Intecna - Pipelines Precommissioning Operations Services

SPECIAL FOCUS ON PIPELINES PRECOMMISSIONING OPERATIONS

ELETROCOAGULATION PROCESS CRITICAL PARAMETERS

In relation to a hydro test operation, two main factors catalyse corrosion on steel surface and create eventual pipeline damage.

• Bacteria Present in the water
• Dissolved Oxygen

Hydrostatic test waters may provide a number of additives, depending upon the nature of the source water, the time of year of testing and other case specific factors. Additives used in pipeline hydraulic test may include biocides, corrosion inhibitors, oxygen scavengers and leak detection tracers.

Biocides may be added to hydrostatic test waters to kill microorganisms. This may be required to prevent corrosion of the pipeline by sulphate reducing bacteria during testing Corrosion inhibitors are not often added to hydrostatic test waters to prevent corrosion during testing, because the test water is only in the pipeline for a short period and the opportunity for corrosion is limited. Use of such additives is suggestible only for long residence time Oxygen scavengers may be used to prevent pipeline corrosion.

Pipeline dewatering and Pipeline drying after the successful hydro-test, given that water a lead to corrosion or hydrates, this task is critical and must be performed efficiently. The purpose of dewatering is to remove the initial fill/pre-commissioning fluid to prepare for introducing product to the pipeline system or to make the pipeline system ready for drying, The purpose of drying is the removal of any water left in the pipeline after the dewatering operation in order to:

• prevent corrosion
• avoid hydrate formation
• prevent transport product contamination.