Oil & Gas Glossary 1.0

See oil-emulsion water.

The water contained in an emulsion of oil and water. Also called milk emulsion.

A mixture in which one liquid, termed the dispersed phase, is uniformly distributed (usually as minute globules) in another liquid, called the continuous phase or dispersion medium. In an oil-water emulsion, the oil is the dispersed phase and the water the dispersion medium; in a water-oil emulsion, the reverse holds. A typical product of oilwells, water-oil emulsion is also used as a drilling fluid.

Any conventional or special water-base mud to which oil has been added. The oil becomes the dispersed phase and may be emulsified into the mud either mechanically or chemically. Also called oil-emulsion mud.

When the opposite occurs of what is intended in a drilling fluid. In an invert water-in-oil emulsion, the emulsion is said to be flipped when the continuous and dispersed phases reverse.

The process by which a single quantity of crude oil emulsion is broken into oil and water. The emulsion is gathered and stored in a tank or container prior to treating.

A water-base mud in which water is the continuous phase and oil is the dispersed phase. The oil is spread out, or dispersed, in the water in small droplets, which are tightly emulsified so that they do not settle out. Because of its lubricating abilities, an oil-emulsion mud increases the drilling rate and ensures better hole conditions than other muds. Compare oil mud.

Process of separating, or breaking down, an emulsion into oil and water in a vessel or tank on a continuous basis (i.e., no interruption of flow of emulsion into the tank or vessel). Compare batch treating.

See invert-emulsion mud, water loss, fluid loss.

A material that causes water and oil to form an emulsion. Water normally occurs separately from oil; if, however, an emulsifying agent is present, the water becomes dispersed in the oil as tiny droplets. Or, rarely, the oil may be dispersed in the water. In either case, the emulsion must be treated to separate the water and the oil.

Oil that has risen to the surface of the mud but which was previously combined with the mud as emulsion.

2. the combining of globules in an emulsion caused by molecular attraction of the surfaces.

Any drilling fluid, usually oil-base or invert-emulsion muds, the continuous phase of which does not conduct electricity, e.g., oil.

A two-phase system, similar to an emulsion, in which the dispersed phase is a gas or air.

Container or vessel enclosing an arrangement of tubes and a firebox in which an emulsion is heated before further treating, or in which natural gas is heated in the field to prevent the formation of hydrates.

A round cluster of hydrocarbon chains formed when the amount of surfactant in an aqueous solution reaches a critical point. The micelles are able to surround and dissolve droplets of water or oil, forming an emulsion.

A drilling mud, e.g., oil-base mud and invertemulsion mud, in which oil is the continuous phase. It is useful in drilling certain formation that may e difficult or costly to drill with water-base mud. Compare oil emulsion mud.

A vertical or horizontal vessel into which oil or emulsion is run to allow any water not emulsified with the oil (free water) to drop out.

The settling or rising of the particles of the dispersed phase of an emulsion. Identifiable by a difference in color shading of the layers formed. Creaming can be either upward or downward, depending on the relative densities of the continuous and dispersed phases.

A vessel that heats an emulsion and removes water and gas from the oil to raise it to a quality acceptable for a pipeline or other means of transport. A heater-treater is a combination of a heater, free-water knockout, and oil and gas separator.

To remove water from a substance. Dehydration of crude oil is normally accomplished by treating with emulsion breakers. The water vapor in natural gas must be removed to meet pipeline requirements; a typical maximum allowable water vapor content is 7 pounds per million cubic feet per day.

The liquid in which solids are suspended or droplets of another liquid are dispersed; sometimes called the external phase. In a water-in-oil emulsion, oil is the continuous phase.

An expressions of the relative attraction of an emulsifier for water and oil, determined largely by the chemical composition and ionization characteristics of a given emulsifier. The HLB of an emulsifier is not directly related to solubilit5y, but it determines the type of emulsion that tends to be formed. It is an indication of the behavioral characteristics and not an indication of emulsifier efficiency.