Abstract The paper describes experiments completed in June 2000 as part of the STRIDE JIP – Steel Risers in Deepwater Environments 1,2.
Environments1,2 . The tests investigated the interaction between a soft clay seabed, typical of deepwater developments, and a steel catenary riser (SCR). ROV surveys of deepwater SCR’s attached to floating production vessels have shown that they can cut deep trenches into the seabed. The following objectives were set:
- (1) To assess the effect of seabed to SCR interface forces on local riser stresses for wave and slow drift vessel motions
- (2) To assess the effect of different riser trenches on local riser stresses for wave and slow drift vessel motions
- (3) To identify the key trenching mechanisms and rates.
- (4) To use the test program findings to benchmark riser FEA tools, and to adjust modelling parameters to better simulate the real case as necessary.
To achieve this, the seabed end of a deepwater SCR was simulated using a 360-ft long 6-inch diameter steel pipe, hung as a catenary across the soft seabed of a tidal harbour. A particular harbour location was found that had seabed properties similar to those of a deepwater Gulf of Mexico seabed. The top end of the pipe string was then actuated with carefully controlled wave and vessel drift motions to simulate a spar platform in 3,300-ft water depth.
If you would like a copy of this technical paper.