دیکشنری تخصصی مهندسی نفت - نسخه آنلاین

n: the measures used to prevent or reduce the effects of corrosion. These practices can range from simply painting metal, to isolating it from moisture and chemicals and insulating it from galvanic currents, to cathodic protection, in which a galvanic or impressed direct electric current renders a pipeline cathodic, thus causing it to be a negative element in the circuit. The use of chemical inhibitors and closed systems are other examples of corrosion control.

n: The process of dissolving matrix metal of diamond bit by acid soluble method and galvanic corrosion and reclaiming the diamond that can be used again.

corrosion between two dissimilar metals - couplings, centralizers, pumps, packers, profiles – usually severe metal loss on one metal near contact point. May see galvanic loss on a single metal with current.

n: the production of current flow when two dissimilar metals are placed in an electrolyte.

n: in cathodic protection, a sacrificial anode that produces current flow through galvanic action. See sacrificial anode.

sacrificial anode.

n: electrolytic cell created by the difference in electrical potential between two dissimilar metals.

n: a type of corrosion that occurs when a small electric current flows from one piece of metal equipment to another. It is particularly prevalent when two dissimilar metals are present in an environment in which electricity can flow (as two dissimilar joints of tubing in an oil or gas well).

a ranking of metals from the easiest corrodible (magnesium) to the most difficult.

n: thin. dense oxide scale that forms on the surface of newly manufactured steel as it cools. Mill scale can become cathodic to its own steel base. forming galvanic corrosion cells.

an iron oxide on the pipe walls that is formed during pipe manufacture.

n: in cathodic protection. anodes made from metals whose galvanic potentials render them anodic to steel in an electrolyte. They are used up. or sacrificed.

a metal slug, lower in the electromotive series than steel that is hard wired to the casing and buried in a bed of wet soil or below the surface of the water. The corrosion cell in the well then transfers the current to the new anode and the steel in the