Oil and Gas Terms Beginning with “H” — Page 4

Hot waterflooding is a thermal enhanced oil recovery (EOR) method in which heated water (typically heated to 100-200°C at surface and injected while still hot) is injected into a reservoir through specifically… Read more →

In wireline logging, a housing is the outer steel case of a cartridge or a sonde that encloses and protects the electronics, power supplies and sensors of a downhole logging tool, isolating them from the borehole… Read more →

Huff and puff is the colloquial term for cyclic injection processes in which a single wellbore is used alternately as both an injector and a producer to enhance hydrocarbon recovery from reservoirs that would otherwise… Read more →

Humic acid is a complex mixture of high-molecular-weight organic compounds derived from the decomposition of plant and animal matter in soil and sedimentary deposits — in the oilfield, humic acid and its derivatives… Read more →

Moisture (water vapor) in a gaseous atmosphere, such as in air. It is quantified as relative humidity. Read more →

(noun) An instrument used to measure the moisture content or relative humidity of a gas stream, ambient air, or process environment. In gas processing and pipeline operations, humidity meters monitor water vapour levels… Read more →

Humping, in drilling engineering and well mechanics, refers to the upward buckling or sinusoidal bowing of a drill string or casing string in a deviated or horizontal wellbore under axial compressive loading, creating a… Read more →

Hybrid scale is a form of mineral scale deposit in oilfield production systems that consists of a mixture of two or more distinct scale types — most commonly a combination of carbonate scales (calcium carbonate) and… Read more →

A chemical combination of water and another substance. Gypsum is a hydrate mineral. Its anhydrous equivalent is anhydrite. Read more →

Hydration is the absorption of water by a hygroscopic material, typically a clay mineral or water-soluble polymer, in which water molecules associate with the surface, edges, and interlayer regions of the solid through… Read more →

A hydraulic bypass is a flow path or valve mechanism in a downhole tool or completion assembly that allows wellbore fluid to circulate around (bypass) the tool body rather than being forced through the tool's restricted… Read more →

Hydraulic cement is a powdered binder that sets and hardens into a stone-like solid through a chemical reaction with water called hydration, and critically it continues to set and gain strength even when fully… Read more →

A hydraulic centralizer is a downhole tool that uses wellbore fluid pressure acting on a piston or bladder mechanism to extend radially outward and contact the borehole wall, centering the casing string or drillstring… Read more →

What Is Hydraulic Fracture Monitoring? Hydraulic fracture monitoring (also called fracture diagnostics or HFM ) is the suite of surface and downhole measurement technologies used to characterize the geometry,… Read more →

What Is Hydraulic Fracturing? Hydraulic fracturing stimulates an oil or gas reservoir by pumping fluid at pressures above the formation parting pressure, creating and propping open a network of conductive fractures in… Read more →

Hydraulic head (also called piezometric head or total head) is the total mechanical energy per unit weight of a fluid at a given point in a porous medium or conduit, expressed as a length (in meters or feet of fluid… Read more →

What Is Hydraulic Horsepower? Hydraulic horsepower (also called HHP or hydraulic power ) is a measure of the power delivered by a pump to a fluid, calculated as flow rate in gallons per minute multiplied by pressure in… Read more →

A hydraulic packer is a downhole sealing assembly run as part of a production tubing string that isolates the casing-tubing annulus from formation pressure by expanding an elastomer element radially against the casing… Read more →

A hydraulic power pack (HPP) in oil and gas operations is a self-contained surface or skid-mounted unit that generates, conditions, and supplies high-pressure hydraulic fluid to downhole tools, wellhead equipment, or… Read more →

Hydraulic pumping is an artificial-lift system used in producing oil wells where reservoir pressure is insufficient to lift fluids to surface naturally — operating through a downhole hydraulically driven pump that is… Read more →

A hydraulic release tool (HRT) is a downhole mechanical device that uses applied hydraulic pressure — either through the drill pipe bore or the annulus — to activate a release mechanism that disconnects one section of… Read more →

Hydraulic set describes a downhole tool operating or setting method in which the mechanical action required to activate, expand, or latch the tool is driven by hydraulic pressure applied through the production tubing or… Read more →

A hydrocarbon is any organic chemical compound composed exclusively of carbon and hydrogen atoms, ranging from the simplest possible molecule (methane, CH4, a single carbon with four hydrogen atoms) to complex heavy… Read more →

What Is a Hydrocarbon Indicator? A hydrocarbon indicator (HI) , also called a direct hydrocarbon indicator (DHI), is a seismic amplitude anomaly, reflection characteristic, or attribute that can be related to the… Read more →

What Is a Hydrocarbon Kitchen? Hydrocarbon kitchen (also called the generative kitchen , oil kitchen , or mature source rock fairway ) is the geographic area within a sedimentary basin where source rock has been buried… Read more →

Hydrochloric acid (HCl) is the most widely used stimulation acid in oil and gas well operations, a strong mineral acid consisting of hydrogen chloride gas dissolved in water that reacts readily with calcium carbonate… Read more →

What Is a Hydrocyclone? Hydrocyclone (also called a cyclone separator or liquid cyclone ) is a conical device that uses centrifugal force generated by tangential liquid entry to separate particles by density. Heavier… Read more →

Hydrofluoric acid (HF, aqueous hydrogen fluoride) is a highly corrosive weak acid used in petroleum well stimulation as the primary active ingredient in mud acid (a mixture of HF and hydrochloric acid) for matrix… Read more →

(noun) A blended acid system combining hydrofluoric acid (HF) and hydrochloric acid (HCl), commonly known as mud acid, used in matrix acidising of sandstone formations to dissolve clay minerals, feldspar, and siliceous… Read more →

Hydrogen blistering is a specific form of hydrogen-induced steel failure characterized by the formation of localized blister-like surface deformations or internal cavities filled with high-pressure molecular hydrogen… Read more →