ABSTRACT
Most offshore drilling in shallow to moderate water depths throughout the world is performed from independent three leg jack-up rigs with proven flexibility, mobility, and cost-effectiveness. Depletion of known reserves in the traditional regions and in shallow waters, is resulting in exploration in deeper, unexplored and undeveloped environments with more complex seabed soil conditions. In emerging provinces
and fields, highly layered soils are prevalent, such as at the Sunda Shelf (see Fig. 1), Southeast Asia, Bass Strait (SE of Australia) or offshore India. Layered soil profiles result from various geological processes, including previous crustal desiccation, sand channelling and evolving depositional environments associated with changing sea level (Castleberry II & Prebaharan 1985).
