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

What Is Net Revenue Interest in Oil and Gas? Net revenue interest (NRI) is the fractional share of oil and gas production revenue that a working interest owner actually receives after all royalties, overriding… Read more →

What Are Neural Networks in Oil and Gas? Neural networks in oil and gas are computational models inspired by biological brain architecture, consisting of interconnected layers of mathematical nodes (neurons) that learn… Read more →

The neutral point in a drill string is the depth at which the axial stress in the pipe transitions from compression (below the neutral point, in the lower portion of the drill string where the weight-on-bit reaction… Read more →

Neutralization in oilfield chemistry is the chemical reaction between an acid and a base (alkali) to form a salt and water, in which the hydrogen ions (H+) from the acid combine with the hydroxide ions (OH-) from the… Read more →

In oilfield chemistry and drilling fluid operations, a neutralizing solution is a chemical treatment — acid or base — deliberately applied to counteract an undesirable acidic or alkaline condition in a mud system,… Read more →

Neutron capture in nuclear well logging is the process by which a slow (thermal) neutron is absorbed by an atomic nucleus — particularly by hydrogen nuclei in formation water and hydrocarbons, and by chlorine, boron,… Read more →

A neutron generator is a device that produces high-energy neutrons through nuclear reactions induced by a charged particle accelerator — used in pulsed neutron logging tools, some specialized neutron porosity… Read more →

Neutron interactions in oilfield logging refers to the various physical processes by which neutrons from a logging tool's source collide with and exchange energy with atomic nuclei in the surrounding formation rock and… Read more →

Normally synonymous with a neutron porosity log. However, the term is sometimes broadened to include an activation log. Read more →

What Is a Neutron Porosity Log? A neutron porosity log bombards the formation with fast neutrons from an AmBe or Cf-252 source and measures the flux of slowed (epithermal) or fully thermalised (thermal) neutrons… Read more →

What Is a Neutron Activation Log? A neutron activation log is a nuclear wireline or LWD measurement that irradiates the formation with fast neutrons from a downhole neutron source and records the gamma rays emitted by… Read more →

What Is a Nipple? A nipple, formally called a landing nipple, is a short, heavy-wall steel sub machined into a production tubing string during completion to provide a polished sealbore and a locking profile.… Read more →

Nipple down (also written as nipple-down or nippling down) is the process of systematically disassembling and removing the blowout preventer (BOP) stack, wellhead pressure control equipment, or surface well control… Read more →

The process of assembling well-control or pressure-control equipment on the wellhead. Read more →

A nitrified fluid is a stimulation fluid in which nitrogen gas is dispersed into a liquid base, creating a two-phase mixture that is lighter and more compressible than the liquid alone. The nitrogen is blended into the… Read more →

A nitrogen cushion is a volume of compressed nitrogen gas deliberately introduced into a well, pipeline, vessel, or production system to serve as an inert pressure medium that physically separates or displaces other… Read more →

Nitrogen injection is an enhanced oil recovery (EOR) process in which nitrogen gas (N2) is injected into an oil reservoir to increase the oil recovery factor — operating through different recovery mechanisms depending… Read more →

(noun) A well activation technique in which nitrogen gas is injected into the tubing or annulus to lighten the hydrostatic column and reduce bottomhole pressure, enabling reservoir fluids to flow to the surface.… Read more →

Nitrogen lift is a well intervention technique in which inert nitrogen gas (N2) is circulated into the production conduit — typically through coiled tubing run into the wellbore — to displace and unload the liquid… Read more →

Nitrogen lifting is a well intervention technique that injects nitrogen gas into a wellbore to reduce the weight of the fluid column inside the production tubing, allowing the well to flow when it could not flow on its… Read more →

A nitrogen unit in oil and gas well services is a specialized pumping system that generates and delivers high-pressure, high-volume nitrogen gas for a wide variety of wellbore operations — including well unloading… Read more →

A no-go landing nipple is a subsurface completion component installed in the production tubing string that provides a fixed depth reference point and a locking profile for wireline-conveyed downhole tools, incorporating… Read more →

Noise in oil and gas engineering refers to any unwanted signal or measurement variation that obscures or distorts the desired information — appearing across multiple technical disciplines including seismic data… Read more →

What Is a Noise Log? A noise log is a production logging tool that is lowered into a wellbore to detect and characterize acoustic noise generated by fluid movement, recording the frequency spectrum and amplitude of… Read more →

A nominal filter is a filter classified by a rating that describes the approximate particle size it will remove at a stated capture efficiency rather than an absolute cutoff, used widely in the cleaning and treatment of… Read more →

What Is Non-Darcy Flow? Non-Darcy flow (also called inertial flow, turbulent flow, or high-velocity flow) is fluid movement through porous media in which the relationship between flow rate and pressure gradient deviates… Read more →

A non-Newtonian fluid is any fluid whose viscosity is not constant across all shear rates — meaning the ratio of shear stress to shear rate changes depending on how fast the fluid is being deformed, in contrast to a… Read more →

A nonconductive drilling fluid is a drilling mud whose continuous phase is an electrical insulator rather than a conductor, with electrical resistivity sufficiently high that it cannot complete the current path required… Read more →

A nonconformity is a type of unconformity in which younger sedimentary strata rest directly on older igneous or metamorphic rocks, recording a major gap in the geologic record where the crystalline basement was… Read more →

Nonhydrocarbon contaminants are the non-combustible or corrosive components that occur alongside oil and gas in raw production, principally hydrogen sulfide (H2S), carbon dioxide (CO2), nitrogen (N2), and water,… Read more →