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

A primary recovery mechanism in which the pressure from free water is sufficient to move hydrocarbons out of the reservoir, into the wellbore and up to surface.Waterdrive reservoirs can have bottomwater drive or… Read more →

A method of secondary recovery in which water is injected into the reservoirformation to displace residual oil. The water from injection wells physically sweeps the displaced oil to adjacent production wells. Potential… Read more →

Water and dissolved gas volume at reservoir conditions divided by water volume at standard conditions. This value can often be neglected, since it is always close to 1.0. Read more →

A source of energy for acquisition of marineseismic data that shoots water from a chamber in the tool into a larger body of water, creating cavitation. The cavity is a vacuum and implodes without creating secondary… Read more →

A fluid with water or brine as droplets dispersed into an external phase of oil. Read more →

The replacement of produced fluids by formation water. Most petroleum reservoirs are underlain by water, and water influx into a reservoir almost always takes place at some rate when gas or oil is produced. Whether… Read more →

Jargon applied to a mud additive used to control fluid loss. Read more →

A chemical used in preparation and maintenance of an emulsionmud, which is a water mud containing dispersed oil (or a synthetic hydrocarbon). Numerous types of emulsifiers will disperse oil into water muds, including… Read more →

The volume of produced water associated with oil production. In waterdrive reservoirs, water production can be significantly higher than oil production from a field. Consequently, treatment and disposal of produced… Read more →

The fraction of water in a given pore space. It is expressed in volume/volume, percent or saturation units. Unless otherwise stated, water saturation is the fraction of formation water in the undisturbed zone. The… Read more →

In a cementslurry, the ratio of water to cement expressed as percent; the number of parts of water used to mix with 100 parts of cement. Read more →

A test for water mud or oil mud, generally known as the retort test. Proper procedures for retort tests have been published by API. The test is a distillation of a mud sample that measures condensed oil and water… Read more →

An enhanced oil recovery process whereby water injection and gas injection are alternately injected for periods of time to provide better sweep efficiency and reduce gas channeling from injector to producer. This… Read more →

A drilling fluid (mud) in which water or saltwater is the major liquid phase as well as the wetting (external) phase. General categories of water-base muds are fresh water, seawater, salt water, lime, potassium and… Read more →

The marine equivalent of ground roll. Water-bottom roll consists of a pseudo-Rayleigh wave traveling along the interface of the water and the seafloor. As the use of seabed receiver systems increases, noise from… Read more →

A device for determining the water holdup in a producing well by measuring the capacitance or impedance of the fluid. The term is a misnomer because water cut is not the same as water holdup except in the unlikely case… Read more →

The resistivity of a sample completely filled with water. Called Ro, it is used in contrast to the resistivity of a sample only partially filled with water, Rt. The ratio Rt / Ro is called the resistivity index, I. Read more →

A record of the velocity and direction of water flowing in and around a borehole based on oxygen activation. The log may also include estimates of the flow volume and the distance from tool to flowing water. Water, and… Read more →

A fluid with water or brine as droplets dispersed into an external phase of oil. Read more →

A chemical used in preparation and maintenance of an emulsion mud, which is a water mud containing dispersed oil (or a synthetic hydrocarbon). Numerous types of emulsifiers will disperse oil into water muds, including… Read more →

In a cementslurry, the ratio of water to cement expressed as percent; the number of parts of water used to mix with 100 parts of cement. Read more →

Describing the preference of a solid to be in contact with a water phase rather than an oil or gas phase. Water-wet rocks preferentially imbibe water. Generally, sandstones and carbonates are water-wet before contact… Read more →

What Is Water-Oil Ratio? The water-oil ratio (WOR) is the volume of water produced per unit volume of oil produced from a well or field — typically expressed in stock tank barrels of water per stock tank barrel of oil… Read more →

A primary recovery mechanism in which the pressure from free water is sufficient to move hydrocarbons out of the reservoir, into the wellbore and up to surface.Waterdrive reservoirs can have bottomwater drive or… Read more →

What Is a Waterflood in Oil and Gas? A waterflood is a secondary oil recovery method in which water is injected into a reservoir through dedicated injection wells to maintain reservoir pressure and physically displace… Read more →

The first indication of increased crude-oil production as the result of a waterflooding project. Read more →

(noun) A secondary oil recovery method in which water is injected into a reservoir through dedicated injection wells to maintain reservoir pressure and physically displace oil toward producing wells. Waterflooding is… Read more →

A periodic vibrational disturbance in which energy is propagated through or on the surface of a medium without translation of the material. Waves can be differentiated by their frequency, amplitude, wavelength and speed… Read more →

A mathematical expression to represent wavedisplacement and wave velocity (V) as functions of space (x,y,z) and time (t). Read more →

The shape of a wave, typically shown as a graph of amplitude (or other quantity of interest) versus time. Read more →