...1. Introduction 1.1 Mobile jack-up rig and spudcan foundation Most offshore drilling in water depths up to 150m is performed from self-elevating jack-up rigs because of their proven flexibility, mobility and cost- effectiveness. These jack-ups typically consist of three independent truss legs, each...

... be moved up and down the legs by means of a rack and pinion system. Large, nearly circular cans are at the base of the legs. These cans are known as spudcans, and they form the foundation of the platform. A jack-up rig can be transported to the site by means of tugs. With the legs jacked up and the hull...

... soft clay, must be assessed. This is because in these conditions the spudcan can push the stronger overlying layer into the softer underlying soil. Known as a punch-through, the subsequent re- duction of vertical load can cause the jack-up leg to uncontrollably penetrate. Several platform failures have...

...- ezocone and ball are deemed more suitable to penetrate through sand due to structural compatibility. Considering the huge dimension of spudcan and its limited penetration in sand, the stress level induced strength variation can vary the piezocone and spudcan resistance profiles developed in the sand...

...Proceedings of the 6th International Offshore Site Investigation and Geotechnics Conference: Confronting New Challenges and Sharing Knowledge, 11 13 September 2007, London, UK 285 1. Introduction 1.1 Jack-up and spudcan background Jack-up units are commonly used for oil or gas exploita- tion...

... be problematic. The dif- ficulties are magnified if the new spudcan locations do not coincide with the existing craters (see Figure 1). Possible solutions to the problem are stomping and crater infilling. In many cases, the option of stomping may not be desir- able due to rig-time considerations, weather...

... upstream oil & gas contractor jack-up foundation assessment hazard foundation foundation assessment procedure interpretation reliability site assessment operator bearing capacity applicability soil condition spudcan geotechnical data assessment asia jack-up punch-through...