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The in situ coating process has proven in many parts of the world to be a viable alternative for rehabilitating corroded pipe interiors with a wide range of diameters and lenths. Compared to replacement with new pipeline, this one-run field process is cost-effective. The coating effectively controls internal pipeline corrosion through the application of multiple coats of a high-build liquid epoxy that coves the entire internal surface of the pipeline including girth welds, corrosion pits, channels, corrosion lakes or general corrosion and other internal pipeline imperfections, thus delaying leaks and extending the remaining pipeline service life.
Surface, buried, and subea pipelines have been coated in various geographies ranging from the North Sea, North America, Continental Europe, and Africa to Hong Kong and Indonesia. This article details the in situ coating process and then reports on an assessment of the process in rehabilitating piplines suffering from internal corrosion at an oil desert field complex in Saudi Arabia. A trial was required to quality the technology within a Saudi Arabia pipelines network system.
History of the In Situ Coating Process
The in situ coating process was developed to apply an epoxy barrier coating to the internal surfaces of piplines to prevent future corrosion and extend pipline useful life. The process has been successfully undertaken for more than 30 years in many parts of the world. More than 150 new and existing piplines have been coated successfully, with diameters ranging from 15 to 75 cm (6 to 30 inches) and in lengths up to 25 km (16 miles). The coating process is designed to provide full internal coverage, including the coating of girth welds, bends, pits, general corrosion and erosion, and other surface discontinuities.
While the bulk of the applications have been in the oil and gas industry, coatings have been applied to other pipelines including water, chemical, food, and fuel logistics. Exposure environments for all applications have varied widely. The coated pipelines have a long history of post-coating service, with certain lines coated as far back as 1978 that are still in service. To the author's knowledge, no pipelines have been withdrawn from service due to a compromise of the coating applied using this process, except for demolished or mothballed pipe.
Outside of extending pipeline life (negating...