LEXICON
of TERMS
Learn
how to talk like an Oilman
Over 400 Oil & Gas and
related investment terms defined |
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D-G |
Deductions
- Tax items which may be subtracted from gross income to arrive
at taxable income in Federal income tax computations.
Deed
- A written document by which the title to a property is transferred
from one party (the grantor) to another (the grantee).
Deepwater
port - An offshore marine terminal designed to accommodate
large vessels such as VLCCs and tankers, connected to the shore
by submerged pipelines.
Delay
rental - Cash payments to the mineral rights owner
(lessor) by the working interest owner (lessee), for the privilege
of postponing the commencement of drilling operations on the
leased property.
Deliverability
- A well's tested ability to produce.
Depletion,
restoration of - In federal income taxation, the adding
back to income of depletion allowance taken on minerals not
produced.
Development
- well A well drilled in an already discovered oil or gas field.
Diesel
oil - A petroleum fraction composed primarily of aliphatic
(linear of unbranched) hydrocarbons. Diesel oil is slightly
heavier than kerosene.
Differential-pressure
sticking - A condition in which a section of drillpipe
becomes stuck in deposits on the wall of the borehole.
Directional
drilling - Drilling at an angle, instead of on the
perpendicular, by using a whipstock to bend the pipe until it
is going in the desired direction. Directional drilling is used
to develop offshore leases, where it is very costly and sometimes
impossible to prepare separate sites for every well; to reach
oil beneath a building or some other location which cannot be
drilled directly; or to control damage or as a last resort when
a well has cratered. It is much more expensive than conventional
drilling procedures.
Distillate
- Liquid hydrocarbons, usually colorless and of high
API gravity, recovered from wet gas by a separator that condenses
the liquid out of the gas. The present term is natural gas.
Distillate
fuel oil - A term subject to a variety of definitions.
Sometimes the definition is based on the method of production,
but other definitions are based on boiling range, viscosity,
or use.
Distributor
- A wholesaler of gasoline and other petroleum products;
also know as a jobber. Distributors of natural gas are almost
always regulated utility companies.
Division
Order - A contract for the sale of oil or gas, by the
holder of a revenue interest in a well or property, to the purchaser
(often a pipeline transmission company).
Domestic
production - Oil and gas produced in the United States
as opposed to imported product.
Downhole
- Refers to equipment or operations that take place
down inside a borehole.
Downstream
- All operations taking place after crude oil is produced,
such as transportation, refining, and marketing.
Drill
bit - The part of the drilling tool that cuts through
rock strata.
Drill
string - Also called drill pipe or drill stem. Thirty-foot
lengths of steel tubing screwed together to form a pipe connecting
the drill bit to the drilling rig. The sting is rotated to drill
the hole and also serves as a conduit for drilling mud.
Drilling
- The act of boring a hole through which oil or gas
may be produced if encountered in commercial quantities.
Drilling
break - A sudden increase in the rate of drilling.
Drilling
fund - The generic term employed to describe a variety
of organizations established to attract venture capital to oil
and gas exploration and development. Typically the fund is established
as a joint venture or limited partnership.
Drilling
mud - A mixture of clay, water, chemical additives,
and weighting materials that flushes rock cuttings from a well,
lubricates and cools the drill bit, maintains the required pressure
at the bottom of the well, prevents the wall of the borehole
from crumbing or collapsing, and prevents other fluids from
entering the well bore.
Drilling
platform - An offshore structure with legs anchored
to the sea bottom that supports the drilling of up to 35 wells
from one location.
Drilling
rig - The surface equipment used to drill for oil or
gas, consisting chiefly of a derrick, a winch for lifting and
lowering drill pipe, a rotary table to turn the drill pipe,
and engines to drive the winch and rotary table.
Drillstem
test - A test through the drill pipe prior to completion
to determine if oil or gas is present in a formation.
Dry
hole - A well that either produces no oil or gas or
yields too little to make it economic to produce.
Dry
natural gas - Natural gas containing few or no natural
gas liquids (liquid petroleum mixed with gas).
Dual
completion - Completing a well that draws from two
or more separate producing formations at different depths. This
is done by inserting multiple strings of tubing into the well
casing and inserting packers to seal off all formations except
the one to be produced by a particular string.
Due
Diligence - In an offering of securities, certain parties
who are responsible for the accuracy of the offering document,
have an obligation to perform a "due diligence" examination
of the issuer; issuer's counsel, underwriter of the security,
brokerage firm handling the sale of the security. Due diligence
refers to the degree of prudence that might properly be expected
from a reasonable man, on the basis of the significant facts
which relate to a specific case.
Economic
interest - An interest in oil and gas in the ground.
It entitles the owner to a deduction from gross income derived
from production of that oil and gas as specified in Federal
income tax regulations.
Electrical
well logging - A method of oil exploration that originated
with Conrad Schlumberger, who first tested it in 1927 on a
1,500-meter well in France. As used today, the process is
very simple. Current passes into the ground, through the resistive
medium and into the sonde. The resulting charts show the varying
resistance, the conductance, and the self-potential of the
strata surrounding the well at every level, and geophysicists
use them to assay whether petroleum is present in a formation.
Enhanced
oil recovery - Injection of water, steam, gases or
chemicals into underground reservoirs to cause oil to flow
toward producing wells, permitting more recovery than would
have been possible from natural pressure or pumping alone.
Ethanol
- The two-carbon-atom alcohol present in the greatest
proportion upon fermentation of grain and other renewable
resources such as potatoes, sugar, or timber. Also called
grain alcohol.
Expenses
(Tax Usage) - Expenditures for business items that
have no future life (such as rent, utilities, or wages) and
are incurred in conducting normal business activities.
Exploration
- The search for oil and gas. Exploration operations
include: aerial surveys, geophysical surveys, geological studies,
core testing and the drilling of test wells.
Exploratory
well - A well drilled to an unexplored depth or in
unproven territory, either in search of a new reservoir or
to extend the known limits of a field that is already partly
developed.
External
casing packer - A device used on the outside of the
well casing to seal off formations or protect certain zones.
The packer is run on the casing and expanded against the wall
of the borehole at the proper depth by hydraulic pressure
or fluid pressure from the well.
Extraction
plant - A plant for the extraction of the liquid
constituents in casinghead gas or wet gas.
Farm in - When one company drills wells or performs
other activity on another company's lease in order to earn an
interest in or acquire that lease.
Farm
out agreement - An arrangement in which the responsibility
of exploration and development is shifted (by assignment) from
the working interest owner to another party.
Farmer's
oil - An expression that refers to the landowner's share
of oil from a well drilled on his property. This royalty is traditionally
one-eighth of the produced oil free of any expense to the landowner.
Fault
- A break in the continuity of stratified rocks or even
basement rocks. Faults are significant to oilmen because they
can form traps for oil when the rock fractures, they can break
oil reservoirs into noncommunicating sections, they help produce
oil accumulations, and they form traps on their own.
Fault
trap - A geological formation in which oil or gas in
a porous section of rock is sealed off by a displaced, nonporous
layer.
Fee
lands - Privately owned, nonpublic lands.
Feet
of pay - The thickness of the pay zone penetrated in
a well.
Field
- A geographical area under which one or more oil or
gas reservoirs lie, all of them related to the same geological
structure.
Filter
cake - A plastic-like coating that builds up inside the
borehole. Such buildup can cause serious drilling problems, including
sticking of the drillpipe.
Fishing
- Recovering the tools or pipe that have been accidentally
lost down the borehole by using specially designed tools that
screw into or grab the missing equipment.
Fishing
tools - Special instruments equipped with the means for
recovering objects lost while drilling the well.
Five-spot
waterflood program - A secondary-recovery operation in
which four injection wells are drilled in a square pattern with
the production well in the center. Water from the injection wells
moves through the formation, forcing oil toward the production
well.
Flange
up - To complete the drilling of a well.
Flaring
- The burning of gas vented through a pipe or stack at
a refinery, or a method of disposing of gas while a well is being
drilled. Flaring is regulated by state agencies. Venting (letting
gas escape unburned) is generally prohibited.
Flooding
- One of the methods of enhanced oil recovery. Water
flooding or gas flooding might be considered secondary recovery
methods.
Flow
Through concept - In ventures structured as partnerships
(or S corporations), certain items of tax significance (profit,
loss, etc.) are passed on to the partners (or S corporation shareholders)
in the venture. In a venture structured as a "C" corporation,
the responsible tax-paying party would be the corporation itself
(not its shareholders).
Flowing
well - A well that produces through natural reservoir
pressure and does not require pumping.
Formation
- A geological term that describes a succession of strata
similar enough to form a distinctive geological unit useful for
mapping or description.
Fossil
fuels - Fuels that originate from the remains of living
things, such as coal, oil, natural gas, and peat.
Fracturing
- A well stimulation technique in which fluids are pumped
into a formation under extremely high pressure to create or enlarge
fractures for oil and gas to flow through. Proppants such as sand
are injected with the liquid to hold the fractures open.
Front-end
costs - Costs that are paid out of initial investment
in a venture, first, before the venture activities actually begin.
Fuel
oil - See Heating oil.
Future
prices - Refers to the New York Mercantile Exchange (NYMEX)
which introduced futures contracts for crude oil in 1985 and natural
gas in 1990.
Gamma-ray
logging - A technique of exploration for oil in which a
well's borehole is irradiated with gamma rays. The varying emission
of these rays indicates to geologists the relative density of the
rock formation at different levels.
Gas
cap - The gas that exists in a free state above the oil
in a reservoir.
Gas
condensate - Liquid hydrocarbons present in casinghead
gas that condense when brought to the surface.
Gas
lift - A recovery method that brings oil from the bottom
of a well to the surface by using compressed gas. Gas pumped to
the bottom of the reservoir mixes with fluid, expands it, and
lifts it to the surface.
Gas-cut
mud - Drilling mud permeated with bubbles of gas from
downhole. The circulation of such mud can be severely impaired,
seriously affecting drilling operations.
Gas-oil
ratio - The number of cubic feet of natural gas produced
along with a barrel of oil.
Gasoline
- A volatile, inflammable, liquid hydrocarbon mixture.
General
partner - In a limited partnership, the general partner
is responsible for managing the partnership's activities (and
is commonly the party that put the deal together). His liability
to the partnership's creditors is limited.
Geophones
- The sound-detecting instruments used to measure sound
waves created by explosions set off during seismic exploration
work.
Geophysicist
- A geophysicist applies the principles of physics to
the understanding of geology.
Geothermal
energy - Energy produced from subterranean heat.
Gravimeter
- A geophysical device that has been particularly useful in finding
salt domes. Actually, it is a weight on a spring. The spring gets
longer in high-gravity areas and shorter in areas of gravity-minus.
Magnetism helps the oil geologist understand its measurements
Gross
income - Total income from an activity, before deduction
of (1) items that may be treated as expenses (such as intangible
drilling costs), and (2) allowed tax items (such as depletion
allowance, depreciation allowance, etc.).
Groundwater
- The water in underground rock strata that supplies
wells and springs.
Guaranteed
payments - Payments by a partnership to one or more of
its partners for services rendered.
Gun
perforation - A method of creating holes in a well casing
downhole by exploding charges to propel steel projectiles through
the casing wall. Such holes allow oil from the formation to enter
the well.
Gusher
- A well drilled into a formation in which the crude
is under such high pressure that at first it spurts out of the
wellhead like a geyser. Gushers are rare today owning to improved
drilling technology, the use of drilling mud to control downhole
pressure, and oilmen's recognition of their wastefulness.