Controlling top of the line corrosion in hydrocarbon pipelines

A process for applying corrosion inhibitor inside a hydrocarbon pipeline carrying a hydrocarbon mixture where a corrosion inhibitor is delivered to the gas space in the line for the length of the pipeline, the process comprising:

• a) adding a foaming agent, a corrosion inhibitor and a foaming gas to the hydrocarbon pipeline,
• wherein the foaming agent and corrosion inhibitor are chemically compatible with the hydrocarbon mixture to form a foam with a concentration of corrosion inhibitor carried in the foam to contact the top of the line within the pipeline and that maintains a volume of corrosion inhibitor carrying foam sufficient to continuously apply the foam to the top of the line along the full extent of the pipeline,
• wherein the foaming agent is selected from the group consisting of:
• alkylpolyglycoside, sodium olefin sulfonate, and sodium olefin sulfonate, and
• wherein the corrosion inhibitor is selected from the group consisting of:
• octylamine caprylate, a fatty acid imidazoline/amide, and decylamine caprylate;
• and
• b) adding a foam breaking agent to the pipeline at the end of the line to break the foam and render the foam substantially non-foaming to prevent foaming during subsequent processing thereof.