Coiled Tubing Glossary...

Carbonate Rock: A sedimentary rock primarily composed of calcium carbonate (limestone) or calcium magnesium carbonate (dolomite) which often make up our petroleum reservoirs.

Casing Cementing Temperature: the temperature of a cement slurry while it is being displaced at the maximum cementing depth in a casing cementing operation.

Casing Cementing: the practice of filling the annulus between casing and hole with cement to prevent fluid migration between permeable zones and to support the casing.

Casing: steel pipe placed in a wellbore as drilling progresses to prevent the wall of the hole from caving in during drilling, to provide protection for subsequent casing or tubing strings and to provide a means of extracting petroleum if the well is productive.

Casing Head: a heavy, flanged steel fitting that connects to the first string of casing and provides a housing for the slips and packing assemblies by which intermediate strings of casing are suspended and the annulus sealed off [also called a spool].

Cement Casing: To fill the annulus between casing and open hole with cement to support the casing and prevent migration of fluids or gas between permeable zones.

Cement Channeling: the rising of cement between the casing and the borehole wall when the slurry fails to rise uniformly throughout the annulus.

Cement Plug: a portion of cement placed at some point in the wellbore to seal it.

Cement Retainer: a tool set temporarily in the casing or well to prevent the passage of cement1 thereby forcing it to follow another designated path. It is used in squeeze cementing and other remedial cementing jobs.

Cement System: the combination of materials which make up an oil-well cement slurry channeling (see cement channeling).

Cement: a powder made of limestone, clay, and some other materials used as mortar and concrete.

Cementing Basket: a collapsible or folding metal cone that fits against the walls of the wellbore to prevent the falling of cement.

Cementing: the application of a liquid slurry of cement and water to various points inside or outside the casing.

Centralizer: A device placed around casing to keep the casing centered in the hole.

Cheater: A length of pipe fitted over a wrench handle to increase the leverage of the wrench.

Check Valve: A valve that allows flow through it in one direction only. This device can be installed at the coiled tubing connector and allows fluid to be circulated down the string but prevents backflow. This device may be a ball-and -seat type or flapper type.

Choke Line Valve: The valve(s) connected to the end part of the well control stack which controls the flow to the choke.

Choke: A device with either a fixed or a variable aperture used to control the rate of flow of liquids and/or gas.

Christmas Tree: A term applied to the combination of valves and fittings assembled above the top of the tubing spool on a completed well to contain well pressure and control the flow of hydrocarbons and other fluids.

Circulate: To pass from one point throughout a system and back to the starting point.

Circulating Pressure: the pressure at a specified depth required to circulate a fluid in a well at a given rate.

Circulation: The movement of fluid or gas, from a vessel on surface, down a tubular string, returning up the annulus and back to a vessel or pit on surface.

Clinker: the finely powdered limestone and other matter fused together as the first stage in the manufacture of Portland cement.

Closing Ratio: The ratio of the wellhead pressure to the hydraulic actuation pressure required to close the well control component.

Collapse Pressure: The amount of pressure required to flatten the sides of pipe.

Collapse: The flattening of the coiled tubing due to external pressure or external pressure combined with either tension or bending.

Collar: A coupling device used to join two lengths of pipe.

Collector: The means of transferring electrical signals from the rotating coiled tubing reel to a stationary plug and so onwards to remote surface instrumentation.

Compressive Strength: the degree of resistance of a material to force acting along one of the axes in a manner tending to crush it, usually expressed in pounds of force per square inch of surface affected. Also, the amount of pressure required to overcome the tensile strength of cement.

Concentric Operations: Well operations conducted using small diameter coiled tubing inside of conventional tubing or tubingless completion's. This is normally performed with the Christmas tree in place using a small rig or hoisting unit.

Conductor Pipe: A short string of large diameter pipe. Its principal function is to keep the top of the wellbore open and to provide a means of conveying the upflowing drilling fluid from the wellbore to surface.

Control Panel: An enclosure displaying an array of switches, push buttons, lights, valves, various pressure gauges, and/or meters to control or monitor coiled tubing operating functions.

Core Diameter: The diameter of the core of the work reel onto which the coiled tubing is spooled.

Critical Pressure: As pertaining to Nitrogen: The pressure necessary to condense a gas at the critical temperature.

Critical Temperature: As pertaining to Nitrogen: The temperature at which a gas can be liquefied by the critical pressure; above this temperature, the gas cannot be liquefied at any pressure.

Crosslink: A crosswise connecting part that links parallel chains in a complex chemical molecule (such as a polymer)

CYCLE: The name for the BJ SERVICES CT life monitoring system. All bases have access to it and updates are based upon information written on specific sheets by the job supervisor. For more information contact the Operations Engineering Department.

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