دیکشنری تخصصی مهندسی نفت - نسخه آنلاین

n: a method of improved recovery in which alkaline chemicals such as sodium hydroxide are injected during a water flood or combined with polymer flooding. The chemicals react with the natural acid present in certain crude oils to form surfactants within the reservoir. The surfactants enable the water to move additional quantities of oil from the depleted reservoir. Compare chemical flooding, polymer flooding, water flooding.

n: see alkaline (caustic) flooding, micellarpolymer flQoding.

one of several methods involving injecting a chemical into a formation to improve the production of hydrocarbon. May be from an injection well to a production well or injection into a producer with a soak period before recovery.

n: any of many processes in the oil industry that involve the use of a chemical to effect an operation. Some chemical treatments are acidising, crude oil demulsification, conclusion inhibition, paraffin removal, scale removal, drilling fluid control, refinery and plant processes, cleaning and plugging operations, chemical flooding, and water purification.

n: (EOR) 1. the introduction of artificial drive and displacement mechanisms into a reservoir to produce a portion of the oil unrecoverable by primary recovery methods. To restore formation pressure and fluid flow to a substantial portion of a reservoir, fluid or heat is introduced through injection wells located in rock that has fluid communication with production wells. See alkaline (caustic) flooding, gas injection, micellar-polymer flooding, primary recovery, secondary recovery, tertiary recovery, thermal recovery, waterflooding. 2. the use of certain recovery methods that not only restore formation pressure but also improve oil displacement or fluid flow in the reservoir. These methods may include chemical flooding, gas injection, and thermal recovery.

one or more of a variety of processes that seek to improve recovery of hydrocarbon from a reservoir after the primary production phase.

n: a stable. translucent micellar emulsion of oil. one or more surface active agents. water. and sometimes an electrolyte. A microemulsion is classed as an emulsion because it is a mixture of immiscible substances (oil and water) and because it can have oil-in-water and waterin- oil phases. It can also have a phase in which neither oil nor water is dispersed. however, but are alternated in layers. A microemulsion has certain properties that are like a solution rather than an emulsion: it is optically clear rather than clouded. and it is stable, i.e.. the oil and water do not separate. Microemulsions are used for chemical flooding of reservoirs. See chemical flooding, emulsion. solution.

an emulsion with very tiny, highly dispersed bubbles. May be very stable and highly viscous when the internal phase is high (>75%).

n: a method of enhanced recovery in which various hydrocarbon solvents or gases (such as propane, LPG, natural gas, carbon dioxide, or a mixture thereof) are injected into the reservoir to reduce interfacial forces between oil and water in the pore channels and thus displace oil from the reservoir rock. See chemical flooding. gas injection. micellar-polymer flooding.

n: a type of miscible drive in which a polyrner is injected into an injection well to allow oil and water to rnix and flow to a producing well. See miscible drive. Corn pare alkaline (caustic) flooding, chemical flooding, waterflooding.

n: a carbohydrate composed of many monosaccharides. Polysac- charides are used to adjust the viscosity of water slugs in chemical flooding operations.

n: 1. an injection of water prior to chemical flooding that is used to induce reservoir conditions favorable to the surfactant solution by adjusting reservoir salinity and reducing ion concentrations. A preflush may also be used to obtain advance information on reservoir flow patterns. 2. fluid injected prior to the acid solution pumped into a well in an acid-stimulation treatment;sometimes called a spearhead. Compare overflush.

n: a soluble compound that concentrates on the surface boundary between two substances such as oil and water and reduces the surface tension between the substances. The use of surfactants permits the thorough surface contact or mixing of substances that ordinarily remain separate. Surfactants are used in the petroleum industry as additives to drilling mud and to water during chemical flooding. See micellar- polymer flooding, surfactant mud.

n: A chemical that acts as a surface active agent. This term encompasses a multitude of materials that function as emulsifiers, dispersants, oil-wetters, water-wetters, foamers and defoamers. The type of surfactant behavior, whether acting as an emulsifier o

a chemical that is attracted to the surface of a fluid and modifies the properties such as surface tension.