Oil and Gas Terms Beginning with “M” — Page 7

The moving-source method is a geophysical survey technique in which the energy transmitter and the measurement receivers travel together as a unit, maintaining a fixed spacing relative to each other throughout the… Read more →

Abbreviation for mils (thousandths of an inch) per year penetration, a unit of measurement for the corrosion rate of a coupon. Read more →

In drilling operations, "mud" is the industry's universal colloquial term for drilling fluid — the engineered fluid that is continuously circulated from surface pumps, down through the drillstring, out through the bit… Read more →

Mud acid is a blend of hydrochloric acid (HCl) and hydrofluoric acid (HF) used as the primary acidizing fluid for removing formation damage in sandstone reservoirs — specifically attacking the clay minerals, fines, and… Read more →

A material added to a drilling fluid to perform one or more specific functions, such as a weighting agent, viscosifier or lubricant. Read more →

A mud aging cell is a laboratory pressure vessel used to simulate the thermal and pressure conditions that a drilling fluid will experience in a deep wellbore, by heating a sample of the mud at elevated temperature and… Read more →

Large diameter pipe placed outside the gas anchor to reduce the amount of solids carried by the formation liquid entering the subsurface sucker-rod pump. Read more →

A mud balance is a simple, portable beam balance instrument used at the rig site to measure the density (weight) of drilling fluids, cement slurries, and completion fluids — consisting of a fixed-volume sample cup… Read more →

A mud cleaner is a specialized solids control device that combines a desilter (a bank of hydrocyclone cones) with a fine vibrating screen mounted directly beneath the hydrocyclone underflow discharge, allowing the fine… Read more →

A mud cup in drilling operations is a simple but essential field measurement device used to determine the flow time (funnel viscosity) of drilling fluid as a quick quality check of the fluid's rheological state,… Read more →

What Is a Mud Engineer? Mud engineer (also called a drilling fluids engineer or mud tech) is a specialized drilling fluids professional employed by a service company such as Halliburton, SLB (Schlumberger), Baker… Read more →

A mud hopper (also called a hopper, mixing hopper, or jet hopper) is a surface drilling fluid mixing device that uses a high-velocity jet of circulating drilling mud to create a venturi effect that draws dry powdered… Read more →

The place where mud additives are kept at the rig, also known as the sack room. Read more →

A mud-in sample is a drilling fluid sample taken from the suction pit (the last pit in the active mud system flow series, located just before the mud goes into the rig pumps and is sent down the wellbore through the… Read more →

What Is a Mud Motor? A mud motor converts the hydraulic energy of circulating drilling fluid into mechanical rotation of the drill bit, enabling the bit to turn independently of the drillstring. Deployed as the lowest… Read more →

A mud-out sample (also written as mud out sample) is a sample of drilling fluid collected from the return flow line (the flowline or possum belly) as the mud circulates back to the surface from the downhole annulus —… Read more →

A mud oven is a laboratory drying oven used at the drilling rig or wellsite to dry mud, cuttings, and core samples by evaporating water and oil at controlled temperatures, providing quantitative data on the moisture… Read more →

A mud pit is a surface container or series of interconnected tanks on a drilling rig that stores, conditions, and recirculates water-based or oil-based drilling fluid (mud) throughout the well construction operation;… Read more →

A mud program is a formal engineered plan developed for a specific well that establishes the predicted requirements and design parameters for the drilling fluid system at various intervals of the wellbore depth —… Read more →

A mud report is the standardized documentation prepared by the rig site mud engineer on a daily basis throughout drilling operations to capture the comprehensive operational and chemistry information about the mud… Read more →

A mud tracer is a nonreactive material added to the drilling fluid at the surface that travels with the mud through the drillstring and back up the annulus, allowing the time of arrival of the tagged fluid slug at the… Read more →

What Is Mud Weight? Mud weight measures the density of drilling fluid circulating through the wellbore during drilling operations, expressed in pounds per gallon (ppg), kilograms per cubic meter (kg/m³), or specific… Read more →

A mud-aging cell is a sealed, pressurized laboratory vessel used to evaluate the stability of drilling fluid formulations under simulated downhole temperature and pressure conditions — specifically, the hyphenated form… Read more →

A mud-in sample is a drilling fluid sample taken from the suction pit (the last pit in the active mud system flow series, located just before the mud goes into the rig pumps and is sent down the wellbore through the… Read more →

A mud-out sample (also written as mud out sample) is a sample of drilling fluid collected from the return flow line (the flowline or possum belly) as the mud circulates back to the surface from the downhole annulus —… Read more →

Mudding off is the unintentional plugging or severe permeability reduction of a productive formation by the invasion of drilling mud solids, bridging particles, or mud filtrate into the pore system immediately adjacent… Read more →

Mudding up is the drilling operations practice of systematically increasing the density (weight) of a drilling fluid by adding weighting materials (typically barite, calcium carbonate, or hematite) to the active mud… Read more →

Mudrock is a collective term for fine-grained clastic sedimentary rocks composed predominantly of particles smaller than 0.0625 mm (the silt-clay boundary), encompassing shale, mudstone, claystone, and siltstone, and… Read more →

A multi-capacitance flowmeter is a production logging tool that uses an array of capacitance sensors positioned at multiple radial locations across the borehole cross-section to measure the local dielectric permittivity… Read more →

Multicomponent seismic data refers to seismic recordings that capture ground motion in more than one direction — typically three orthogonal components (3C: vertical Z, horizontal inline X, and horizontal crossline Y) —… Read more →