Analysis of Collision between Offshore Pipelines and Risers
|School||Harbin Engineering University|
|Course||Design and manufacture of ships and marine structures|
|Keywords||Deepwater riser Local collision FEM Impact force Contact surface|
Offshore oil and gas development riser system is the weakest component system is one of the offshore oil development \Marine environment in a crowded, and the internal fluid in the wave and current action in the external environment, the upper module movement, VIV incentives under the effects of three, between the riser and the pipeline may cause structural damage collisions. This will not only bring huge economic losses to the environment will be irreparable adverse effects. Collision analysis riser riser design in recent years become an important part of the essential, more and more engineering attention. Most of the current design criteria specified in the design of the riser array set aside enough space between the riser to prevent the occurrence of contact and collisions. But with the development of the deepwater offshore oil and gas forward, the likelihood of collision will be greatly improved, adequate space will cause great economic costs. Therefore, in the event of collision, collision response which factors influence the most sensitive, this article will examine the issue. Some previous researchers usually riser collision object is assumed to be rigid, but the actual situation is not so in the moment of the collision riser, two risers in varying degrees of deformation, this article will risers are considered deformable body treatment. This article will use the three-dimensional finite element analysis software ABAQUS standpipe touch disturbing event is modeled using explicit dynamic solver calculations, and the results are discussed and analyzed. In this paper, the problem of interference riser touch the basic theories and research methods, including a simplified model of the riser collision involved mass method, API recommended method, energy method. Since the riser contact problem is the problem of collisions, this article will introduce problem solving used by the contact surface, the contact force theory and ABAQUS finite element analysis software explicit dynamic solver Explicit, detailed discussion of explicit dynamic solver in the calculation of the riser collision Power on implicit solver comparative advantage. In this paper, ABAQUS build risers local collision three dimensional finite element model, and use explicit dynamic solver draw the structure accordingly, by setting different collision between the riser angle, impact velocity, the calculated results were compared, draw conclusions. This article also covering the establishment of a chloroprene rubber riser model and calculation results by the collision response with bare tube comparing rubber coated riser draw conclusions protective effect. Also studied several initial conditions riser injury discussed riser overall response of the collision.