Oil and gas terminology · MLC-0103

Oil and gas terms: I (139)

• ICDAn abbreviation for Inflow Control Device, a downhole tool installed in a well completion to manage the flow...
• ICVAn abbreviation for inflow control valve, a downhole device installed as part of a well completion to manage...
• IDAn abbreviation for inside diameter, referring to the measurement across the interior of a tubular component...
• Ideal gasA theoretical gas composed of randomly moving point particles that interact only through elastic collisions...
• IEOMAn abbreviation for Invert Emulsion Oil Mud, a type of drilling fluid where water is dispersed as droplets...
• IgneousDescribing rocks formed from the cooling and solidification of molten magma or lava. These rocks originate...
• IIPThe abbreviation for "Initial-In-Place," referring to the total volume of hydrocarbons (oil or gas) estimated...
• IlliteA common clay mineral belonging to the mica group, characterized by its non-expanding lattice structure. It...
• IlmeniteA naturally occurring iron titanium oxide mineral (FeTiO3) that can be used as a weighting agent in drilling...
• IMAn abbreviation for medium induction, the intermediate-depth induction resistivity curve recorded by a dual...
• ImageA visual representation of subsurface geological structures derived from processed seismic data, often...
• Image recognitionA technology that enables computers to identify and classify objects, people, text, and actions within images...
• ImbibitionThe process where a wetting fluid spontaneously displaces a non-wetting fluid within a porous medium due to...
• ImmatureDescribing organic matter in source rocks that has not yet reached the temperature and pressure conditions...
• ImmiscibleDescribing two or more fluids that do not mix to form a single homogeneous phase, such as oil and water. In...
• ImpedanceA measure of the resistance a medium offers to the propagation of seismic waves, calculated as the product of...
• ImpellerA rotating component within a flowmeter, typically a spinner, that is driven by the movement of fluid in the...
• ImpermeableDescribing a rock or material that does not allow fluids to pass through it, or allows passage only at...
• Impermeable barrierA subsurface feature, such as a sealing fault, a pinch-out or a change to non-porous rock, that stops or...
• Impressed current anodesElectrodes used in cathodic protection systems that are connected to an external direct current power source...
• Improved oil recoveryAny practice that raises the fraction of oil recovered from a reservoir, including improved reservoir...
• Impulse activationAn oxygen activation method for detecting water flow in which a neutron generator fires a short burst that...
• Impulsive seismic dataSeismic data acquired using a source that generates a short-duration, high-amplitude pulse, such as dynamite...
• In lineA direction in a 3D seismic survey that runs parallel to the acquisition direction of the seismic source and...
• In situA Latin phrase meaning "in position" or "in its original place," describing materials, properties, or...
• In situ combustionAn enhanced oil recovery process that involves igniting a portion of the heavy oil within the reservoir by...
• In situ fluid analysisThe measurement and characterization of reservoir fluids directly within the wellbore, without bringing...
• In situ viscosity evaluationThe downhole measurement of a reservoir fluid's resistance to flow under its original pressure and...
• Incident angleThe angle between an incoming ray and the normal to a reflecting or refracting interface. Snell's law uses it...
• InclinationThe angle of deviation of a wellbore from a true vertical path, measured in degrees. It is one of the two...
• InclinometerA sensor that measures tilt, meaning the angle of a surface or borehole away from vertical, using gravity as...
• IncompetentDescribing a rock unit that deforms readily by flow or folding under stress, rather than by fracturing...
• IndicatorA substance that undergoes a distinct change, such as a color change, in response to a specific chemical...
• Indicator methodsGeostatistical techniques that model the spatial distribution of categorical variables, such as facies types...
• Indicator modelsGeostatistical models that represent the spatial distribution of categorical variables, such as lithofacies...
• Induced gamma ray spectroscopyA nuclear logging technique that measures the energy spectrum of gamma rays emitted by atomic nuclei in the...
• Induced particle pluggingA technique for conformance control in which solid particles are injected into a reservoir to selectively...
• Induced polarizationA geophysical method that measures the voltage decay in the ground after the cessation of an injected...
• InductionA logging method that measures the electrical conductivity of a formation without direct electrode contact...
• Induction electrical surveyA well logging operation that measures formation resistivity using the principles of electromagnetic...
• Inelastic neutron scatteringA nuclear interaction where a high-energy neutron collides with an atomic nucleus, loses a discrete amount of...
• Inert sulfideA metal sulfide, such as pyrite, that stays chemically stable and does not release hydrogen sulfide when a...
• Inertial resistanceThe opposition to fluid flow through porous media that arises from the acceleration and deceleration of the...
• Infill drillingThe practice of drilling additional wells within an existing developed oil or gas field. This increases the...
• Infinite acting radial flowA flow regime observed during a well test where the pressure disturbance has not yet reached any reservoir...
• Infinite-acting reservoirA reservoir that behaves as if it has no outer boundaries during the duration of a pressure transient test...
• Infinite-conductivity fractureA theoretical hydraulic fracture that offers no resistance to fluid flow along its length, meaning the...
• Inflatable packerA downhole tool that uses a rubber element inflated with fluid or gas to seal the annulus between the...
• Inflow control deviceA passive downhole component installed in a well completion to restrict and balance the flow of fluids from...
• Inflow control valveA remotely adjustable downhole device that actively manages the flow of fluids from specific reservoir...
• Inflow performance relationshipA graphical or mathematical representation of a well's ability to produce fluids from the reservoir to the...
• Information theoryA mathematical framework for quantifying information content and uncertainty in data, applied in reservoir...
• InhibitTo prevent or reduce the undesirable reactions of drilling fluid components with the formation or with other...
• Inhibited acidAn acid solution, typically hydrochloric or hydrofluoric acid, that contains chemical additives designed to...
• InhibitionThe chemical process of preventing or slowing the swelling, hydration, and dispersion of clay and shale...
• Inhibitive mudA drilling fluid formulated with specific chemical additives to prevent or reduce the hydration and...
• InhibitorA chemical additive introduced into a fluid system to prevent or reduce undesirable reactions, such as...
• Initial flow periodThe first, brief flow of a drillstem test, lasting only minutes, in which the tester valve is opened to draw...
• Initial reservoir pressureThe pressure within a petroleum reservoir before any fluid production has occurred. This pressure represents...
• Initial shut-in periodThe first shut-in of a drillstem test, which follows the brief initial flow period. With the tester valve...
• Injection gasNatural gas that is compressed and pumped into a reservoir to maintain pressure, displace oil, or enhance...
• Injection lineA pipeline or conduit used to transport fluids, such as water, gas, or chemicals, from a surface facility to...
• Injection mandrelA side-pocket mandrel installed in the tubing string to hold a retrievable injection valve, either a gas-lift...
• Injection patternThe geometric arrangement of injection wells relative to production wells in a reservoir during fluid...
• Injection pressureThe fluid pressure at the wellhead or sandface of an injection well, required to force fluids into a target...
• Injection pulsed neutron logA type of pulsed neutron log specifically run in injection wells to monitor the movement and distribution of...
• Injection pumpA high-pressure positive displacement or centrifugal pump at the surface that injects liquid into a well, for...
• Injection testA procedure to determine the properties of a formation by pumping fluid into it at a controlled rate and...
• Injection waterWater forced into a reservoir to support pressure, sweep hydrocarbons toward producing wells, or serve as a...
• Injection wellA well used to force fluids into an underground formation as part of secondary recovery, pressure...
• Injection-well testingA diagnostic procedure performed on wells used to inject fluids, such as water or gas, into a reservoir to...
• InjectiteA sedimentary intrusion formed when fluidized sediment, such as sand or mud, is forcibly injected into...
• Injectivity testA procedure to determine the rate and pressure at which fluids can be pumped into a target formation without...
• Injector headThe primary component of a coiled tubing unit that grips, pushes, and pulls the coiled tubing string into and...
• Inner seat ringA component within a valve that provides a sealing surface for the valve's closure element, such as a gate or...
• InsertA replaceable component within a drilling bit or other downhole tool, designed to perform a specific function...
• Inside blowout preventerA one-way valve installed in the drill string to control flow up the pipe during a well control event, acting...
• Inside diameterThe measurement of the open, hollow space within a tubular good such as drill pipe, casing, or tubing. This...
• Inside-out air seat testA method for testing the sealing integrity of a valve seat by applying air pressure from the inside of the...
• Instrumented pigA self-contained device, also known as a smart pig or intelligent pig, that travels through a pipeline to...
• Intelligent wellA well equipped with downhole sensors, control valves, and communication systems that allow for remote...
• IntensifierA device that increases the pressure of a fluid, typically hydraulic fluid, to a higher level than the input...
• Interfacial tensionThe force per unit length existing at the interface between two immiscible fluids, such as oil and water. It...
• Interference testingA well test conducted by producing from one well (the active well) and observing the pressure response in one...
• IntermediateA product of a refining or chemical process that is neither the initial raw material nor the final finished...
• Intermediate casingA string of steel pipe set and cemented in a wellbore after the surface casing but before the production...
• Intermediate casing stringA string of casing run into a wellbore after the surface casing but before the production casing. It isolates...
• Intermittent gas liftA method of artificial lift where gas is injected into the tubing string at intervals, rather than...
• Internal phaseThe discontinuous liquid phase in an emulsion, which is dispersed as droplets within the continuous external...
• Internal pulling toolA specialized wireline tool designed to retrieve downhole flow-control devices by engaging an internal...
• International nautical mileA unit of length used in marine and aeronautical navigation, defined as exactly 1,852 meters. It is based on...
• InterpolationThe process of estimating unknown values of a reservoir property at unmeasured locations based on known...
• InterpretationThe process of analyzing geophysical and geological data to create a model of the subsurface structure and...
• Interstitial gasNatural gas held as a free phase within the pores between the grains of a reservoir rock, as opposed to gas...
• Interstitial waterWater that occupies the pore spaces within a rock or sediment formation. This water can be connate, meaning...
• Interval methodA technique in production logging that measures fluid velocity or holdup over a defined vertical section of...
• Interval timeThe two-way travel time for a seismic wave to traverse a specific geological layer or interval. It is derived...
• Interval transit timeThe time it takes for a seismic wave to travel a unit distance through a specific geological formation...
• Interval velocityThe speed at which a seismic wave travels through a specific layer of rock between two depth or time markers...
• Interwell tomographyA geophysical technique that uses seismic or electromagnetic waves transmitted between boreholes to create a...
• Invaded zoneThe region of a reservoir formation where drilling fluid filtrate has displaced the original formation...
• InvasionThe process by which drilling fluid filtrate penetrates a permeable formation, displacing the native...
• InverseA mathematical technique used to determine the properties of a subsurface formation from observed...
• Inverse filterA digital signal processing tool designed to reverse the effects of a known filtering process on a recorded...
• Inverse problemThe process of calculating a model of the Earth's subsurface properties from a set of observed geophysical...
• InversionA geological process where a basin or rift structure that previously underwent extension is later subjected...
• Invert emulsionA drilling fluid where oil forms the continuous external phase and water is dispersed as droplets within it...
• Inverted five-spotA regular five-well pattern in which one injection well sits at the center of a square and four production...
• Invert-emulsion oil mudA drilling fluid system where oil is the continuous phase and water is emulsified within it, forming a...
• IOAn abbreviation for isomerized olefin, a synthetic base fluid for non-aqueous drilling fluids made by...
• Ion exchangeA reversible chemical process where ions from a solid material are exchanged with ions in a surrounding...
• IPAn abbreviation for induced polarization, a geophysical method that measures the voltage decay in the ground...
• IPAThe abbreviation for isopropyl alcohol, also called isopropanol or 2-propanol, a colourless, flammable...
• IPRAn abbreviation for Inflow Performance Relationship, which is a curve representing the relationship between...
• Iron carbonateA scale-forming mineral, FeCO3, that precipitates in drilling fluids and production systems, especially in...
• Iron oxideA chemical compound of iron and oxygen, often encountered in drilling fluids as a contaminant or as a...
• Iron stabilizerA chemical additive used in acidizing treatments to prevent the precipitation of iron compounds, which can...
• Iron sulfideA chemical compound of iron and sulfur, such as pyrite (FeS2) or pyrrhotite (FeS). It can form in drilling...
• Iron-oxidizing bacteriaMicroorganisms that obtain energy by oxidizing ferrous iron to ferric iron, often leading to the formation of...
• Irreducible waterThe volume of water held within the pore spaces of a rock by capillary forces that cannot be displaced by...
• ISOAn independent non-governmental organization based in Geneva that publishes international consensus...
• IsochoreA contour line on a map joining points where a stratigraphic unit has the same true vertical thickness...
• IsochronA line on a seismic section or map connecting points of equal two-way traveltime for a seismic reflection. It...
• Isochron mapA contour map that displays the two-way travel time to a specific seismic horizon across a survey area. The...
• Isochronal testA well test designed to determine the deliverability of a gas well by flowing it at several different rates...
• Isolated porosityThe part of a rock's pore volume made up of pores that are sealed off from other pores and from the wellbore...
• Isomerized olefinA type of synthetic base oil derived from olefins that have undergone an isomerization process to alter their...
• IsopachA contour line on a map joining points where a stratigraphic unit has the same true stratigraphic thickness...
• IsopropanolA colourless, flammable secondary alcohol, 2-propanol (C3H8O), that mixes fully with water and with many...
• Isopropyl alcoholA clear, flammable organic compound commonly used in drilling fluids as a solvent or defoamer. It assists in...
• IsostasyThe state of gravitational equilibrium between the Earth's lithosphere and asthenosphere, such that the...
• IsostaticRelating to the state of gravitational equilibrium between the Earth's lithosphere and asthenosphere, where...
• Isostatic correctionA correction applied to gravity data to account for the gravitational effect of large, low-density crustal...
• IsotropicDescribing a material or medium whose physical properties are the same in all directions. In geology, an...
• Isotropic formationA rock formation in which a given physical property, such as permeability or elastic modulus, has the same...
• Isotropic permeabilityA condition where the permeability of a porous medium is the same in all directions from a given point. A...
• IsotropyThe property of a material exhibiting uniform physical characteristics in all directions. In the context of...
• Iterative forward modelingA method for determining subsurface properties by repeatedly adjusting a geological model and calculating its...
• Iterative methodsComputational procedures that repeatedly apply a set of calculations to refine an initial estimate until a...

139 of 4,469 terms in Oil and gas terminology (MLC-0103). Request the full dataset.