Continuous structural monitoring of oil rig sub-sea structures for flooded member detection using underwater ultrasound

摘要

An underwater ultrasound system for detecting flooding in the hollow sub-sea structures of offshore steel oil rigs is presented. A sensor, attached to a sub-sea structure and powered by seawater, transmits underwater ultrasound chirp-encoded signals to a real-time digital signal processing monitoring system at surface level. Experiments performed using a jointed steel pipe structure 1 ton in weight, with dimensions of 7 m × 0.5 m × 16 mm, completely immersed in seawater showed excellent performance using a central excitation frequency of 38 kHz, over distances of 100 m.