Offshore Routing of Large Diameter Pipelines through High Relief Outcrops

摘要

The pipelaying operation for the Gulf of Mexico's first floating production, storage and offloading system (FPSO) at the KuMaZa development in Mexican waters was a challenging one due to the extreme roughness of the seabed at the field and the combination of large diameter pipelines and routing requirements. This project was faced with the challenge of ensuring that the pipelines, laid in curves on highly uneven ground, retained their integrity despite the high environmental loading. Working in close coordination with Global Industries' engineering department, DeepSea's approach was to identify an optimized routing of the pipelines and provide a satisfactory rock berm support layout over the rough terrain, while minimizing the quantity of rock used in the berms and maintaining the extremely tight schedule, given the huge quantities of rock placed on the seabed. This paper discusses the 'live engineering' approach: using a combination of industry-standard tools and proprietary techniques to not only ensure acceptable rock berm configuration for pipe laying but also to optimize the quantities. It outlines the considerations that led to the modification of the installation design, and the factors that contributed to an extended engineering process leading to the ability to hydrotest the lines prior to completion of the final rock dumping for pipeline support and stability.