Parameters Study On Effects Of Steel Catenary Risers Subjected To Environmental Loadings

With the continuous development of oil and gas production technology in deepwater, Steel catenary riser (SCR) is thought to be the preferred riser type for oceanengineering development. On the effects of complex marine environmental loadings,the SCR especially on the suspension point and the touchdown point will have acomplex dynamic response. Under the repeated action of the wind, wave andplatform movement, the fatigue damage of the suspension point and the touchdownpoint will affect the safety of production. So further parametric study is necessary forthe effects of environmental loadings on SCR.This paper firstly introduces the structural characteristics, key technologies andresearch status at home and abroad of the Steel catenary riser. Then by a detailedstudy of the marine environmental loadings on SCR and riser-soil interaction, thispaper decided to adopt the finite element software ABAQUS to analyze the SCRmodel, and used the nonlinear spring element to simulate the riser-soil interaction.By adjusting the parameters of the environmental loadings on the SCR, the influenceon SCR dynamic response which caused by the floating body motion, waveamplitude, wave period and current velocity is studied. The results show that theimpact on the SCR by the floating body motion that along the axis of riser on thesuspension point is the largest one. With the increase of wave amplitude, thedynamic response of the riser on the suspension point and touchdown point willincrease. When the wave amplitude is small, the nonlinear character of seabed doesnot affect the interaction between riser and seabed, so using linearly elastic soil tosimulate the seabed is feasible. When the wave amplitude is large, the result byforegoing method is larger than the true value. With the increase of wave period, thedynamic response of the riser decrease to steady. With the increase of current speed,the touchdown point departs away from the suspension point, and the stress range oftouchdown point decrease to steady, while the stress range of the suspension point isincreasing.