Technical
Thesaurus oil & gas
M
Magma
Molten material originating
from deep within the Earth's crust; the material from which igneous rocks form.
Magnetic brake
Also called an
electrodynamic brake. See electrodynamic brake.
Magnetic survey
This measures variations in
the Earth's magnetic field caused by the presence of rock structures and is
used to detect sedimentary areas. This type of survey is usually carried out by
air.
Magnetometer
Towed sensor for detection
of sea-bed or buried ferrous masses (e.g. pipelines, anchors, wreckers).
Magnetometer survey
A geological survey method
in which sedimentary basins are identified and their size determined by
measuring the magnetic properties of the underlying igneous rocks.
Make hole
To deepen the hole made by
the bit; to drill ahead.
Make up
1. To assemble and join
parts to form a complete unit (as to make up a string of casing). 2. To screw
together two threaded pieces. 3. To mix or prepare (as to make up a tank of
mud). 4. To compensate for (as to make up for lost time).
Make up cathead
A device attached to the
shaft of the drawworks that is used as a power source for screwing together
joints of pipe; usually located on the driller's side of the drawworks. See
cathead.
Make up torque
The power necessary to
screw a joint of pipe into another sufficiently tight to hold and seal and not
loosen under working conditions.
Making a connection
The act of screwing a
length of drill pipe onto a drill string suspended in a well bore, i.e.
lengthening the drill string by one section of pipe during a drilling
operation.
Making up a joint
The act of screwing
individual sections of pipe together to form a longer length.
Making-a trip
See round trip.
Male end
A pipe, rod, or coupling
with threads cut on the outside. See pin end.
Man hours
The total hours
required/used to complete a job assuming one man only is performing the job.
Mandrel
Wireline mandrel. A piece
of wireline equipment which locates, locks and often seals in landing nipples
installed at predetermined depths in tubing strings. Control equipment to be
placed in the tubing string, e.g. plug, choke, safely valve, etc., is connected
to the bottom of the mandrel.
Manifest
A document issued by a
shipper covering oil or products to be transported.
Manifold
Piping arrangement which
allows one stream of liquid or gas to be divided into two or more streams.
Manometer
An instrument used for the
measurement of gaseous pressures or pressure differentials in a system.
Manway
A port in the wall or cover
of a tank or reactor, for inspection purposes or for charging the vessel with
raw materials or additives.
Marginal field
A field that mayor may not
produce enough net income to make it worth developing at a given time, should
technical or economical conditions change such a field may subsequently become
commercial.
Marginal riser
The pipe which connects an
exploration rig, drilling platform or production platform to a subsea wellhead
or subsea pipeline during drilling or production operations.
Marine riser
The pipe which connects an
exploration rig, drilling platform or production platform to a sub-sea wellhead
or sub-sea pipeline during drilling or production operations.
Mass balance
A reconciliation of the
masses of petroleum or petroleum products entering and leaving a system. Losses
and own usage within the system are accounted for.
Massif
A consolidated mass of rock
forming part of a continent or mountain range which has relatively uniform
characteristics.
Mast
A portable derrick capable
of being erected as a unit, as distinguished from a standard derrick that
cannot be raised to a working position as a unit. For transporting by land, the
mast can be divided into two or more sections to avoid excessive length
extending from truck beds on the highway. Compare derrick.
Master bushing
A device that fits into the
rotary table. It accommodates the slips and drives the kelly bushing so that
the rotating motion of the rotary table can be transmitted to the kelly. Also
called rotary bushing. See slips and kelly.
Master schedule
An overall graphical time
schedule for the various activities related to a project.
Maturation
The effect of temperature
and time on potential source rock, with respect to hydrocarbon generation.
Immature -not yet at the generation stage. Mature -capable of generation. Over
mature -beyond the stage when liquid hydrocarbons have broken down into gaseous
hydrocarbons. It is dependant on the geological history of the area in terms of
burial, deformation and erosion.
MD
The linear distance of a
well measured along its drilled projection.
Mean high water (MHW)
The average height of the
high waters at a place over a 19-year period.
Mean low water (MLW)
The average height of all
low waters at a place over a 19-year period.
Mean sea level (MSL)
The average height of the
surface of the sea at a tide station for all stages of the tide over a given
period, usually determined from hourly height readings measured from a fixed
predetermined reference level (datum).
Mechanical rig
A drilling rig in which the
source of power is one or more internal-combustion engines and in which the
power is distributed to rig components through mechanical devices (as chains,
sprockets, clutches, and shafts), It is also called a power
Median line
The dividing line between
two national sectors of an ocean or sea; the focus of points equidistant from
the territorial boundaries of the countries concerned.
Mercaptans
Compounds of carbon,
hydrogen and sulphur found in sour crude and gas; the lower mercaptans have a
strong, repulsive odour and are used, among other things, to odourise natural
gas.
Mesozoic era
The era of geological time
(comprising the Triassic, Jurassic and Cretaceous Periods) which began roughly
230 million years ago and ended roughly 60 million years ago; the era in which
many oil and gas producing source rocks were laid down in the
Metallurgist
A scientist whose work
relates to the study of the properties of metals and ores.
Metamorphic rocks
Rocks changed considerably
from their original composition and structure by heat and pressure.
Methane
The hydrocarbon with the
lightest molecule (CH4); the first member of the paraffin (alkane) series -a
gas under normal conditions.
Methyl tertiary-butyl ether (MTBE)
A lead-free, anti-knock
compound added to petrol.
Metric tonne
Equivalent to 1000 kilos,
2204.61 Ibs., or .9842 tons.
Microwave link
A communications system
between two points involving the use of a beamed carrier wave in the microwave
region of the electromagnetic spectrum.
Middle distillate
A phrase used to denote
those distillates in the boiling point range immediately below that of kerosene
and to include diesel fuel and the various gas oil cuts. It is frequently but incorrectly
used to denote the whole range of distillates at atmospheric pressure other
than LPG, gasolines and naphthas.
Milling
To remove a packer or junk,
or to cut a "window" in a well's casing with a milling tool lowered
into the hole on the drill string.
Milling tool
A grinding or cutting tool
used on the end of the drill pipe to pulverise a piece of downhole equipment or
to cut the casing.
Mineral rights
The ownership of any
minerals that may exist in the strata beneath a particular area.
Miscible
Descriptive of substances,
usually liquids, which mix together to form a homogeneous mixture.
Mist
Airborne particles of a
liquid which have condensed on dust particles.
Mixing mud
The preparation of drilling
mud by mixing water or other fluids with clays and dry chemicals.
Mixture
A co-mingling of two or
more substances in which each substance retains its chemical nature and
identity.
Navigation receiver,
usually offshore (beacon).
Mobilisation (mob)
The initial stage of survey
or other work: often involves lump sum payment for acceptance trials, transit,
costs, calibrations etc.
Module
A package of plant,
equipment, etc., installed on (or for installation on) an offshore structure
such as a production platform.
Molecular weight
A measure of the mass of
the molecule of a chemical compound.
Molecule
The smallest particle of a
compound that is capable of independent existence while retaining its
individual properties.
Monkeyboard
A high-level platform in
the derrick on which the derrick man works.
Monomer
A simple molecular unit
(such as ethylene or styrene) from which a polymer can be made.
Moonpool
The open hole in the centre
of the hull of a drillship through which drilling takes place. Also called
moonwell.
Motor oil
Refined lubricating oil,
usually containing additives, used as a lubricant in internal combustion
engines.
Motor spirit
The light fuel used in
spark ignition engines in cars, motor cycles etc.; often referred to as petrol
or gasoline.
Motorman
The man responsible for the
care and operation of the drilling engines.
Mouse hole
A shallow hole in the
drilling floor near the drilling table in which the kelly joint and other
stands of pipe are temporarily stored while making a connection; sometimes
called the rat hole.
Mouse hole connection
The procedure of adding a
length of drill pipe or tubing to the active string in which the length to be
added is placed in the mouse hole, made up to the kelly, then pulled out of the
mouse hole, and subsequently made up into the string.
Mud
See drilling mud.
Mud cake
The sheath of mud solids
that forms on the wall of the hole when the liquid from the mud filters into
the formation; also called wall cake or filter cake.
Mud circulation
The act of pumping mud
downwards to the bit and back up to the surface by normal circulation or
reverse circulation. See normal circulation and reverse circulation.
Mud engineer (mud man)
The service man in charge
of maintaining the mud systems on a drilling rig to the specifications set out
in the drilling programme.
Mud gun
A pipe that shoots a jet of
drilling mud under high pressure into the mud pit to mix additives with the
mud.
Mud logging
The recording of
information derived from examination and analysis of formation cuttings made by
the bit and mud circulated out of the hole. A portion of the mud is diverted
through a gas-detecting device. Cuttings brought up by the mud are examined
under ultraviolet light to detect the presence of oil or gas. Mud logging is
often carried out in a portable laboratory set up at the well.
Mud pits
Large steel storage pits
through which the drilling mud is circulated.
Mud polymer
A chemical compound
produced by the polymerisation process used as an additive to drilling mud to
obtain a specific property such as an emulsion, low filtration losses, high/low
viscosity, prevent foaming, block small pore spaces etc.
Mud pumps
Pumps used to circulate
drilling mud at the desired pressure and flow rate; also called slush pumps.
Mud return line
A trough or pipe placed
between the surface connections at the well bore and the shale shaker, through
which drilling mud flows upon its return to the surface from the hole.
Mud screen
See shale shaker.
Mud weight
The density of the drilling
mud -usually recorded in pounds per gallon; the mud weight is changed by
varying the concentration of solids in the mud.
Multinational
A company that has
investments in more than one country and is organised on an international
basis.
Multiple completion
The completion of a well in
more than one producing formation. Each production zone will either have its
own tubing installed (multiple string multiple completion), extending up to the
christmas tree, or all zones produce through one tubing string (single string
multiple completion).
Multiservice
vessel (MSV)
A support vessel designed
to provide a variety of construction, fabrication, diving, emergency and other
services to offshore installations.