A NOVEL ULTRASONIC INSPECTION SYSTEM FOR FLOODED MEMBER DETECTION OFFSHORE

The demand for oil and gas resources has led the search and recovery o f offshore, encountering in the process some of the most inhospitable working environments. The large structures employed to extract the hyd rocarbons have to withstand very severe operating conditions, such as fatigue and corrosion. Consequently, there are regulatory guidelines r egarding the monitoring of structural integrity for continuous safe op eration. The size of installations and the cost of implementing work o ffshore have led to the requirement for fast and reliable inspection t echniques to provide the necessary data on structural integrity One of those techniques is Flooded Member Detection (FMD), which involves th e detection of water in normally air-filled members of steel jacket in stallations. Confirmation of water indicates the presence of a through wall defect in that particular section of the structure. This paper p resents on overview of the work involved in the design, development an d trial implementation of a prototype ultrasonic FMD tool. The system is based around a multi-frequency ultrasonic array incorporating 1-3 c onnectivity ceramic/epoxy transducers. The system also comprises a dat a acquisition and analysis package linked to an expert knowledge base to provide automatic analysis of the ultrasonic data generated by the array.