FEM analysis of deepwater drilling risers under the operability and hang-off working conditions

Abstract

In recent years, numerous exploration activities of oil and gas industry have been conducted in ultra deep water. The global offshore industry is building systems today for drilling in even deeper water, progressively using new technologies, and significantly extending existing technologies. This is the general trend in the offshore oil and gas industry. So the technology of ultra-deepwater risers, which is the main tool in drilling oil, is more and more standard. This paper manly focuses on the global analysis of the drilling risers. And it is divided into two parts, operability analysis and hang-off analysis that are used to check the design of the riser. In this paper, the rotation angle and stress of the riser in the drilling mode are calculated to determine the operability envelop. The number of the buoyancy modules has been determined and according to the API standard, all the worked out values have been checked out. From all the above, it is concluded that the operability envelop is relatively small under harsh condition and the number of the buoyancy modules is a little large. And above all, the design of this riser is successful.

摘 要

近年来, 在深海进行油气开发的技术进展日新月异, 全世界的海洋工程公司都在用更新的科技手段努力向更深的海域拓展, 向深海进军已经成为了整个海洋石油工业的总体趋势。 作为连接平台设备和海底的重要设备, 深海海洋立管的设计和使用也越来越趋向标准化。 该文以某深海立管为例, 从操作工况和悬挂工况两个方面探讨了钻井立管的整体分析中遇到的主要问题并进行了相关的校核。 该文的具体工作包括计算了立管在钻探模态下的旋转角度和应力分布, 确定了操作半径、 浮箱数目等要素, 并根据API 规范进行了校核。 根据计算的结果可以看出, 所选的立管在恶劣海况下的操作半径相对较小, 而确定的浮箱数略多, 相关结论对立管的初步设计具有较好的参考意义。