Monday, August 31, 2015

Drilling fluids processing glossary E

Eductor. (1) A device utilizing a fluid stream discharging under high pressure from a jet through an annular space to create a vacuum. When properly arranged, it can evacuate degassed drilling fluid from a vacuum-type degasser. (2) A device using a high-velocity jet to create a vacuum that draws in liquid or dry material to be blended with drilling fluid.
Effective screening area. The portion of a screen surface available for solids separation.
Effluent. A discharge of liquid. Generally used to describe a stream of liquid after some attempt at separation or purification has been made. See: discharge.
Elastomer. Any rubber or rubber-like material (such as polyurethane).
Electric logging. Logs run on a wire line to obtain information concerning the porosity, permeability, density, and/or fluid content of the formations drilled. The drilling-fluid characteristics may need to be altered to obtain good logs.
Electrolyte. A substance that dissociates into charged positive and negative ions when in solution or a fused state. This electrolyte will then conduct an electric current. Acids, bases, and salts are common electrolytes.
Elevation head. The pressure created by a given height of fluid. See: hydrostatic pressure head.
Emulsifier. A substance used to produce a mixing of two liquids that do not solubilize in each other or maintain a stable mixture when agitated in the presence of each other. Emulsifiers may be divided into ionic and nonionic agents, according to their behavior. The ionic types may be further divided into anionic, cationic, and, depending on the nature of the ionic groups.
Emulsion. A substantially permanent heterogeneous mixture of two or more liquids that do not normally dissolve in each other but are held in a dispersed state, one within the other. This dispersion is accomplished by the combination of mechanical agitation and presence of fine solids and/or emulsifiers. Emulsions may be mechanical, chemical, or a combination of the two. Emulsions may be either oil-in-water or water-in-oil. See: interfacial tension, surface tension.
Emulsoid. Colloidal particle that takes up water.
Encapsulation. The process of totally enclosing electrical parts or circuits with a polymeric material (usually epoxy).
End point. Indicates the end of a chemical testing operation when a clear and definite change is observed in the test sample. In titration, this change is frequently a change in color of an indicator or marker added to the solution, or the disappearance of a colored reactant.
Enriching. The process of increasing the concentration of a flammable gas or vapor to a point at which the atmosphere has a concentration of that flammable gas or vapor above its upper flammable or explosive limit.
Extreme pressure (EP) additive. See: extreme pressure lubricant.
EPL. Extreme pressure lubricant. See: extreme pressure lubricant. epm.
Equivalents per million. See: equivalents per million, parts per million.
Equalizer. An opening for flow between compartments in a surface fluid holding system.
Equivalent circulating density (ECD). The effective drilling-fluid weight at any point in the annulus of the well bore during fluid circulation. ECD includes drilling-fluid density, cuttings in the annulus, and annular pressure loss. See: annular pressure loss.
Equivalent spherical diameter (ESD). The theoretical dimension usually referred to when the sizes of irregularly shaped particles are discussed.These dimensions can be determined by several methods, such as settling velocity, electrical resistance, and light reflection. See: particle size.
Equivalent weight. The atomic weight or formula weight of an element, compound, or ion divided by its valence. Elements entering into combination always do so in quantities to their equivalent weights. Also known as combining weight.
Equivalents per million (epm). Unit chemical weight of solute per million unit weights of solution. The epm of a solute in solution is equal to the ppm (parts per million) divided by the equivalent weight. See: parts per million.
ESD. Equivalent spherical diameter. See: equivalent spherical diameter,particle size.
Extreme pressure lubricant (EPL). Additives to the drilling fluid that impart lubrication to bearing surfaces when subjected to extreme pressure conditions.