Case Study - Composite Solutions
10” carbon steel subsea oil pipeline pipe operating at 800 psi (55 bar) has a total of 212 metal loss feature cluster detected. Majority of these defects are internal metal losses feature and is distributed all along the pipeline. Three dents were also detected in the pipeline at log distance of 702.55m, 705.60m and 723.02m located at the subsea section of the pipe in approximately 28m deep of water. The company required immediate repairs to the pipeline to prevent an unexpected shutdown or catastrophic rupture in the pipeline.
The project was planned to be executed under favorable tide and weather conditions. The section of the pipeline was staged for repairs be manageable sections, where commercial divers grit blasted the surface to remove rust, paint, and other foreign matter in accordance with Sa2.5 or NACE No. 2/ SSPC-SP10 to promote adhesion. The dents were filled with filled with a high-compression-strength, load transferring filler epoxy. The repair was staged into manageable sections for proper installation. A special blend of subsea epoxy was saturated into a dry weave fabric and applied as a primer layer onto the submerged pipe to provide corrosion protection over the bare steel pipe and to promote wet adhesion. The composite sleeve was applied based on code compliant engineering over the section of pipe.
The composite system fully restored the pipeline to its original integrity and restored the pipe’s operating pressure to enable full pipeline operations with no disruption to the continuing service. The solution eliminated the need to immediately replace the defective section of pipe.