Page 298 - Shale Shakers Drilling Fluid Systems

280 SHALE SHAKERS AND DRILLING FLUID SYSTEMS

solid particle that cannot be removed by draining or centrifugal force. See:
Absorption, Adsorption, Adsorb, Adsorbed Liquid, Bound Liquid.

Adsorbed Liquid The liquid film adhering to the surfaces of solid particles, which cannot
be moved by draining, even with centrifugal force. See.- Absorb, Absorp-
tion, Adsorption, Adsorb, Bound Liquid.

Adsorption A surface phenomenon exhibited by a solid (adsorbent) to hold or con-
centrate gases, liquids, or dissolved substances (adsorptive) upon its sur-
face, a property due to adhesion. For example, water, held to the out-
side surface of hydrated bentonite, is adsorbed water. Adsorption refers
to liquid that is on the outside of some material, and absorbed refers to
the liquid that becomes part of the material. See.- Absorb, Absorption,
Adsorb, Adsorbed Liquid, Bound Liquid.

Aeration (1) The technique of injecting air or gas in varying amounts into a drill-
ing fluid for the purpose of reducing hydrostatic head. (2) The inadvert-
ent mechanical incorporation and dispersion of air or gas into a drilling
fluid. If not selectively controlled, it can be very harmful. See: Air Cut-
ting, Gas Cut.

Agglomerate The larger groups of individual particles usually originating in sieving or
drying operations.

Agglomeration A group of two or more individual particles held together by strong forces.
Agglomerates are stable to normal stirring, shaking, or handling as pow-
der or a suspension. They may be broken by drastic treatment such as
the ball milling of a powder or the shearing of a suspension.

Aggregate To gather or "clump" together. A flocculated drilling fluid will aggregate
if more flocculant is added.

Aggregation (1) Formation of aggregates. (2) In drilling fluids, aggregation results in
the stacking of the clay platelets face-to-face. As a consequence, the
viscosity and gel strength of the fluid decreases.

Agitation The process of rapidly moving a slurry within a tank to obtain and main-
tain a uniform mixture.

Agitator A mechanically driven mixer that stirs the drilling fluid by turning an
impeller in the bottom of a drilling fluid compartment to assist in blend-
ing liquids, suspending solids, and maintaining an even consistency in the
drilling fluid. See: Mechanical Agitator, Mechanical Stirrer, Mud Gun.

Air Cutting The inadvertent mechanical incorporation and dispersion of air into a
drilling fluid system. See: Aeration, Gas Cut.

Air Lock A condition causing a centrifugal pump to stop pumping because of a
large bubble of air or gas in the center of the pump impeller. This pre-
vents the liquid from entering the pump suction. See: Air Locking.

Air Locking See: Air Lock.

Alkali Any compound having pH properties higher than the neutral state. See.- Base.

Alkalinity The combining power of a base measured by the maximum number of
equivalents of an acid with which it can react to form a salt. In water