Global Analysis of Ultra-Deepwater Drilling Risers

In recent years, the exploration activity of oil and gas industry in ultra deepwater is numerous. 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 of 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 the paper, the following is discussed: 1. Calculation of the rotation angle and stress of the Riser in the drilling mode, as well as the stroke of the telescopic joint; 2. Determination of the operability envelop; 3. Calculation of the rotation angle and stress of the Riser on the hang-off condition, and the telescopic joint’s stroke; 4. Determination of the number of the buoyancy module; 5. Check all the worked out values according to the API standard. From all the above, it is obtained that the operability envelop is relatively small on the harsh condition and the number of the buoyancy modules is a little large. And above all, the design of this Riser is successful.