Piled foundations on the North West Shelf

Woodside jointly owns and is operator of five piled platforms in the North West Shelf (NWS): North Rankin A (NRA, 1984), Goodwyn A (GWA, 1995), Angel (2008), Pluto LNG (2010) and North Rankin B (NRB, 2012). All these platforms have piled foundations in carbonate soils, although none of these foundations are the same. These variations result partly from the differences in soil conditions, but more importantly from the lessons learnt from the NRA and GWA pile installations. This paper will take the reader on a journey through recent time and describe the piled foundations for each platform together with the philosophy behind each design. It is a journey where Woodside showcases that it embraced the unexpected results during the installation of NRA (first experience of cyclic behaviour of carbonate soils) and GWA (deformation to steel driven piles) and developed robust (Angel and NRB) and innovative (grooving of drilled and grouted piles at Pluto) piled foundations for their platforms at the calcareous North West Shelf.