Page 321 - Shale Shakers Drilling Fluid Systems

GLOSSARY 303

High-pH Drilling Fluid A drilling fluid with a pH range above 10.5. A high-alkalinity drilling fluid.
See: pH.
High-Yield Clay A classification given to a group of commercial drilling clay preparations
having a yield of 35 to 50 bbl/ton, an intermediate rating between ben-
tonite and low-yield clays. High-yield drilling clays are usually prepared
by peptizing low-yield calcium montmorillonite clays or, in a few cases,
by blending some bentonite with the peptized low-yield clay. See.- Low-
Yield Clay, Bentonite.

HLB See: Hydrophilic-Lipophilic Balance.

Homogeneous Of uniform or similar nature throughout; or a substance or fluid that has
the same property or composition at all points.
Hookstrips The hooks on the edges of a screen section of a shale shaker that ac-
cept the tension member for screen mounting.

Hookstrip Panel One of the two main screen panel-types, which consists of one to three
layers of screen bordered by metal strips running parallel to the loom.
The metal strips have a "U"-shaped cross-section that allow them to be
secured and stretched by the shaker tensioning drawbars. These screens
are nonpretensioned. See: Rigid Frame Panel.

Hopper A large, funnel-shaped or cone-shaped device for mixing desirable dry
solids or liquids into a drilling fluid stream to uniformly mix these desir-
able components into the slurry. The solids are wetted prior to entry into
the drilling fluid system. The system usually consists of a jet nozzle, an
open top hopper, and downstream venturi. See: Mud Hopper.
Horsepower The rate of doing work or of expending mechanical energy (i.e., horse-
power) is work performed per unit of time.
• 1 hp - 550 ft-lb/sec = .7067 Btu/sec. = 0.7457 kilowatt
• Rated horsepower, converted to kilowatts—horsepower x 0.746
= kilowatts
• Motor nameplate horsepower is the maximum steady load that the
motor can pull without damage.

Horsepower-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

Horseshoe Effect The "U" shape formed by the leading edge of drilling fluid moving down
a shale shaker screen. The drilling fluid usually tends to pass through the
center of a crowned screen faster than it passes through the edges,
thereby creating the "U" shape.

HTHP High Temperature High Pressure.

HTHP Filter Press A device used to measure the fluid loss under HTHP conditions. See.- HTHP
Fluid Loss.
HTHP Fluid Loss The fluid loss measured under HTHP conditions, usually 300°F and 500
psi differential pressure. See: HTHP Filter Press.