Oil & Gas Terms in Category C

Clfp

Abbreviation: choke-line friction pressure.

Cement (completions)

Typically the portland, silicate, and/or pozzilin, etc., mixtures used to form a stone-like permanent seal between the pipe and the formation.

Casing centralizer

1.

A device secured around the casing at the regular intervals to center it in the hole.

Casing that is centralized allows a more uniform cement sheath to form around the pipe.

2.

One of several centralizer designs intended to keep the casing better centered in the borehole to get better cement jobs.

Computer control

A system whereby the end devices in the field (switches, valves, gauges, alarms, etc.) are controlled by a program placed in the computer.

Casing seal receptacle

A casing sub containing a seal bore and a left-handed thread, run as a crossover between casing sizes, to provide a tubing anchor.

Calcium carbonate

A chemical combination of calcium, carbon, and oxygen.

It is the main constituent of limestone.

It forms a tenacious scale in water-handling facilities and is a cause of water hardness.

Cat

A crawler-type tractor.

Cement retainer

A tool set temporarily in the casing or well to prevent the passage of cement, thereby forcing it to follow another designated path.

It is used in squeeze cementing and other remedial cementing jobs.

Caving

Collapsing of the walls of the wellbore.

Also called sloughing.

Cementer

A generic term used to describe a retrievable service squeeze tool; used in remedial cementing.

Crown lands

Government owned land.

Calcium contamination

Dissolved calcium ions in sufficient concentration to impart undesirable properties, such as flocculation, reduction in yield of bentonite, and increased fluid loss, in a drilling fluid.

See also calcium carbonate, calcium sulfate, gypsum.

Change house

A small building, or doghouse, in which members of a drilling rig or roustabout crew change clothes, store personal belongs, and so on.

Casing pressure

Gas pressure built up between the casing and tubing.

Casing seal test

A procedure whereby the formation immediately below the casing shoe is subjected to a pressure equal to the pressure expected to be exerted later by a higher drilling glut density or by the sum of a higher drilling fluid density and back-pressure created by a kick.