Analysis Of Collision Between Offshore Pipelines And Risers

Offshore oil and gas development risers system is one of the weakest component in the offshore oil and gas development system, also regarded as a "bottleneck" problem. In the crowded marine environment, under the effects of the three factors such as internal and external environment of wave action, the topside displacement and VIV, risers and pipelines may have the structural damage caused by collision. This will not only bring huge economic losses, but also will be irreversible adverse effects to the environment.The analysis of the riser collision in recent years becomes an essential part of the risers design, attracting more and more engineering attention. Most of the current design criteria set that in the riser arrays enough space should be set aside to prevent the occurrence of the contact and impact between the vertical risers.However, with the offshore oil and gas development moving to the deep water, the possibility of a collision will be greatly improved, leaving enough space will result in significant economic costs.Therefore, in the event of collision potential, what factors impact on the most sensitive collision response is worthy of our research.Some previous researchers usually assumed riser collision to be rigid body, while the actual is not the case. In the moment of collision in the risers, two risers have different levels of deformation, so the deformation of the body is considered reasonable treatment. This article will use three finite element analysis software ABAQUS to simulate the risers contact events, use explicit dynamic to calculate, discusses and analyze the results.This paper describes the background of the paper, international and domestic research for riser collision on the history and progress. The second chapter describes a simplification of the riser impact problem, collision participating masses, API recommended, energy method such interference problems riser main collision theory and basic research methods. The third chapter describes the contact surface, contact force theory and finite element analysis software ABAQUS explicit dynamic, and its advantage of riser collision calculation is given. The forth chapter use ABAQUS to establish three finite element model of the risers collision events, by using explicit dynamic the sensitivity of the angle between two risers, the angle of the impact velocity is analyzed, and draw conclusions. Also study the response comparison in a collision of the neoprene coated risers and bare-steel risers. The fifth chapter describes the local and global response of the riser collision and the method of studying the risers collision damage.