| H-crossover |
circulating member with integral landing
nipples |
| H2S form |
hydrogen sulfide |
| half mule shoe |
a cutoff pup joint below a packer used as a
fluid entry device and/or seal assemblies guide |
| hammering-up |
connection of treating line during well
servicing, from pump trucks to tree/well |
| hand |
a worker in the oil industry, especially one
in the field. |
| handy |
a connection that can be unscrewed by hand. |
| hang rods |
to suspend sucker rods in a derrick or mast on
rod hangers rather than horizontally on a rack. |
| hanger |
see casing
hanger, tubing hanger |
| hanger plug |
a device placed or hung in the casing below
the blowout preventer stack to form a pressure tight seal. Pressure is then applied
to the blowout preventer stack to test it for leaks |
| hard shut-in |
in a well-control operation, closing the BOP
without first opening an alternate flow path up the choke line. When the BOP is
closed, pressure in the annulus cannot be read on the casing pressure gauge. |
| hard water |
water that contains dissolved compounds of
calcium, magnesium, or both. Compare soft
water. |
| hatch |
an opening into a tank, usually through the
top deck. |
| hay pulley |
a pulley that is normally attached to the
wellhead at a convenient place for the wireline to pass through as it comes from the
stuffing box sheave before being spooled onto the wireline reel. The hay pulley
prevents any lateral force from being exerted on the lubricator and the wellhead. |
| hay tank |
a tank or enclosure filled with hay-like
materials used to filter oil out of water. |
| heat (a
connection) |
to loosen a collar or other threaded
connection by striking it with a hammer. |
| heater |
container or vessel enclosing an arrangement
of tubes and a firebox in which an emulsion is heated before further treating, or in which
natural gas is heated in the field to prevent the formation of hydrates. |
| heater-treater |
a vessel that heats an emulsion and removes
water and gas from the oil to raise it to a quality acceptable for a pipeline or other
means of transport. A heater-treater is a combination of a heater, free-water
knockout, and oil and gas separator. |
| heaving |
the partial or complete collapse of the walls
of a hole resulting from internal pressures due primarily to swelling from hydration or
formation gas pressures. See caving. |
| hesitation
squeeze |
a method of squeeze cementing in which cement
is pumped in and the pumps are stopped for a few minutes. Pumping is started and
stopped until the desired pressure is obtained. |
| high pH mud |
a drilling fluid with a pH range above 10.5
i.e., a high-alkalinity mud. |
| high-yield
drilling clay |
a classification of commercial drilling-clay
preparations having a yield of 35 to 40 barrels per ton and intermediate between bentonite
and low-yield clays. Usually prepared by peptizing low-yield calcium montmorillonite
clays or, in a few cases, by blending some bentonite with the peptized low yield clay |
| hi-lo cam |
a mechanism in some packers to set and release
the tool with a minimum of rotation |
| hoist |
1. an arrangement of pulleys and wire rope or
chain used for lifting heavy objects; a winch or similar device. 2. the drawworks; to raise or lift |
| hoisting drum |
the large flanged spool in the drawworks on
which the hoisting cable is wound. See drawworks. |
| hold-down |
a mechanical arrangement that prevents the
upward movement of certain pieces of equipment installed in a well. A sucker rod
pump may use a mechanical hold-down for attachment to a seating nipple. |
| hole opener |
a device used to enlarge the size of an
existing borehole, having teeth arranged on its outside circumference to cut the formation
as it rotates. |
| homogeneous |
of uniform or similar nature throughout; a
substance or fluid with the same property or composition everywhere. |
| hook |
a large, hook-shaped device from which the
swivel is suspended. It is designed to carry maximum loads ranging from 100 to 650
tons (90 to 590 tonnes) and turns on bearings in its supporting housing. A
strong spring within the assembly cushions the weight of a stand (90 feet, about 27
meters) of drill pipe, thus permitting the pipe to be made up and broken out with less
damage to the tool join threads. Smaller hooks without the spring are used for
handling tubing and sucker rods. See stand
and swivel. |
| hook load |
the weight of the drill stem that is suspended
from the hook. |
| hook-wall packer |
a packer equipped with friction blocks or drag
springs and slips and designed so that rotation of the pipe unlatches the
slips. The friction springs prevent the slips from turning with the pipe and
assist in advancing the slips up a tapered sleeve to engage the wail of the outside pipe
as weight is put on the packer. Also called a wall-hook packer. See packer. |
| hot oil |
oil production in violation of state
regulations or transported interstate in violation of federal regulations. |
| hot-oil
treatments |
the treatment of a producing well with heated
oil to melt accumulated paraffin in the tubing and the annulus. |
| hot tap |
to make repairs or modifications on a tank,
pipeline, or installation without shutting down operations. |
| humic acid |
organic acids of indefinite composition in
naturally occurring leonardite lignite. The humic acids are the most valuable
constituent. |
| hydrate |
a hydrocarbon and water compound that is
formed under reduced temperature and pressure in gathering, compression, and transmission
facilities for gas. Hydrates often accumulate in troublesome amounts and impede
fluid flow. They resemble snow or ice. |
| hydration |
1. a chemical reaction in which molecular
water is added to the molecule of another compound without breaking it down. 2. reaction of powdered cement with water. The cement
gradually sets to a solid as hydration continues. |
| hydraulic |
1. of or relating to water or other liquid in
motion. 2. operated, moved, or effected by water or
liquid. |
| hydraulic
fracturing |
an operation in which a specially blended
liquid is pumped down a well and into a formation under pressure high enough to cause the
formation to crack open, forming passages through which oil can flow into the wellbore.
Sand grains, aluminum pellets, glass beads, or similar materials are carried in suspension
into the fractures. When the pressure is released at the surface, the fractures
partially close on the proppants, leaving channels for oil to flow through to the well.
Compare explosive fracturing. |
| hydraulic
hammer effect |
a phenomenon in which a pressure concession
occurs by suddenly stopping the flow of liquids in a closed container. Also called
water hammer. |
| hydraulic head |
the force exerted by a column of liquid
expressed by the height of the liquid above the point at which the pressure is
measured. Although "head" refers to distance or height, it is used to
express pressure, since the force of the liquid column is directly proportional to its
height. Also called head or hydrostatic head. Compare hydrostatic pressure. |
| hydraulic
holddown |
an accessory or integral part of a packer used
to limit the packer's upward movement under pressure. |
| hydraulic jar |
see mechanical
jar |
| hydraulic
workover |
a series of hydraulic rams to restrain and
pull tubing under well pressure, temporarily attached to the wellhead for workover. |
| hydrocarbons |
organic compounds of hydrogen and carbon,
whose densities, boiling points, and freezing points increase as their molecular weights
increase. Although composed of only two elements. hydrocarbons exist in a
variety of compounds because of the strong affinity of the carbon atom for other atoms and
for itself. The smallest molecules of hydrocarbons are gaseous; the largest are
solids. Petroleum is a mixture of many different hydrocarbons. |
| hydrochloric acid |
an acid compound, HCI, commonly used to
acidize carbonate rocks. It is prepared by mixing hydrogen chloride gas in
water. Also known as muriatic acid. |
| hydrofluoric-hydrochloric
acid |
mixture of acids used for removal of mud from
the wellbore. See mud acid. |
| hydro-set tool |
a wireline pressure setting tool for setting
permanent downhole tools. |
| hydrogen
ion concentration |
a measure of the acidity or alkalinity of a
solution expressed as pH. See pH. |
| hydrogen sulfide |
a flammable, colorless gaseous compound of
hydrogen and sulfur (H2S) , which in small amounts has the odor of rotten eggs.
Sometimes found in petroleum, it causes the foul smell of petroleum fractions. In
dangerous concentrations, it is extremely corrosive and poisonous, causing damage to skin,
eyes, breathing passages, and lungs and attacking and paralyzing the nervous system,
particularly that part controlling the lungs and heart. In large amounts, it deadens
the sense of smell. Also called hepatic gas of sulfureted hydrogen. |
| hydrolysis |
the break down of a mineral by chemical
reaction with water. |
| hydrometer |
an instrument with a graduated stem, used to
determine the gravity of liquids. The liquid to be measured is placed in a cylinder,
and the hydrometer dropped into it. It floats at a certain level in the liquid (high
if the liquid is light, low if it is heavy), and the stem markings indicate the gravity of
the liquid. |
| hydrophilic |
tending to absorb water. |
| hydrophilic-lipophilic
balance (HLB) |
an expressions of the relative attraction of
an emulsifier for water and oil, determined largely by the chemical composition and
ionization characteristics of a given emulsifier. The HLB of an emulsifier is not
directly related to solubilit5y, but it determines the type of emulsion that tends to be
formed. It is an indication of the behavioral characteristics and not an indication
of emulsifier efficiency. |
| hydrophobic |
tending to repel water |
| hydrostatic head |
see hydrostatic
pressure |
| hydrostatic
pressure |
the force exerted by a body of fluid at
rest. It increases directly with the density and the depth of the fluid and is
expressed in pounds per square inch or kilopascals. The hydrostatic pressure of
fresh water is 0.433 pounds per square inch per foot of depth (9.792 kilopascals per
meter). In drilling, the term refers to the pressure exerted by the drilling fluid
in the wellbore. In a water drive field, the term refers to the pressure that may
furnish the primary energy for production. |
| hydro-trip
pressure sub |
a sub with a ball seat run on top of a
hydraulically set packer to set the packer. |
| hydroxide |
a designation that is given for basic
compounds containing the OH radical. When these substances are dissolved in water,
they increase the pH of the solution. See base. |
| hydroscopic |
absorbing or attracting moisture from the air |
