Field Experimental Study on Vortex-Induced Vibration Behavior of the Drill Pipe for the Ocean Borehole Observatory Installation

Abstract

We conducted two field tests aboard the Drilling Vessel Chikyu (D/V Chikyu) in areas of strong ocean currents (i.e., Kuroshio, Japan) during the March 2010 CK10-01 cruise. The relationship between the amplitude of the vortex-induced vibration (VIV) and the ocean current and ship drift speed were investigated to establish a VIV control method for the ocean borehole observatory installation in the Nankai Trough. These tests demonstrate that the ocean current and ship drift speed mainly control the drill pipe VIV. We find that to install sensitive sensors in a strong current area and avoid damage, the key factors are: 1) lowering the sensor assembly in a low current area; and 2) managing the drift speed of the drilling vessel.