Mercury in Pipelines

2007 - MTS completed a two year study of mercury in a gas transmission pipeline. The research project had three major objectives:

• to characterize the nature and extent of the mercury in the pipeline system.  

• to determine if mercury deposited in the pipeline served to compromise the structural integrity of the pipeline or of equipment in onshore processing facilities.

• to construct options to reduce or eliminate the negative impacts of mercury in the system.

The quantity of mercury in the steel pipe, its chemical nature and the chemical mechanism by which it was attached to the steel surface were investigated. These issues were considered fundamental to understanding corrosion and other pipe degradation modalities. Localized corrosion (pitting or weld attack), environmental cracking and galvanic corrosion interactions were examined from the perspective of mercury in pipe fluids, and from the perspective of mercury chemisorbed to the pipe surface. Methods to remove mercury from the pipeline system, without causing any damage to the pipe, were intensively studied. The focus of remediation was to minimize risk of worker exposure as might be possible during maintenance and inspection activities.