Page 325 - Shale Shakers Drilling Fluid Systems

GLOSSARY 307

Kilowatt-Hour Horsepower-Hour (hp-hr) and Kilowatt-Hour (kw-hr) are units of work.
• 1 hp-hour = 1,980,000 ft-lb = 2545 Btu
• 1 hp-hour = 0.7457 kilowatt hours (kw-hr)
• 1 kw-hour = 1.341 hp-hr = 3413 Btu = 2,655,000 ft-lb

Kinematic Viscosity The ratio of the viscosity (e.g., cp in g/cm-sec) to the density (e.g., g/
cc) using consistent units. In several common commercial viscometers
the kinematic viscosity is measured in terms of the time of efflux (in sec-
onds) of a fixed volume of liquid through a standard capillary tube or
orifice. See.- Marsh Funnel Viscosity.

Laminar Flow The movement of fluid in plates or sections with a differential velocity
across the front of the flow profile that varies from zero at the wall to a
maximum toward the center for flow. These fluid elements flow along
fixed streamlines, which are parallel to the walls of the flow channel.
Laminar flow is the first stage in a Newtonian fluid and the second stage
in a Bingham plastic fluid. This type of motion is also called parallel,
streamline, or viscous flow. See: Plug Flow, Parallel Flow, Turbulent Flow.

LCM See: Lost Circulation Materials.

Lead In a decanting centrifuge, the slurry conducting channel formed by the
adjacent walls of the flutes or blades of the screw conveyor.

Leonardite A naturally occurring oxidized lignite. See: Humic Acid, Lignin.

Light Solids See: Low-Gravity Solids.

Lignin Mined lignin is a naturally occurring special lignite (e.g., leonardite) pro-
duced by strip mining from special lignite deposits. The active ingredi-
ents are the humic acids. Mined lignins are used primarily as thinners, which
may or may not be chemically modified. See: Leonardite, Humic Acid.

Lignosulfonates Organic drilling fluid additives derived from by-products of the sulfite
paper manufacturing process from coniferous woods. Some of the com-
mon salts, such as ferro-chrome, chrome, calcium, and sodium, are used
as deflocculants, while other lignosulfonates are used selectively for cal-
cium treated systems. In large quantities, the "heavy metal" ferro-chrome
and chrome salts are used for fluid loss control and shale inhibition.

Lime Ca(OH) 2. Commercial form of calcium hydroxide.

Lime Treated Drilling Fluids Commonly referred to as "lime-based" muds. These high pH systems con-
tain most of the conventional freshwater drilling fluid additives to which
slaked lime has been added to impart special inhibition properties. The
alkalinities and lime contents of the fluids may vary from low to high.
See: Calcium Treated Drilling Fluids.

Limestone Ca(CO) 3. See: Calcium Carbonate.

Line Sizing Ensuring that the fluid velocity through all piping within the surface sys-
tem has the proper flow and pipe diameter combination to prevent sol-
ids from settling and pipe from eroding. Generally, fluid flow should be
between 5 and 9 ft/sec as determined by the following: