The Arctic oilfields make corrosion mitigation difficult. Piping systems vary, pipe configurations vary, operating temperatures vary, and frigid conditions exist most of the year.
One pipe system’s configuration is simply called “bundled pipe” because that’s exactly what it is – four pipes welded into a bundle, then insulated and jacketed with molded polyisocyanurate insulation and a galvanized jacket. Therein is a system that isn’t moisture-sealed and contains air gaps between all the pipes, which vary in temperature. The system is not waterproof.
The process of remediation begins via portable X-ray shot directly through the jacketing and insulation at varying angles to find corrosion sites. Areas where corrosion is found are marked for remediation by spray painting onto the existing mechanical jacket. The next step is the removal and disposal of the old metal jacket and insulation. A physical inspection of the corrosion damage is then done. The method of surface preparation is made. On this project, the areas were wire brushed or cleaned with pot scrubbers.
A second physical inspection occurs, and areas that have been surface prepped are marked with flagging tape noting that they are ready for further remediation.
Stopping the corrosion that was found and preventing new corrosion in the future was addressed by using Polyguard’s RG 2400, a gel product (nicknamed “Blue Goo”) that is applied by glove to the entire pipe surface. A newly designed insulation kit was used of polyisocyanurate insulation with holes in the bottom to allow water to drain (if any enters the system). The insulation was oversized and installed with spacers on the pipe so that it did not rest on the pipe. This new insulation system was applied and banded in place, and a new galvanized metal jacketing system with weep holes was installed.
A considerable undertaking (spans over 36 miles of this bundled piping system) in the third year of work, completion is scheduled for next summer.