The pressure at which a tube, or vessel, will catastrophically deform as a result of differential pressure acting from outside to inside of the vessel or tube. the collapse-pressure rating of perfectly round tubing is relatively high. however, when the tubing is even slightly oval, the differential pressure at which the tube will collapse may be significantly [...]

A dart-shaped drill pipe inside blowout preventer installed on top of the drill stem when the well is kicking through the drill stem. it is stabbed in open then closed against pressure.

The average pressure within the reservoir at any given time. determination of this value is best made by bottomhole pressure measurements with adequate shut-in time. if a shut-in period long enough for the reservoir pressure to stabilize is impractical, then various techniques of analysis by pressure buildup or drawdown tests are available to determine static [...]

1. a scale of pressure differences in which there is a uniform variation of pressure from point to point. for example, the pressure gradient of a column of water is about 0.433 pounds per square inch per foot (9.794 kilopascals per meter) of vertical elevation. the normal pressure gradient in a formation is equivalent to [...]

Pressure of the annular fluid on the casing at the surface when a well is shut in.

An adaptive drilling process used to precisely control the annular pressure profile throughout the wellbore (iadc definition).

A measurement in the well of the pressure vs. depth. useful for spotting liquid levels, leaks, fluid entries, etc.

Pressure of the annular fluid on the casing at the surface when a well is shut in

The pressure lost in a pipeline or annulus due to the velocity of the liquid in the pipeline, the properties of the fluid, the condition of the pipe wall, and the alignment of the pipe. in certain mud-mixing systems, the loss of head can be substantial

A method of determining the amount of pressure that is allowed to appear on the casing pressure gauge as a kick is circulated out of a well. in general, it is determined by slowly pumping mud into the well while it is shut in and observing the pressure at which the formation begins to take [...]

Repressuring of an oil-field to maintain original pressure. the use of water flooding or natural gas recycling during primary recovery to provide additional formation pressure and displacement energy that can supplement and conserve natural reservoir drives. although commonly begun during primary production, pressure maintenance methods are often considered to be a form of enhanced oil [...]

A sudden, usually short-duration, increase in pressure. when pipe or casing is run into a hole too rapidly, an increase in the hydrostatic pressure results, which may be great enough to create lost circulation

Formation fluid pressure equivalent to about 0.465 pounds per square foot of depth from the surface. if the formation pressure is 4,650 pounds per square inch at 10,000 feet, it is considered normal.

The lowest internal pressure at which a failure (of pipe) will take place.

The force exerted by a body of fluid at rest. it increases directly with the density and the depth of the fluid and is expressed in pounds per square inch or kilopascals. the hydrostatic pressure of fresh water is 0.433 pounds per square inch per foot of depth (9.792 kilopascals per meter). in drilling, the [...]