Pipeline Walking Mitigation
Pipeline Walking of High Temperature, High Pressure (HTHP) pipelines is a unique challenge for the oil and gas industry caused by cyclic expansion. This results in progressive movement of pipelines away from or toward their fixed end terminations. Pipe Clamping Mattresses efficiently and reliably restrain pipelines, preventing walking and reducing feed-in stresses to expansion spools.
Pipeline Walking has traditionally been restrained by either applying anchor piles clamped to the pipeline, conventional concrete mattresses or rock dumping. The adverse disadvantage of rock-dumping and concrete mattresses is that over 60% of the mass is wasted, acting only on the seabed. Furthermore, rock berms and mattresses are susceptible to the igloo effect driven by tunnel scour and progressive break out of the pipeline. This wasted mass unnecessarily drives up delivery and installation costs. Piles typically have to be applied at the pipeline endpoint, increasing the total restraint load required by up to 10 times with a proportional increase to installation and material costs. Clamping interfaces often require coating removal, inline welded clamps and chain tensioners all of which are slow and expensive to install.
Over 60% of the mass of concrete mattresses and rock is wasted on walking mitigation.
In response to these disadvantages, MMA and Shell Global Solutions (Shell) developed a new, more reliable walking mitigation method – the pipe clamping mattress (PCM). The PCM addresses the challenges faced by operators implementing conventional methods with one elegant solution. It increases buckle control and axial friction and secures both flexible and rigid pipes. PCMs can be retrofit using common light construction vessels without removing existing coatings.
For more information on our pipeline walking mitigation services offering, please contact our team at:
+61 8 9431 7431
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