Integrated Acoustic Unit I.A.U.: A Novel Technology for Continuous Piggability Detection During Pipeline Laying Operation

Abstract

Abstract In the offshore oil and gas industry the pipeline integrity during the whole life cycle is an aspect of paramount importance. During Installation phase pipeline structural integrity can be compromised by fabrications defects and by the action of external forces in case of accidental events, that could generate pipe instability and, in the worst-case scenario, thepipe collapse. Current offshore regulations provide the requirements to be respected during pipelaying operations in terms of Buckle Detection to meet the pipeline Piggability requirements. The debate on the use of a Mechanical Buckle Detector (MDB), i.e., a gauge plate trolley pulled through the pipeline by a wire connected to the vessel and placed at a certain distance behind the touchdown point, is still open. Indeed, Buckle Detection by deploying the MBD may introducesome operational risks, i.e., the cable break, the stacking during motion and the damage of the internal coating. This may lead toadditional vessel time, extra launch/recovery operations and false readings/bias. With the main target to overcome the above issues, Saipem has developed a tool based on acoustic technique to detect deformations of the internal sections of pipes during installation operations: the Integrated Acoustic Unit, IAU (Patented Technology, see Ref. [1]). The tool works by means of a non-intrusive technique andcan provide the continuous characterization of the whole pipe span up to the touchdown point in a single shot. This paper gives an overview of recent developments of Saipem Integrated Acoustic Unit. It describes the working principle and the available IAU Functions, the pipe defects characterization campaign through modelling (FEA) and laboratory tests, the system validation activity through the experimental campaign, the third-party qualification and the new Saipem Procedure for Technology Qualification that was at the basis of the process.