The effect of seabed features on the stability of offshore pipeline

In this paper taking the DF1-1 Gas Field submarine pipeline route as an example,based on the multi-beam soundering,side scan sonar and Sub-bottom profile surveys,seabed sediment analysis,current measurement and in-situ monitoring result of seabed process,together with the collected data including wave and current,the scouring,transportation and sedimentation processes of seabed sediment under hydrodynamic conditions along the DF1-1 pipeline route are discussed in this paper.These processes can rebuild seabed geomorphology greatly and have an important influence on pipeline stability as a result.Based on the above analysis,it is strongly recommended that before pipeline laying,submarine hydrodynamic pattern along the pipeline route must be studied and seabed features affecting pipeline stability should be identified.In the end,some solutions under different situations are provided to reduce the adverse influences of the hazardous features on seabed pipeline stability.