high, the alarm may sound to warn the driller of lost circulation
or a kick.
pitman n: the arm that connects the crank to the
walking beam on a pumping unit by means of which rotary motion is converted to
plug n: any object or device that blocks a hole or
passageway (such as a cement plug in a borehole).
plug and abandon (P&A) v: to place cement plugs into a dry hole and
plug back v: to place cement in or near the bottom
of a well to exclude bottom water, to sidetrack, or to produce from a
formation higher in the well. Plugging back can also be accomplished with a
mechanical plug set by wireline, tubing, or drill pipe.
plug-back cementing n: a secondary cementing
operation in which a plug of cement is positioned at a specific point in the
well and allowed to set.
plunger n: 1. a basic component of the sucker rod
pump that serves to draw well fluids into the pump. 2. the rod that serves as
a piston in a reciprocating pump. 3. the device in a fuel-injection unit that
regulates the amount of fuel pumped on each stroke.
pole mast n: a portable mast constructed of tubular
members. A pole mast may be a single pole, usually of two different sizes of
pipe telescoped together to be moved or extended and locked to obtain maximum
height above a well. Double-pole masts give added strength and stability. See
polished rod n: the topmost portion of a string of
sucker rods. It is used for lifting fluid by the rod-pumping method. It has a
uniform diameter and is smoothly polished to seal pressure effectively in the
stuffing box attached to the top of the well.
polycrystalline diamond compact (PDC) n: a disk (a
compact) of very small synthetic diamonds, metal powder, and tungsten carbide
powder that are used as cutters on PDC bits.
porosity n: 1. the condition of being porous (such
as a rock formation). 2. the ratio of the volume of empty space to the volume
of solid rock in a formation, indicating how much fluid a rock can hold.
portable mast n: a mast mounted on a truck and
capable of being erected as a single unit. See telescoping mast.
possum belly n: 1. a receiving tank situated at the
end of the mud return line. The flow of mud comes into the bottom of the
device and travels to control mud flow over the shale shaker. 2. a metal box
under a truck bed that holds pipeline repair tools.
generating system n: a diesel, LPG, natural gas, or gasoline engine
along with a mechanical transmission or generator for producing power for the
power wrench n: a wrench that is used to make up or
break out drill pipe, tubing, or casing on which the torque is provided by air
or fluid pressure. Conventional tongs are operated by a mechanical pull
provided by a jerk line connected to a cathead.
preflush n: 1. an injection of water prior to
chemical flooding that is used to induce reservoir conditions favorable to the
surfactant solution by adjusting reservoir salinity and reducing ion
concentrations. A preflush may also be used to obtain advance information on
reservoir flow patterns. 2. fluid injected prior to the acid solution pumped
into a well in an acid-stimulation treatment; sometimes called a spearhead.
pressure depletion n: the method of producing a gas
reservoir that is not associated with a water drive. Gas is removed and
reservoir pressure declines until all the recoverable gas has been expelled.
preventer n: shortened form of blowout preventer.
See blowout preventer.
preventive maintenance n: a system of conducting regular checks,
routine maintenance and testing of equipment to lengthen the service life and
to potentially permit replacement or repair of weakened or faulty parts before
equipment failure results.
primary recovery n: the first stage of oil
production in which natural reservoir drives are used to recover oil, although
some form of artificial lift may be required to exploit declining reservoir
production n: 1. the phase of the petroleum industry that deals with
bringing the well fluids to the surface and separating them and storing,
gauging, and otherwise preparing the product for delivery. 2. the amount of
oil or gas produced in a given period.
production casing n: the last string of casing set in a well, inside of
which is usually suspended a tubing string.
production maintenance n: the efforts made to minimize the decline in a
well’s production. It includes, for example, acid-washing of casing
perforations to dissolve mineral deposits, scraping or chemical injection to
prevent paraffin buildup, and various measures taken to control corrosion and
production packer n: any packer designed to make a
seal between the tubing and the casing during production.
production rig n: a portable servicing or workover
unit, usually mounted on wheels and self-propelled. A wellservicing unit
consists of a hoist and engine mounted on a wheeled chassis with a
self-erecting mast. A workover rig is basically the same, with the addition of
a substructure with rotary, pump, pits, and auxiliaries to permit handling and
working a drill string.
production test n: a test of the well’s producing
potential usually done during the initial completion phase.
production tubing n: a string of tubing used to
produce the well.
production well n: in fields in which improved recovery techniques are
being applied, the well through which oil is produced.
productivity test n: a combination of a potential
test and a bottomhole pressure test the purpose of which is to determine the
effects of different flow rates on the pressure within the producing zone of
the well to establish physical characteristics of the reservoir and to
determine the maximum potential rate of flow.
propping agent n: a granular substance (sand grains,
aluminum pellets, or other material) that is carried in suspension by the
fracturing fluid and that serves to keep the cracks open when fracturing fluid
is withdrawn after a fracture treatment.
pulling unit n: a well-servicing outfit used in
pulling rods and tubing from the well. See production rig.
pulsed neutron logging device n: a measuring
instrument run inside casing to obtain an indication of the presence or
absence of hydrocarbons outside the casing, to determine water saturation in a
reservoir behind casing, to detect water movement in the reservoir, to
estimate porosity, and to estimate water salinity.
pulsed-neutron survey n: a special cased hole
logging method that uses radioactivity reaction time to obtain measurements of
water saturation, residual oil saturation, and fluid contacts in the formation
outside the casing of an oil well.
pump n: a device that increases
the pressure on a fluid or raises it to a higher level. Various types of pumps
include the bottom hole pump, centrifugal pump, hydraulic pump, jet pump, mud
pump, reciprocating pump, rotary pump, sucker rod pump, and submersible pump.
pump barrel n: the cylinder or liner in which the
plunger of a sucker rod pump reciprocates.
pump-down adj: descriptive of any tool or device
that can be pumped down a wellbore. Pump-down tools are not lowered into the
well on wireline; instead, they are pumped down the well with the drilling
pumping unit n: the machine that imparts
reciprocating motion to a string of sucker rods extending to the positive
displacement pump at the bottom of a well. It is usually a beam arrangement
driven by a crank attached to a speed reducer, coupled to a motor.
pump jack n: a surface unit similar to a pumping
unit but having no individual power plant. Usually, several pump jacks are
operated by pull rods or cables from one central power source.
pump rate n: the speed, or velocity, at which a pump
is run. In drilling, the pump rate is usually measured in strokes per minute.
pup joint n: a length of drill or line pipe, tubing,
or casing shorter than range 1 (18 feet or 6.26 meters for drill pipe) in
pusher n: shortened form of toolpusher.