BAKER HUGHES - Drilling Fluids Reference Manual

GLOSSARY OF TERMS
the cyclone type separator in which the fluid energy alone provides the separating force. See Cyclone
and Desander.
Chemicals - In drilling-fluid terminology, a commercial additive used to alter drilling fluid physical
or chemical properties.
Chemical Barrel - A container used to make additives soluble prior to being discharged into the
mud system.
Chromate - A compound in which chromium has a valence of 6, e.g., sodium bichromate. Chromate
may be added to drilling fluids either directly or as a constituent of chrome lignites or chrome
lignosulfonates. In certain areas, chromate is widely used as an anodic corrosion inhibitor, often in
conjunction with lime. The plus 6 valence chrome compounds carry environmental restraints.
Chrome Lignite - Mined lignite, usually leonardite, to which chromate has been added and/or
reacted. The lignite can also be causticized with either sodium or potassium hydroxide.
Circulation - The transport of drilling fluid through the circulating system back to the original
starting point which is usually the suction pit. The time of travel from point A back to point A is
referred to as the circulating time.
Circulation, Loss of (or Lost) - The result of whole drilling fluid escaping into the formation by
way of crevices or porous media. It is the loss of whole mud to the formation.
Circulation Rate - The volume flow rate of the circulating drilling fluid usually expressed in gallons
or barrels per minute, i.e. a unit of time to discharge a given volume.
Clabbered - A slang term commonly used to describe moderate to severe flocculation of fluid due to
various contaminants; also called "gelled up".
Clay - A plastic, soft, variously colored earth, commonly a hydrous silicate of alumina, formed by
the decomposition of feldspar and other aluminum silicates. See also Attapulgite, Bentonite, High
Yield, Low Yield, and Natural Clays. Clay minerals are essentially insoluble in water but disperse
under hydration, shearing forces such as grinding, velocity effects, etc., into the extremely small
particles varying from submicron to 100-micron sizes.
Clay Extender - Any of several substances, usually high molecular weight organic compounds that,
when added in low concentrations to a bentonite or to certain other clay slurries, will increase the
viscosity of the system, e.g., polyvinyl acetatemaleic anhydride copolymer. See Low Solids Fluids.
BAKER HUGHES DRILLING FLUIDS
REFERENCE MANUAL
REVISION 2006 15-10