Subcon, a global leader in subsea stabilisation, has announced a new method to mitigate pipeline walking. Developed in cooperation with Shell Global Solutions (Shell), it is an engineered ‘pipe clamping mattress’ (PCM).
The technique was first developed on Shell’s Malampaya Project; as an alternative to traditional rock dumping. The results were so encouraging that a further 15 PCMs were deployed on the same field in Q1 2018.
‘When rock-dumping or concrete matts are deployed for walking mitigation, the vast majority of load is wasted because it is passed straight onto the seabed’ explained Subcon CEO Matthew Allen.
Addressing pipeline-walking with PCM’s rather than rock-dumping also eliminates the need for fall-pipe vessel and competent rock.
Future field developments may consider a ‘wait-and-see’ philosophy for pipeline walking, thereby eliminated suction pile fabrication and installation. As pipeline-walking is an uncommon and slow process, remediation can be achieved using post-installed PCM’s. Overall, a significant project saving.
Shell has a US patent pending for the PCM and has now released the PCM option to the market via a global licensing agreement with Subcon. Shell presented a technical paper on the Malampaya PCM’s at the Houston OTC.