Parameters Study On Dynamic Response Of Steel Catenary Riser And Research On Section Weight-Optimization

Steel catenary riser(SCR) as a new type, is thought to be the preferred riser in the development of deepwater oil and gas. SCR operates in a very complex environment, bearing wave, current loading, movement of floating, seabed friction and so on. All of these loading applied together makes the dynamic of SCR very complicated.This paper uses the finite element software ABAQUS to model the whole SCR. During the modeling process, vertical and lateral non-linear springs are built along the SCR in the touchdown section, according to the P-y curve model in vertical seabed direction and the trilinear model in the lateral seabed direction. Then the dynamic response of the whole SCR is calculated by applying wave, current loading and the movement of floating. Then the influence on the dynamic response of SCR is studied by adjusting the current direction, the initial suspension angle, inner diameter, wall thickness. The results show that the time history stress of the location near touchdown area is more sensitive to the direction of the current. When the direction of the current is in the plane of SCR, the maximum dynamic stress is larger than other directions. With the increase of the initial suspension angle, the location of maximum time history stress moves to the bottom fixed point and the maximum stress of SCR is reduced, while it increases in the suspension and stream lines. With the increase of wall thickness, the stress becomes less. The dynamic stress changes little although the diameter of SCR increases.Additionally, the impact of weight changes on the dynamic response is studied by applying different density coating. It show that the end point of sagging section with heavy coating has a specific position at which the stress level was most reduced. Moving this end either closer to or further from the TDP will increase the stress level. This position needs to be noticed. Weight optimized coating for SCR can improve the dynamic response at TDA, which can be used as a way to improve the reliability of SCR.