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

The pressure registered in the wellhead of a producing well. Read more →

An in situ combustion technique in which water is injected simultaneously or alternately with air into a formation.Wet combustion actually refers to wet forward combustion and was developed to use the great amount of… Read more →

Natural gas containing significant heavy hydrocarbons. Propane, butane and other liquid hydrocarbons can be liquefied. Read more →

Oil that contains basic sediment and water (BS&W). Read more →

The proportion of a wet clay that is clay-bound water. A formation that has 100% clay would have a porosity equal to the wet-clay porosity (WCLP), all of it being clay-bound water, and a volume of dry clay equal to (1 -… Read more →

What Is Wettability in Oil and Gas Reservoirs? Wettability is the tendency of one fluid to spread on or adhere to a solid surface in the presence of another immiscible fluid. In petroleum reservoirs, it describes which… Read more →

A type of damage in which the formationwettability is modified, generating a change in relative permeability that eventually affects well productivity.Surfactants or other additives in drilling fluids, especially… Read more →

A complete section of a conventionally drilled core. The section may be up to about 2 feet [0.6 m] in length, with typical core diameters lying between 1.75 and 5.25 in. [4.4 and 13.3 cm]. The term full-diameter core is… Read more →

A dilution process which involves selective dumping of the active system (such as sand traps and "bottoms up" mud) and replacement of the lost volume with fresh mud. This process has proved economical with inhibitive… Read more →

A dilution process which involves selective dumping of the active system (such as sand traps and "bottoms up" mud) and replacement of the lost volume with fresh mud. This process has proved economical with inhibitive… Read more →

A common seismic display that shows trace amplitude versus time as an oscillating line about a null point. Read more →

An exploration well. The significance of this type of well to the drilling crew and well planners is that by definition, little if anything about the subsurface geology is known with certainty, especially the pressure… Read more →

A valve located on the side of a Christmas tree or temporary surface flow equipment, such as may be used for a drillstem test. Two wing valves are generally fitted to a Christmas tree. A flowing wing valve is used to… Read more →

(noun) A rubber or elastomeric plug pumped inside casing or drillpipe to separate different fluids and wipe the inner wall clean during cementing or displacement operations. Top and bottom wiper plugs are used in… Read more →

An abbreviated recovery and replacement of the drillstring in the wellbore that usually includes the bit and bottomhole assembly passing by all of the openhole, or at least all of the openhole that is thought to be… Read more →

A safety device attached to the slickline at surface between the hay pulley and stuffing-box pulley. The wire clamp generally is applied when the slickline is to be stationary for a period of time. This prevents the… Read more →

A type of screen used in sand control applications to support the gravel pack. The profiled wire is wrapped and welded in place on a perforated liner. Screen is available in a range of sizes and specifications,… Read more →

A general term used to describe well-intervention operations conducted using single-strand or multistrand wire or cable for intervention in oil or gas wells. Although applied inconsistently, the term commonly is used in… Read more →

A downhole tool used to cut slickline from a tool string that is stuck or jammed in a wellbore. The wireline cutter is attached to the slickline at surface and dropped down the wellbore. When the cutting tool impacts… Read more →

Test taken with a wireline formation tester. The wireline formation pressure measurement is acquired by inserting a probe into the borehole wall and performing a minidrawdown and buildup by withdrawing a small amount of… Read more →

What Is a Wireline Formation Tester? A wireline formation tester (WFT) deploys on a wireline cable into a drilled wellbore, sets a probe or inflatable packer against the borehole wall, and measures virgin formation… Read more →

A fishing tool used for the retrieval of broken or cut slickline from the wellbore. Wireline grabs are intended to catch and engage wireline that has been bunched or nested in the wellbore. For that reason, they are… Read more →

What Is a Wireline Log? A wireline log is a continuous, depth-indexed record of physical formation properties acquired by lowering electrically powered sensor tools into a wellbore on a multi-conductor armored cable… Read more →

A type of safety valve in which the principal components can be run and retrieved by wireline or slickline. The valve assembly is landed in a ported nipple that is equipped with a control line connected to the surface… Read more →

An interactive computer suitable for seismic data processing, interpretation and modeling that is particularly useful for studies of large quantities of seismic data, particularly 3D seismic data. Read more →

A generic term used to describe a tubing string used to convey a treatment or for well service activities. Both coiled and jointed tubing strings are referred to as work strings. Read more →

What Is Working Interest in Oil and Gas? A working interest (WI) in oil and gas is an ownership interest in a lease or well that carries the right to explore, drill, and produce — and the obligation to pay a… Read more →

The process of performing major maintenance or remedial treatments on an oil or gas well. In many cases, workover implies the removal and replacement of the production tubing string after the well has been killed and a… Read more →

A well-control fluid, typically a brine, that is used during workover operations. Since the wellbore is in contact with the reservoir during most workover operations, workover fluids should be clean and chemically… Read more →

A high-porosity, high-permeability channel that develops when heavy oil is produced simultaneously with sand (during cold heavy oil production with sand, or CHOPS). Wormholes develop in a radial pattern away from the… Read more →