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

Unloading in oil and gas production refers to the process of removing liquid accumulation from a wellbore or production tubing string to allow a well to flow naturally or to restore gas production that has been impaired… Read more →

Unsteady-state flow, also called transient flow, is a reservoir or wellbore flow condition in which pressure and flow rate are changing with time at every point in the reservoir because pressure disturbances have not… Read more →

An unweighted mud is a drilling fluid that contains no commercial weighting material (such as barite, hematite, or calcium carbonate) to increase its density above the natural density contributed by the base fluid and… Read more →

Updip is a directional descriptor in petroleum geology and reservoir engineering referring to the direction that lies farther up the slope of a dipping geological formation, stratigraphic surface, or structural contour,… Read more →

An upgrader in the oil sands and heavy oil industry is an industrial processing facility that converts bitumen or heavy crude oil (with API gravity typically between 8 and 14 degrees) into a lighter, higher-quality… Read more →

An upset is the thickened, reinforced section forged at the end of a tubular such as drillpipe, casing, or production tubing, where extra wall thickness and outside diameter are added to compensate for the metal that… Read more →

Pertaining to equipment, facilities or systems located in the wellbore or production train above the surface choke or Christmas tree. Read more →

The stage of downhole pumping at which the polished rod is going up and the downhole pump is pumping fluid. Read more →

Upward continuation is a potential field data processing technique that mathematically transforms a gravity or magnetic field measurement recorded at one elevation to the field values that would have been observed at a… Read more →

What Is Uranium in Well Logging? Uranium, in the context of well logging, is one of three naturally radioactive elements — uranium, thorium, and potassium — resolved by spectral gamma ray tools from the total natural… Read more →