Subsea Pipeline Engineering Challenges in Sand Wave Area: The Lufeng Feed Project

Abstract Lufeng oilfields are located in the Pearl River Mouth Basin, South China Sea, where significant sand wave is located. The water depth of the area is 140 to 330 m. Sand waves are present around LF15-1. A study on the sand waves is required to assess the impact of the sand waves on the pipeline design. Due to its special seabed characteristic, it is challenging for the subsea pipeline engineering. This paper presents the Lufeng sand wave pipeline project on general basis. Collect and review available information including metocean, bathymetric data and soil data and carry out general morphological analysis for the project area including seabed erodibility assessment and analysis of sediment transport potential. Identify morphological features and bed forms in the project area and analyze characteristics of the sand waves. Sand wave migration and mobility are predicted and the pipeline route (least dredging/trenching and least free spans) is optimize considering on-bottom stability, in-place strength, global buckling and installation. Determine burial (dredging/trenching) requirements assuring pipeline stability/integrity. The main challenges faced are summarized, some preliminary results are also presented. Discussions about the solutions are also included, which may shed light to similar projects.