Jack-Up Site Assessment: The Voyage to an ISO Available to Purchase

As a mobile offshore unit, a jack-up can float, self-elevate and then impose proofing loads on the seabed to establish a safe working envelope for subsequent drilling or construction activities. Jack-up site assessment has seen significant advances over the 50 or more years that jack-ups have been deployed offshore. The advances have occurred as a result of both the improvements that have been seen in the analytical tools and also as a result of the many significant strides in our understanding of the physics of the jack-up and the ocean environment. Jack-ups, due to their semi-compliant nature, pose particularly difficult challenges to the designer and operator — more so than most offshore structures. This requires cutting edge technologies to assure that practical solutions can be reached without either too much conservatism or too little safety. These advances have often occurred, or been encouraged, as a result of the engagement of the operators hiring the jack-ups and their technical overseers such as Jan Vugts. Jan was instrumental in initiating the Shell study into jack-up site assessment that resulted in a follow-up JIP which developed the SNAME Recommend Practice. Since then ISO 19905-1 has been under development and Jan has provided both encouragement and also very detailed review comments. This paper charts the voyage from the early days of jack-up site assessment through to the development of the ISO and highlights some of the key technical developments.