Page 304 - Shale Shakers Drilling Fluid Systems

286 SHALE SHAKERS AND DRILLING FLUID SYSTEMS

yield, increase in fluid loss, and so forth. See: Calcium Sulfate, Gyp, An-
hydrite, Lime, Calcium Carbonate.

Calcium Hydroxide Ca(OH) 2. The active ingredient of slaked lime. It is also the main con-
stituent in cement (when wet) and is referred to as "lime" in field termi-
nology. See: Lime.
Calcium Sulfate Anhydrite (CaS0 4), plaster of Paris (CaS0 4«^H 2O), and gypsum (CaS0 4*2H 2O).
Calcium sulfate occurs in drilling fluids as a contaminant or may be added
as a commercial product to certain drilling fluids to impart special in-
hibitive properties. See.- Gypsum, Anhydrite.

Calcium Treated Drilling Drilling fluids to which quantities of soluble calcium compounds have
Fluids been added or allowed to remain from the formation drilled in order to
impart special inhibitive properties to the drilling fluid.

Calendered Wire Cloth Wire cloth that has been passed through a pair of heavy rollers to re-
duce the thickness of the cloth, or to flatten the intersections of the wire,
and produce a smooth surface. This process is usually done to the coarser
backing clothes. See.- Market Grade Cloth, Mill Grade Cloth.

Capacity The maximum volume flowrate at which a solids control device is de-
signed to operate without detriment to separation. See: Feed Capacity,
Solids Discharge Capacity.

Cascade Gravity-induced flow of fluid from one unit to another.

Cascade Shaker Arrangement A system that processes the drilling fluid through two or more shakers
arranged in series.

Cation The positively charged particle in the solution of an electrolyte that, un-
der the influence of an electrical potential, moves toward the cathode
+
4+
+
+
++
+++
(negative electrode). Examples are Na , H , NH , Ca , Mg , and Al .
Cation Exchange Capacity The total amount of cations adsorbed on the basal surfaces or broken
(CEC) bond edges of a clay sample, expressed in milli-equivalents per 100 grams
of dry clay. See: Base Exchange, Methylene Blue Titration, Methylene Blue
Test, MET, CEC.
Caustic See: Sodium Hydroxide.
Caustic Soda See: Sodium Hydroxide.

Cave-In A severe form of sloughing. See.- Sloughing.

Cavernous Formation A formation having voluminous voids, usually the result of dissolution
by formation waters that may or may not be still present.

Caving A severe form of sloughing. See: Sloughing, Heaving.

Cavitation The formation and collapse of low pressure bubbles in a liquid. Cavita-
tion in centrifugal pumps occurs when the pressure within the impeller
chamber decreases below the vapor pressure of the liquid. As these va-
por bubbles move to the impeller tip and into a higher pressure region,
they implode or collapse. The pressure at the suction entry may be con-
siderably below atmospheric pressure if the pressure loss in the suction
line is too large, the flowrate from the pump is too large for the inlet