• About Total
• Our Energies
• Our Challenges
• Search

You are here:Home Glossary - Letter C

• Text size
  • -A
  • +A

Glossary

This glossary more specifically relates to oil and gas exploration and production terms.

• A
• B
• C
• D
• E
• F
• G
• H
• I
• J
• K
• L
• M
• N
• O
• P
• Q
• R
• S
• T
• U
• V
• W
• X
• Y
• Z

Carbon:

Very common element (C) present in all living beings.

Casing:

Set of steel tubular elements used to line the inner wall of a drill hole, to consolidate it. The casing is secured by cementing the annular space between the hole wall and the casing. Each time a tubing is installed, the well diameter is reduced, so that the tubing in a well forms a telescopic assembly. The tubes have a standard length of nine meters, and are assembled by threaded sleeves.

Catalysts:

Chemical compounds that facilitate or promote a reaction by their presence or action.

Catalytic cracking:

This conversion operation takes place at very high temperatures (500° Celsius) in the presence of a catalyst. It serves to break up large hydrocarbon molecules into smaller ones.

Cell:

Fundamental unit of living beings, generally consisting of a membrane which surrounds the cytoplasm containing the nucleus.

Cementing:

Injection of cement into the annulus (space) between the casing and the well wall to consolidate the latter and reduced water influxes.

Centrifugal:

Tending to move away from the center. The opposite is "centripetal", meaning "center-seeking".

Christmas tree:

Oil industry term for "wellhead".

Coalbed methane:

natural gas trapped in coal seams.

Completion (well):

All operations (tubing, installation of valves, wellhead, etc.) to bring a production well into operation.

Concession (oil or gas):

Deed entitling holder to produce from and/or explore a stipulated tract of land following discovery of a commercial reservoir.

Conversion:

this stage in the refining process consists in "breaking up" the large molecules into smaller ones in order to produce lighter compounds. Processes involved include catalytic cracking and viscosity reduction (visbreaking).

Core:

See core-sampling.

Core-sampling (or coring):

During drilling, cylindrical samples of rock known as "core samples" are removed in order to study the characteristics of the terrain.

Crude oil:

Unrefined oil.

Crust (earth's):

Surface layer of the earth (down to a depth of N meters)