Research Of Suction Foundation Design For Deep Water Manifold

In the 21 st century,along with the exhaustion of the oil resources in land and offshore,it is imperative for oil industry to draw attention to the deep water and ultra-deep water inside of shallow water.As a high-profile solution of deep water engineering in offshore oil industry,subsea production system has advantages in safety,reliability and wide range of application.Manifold is an important part of subsea production system.Most of the manifolds are fixed on the seabed with anchor.As a new type of the anchor technology,suction foundation is widely used with the superiority of large bearing capacity and some other features.The two main design factors for controlling the size of suction foundation are the penetration resistance and the bearing capacity.In this article,a geotechnical survey was carried out by investigation of literature and document of South China sea,and the parameters of deep clay of the south China sea was determined during the survey.By using the general finite element software ABAQUS,a coupled two-dimensional axisymmetric finite element model was built to analysis the bearing capacity and penetration process of suction foundation.This article utilized the simplified RITSS technology(based on mesh to mesh solution mapping)writing a script to provide an automatic modeling method of ABAQUS with programming language Python.This script was used to analysis the penetration process with weight,static pressure and suction pressure.The result of this penetration process shows the differences of the height of soil plug and resistance of penetration.The conclusion of soil deformation and characteristics of penetration process was drawn in this chapter.On the basis of analysis of penetration process,the calculation of suction foundations with different slenderness ratios was carried out to find out the mechanism of bearing capacity with the influence of stress after the penetration.This article summarized the reduction of bearing capacity with different ways of penetration.