This paper considers some of the challenges and learnings associated with the application of chemicals for preservation of coated pipe/flowline for a major liquefied-natural-gas (LNG) project in Australia. This includes a comparison of the effectiveness of biocide and oxygen-scavenger chemistries for treating seawater. The complete paper also discusses monitoring philosophies and the unique approach taken in designing and optimizing the chemical-injection system to address the environmental and technical challenges of this project.
Introduction
Hydrostatic testing (gauge testing) is undertaken before commissioning new pipelines as a requirement to confirm the global integrity of an installed pipeline system that will carry fluids (gases or liquids) under pressure. Pressurization can be performed with gases such as air, nitrogen, and natural gas, or petroleum products or water.
