Ann: Gibb Maitland No1 Sidetrack - Weekly Drillin, page-25

re: Ann: Gibb Maitland No1 Sidetrack - Weekly... The Kidson 1 well to the south had two massive salt layers (500m and 160m thick) in the Carribuddy Unit which are major drilling concerns and I believe it likely that these became mobile and slumped onto the drill bit and drill string.

So maybe NSE have decided that they need to side-track the well above top salt hence the kick off at 900m, which is just below the 13 3/8 inch casing set at 826m on the 11/12 December 2012.