Page 322 - Shale Shakers Drilling Fluid Systems

304 SHALE SHAKERS AND DRILLING FLUID SYSTEMS

Humic Acid Organic acids of indefinite composition found in naturally occurring
leonardite lignite. The humic acids are the active constituents that assist
in the positive adjustment of drilling fluid properties. See.- Lignin.

Hydrate A substance containing water combined in molecular form (such as
CaSO 4»2H 2O). A crystalline substance containing water of crystallization.
Hydration The act of a substance to take up water by means of absorption and/or
adsorption; usually results in swelling, dispersion, and disintegration into
colloidal particles. See: Absorb, Absorption, Adsorb, Adsorbed Liquid.
Hydroclone See.- Cyclone, Hydrocyclone.

Hydrocyclone A liquid-solids separation device that uses centrifugal force for settling.
Fluid enters tangentially and spins inside the cone. The heavier solids
settle to the walls of the cone and move downward until they are discharged
at the cone bottom (cone apex). The spinning fluid travels partway down
the cone and then back up to exit out the top of the cone through the
vortex finder.

Hydrocyclone Balance Point (1) That adjustment of the apex that creates an opening approximately
the same diameter as the air cylinder inside of the hydrocyclone. (2) In
the field, to adjust a balanced design hydrocyclone during the setup of
the solids control system so that it discharges only a slight drip of water
at the underflow opening.

Hydrocyclone Size The maximum inside working diameter of the cone part of a hydrocyclone.

Hydrocyclone Underflow The discharge stream from a hydroclone that contains a higher percent-
age of solids than does the feed. See.- Solids Discharge.

Hydrogen Ion Concentration A measure of either the acidity or alkalinity of a solution, normally ex-
pressed as pH. See.- pH.

Hydrolysis The reaction of a salt with water to form an acid or base. For example,
soda ash (Na 2CO 3) hydrolyzes basically, and hydrolysis is responsible for
the increase in the pH of water when soda ash is added.

Hydrometer A floating instrument for determining the specific gravity or density of
liquids, solutions, and slurries.
Hydrophile Any substance, usually in the colloidal state or an emulsion, which is wet-
ted by water (i.e., it attracts water or water adheres to it). See.- Lipophile.

Hydrophilic A property of a substance having an affinity for water or one that is
wetted by water. See: Lipophilic.

Hydrophilic-Lipophilic The relative attraction of an emulsifier for water and for oil. It is deter-
Balance mined largely by the chemical composition and ionization characteristics
of a given emulsifier. The HLB of an emulsifier is indirectly related to its
solubility, but it determines the type of an emulsion that tends to be
formed. It is an indication of the behavioral characteristics and not an
indication of emulsifier efficiency.

Hydrophobe Any substance, usually in the colloidal state, that is not wetted by water.
Hydrophobic Any substance, usually in the colloidal state or an emulsion, which is not
wetted by water (i.e., it repels water or water does not adheres to it).