ABSTRACT

Methods of internal corrosion protection used in the oil and gas industry include: internal coatings, dehydration, chemical injection, cleaning pigging, buffering, and internal cathodic protection. Internal corrosion refers to corrosion occurring on the inside of a pipeline. This type of corrosion often results from the presence of molecules such as carbon dioxide, hydrogen sulfide, water, organic acids, microorganisms, and other molecules. Typically, these molecules react with the internal pipe surface through anodic and cathodic reactions. The rate of internal corrosion depends on the concentration of these corrosive molecules, the temperature, the flow velocity, and the surface material. Black powder in gas pipelines is usually corrosion products formed by internal pipeline corrosion but can also be particles from mill scale, weld splatter, formation cuttings, and salts. The principal aim for internally coating pipelines is to reduce pipeline friction and internal corrosion.