BAKER HUGHES - Drilling Fluids Reference Manual

GLOSSARY OF TERMS
Barite Plug - A plug made from barite weighting materials that is placed at the bottom of a wellbore.
Unlike a cement plug, the settled solids do not set solid, yet a barite plug can provide effective and
low-cost pressure isolation. A barite plug is relatively easy to remove and is often used as a
temporary facility for pressure isolation or as a platform enabling the accurate placement of
treatments above the plug.
Barite Sag - Terminology used to describe the settling of barite under minimal dynamic conditions
so as to increase the density of the fluid column on the bottom while the density of fluid at the top of
the column decreases. The term does not refer to nor does it reflect the hard settling of barite in the
form of a solid plug.
Barium Sulfate - BaSO 4 . See Barite.
Barrel - A volumetric unit of measure used in the petroleum industry consisting of 42 gal (U.S.).
Barrel Equivalent - A laboratory unit used for evaluating or testing drilling fluids. One gram of
material, when added to 350 ml of fluid is equivalent to 1 lb of material when added to one 42-gal
barrel of fluid.
Base - A compound of a metal, or a metal-like group, with hydrogen and oxygen in the proportion to
form an OH radical, which ionizes in aqueous solution to yield excess hydroxyl ions. Bases are
formed when metallic oxides react with water. Bases increase the pH. Examples are caustic soda and
lime.
Base Exchange - The replacement of cations associated with the clay surface by those of another
species, e.g. the conversion of sodium clay to calcium clay.
Basicity - base pH value above 7.
Beneficiation - Chemical treatment or mechanical processes that improve a mineral or ore for its
designed use. For example, barite and bentonite are beneficiated in order to help them meet certain
specifications for use in drilling fluids.
Bentonite - A plastic, colloidal clay, largely made up of the mineral sodium montmorillonite, a
hydrated aluminum silicate. For use in drilling fluids, bentonite has a yield in excess of 85 bbl/ton of
20 cps viscosity. The generic term "bentonite" is neither an exact mineralogical name, nor is the clay
of definite mineralogical composition.
Bioassay - A laboratory test or other assessment utilizing a living organism, such as mysid shrimp, to
determine the effect of a condition to which the organism is exposed. Such tests are performed under
BAKER HUGHES DRILLING FLUIDS
REFERENCE MANUAL
REVISION 2006 15-6