Tie-in spools are common features of subsea developments. On the INPEX Ichthys Gas Field development project, the tie-in spools were particularly large and heavy, which make them stand out from other developments.
The Ichthys Gas Field is located 220 kilometers offshore from the North West coast of Western Australia in water depths of 250 m to 270 m.
This paper covers the 18" corrosion resistent alloy (CRA) clad and 12" solid CRA production and the 42" carbon steel (CS) tie-in spools of the development. The production tie-in spools were designed for high temperature, high pressure and all the tie-in spools were designed for sour service and a 40-year life. The tie-in spools at flowline ends were designed to accommodate a typical flowline expansion of 2.6 m to 3 m.
The paper presents the design challenges and installation solutions developed for the tie-in spools.