Oil and Gas Terms Beginning with “I” — Page 3

An injection mandrel is a downhole completion component installed in the production tubing string that provides a specifically engineered location and flow path for injecting treatment chemicals, corrosion inhibitors,… Read more →

What Is an Injection Pattern? Injection pattern (also called flood pattern or well pattern) is the geometric arrangement of injection and production wells in a secondary recovery waterflood or enhanced oil recovery… Read more →

The pressure needed to inject fluid into the formation to pressurize or displace hydrocarbons. Read more →

An injection pump in petroleum engineering is any pump used to force fluid into a wellbore, reservoir, pipeline, or process system against a back-pressure that exceeds the fluid's supply pressure, with oilfield… Read more →

An injection test in petroleum engineering and reservoir evaluation is a well test performed by injecting fluid (water, gas, or tracer) into a formation at a controlled rate and pressure, then monitoring the pressure… Read more →

Injection water is treated or untreated water deliberately pumped into a subsurface reservoir through dedicated injection wells to maintain or restore reservoir pressure and physically displace residual oil toward… Read more →

What Is an Injection Well? An injection well is a wellbore used to pump fluids — water, gas, steam, CO₂, or chemical solutions — into a subsurface formation for the purpose of maintaining reservoir pressure, enhancing… Read more →

What Is Injection Well Testing? Injection well testing analyses the pressure response of wells in which fluid is being injected into a reservoir — most commonly in water injection for pressure maintenance or enhanced… Read more →

An injection/pulsed neutron log (PNL) is a through-casing formation evaluation technique in which a downhole tool emits short bursts (pulses) of high-energy neutrons (14 MeV) from a pulsed neutron generator (PNG) into… Read more →

What Is an Injectivity Test? Injectivity test (also called an injection well test or constant-rate injection test) is a pressure transient test conducted on an injection well by injecting fluid at a constant rate and… Read more →

The injector head is the mechanical drive unit of a coiled tubing unit that grips the continuous coiled tubing string and provides the thrust force needed to push the string into the wellbore against wellbore pressure,… Read more →

In wireline well logging, an insert is the printed block placed on a log that states the scales of the curves displayed and the depth scale used over the interval, so that anyone reading the log can correctly interpret… Read more →

A valve in the drillstring that may be used to prevent the well from flowing uncontrollably up the drillstring. Read more →

Inside or inner diameter. Casing, tubing and drillpipe are commonly described in terms of inside diameter and outside diameter (OD). Read more →

An instrument hanger is a small downhole locking tool used to temporarily suspend memory pressure and temperature gauges, downhole flowmeters, or other survey instruments inside a producing or shut-in wellbore. The tool… Read more →

An instrumented pig, also called a smart pig or in-line inspection (ILI) tool, is a self-contained sensor platform launched into a pressurized pipeline and propelled by the flowing product (crude oil, natural gas, NGLs,… Read more →

What Is an Intelligent Well? Intelligent well (also called a smart well or i-well) is a completion incorporating permanently installed downhole sensors and remotely operated flow control devices — specifically interval… Read more →

An intensifier is a downhole tool that sits in the drillstring directly above a drilling jar and roughly doubles the impact force the jar delivers when it fires. Drilling jars are used to free stuck pipe, fishing tools,… Read more →

What Is Interfacial Tension? Interfacial tension (also called IFT or surface tension when one phase is a gas) is the energy per unit area at the boundary between two immiscible fluids — most commonly oil and water, or… Read more →

What Is Interference Testing? Interference testing (also called an interference test or interwell pressure test) is a pressure transient test in which one well — the active well — is produced or injected at a constant… Read more →

Referring to any particle in the size range 250 to 2000 microns. Read more →

What Is Intermediate Casing? Intermediate casing (also called protective casing or long string in some regional contexts) is a casing string set between the surface casing and the production casing in a multi-string… Read more →

An intermediate casing string is a steel pipe casing run and cemented in the wellbore between the surface casing and the production casing, serving the critical function of isolating formations with abnormal pore… Read more →

What Is Intermittent Gas Lift? Intermittent gas lift (also called intermittent lift or cyclic gas lift) is an artificial lift method in which high-pressure gas is injected into the production tubing in periodic slugs or… Read more →

Internal flash in oil and gas production and processing operations refers to the spontaneous vaporization (flashing) of dissolved light hydrocarbon components from a liquid stream when the liquid undergoes a pressure… Read more →

The discontinuous phase of an emulsion, the dispersed droplets of emulsified fluid. Read more →

An internal pulling tool is a downhole retrieval device, run on slickline, braided line, or coiled tubing, that engages the inside bore of a fishing neck to recover plugs, locks, separation tools, subsurface safety… Read more →

Interpolation in petroleum geoscience and engineering is the mathematical process of estimating values of a property (porosity, permeability, formation thickness, oil saturation, seismic velocity) at unsampled locations… Read more →

In geophysics and petroleum geology, interpretation is the disciplined process of analyzing acquired data to build reasonable, testable models of the subsurface and to predict the properties, structures, and fluid… Read more →

Interstitial gas in coal seam and shale gas reservoir analysis is the gas stored within the pore space of the rock matrix (the open pore volume between grains, fractures, and cleat networks) as free compressed gas under… Read more →