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

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

Wet combustion is a variant of in-situ combustion (ISC) enhanced oil recovery in which water is co-injected with compressed air into the reservoir, generating steam in the hot burned zone behind the combustion front and… 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 →

Wet-clay porosity (also called total clay porosity or clay-associated porosity) refers to the pore volume associated with clay minerals in a reservoir rock — a quantity that includes both the interstitial water trapped… 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 →

Wettability change in petroleum reservoir engineering refers to the alteration of the natural wetting preference of reservoir rock surfaces — from the original water-wet or mixed-wet condition toward oil-wet or from… Read more →

A whole core is a complete cylindrical section of formation rock recovered from the wellbore through conventional coring operations — typically up to approximately 2 feet (0.6 m) in length per individual section, with… Read more →

Whole mud dilution in drilling fluid management is the solids control technique of selectively discarding a portion of the active drilling mud system (the portion with the highest concentration of fine, undesirable… Read more →

Whole mud dilution in drilling fluid management is the solids control technique of selectively discarding a portion of the active drilling mud system (the portion with the highest concentration of fine, undesirable… Read more →

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

A wildcat well (also called a wildcat or wildcat exploration well) is an exploratory oil or gas well drilled in an area with little or no previous production history — targeting an unproven geological prospect where the… Read more →

A wing valve is a manually or actuator-operated shutoff valve positioned on the "wing" (horizontal side outlet) of a Christmas tree — the assembly of valves, spools, and fittings installed on top of a producing or… 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 →

A wiper trip is a drilling operation in which the drill string is pulled out of the hole some distance (or all the way to surface) and then run back to bottom, primarily to condition the wellbore by cleaning out… Read more →

A wire clamp in oilfield operations is a mechanical fastening device used to secure, terminate, or connect wire rope (wireline, cable, or guy wire) by gripping the wire between a shaped saddle and a U-bolt that is… Read more →

A wire-wrapped screen (also called a wire-wound screen or continuous slot screen) is a sand control completion device consisting of a perforated base pipe wrapped with a continuous triangular wire coil in which the gap… Read more →

Wireline in the oil and gas industry refers to a method of well intervention and formation evaluation that uses a single-conductor or multi-conductor armored cable (the wireline) lowered into a wellbore from a surface… Read more →

A wireline cutter is a downhole tool deployed on a wireline or slickline to sever a stuck wireline, electric line, or coiled tubing in the wellbore at a specific depth, allowing the operator to recover the… Read more →

What Is a Wireline Formation Test? A wireline formation test (WFT) is a formation evaluation operation in which a modular formation tester tool — most commonly the Schlumberger MDT, Baker Hughes RCI, or Halliburton RDT… 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 wireline grab in oil and gas well operations is a downhole fishing tool specifically designed to engage and retrieve a wireline cable, braided line, or slickline that has become stuck or parted in the wellbore, using… Read more →

A wireline log is a continuous record of formation properties measured by sensors lowered into the wellbore on an electrically conductive cable (the wireline). The logging tool string is lowered to the bottom of the… Read more →

A wireline-retrievable safety valve (WRSV) is a subsurface safety valve designed to be installed and removed from the production tubing using wireline (slickline or electric line) without requiring the tubing string to… Read more →

In oil and gas geoscience, a work station is an interactive computer system configured for seismic data processing, interpretation, and modeling, distinguished from an ordinary office computer by its high-performance… Read more →

A work string is the tubing string run into a well to convey a treatment or to carry out a well service or intervention activity, as distinct from the permanent production tubing that stays in the well during normal… 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 →

A workover is the process of performing major maintenance, remedial treatments, or production-enhancement operations on an existing producing oil or gas well that has experienced declining productivity, mechanical… Read more →

A workover fluid is a well-control fluid placed in a wellbore before or during a workover operation (pulling and replacing production tubing, cleaning out sand or scale, reperforating, stimulating, or performing zone… Read more →

A wormhole in petroleum engineering is a highly conductive dissolution channel created when acid (typically hydrochloric acid for carbonate formations or hydrofluoric acid for sandstone) reacts preferentially with the… Read more →