IODP

doi:10.2204/iodp.pr.326.2011

Preliminary scientific assessment

The limited objectives of Expedition 326 were eventually completely met, albeit with setbacks and a necessary, though little-precedented, extension of the duration of the expedition. The wellhead, 36 inch conductor, and 20 inch casing were set and cemented to a depth somewhat in excess of the minimum requirement set out for this top hole portion of the planned riser borehole. The loss of a substantial length of 20 inch casing in the water column, presumably due to the strong current and VIV, was a costly problem. However, the lesson learned about how to deploy casing and other pipe through the Kuroshio Current using the vibration-damping rope coils proved to be key to the success of the second attempt. The outcome is that the stage is now set for riser drilling of Hole C0002F during future expeditions.