Friday, September 25, 2015

Drilling fluids processing glossary M

Main shaker. The shale shaker that processes drilling fluid from the flowline through the finest-mesh screen.
Manifold. (1) A length of pipe with multiple connections for collecting or distributing fluid. (2) A piping arrangement through which liquids, solids, or slurries from one or more sources can be fed to or discharged from a solids-separation device.
Market grade cloth. A group of industrial wire cloth specifications selected for general-purpose work, made of high-strength, square mesh cloth in several types of metals. The common metal for oilfield use is 304 or 316 stainless steel. The wire diameters are marginally larger than mill grade cloth, resulting in a lower percentage of open area. Market grade and mill grade cloths are used mostly as support screens for fine-mesh screens. See: mill grade cloth, tensile bolting cloth, ultrafine wire cloth, support screen, and calendered.
Marsh funnel. An instrument used in determining the Marsh funnel viscosity. The Marsh funnel is a container with a fixed orifice at the bottom so that when filled with 1500 cc freshwater, 1 qt (946 ml) will flow out in 26±0.5 sec. For 1000 cc out, the efflux time for water is 27.5 ±sec. It is used for comparison values only and not to diagnose drilling fluid problems. See: API Bulletin RP 13B, funnel viscosity,
Marsh funnel viscosity, kinematic viscosity.
Marsh funnel viscosity. Commonly called funnel viscosity. The Marsh funnel viscosity is reported as the time, in seconds, required for 1 qt of fluid to flow through an API standardized funnel. In some areas, the efflux quantity is 1000 cc. See: API RP 13B, funnel viscosity, kinematic viscosity, Marsh funnel.
Martin’s radii. The distance from the centroid of an object to its outer boundary. The direction of this measurement is specified by the azimuth orientation of the line (the radii in the 0°, 90°, 180°, 270°angle from horizontal).
Mass. The inertial resistance of a body to acceleration, considered in classical physics, to a conserved quantity independent of speed. The weight of a body is the product of the mass of the body and the acceleration of gravity for the specific location. In space the mass would stay constant but the weight would disappear as the gravitational acceleration approaches zero.
MBT. Methylene blue test. See: methylene blue test.
Mechanical agitator. A device used to mix, blend, or stir fluids by means of a rotating impeller blade. See: agitator, mechanical stirrer.
Mechanical stirrer. See: agitator, mechanical agitator.
Median cut. The median cut is the particle size that reports 50% of the weight to the overflow 50% of the weight to the underflow. Frequently identified as the D50 point. See: cut point.
Medium (solids). Particles whose diameter is between 74 and 250 microns.
Membrane nitrogen. Air from which water and oxygen have been removed by a filter (membrane) system.
Meniscus. The curved upper surface of a liquid column, concave when the containing walls are wetted by the liquid and convex when they are not wetted.
Mesh. (1) The number of openings (and fraction thereof) per linear inch in a screen, counted in both directions from the center of a wire. (2) An indication of the weave of a woven material, screen or sieve. A 200 mesh sieve has 200 openings per linear inch. A 200 mesh screen with a wire diameter of 0.0021 inch (0.0533 mm) has an opening of 0.0029 in. (0.074) mm and will pass a spherical particle of 74 microns diameter. See: micron.
Mesh count. Such as 30X30, or often 30 mesh, indicating the number of openings per linear inch of screen; and a square mesh. A designation of 70X30 mesh indicates rectangular mesh with 70 openings per inch in one direction and 30 openings per inch in a perpendicular direction.
Mesh equivalent. As used in oilfield drilling applications, the U.S. Sieve number that has the same-size opening as the minimum opening of the screen in use.
Methylene blue test. A test that serves to indicate the amount of active clay in a fluid system, clay sample, or shale sample. Methylene blue is titrated into a slurry until all of the negative charge sites are covered with the methylene blue. This indicates the number of active charge sites present in the slurry. See: base exchange, methylene blue titration,
MBT, cation exchange capacity, CEC.
Methylene blue titration. Methylene blue is a cation that seeks all negative charges on a clay surface after the surface has been properly prepared (see API RP13B). By titrating with a known concentration, this test provides an indication of the amount of clay present in the drilling fluid. See: methylene blue test, MBT, cation exchange capacity, CEC.
Mf. The methyl orange alkalinity of the filtrate, reported as the number of milliliters of 0.02 normal sulfuric acid required per milliliter of filtrate to decrease the pH to reach the methyl orange endpoint (pH 4.3).
Mica. Naturally occurring mineral flake material of various sizes used in controlling lost circulation. An alkali aluminum silicate.
Micelles. Organic and inorganic molecular aggregates occurring in colloidal solutions. chains of individual structural units chemically joined to one another and deposited side by side to form bundles. When bentonite hydrates, certain sodium, or other metallic ions go into solution, the clay particle plus its complement of ions is technically known as a micelle.
Micron. A unit of length equal to one-thousandth of a millimeter. Used to specify particle sizes in drilling fluids and solids control discussions (25,400 microns¼1 inch).
Mil. A unit of length equal to 1/1000 inch.
Milk emulsion. See: oil-in-water emulsion drilling fluid.
Mill grade cloth. A group of industrial wire cloth specifications with lighter wire than market grade cloth. The standard wire diameter of the grade produces a median percentage of open area. Market grade and mill grade cloths are used mostly as support screens for fine-mesh screens. See: market grade cloth, tensile bolting cloth, ultra-fine wire cloth, support screen, and calendered.
Millidarcy. 1/1000 darcy. See: darcy.
Milliliter. A metric system unit for the measurement of volume. Literally 1/1000th of a liter. In drilling-fluid analyses, this term is used interchangeably with cubic centimeter (cc). One quart is equal to approximately 946 ml.
Mini still. An instrument used to distill oil, water, and any other volatile material in a drilling fluid to determine oil, water, and total solids contents as volume percentage. See: distillation, mud still.
Mist drilling. A method of rotary drilling whereby water and/or oil is dispersed in air and/or gas as the drilling fluid. See: foam. ml. See: milliliter.
Molecule. Atoms combine to form molecules. For elements or compounds, a molecule is the smallest unit that chemically still retains the properties of the substance in mass.
Monovalent. See: valence.
Montmorillonite. A clay mineral commonly used as an additive to drilling muds. Sodium montmorillonite is the main constituent of bentonite. Each platelet of the crystalline structure of montmorillonite has two layers of silicon tetrahedra attached to a center layer of alumina octhahedra. The platelets are thin and have a broad surface. Exchangeable cations are located on the clay surfaces between the platelets. Calcium montmorillonite is the main constituent in low-yield clays. See: gel,
Mud. See: drilling fluid, which is the preferred term.
Mud analysis. See: drilling fluid analysis, API RP 13B.
Mud balance. A beam-type balance used in determining drilling-fluid density (mud weight). It consists primarily of a base, a graduated beam with constant volume cup, lid, rider, knife-edge, and counterweight. See: API RP 13B.
Mud box. See: back tank, possum belly.
Mud cleaner. A device that places a screen in series with the underflow of hydrocyclones. The hydrocyclone overflow returns to the mud system, and the underflow reports to a vibrating screen. Solids discharged from the screen are discarded and the screen throughput returns to the system.
Mud compartment. A subdivision of the removal, additions, or check/ suction sections of a surface system. See: mud pits, mud tanks.
Mud ditch. A trough built along the upper edge of many surface systems that is used to direct flow to selected compartments of the surface system. See: mud pits, mud compartment.
Mud engineer. See: drilling fluid engineer.
Mud gun. A submerged nozzle used to stir the drilling fluid with a highvelocity stream. See gunning the pits.
Mud hopper. See: hopper.
Mud house. A structure at the rig to store and shelter sacks of materials used in drilling fluids.
Mud inhibitor. Additives such as salt, lime, lignosulfonate, and calcium sulfate that prevent clay dispersion.
Mud logging. A process that helps determine the presence or absence of oil or gas in the various formations penetrated by the drill bit, and assists with a variety of indicators that assist drilling operations. Drilling fluid and cuttings are continuously tested on their return to the surface, and the results of these tests are correlated with the drilling depth for depth of origin.
Mud mixing devices. The most common device for adding solids to the drilling fluid is by means of the jet hopper. Some other devices to assist mixing are eductors, mechanical agitators, paddle mixers, electric stirrers, mud guns, chemical barrels, etc.
Mud pit. See: mud compartments, mud tanks.
Mud pump. Pumps at the rig used to circulate drilling fluids.
Mud scales. See: mud balance.
Mud still. See: distillation, mini still.
Mud tanks. (1) Drilling-fluid system compartments constructed of metal and mounted so they can be moved from location to location, either as a part of the rig (such as on a semisubmersible rig) or separately on unitized skids (as on most land rigs). (2) Earthen or steel storage facilities for the surface system. Mud pits are of two types: circulating and reserve. Drilling-fluid testing and conditioning is normally done in the circulating pit system.
Mud weight. A measurement of density of a slurry usually reported in lb/gal, lb/cu ft, psi/1000 ft or specific gravity. See: density.
Mud/gas separator. A vessel into which the choke line discharges when a ‘‘kick’’ is being taken. Gas is separated in the vessel as the drilling fluid flows over baffle plates. The gas flows through a line to a flare. The liquid mud discharges into the shale shaker back tank. See: gas buster, poor boy degasser.
Mudding off. A condition promoting reduced production caused by the penetrating, sealing or plastering effect of a drilling fluid. See: formation damage.
Mudding up. Process of mixing drilling fluid additives to a simple, native clay water slurry to achieve some properties not possible with the previous fluid.
MW. Abbreviation for mud weight. See: density, mud weight.