BAKER HUGHES - Drilling Fluids Reference Manual

GLOSSARY OF TERMS
Emulsifier or Emulsifying Agent - A chemical additive used to lower the surface tension between
two immiscible liquids which do not mix. Emulsifiers may be divided, according to their behavior,
into ionic and non-ionic agents. The ionic types may be further divided into anionic, cationic, and
amphoteric, depending upon the ionic nature of the active groups.
Emulsion - An intimate mixture of two immiscible liquids one dispersed in the other in small
droplets or particles. Emulsions may be mechanical, chemical, or a combination of the two. They
may be oil-in-water or water-in-oil types.
Emulsoid - Colloidal particles which take up water.
End Point - Indicates the end of some operation or when a definite change is observed. In titration,
this change is frequently a change in color of an indicator which has been added to the solution or the
disappearance of a colored reactant.
Engineer, Fluid - One versed in drilling fluids whose duties are to manage and maintain the various
types of oil-well fluid programs.
EP Additive - See Extreme-Pressure Lubricant.
Epm or Equivalents Per Million - Unit chemical weight of solute per million unit weights of
solution.
Equivalent Circulating Density - For a circulating fluid, the equivalent circulating density in
lbs/gal equals the hydrostatic head (psi) plus the total annular pressure drop (psi) divided by the depth
(ft) multiplied by 0.052.
Equivalent Weight or Combining Weight – The atomic or formula weight of an element,
compound, or ion divided by its valence. Elements entering into combination always do so in
quantities proportional to their equivalent weights.
Extreme-Pressure Lubricant - Additives which, when added to the drilling fluid, impart
lubrication to the bearing surfaces when subjected to extreme pressure conditions, noted as a
reduction in friction, torque, and drag.
Fault - Geological term denoting a formation break, upward or downward, in the subsurface strata.
Faults can significantly affect the selection of fluids and casing program design.
Fermentation - The decomposition process of natural occurring organic molecular structures, e.g.,
starch in which a chemical change is brought about by enzymes, bacteria, or other micro-organisms.
Often referred to as "souring".
BAKER HUGHES DRILLING FLUIDS
REFERENCE MANUAL
REVISION 2006 15-16