Study On Pipe Soil Interaction In The Contact Area Of Steel Catenary Riser

Energy security and ensuring energy supply are of great significance to national development.So far oil remains the most important source of energy,and offshore oil is becoming the most important source of oil supply.The riser and its associated offshore platforms and subsea pipelines constitute a complete system for producing and transporting offshore oil.Among different types of risers,steel catenary risers(SCR)have shown unique advantages in reducing production costs,being suitable for greater mining depth,complying with multi-load and multi-degree of freedom motion,etc.,and have attracted wide attention.The study of SCR is undoubtedly a hot spot in the field of marine engineering,among which the exploration of pipe-soil interaction in the SCR touchdown area is the key and difficult point of the study.The main research contents of this paper are summarized as follows:Firstly,on the basis of reading a large number of literature,the research background,necessity and relevant technical development status of the subject are summarized.Secondly,on the basis of mastering the basic theory of pipe-soil interaction,finite element software ABAQUS and contact analysis method are selected to establish the pipe-soil interaction model.In the process of seting up numerical model,start from a simple two-dimensional pipe-soil model,to gradually improve and establish a more truthful 3d pipe-soil model.SCR pipeline deformation,stress and bending moment are the main research point,and the forming of groove in the SCR touchdown area as well as the variation regularity of pipe stress and bending moment near that area are particularly studied.Finally,based on the 3d pipe-soil model,applying the internal pressure load,external pressure load and the internal plus external pressure load respectively,three cases of SCR pipe-soil model are established,and the groove shape as well as the pipe stress and bending moment distribution under the influence of different pressure load are studied,drawing the conclusion that the impact of internal pressure load and the external pressure load is opposite,thus the effect of the mutual cuts make pipeline operation safer.