Oil and Gas Terms Beginning with “M” — Page 6

Mist drilling is a drilling technique in which the drilling fluid is a mixture of air or gas (typically compressed air, nitrogen, or natural gas) with a small amount of water and surfactant injected to create a fine… Read more →

A mist extractor is a separation device installed in gas processing equipment, production separators, compressor suction vessels, and pipeline scrubbers to remove entrained liquid droplets (water, hydrocarbon… Read more →

Mist flow is a multiphase flow regime in which liquid is dispersed as fine droplets (a mist or aerosol) carried in a continuous high-velocity gas stream, representing the most extreme condition on the flow regime… Read more →

Mixed deposits, in petroleum geology and sedimentology, refer to sedimentary accumulations that contain an admixture of carbonate material (skeletal grains, ooids, peloids, intraclasts, and micrite derived from… Read more →

What Is Mixed Metal Hydroxide? Mixed metal hydroxide (MMH) describes a class of positively charged layered crystal compounds containing Al³⁺, Mg²⁺, and OH⁻ ions that associate with negatively charged bentonite particles… Read more →

A product similar to mixed-metal hydroxide, but based on silicate chemistry. Read more →

A product similar to mixed-metal hydroxide, but based on silicate chemistry. Read more →

What Is a Mobile Offshore Drilling Unit? Mobile offshore drilling unit (also called MODU) is a self-propelled or towed offshore drilling vessel or structure designed to drill exploration and development wells in marine… Read more →

Mobility in reservoir engineering is the ratio of the effective permeability of a phase to the viscosity of that phase, written as M = k_eff / mu, with units of millidarcy per centipoise (mD/cP) in field practice or… Read more →

A mobility buffer in enhanced oil recovery (EOR) is a fluid slug injected between the driving fluid (water, gas, or CO₂) and the resident crude oil during a chemical or miscible displacement process to create a… Read more →

Mobility control in enhanced oil recovery (EOR) refers to the engineering practice of adjusting the relative flow velocities of injected fluid and reservoir oil so that the injected fluid does not race ahead of the oil… Read more →

What Is Mobility Ratio? Mobility ratio (symbol M) is a dimensionless number used in reservoir engineering to quantify the stability of a displacement flood, defined as the mobility of the displacing fluid divided by the… Read more →

In the oil and gas industry, a model is a simplified mathematical, numerical, or conceptual representation of a physical system — a reservoir, a wellbore, a production facility, or an entire field — constructed to… Read more →

The act of constructing a model. Read more →

What Is a Modified Isochronal Test? Modified isochronal test (also called MIT) is a gas well deliverability test designed for low-permeability reservoirs where achieving true static reservoir pressure during each… Read more →

What Is Moldic Porosity? Moldic porosity (also called mold porosity or solution-mold porosity) is a type of secondary porosity found predominantly in carbonate reservoirs, formed when selective dissolution removes… Read more →

A moment, in the statistical sense used throughout reservoir engineering and petrophysics, is the mean or expected value of the product formed by multiplying together a set of one or more variates or variables, each… Read more →

The small platform that the derrickman stands on when tripping pipe. Read more →

The small platform that the derrickman stands on when tripping pipe. Read more →

The chemical unit from which a polymer is made. Read more →

A monopole, in acoustic well logging, describes a transducer that radiates or receives acoustic energy uniformly in all directions, like a pulsating sphere expanding and contracting symmetrically. Because the source has… Read more →

What Is Montmorillonite? Montmorillonite (also called smectite or, in drilling contexts, bentonite clay) is a hydrated aluminum phyllosilicate mineral with a 2:1 layer structure, meaning each crystal unit consists of… Read more →

A monument is a relatively permanent, fixed physical marker set in the ground to record the precise horizontal position, and often the elevation, of a surveyed point. Typical monuments include statutory iron posts,… Read more →

What Is a Moon Pool? Moon pool (also called a drill well or center well) is a vertically oriented, water-filled opening cut through the hull of a drillship or the deck of a semi-submersible drilling rig, through which… Read more →

A mosquito bill is the slender dip tube fitted at the bottom of a subsurface sucker-rod pump, running down inside the gas anchor, that conveys separated formation liquid up into the pump intake while leaving free gas… Read more →

The motorman is the member of a drilling rig crew responsible for the upkeep of the rig's prime movers and power equipment, principally the diesel engines, generators, and associated mechanical systems that supply… Read more →

What Is a Mousehole? A mousehole is a shallow hole drilled below the rig floor and lined with casing or pipe, into which a joint of drillpipe or drill collar is temporarily suspended in preparation for making a… Read more →

Moveable hydrocarbons refers to the fraction of the total hydrocarbon pore volume in a reservoir that can flow through the rock matrix under the prevailing pressure differential, temperature, and fluid properties, as… Read more →

Moved hydrocarbons (also written as moved-hydrocarbons or bulk volume moved, BVM) is a petrophysical quantity defined as the volume of hydrocarbons per unit volume of bulk rock that have been displaced from their… Read more →

Moveout is the systematic change in the arrival time of a seismic reflection as a function of the horizontal distance, called offset, between the seismic source and the receiver that records it. When a shot is fired at… Read more →