Vortex-Induced Vibration (VIV) occurs whenever a current flows past a long slender object. Most people have experienced VIV when trying to move an extended arm quickly across the water in a swimming pool. VIV causes oscillatory motion of long slender structures such as risers and tendons. This results in bending of these structures.
In the early to mid-1980s, as deepwater exploration and production activities began to exceed water depths of 2,000 feet, the need to understand VIV and its impact on fatigue of deepwater structures, particularly risers, became imperative. Early work had focused on single mode VIV. With increased water depths and higher ocean currents, it was clear that deepwater tubulars (production risers, drilling risers, tendons, etc.) would need to withstand modes as high as 20 and 30 in the Gulf of Mexico loop currents. The increased number of participating modes and their interaction made VIV analysis nearly impossible with models at that time.
During this same timeframe, Professor J. Kim Vandiver and his students were developing a program called “SHEAR” used for modeling deepwater tubulars experiencing VIV. Concurrent to Vandiver’s research, Don Allen and Dean Henning were conducting experiments on deepwater tubular VIV in Shell’s current tank facility. As their respective research evolved, Vandiver, Allen and Henning saw the benefit of working together and formed a MIT-Shell Joint Industry Program in the early 1990s. The MIT-Shell Joint Industry Program utilized Vandiver’s SHEAR program and Allen and Henning’s test data to achieve a more robust program named SHEAR7. Li Lee, a graduate student and later as a post-doctoral engineer working with Professor Vandiver, joined the program by writing the SHEAR7 code and provided his own insights into the model using the Shell (Allen and Henning) data.
As a result of the collective research and development efforts, the tall helical strake geometry; a very short tear-drop fairing; and, improved analysis and modeling could reliably suppress VIV and confidently ensure that the vibrations reduced to a safe level for increased, deepwater drilling and production.
Companies and individuals honored are a subset of the many contributors to the research and development of Vortex-Induced Vibration Analysis and Suppression of Deepwater Risers: Don Allen, Shell Oil Company; Dean Henning, Shell Oil Company; Li Lee, Massachusetts Institute of Technology (MIT) and Shell Oil Company; Professor J. Kim Vandiver, Massachusetts Institute of Technology (MIT)