Oil and Gas Terms Beginning with “M” — Page 2

Pertaining to minerals or igneous rocks composed of minerals that are rich in iron and magnesium, dense, and typically dark in color. The term comes from the words magnesium and ferric. Common mafic minerals are olivine… Read more →

The molten rock in the Earth that can either rise to the surface as lava and form extrusive igneous rock or cool within the Earth to form plutonic igneous rock. Read more →

A procedure for determining magnesium ion (Mg+2) concentration in a water-base drilling fluid based upon analyses for both calcium and total hardness. The standard test has been proscribed by API. Magnesium ion (Mg+2)… Read more →

A drilling mud with a significant magnetic susceptibility. The magnetic susceptibility may affect the response of some logging measurements, mainly the induction X signal and nuclear magnetic resonance logs. The most… Read more →

A phenomenon by which a nucleus absorbs electromagnetic radiation of a specific frequency in the presence of a strong magnetic field. Isidor Isaac Rabi (1898 to 1988), an American physicist born in Austria, first… Read more →

(noun) A non-destructive inspection technique used to detect corrosion, pitting, and metal loss in ferromagnetic tubulars and pipelines. The method works by magnetising the pipe wall and measuring distortions in the… Read more →

The study of the Earth's magnetic field, a branch of geophysics that began with the observation by British scientist William Gilbert (1544 to 1603) that the Earth is a magnet. Variations in the magnetic field can be… Read more →

An instrument used to measure the strength or direction of the Earth's magnetic field. Read more →

An electromagnetic method used to map the spatial variation of the Earth's resistivity by measuring naturally occurring electric and magnetic fields at the Earth's surface. These natural EM fields are generated (at all… Read more →

To add a length of drillpipe to the drillstring to continue drilling. In what is called jointed pipe drilling, joints of drillpipe, each about 30 ft [9 m] long, are screwed together as the well is drilled. When the bit… Read more →

To deepen a wellbore with the drill bit. To drill ahead. Read more →

To connect tools or tubulars by assembling the threaded connections incorporated at either end of every tool and tubular. The threaded tool joints must be correctly identified and then torqued to the correct value to… Read more →

Water added to a maintain or dilute a water-mud system. The added water may be fresh water, seawater or salt water, as appropriate for the mud. Make-up water volume is an important parameter in a material balance check… Read more →

Water added to a maintain or dilute a water-mud system. The added water may be fresh water, seawater or salt water, as appropriate for the mud. Make-up water volume is an important parameter in a material balance check… Read more →

A clutched, rotating spool that enables the driller to use the drawworks motor to apply tension to a chain connected to the makeup tongs. This tensioned chain, acting at right angles to the tong handle, imparts torque… Read more →

Gas injected into a gas-condensatereservoir to maintain the pressure level, thus preventing further condensate dropout. Read more →

(noun) Large hydraulic or manual wrenches used on a drilling rig to apply torque to threaded connections when assembling (making up) joints of drillpipe, casing, or tubing. Makeup tongs grip the pipe body or coupling… Read more →

A bar, shaft or spindle around which other components are arranged or assembled. The term has been extended in oil and gas well terminology to include specialized tubular components that are key parts of an assembly or… Read more →

An arrangement of piping or valves designed to control, distribute and often monitor fluid flow. Manifolds are often configured for specific functions, such as a choke manifold used in well-control operations and a… Read more →

The intermediate layer of the Earth beneath the crust that is about 2900 km thick [1820 miles] and overlies the core of the Earth. The mantle consists of dense igneous rocks like pyroxenite and dunite, composed of the… Read more →

A representation, on a plane surface and at an established scale, of the physical features of a part or whole of the Earth's surface or of any desired surface or subsurface data, by means of signs and symbols, and with… Read more →

A well that, for reasons of depletion or natural low productivity, is nearing the limits of viable production and profitability. Read more →

Pertaining to sediments or environments in seas or ocean waters, between the depth of low tide and the ocean bottom. Read more →

(noun) A stratigraphic surface that records a significant increase in water depth across a sedimentary basin, marking a transgressive event in which marine conditions advance landward over previously non-marine or… Read more →

A widespread distinctive rock unit that can be correlated readily over a large area. The most useful marker beds tend to form rapidly, such as during volcanic or geologically instantaneous depositional events, and have… Read more →

A joint of tubing used in a workover or completion tubing string that serves as a position or depth indicator. In most cases, a marker joint is significantly shorter than other joints in the string so that it is easily… Read more →

An agreement by which a party sells production on behalf of a producing company and then remits the proceeds, minus agreed-upon costs and expenses, to the producing company. Read more →

An environment from which water rarely drains that supports primarily grassy vegetation and does not form peat. Read more →

A block of rock that forms a structural or topographic feature, such as a block of igneous of metamorphic rock within an area of mountain building, or orogeny. A massif can be as large as a mountain and is typically… Read more →

The structure used to support the crown block and the drillstring. Masts are usually rectangular or trapezoidal in shape and offer a very good stiffness, important to land rigs whose mast is laid down when the rig is… Read more →