Numerical Simulation of Nearshore Submarine Pipeline Scour under Storm Surge Condition

摘要

Submarine pipelines are widely used to deliver oil and gas in offshore petroleum engineering. Local scour can leads to the suspension of pipelines, which can finally results in the pipeline vibration and damage, even oil leaking and marine pollution. Previous research mainly focus on the scour under constant sea conditions, while under variable sea conditions such as storm surges are less studied. Typhoon storm features fast-moving, short duration and intensive wave actions, which can lead to violent seabed sediment movements usually. Based on the characteristics of waves during typhoon storms passing South China Sea, the idealized and simplified cases were generalized with typical wave parameters, including wave height, wave period, and their changeable rules during storm surge passage. A Navier-Stokes solver FLOW-3D was used to establish 2-D numerical simulations under wave conditions mentioned above, following a procedure of wave height increasing, staying stable, and getting lower gradually, following the rules of a typhoon passage. This paper aims to analyze the submarine pipeline scour rules under extreme sea conditions aforementioned, and provide scientific guidance for submarine pipeline design and protection in the near shore area.