The cementing operation that takes place immediately after the casing has been run into the hole.

It provides a protective sheath around the casing, segregates the producing formation, and prevents the undesirable migration of fluids.

An examination of reservoir fluid in a laboratory under various pressures, volumes, and temperatures to determine the characteristics and behavior of the fluid.

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 mud.

The yield of an oil or gas well; the branch of the industry that brings the oil and gas to the surface for sale.

The phase of the petroleum industry that deals with bringing the well fluids to the surface and separating them and with storing, gauging, and otherwise preparing the product for pipeline.

The amount of oil or gas produced in a given period.

The first stage of oil production in which natural reservoir drives are used to recover oil, although some form of artificial lift may be required to exploit declining reservoir drives.

The force that a fluid (liquid or gas) exerts uniformly in all directions within a vessel, pipe, hole in the ground, and so forth, such as that exerted against the inner wall of a tank or that exerted on the bottom of the wellbore by a fluid.

Pressure is expressed in terms of force exerted per unit of area, as pounds per square inch, or in kilopascals.

A valve that opens at a preset pressure to relieve excessive pressures within a vessel or line.

Also called a relief valve, safety valve, or safety relief valve.

A tank used in the field to receive crude oil as it comes from the well.

Also called a flow tank or lease tank.

A diagnostic tool used to ascertain whether there is a gas leak in the tubing of a gas lift well.

If there is a tubing leak, the pressure on the annulus will equal the pressure on the tubing.

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 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

Prevention of formation fluid flow by maintaining a hydrostatic pressure equal to or greater than formation pressure

The zone or formation from which oil or gas is produced.

See pay sand.

A portable servicing or workover outfit, usually mounted on wheels and self-propelled.

A well servicing unit consists of a hoist and engine mounted on a wheeled chassis with a self-erecting mast.

A workover rig is basically the same, with the addition of a substructure with rotary, pump, pits, and auxiliaries to permit handling and working a drill string.

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 recovery.