Oil & Gas Glossary 1.0

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 chemical substance that minimizes or prevents corrosion in metal equipment.

An organization whose function is to establish standards and recommended practices for the field of corrosion control.

Abbreviation: National Association of Corrosion Engineers.

2. the electrically conductive solution that must be present for a corrosion cell to exist.

The deterioration of metal caused by contact with carbon dioxide in water.

Any of a variety of complex chemical or electrochemical processes, e.g., rust, by which metal is destroyed through reaction with its environment.

Small metal strip which is exposed to corrosive systems for the purpose of determining nature and severity of corrosion.

2. a removable lining or sleeve inserted or screwed into an opening to limit its size, resist wear or corrosion, or serve as a guide.

Embrittlement and subsequent wearing away of metal caused by contact of the metal with hydrogen sulfide.

Sucker rods that have been broken and separated in a pumping well because of corrosion, improper loading, damaged rods, and so forth.

A record showing variations in wellbore diameter by depth, indicating undue enlargement due to caving in, washing, or other causes. The caliper log also reveals corrosion, scaling, or pitting inside tubular goods.

Containing or caused by hydrogen sulfide or another acid gas (e.g., sour crude, sour gas, sour corrosion).

A compound in which chromium has a valence of 6. Chromate may be added to drilling fluids either directly or as a constituent of chrome lignites or chrome lignosulfonates. In certain areas, chromate is widely used as a corrosion inhibitor, often in conjunction with lime.

A flange equipped with plastic pieces to separate its metal parts, thus preventing the flow of electric current. Insulating flanges are often used in cathodic protection systems to prevent electrolytic corrosion and are sometimes installed when a flow line is being attached to a wellhead.