Page 339 - Shale Shakers Drilling Fluid Systems

GLOSSARY 321

Round Trip See. Trip.

RPM Revolutions per minute.

Salt A class of similar compounds formed when the acid hydrogen of an acid
is partially or wholly replaced by a metal or a metallic radical. Salts are
formed by the action of acids on metals, or oxides and hydroxides, di-
rectly with ammonia, as well as by other methods. See: Sodium Chloride.

Saltwater Drilling Fluid A water-based drilling fluid fluid whose external liquid phase contains
sodium chloride or calcium chloride.

Saltwater Mud See: Saltwater Drilling Fluid.

Samples Cuttings obtained for geological information from the drilling fluid as it
emerges from the hole. They are washed, dried, and their depth is recorded.

Sand (1) Particle-size classification for solids larger than 74 microns. (2) A
loose, granular material resulting from the disintegration of rocks with a
high silica content. See.- API Bulletin RP 13B, API Sand.

Sand Content The solids particles retained on a U.S. Standard No. 200 test screen,
expressed as the bulk percent by volume of the drilling fluid slurry sample.
The opening in the test screen is 74 microns. The retained solids may
be of any mineral or chemical composition and characteristic. For ex-
ample, barite, shale, mica, silica, steel, or chert, larger than 74 microns
are called API sand. See: API Sand.

Sand Trap The first compartment and the only unstirred compartment in a well-
designed drilling fluid system intended as a settling compartment.

Scalping Shakers The first set of shale shakers after the flow line in a cascade shaker ar-
rangement. These are usually circular or elliptical motion shakers with
coarse mesh screens that are used to remove the bulk of large-diameter
drilled solids or gumbo. This initial fluid preparation allow the second set
of fine screen shale shakers in the series to operate more efficiently with
less possibility of flooding. See: Fine Screen Shale Shakers, Flooding,
Blinding.

Screen See: Screen Cloth.

Screen Cloth A type of screening surface, woven in square, rectangular, or slotted
openings. See: Wire Cloth.

Screen Support Rubbers Elastomers that cushion the contact between screens and shale shaker
frames.

Screen Underflow The discharge stream from a screening device that contains a greater per-
centage of liquids than does the feed. See.- Liquid Discharge.

Screening A mechanical process resulting in a division of particles on the basis of
size by their acceptance or rejection by a screening surface.

Screening Surface The medium containing the openings for passage of undersize material.

Scroll See: Flute.