Page 331 - Shale Shakers Drilling Fluid Systems

GLOSSARY 313

Mud Weight A measurement of slurry density usually reported in Ib/gal, Ib/cu ft, psi/
1000 ft., or specific gravity. See: Density.
Mud/Gas Separator A vessel into which the choke line discharges when a "kick" is being
taken. Gas is separated in the vessel as the drilling fluid flows over baffle
plates. The gas flows through a line to a flare. The liquid mud discharges
into the shale shaker back tank. See.- Gas Buster, Poor Boy Degasser.

Mudding Off A condition promoting reduced production caused by the penetrating,
sealing, or plastering effect of a drilling fluid. See.- Formation Damage.

Mudding Up Process of mixing drilling fluid additives to a clay/water slurry to achieve
some properties not possible with the previous fluid.

MW Abbreviation for mud weight. See: Density, Mud Weight.

Natural Clays Natural clays, as opposed to commercial clays, are encountered when
drilling various formations. The yield of these clays varies greatly, and
they may or may not be purposely incorporated into the drilling fluid sys-
tem. See.- Attapulgite Clay, Bentonite, High-Yield Clay, Low-Yield Clay, Clay.

Near-Size Particles Solids approximately the same size as a screen opening.

Near-Size Plugging A term used in describing screen plugging and refers to particles with a
dimension only slightly larger than the screen opening. See: Blinding,
Plugging.

Neat Cement A slurry composed only of Portland cement and water.

Negative Deck Angle The angle of adjustment to a screen deck that causes the screened sol-
ids to travel "downhill" to reach the discharge end of the screen surface.
This "downhill" travel decreases the fluid throughput of a screen but usu-
ally lengthens the life of a screen. See: Positive Deck Angle.

Neutralization A reaction in which the hydrogen ion of an acid and the hydroxyl ion of
a base unite to form water, the other ionic product being a salt.

Newtonian Flow See: Newtonian Fluid.

Newtonian Fluid The most basic fluids from the standpoint of viscosity in which the shear
force is directly proportional to the shear rate. These fluids will immedi-
ately begin to move when a pressure or shear stress in excess of zero is
applied. Examples of Newtonian fluids are water, diesel oil, and glycer-
ine. The yield point as determined by a direct indicating viscometer is
zero. See.- Newtonian Flow.

Non-Conductive Drilling Any drilling fluid, usually oil based or invert emulsion drilling fluid, whose
Fluid continuous phase does not conduct electricity. The spontaneous poten-
tial (SP) and normal resistivity cannot be logged, although other logs such
as the gamma rays, induction, acoustic velocity, and so forth, can be run.

Non-Dispersed A condition in which the clays do not separate into individual platelets.
Dispersion is inhibited.

Normal Solution A solution of such a concentration that it contains 1 gram equivalent of
a substance per liter of solution.