Sensorlink (Norway)

Abstract Sand production is a common challenge in oil and gas industry and will lead to loss of wall thickness due to erosion mechanisms. One way of reducing the impact of erosion due to sand is to select weld overlay cladding on the interior of the pipe. Weld overlay cladding is a welding process where one or more metals are added to the original pipe wall to introduce a hard-facing layer and increase service life of the pipe. A monitoring technique to survey the wear rate of the weld overlay cladding based on ultrasound is presented in this paper. An UltraMonit SEC® is designed for permanent subsea installation on an 8-inch elbow to monitor the pipe integrity and detect erosion by measuring the critical elbow wall loss. Monitoring tool consists of multiple (seven) ultrasound sensor segments spread around the outside circumference of the elbow, and each contain 34 ultrasound transducers mounted together with electronics and a temperature sensor. The seven segments of the tool are to be installed topside with subsea cabling between them the retrievable datalogger canister. The tool is non-invasive and provides real-time and online wall thickness data of the subsea spools, pipelines and pipes. In this paper a subsea installation is described and initial measurements from monitoring of weld overlay cladded elbows is presented. Cladded pipes have a rough inner surface that directly affects the quality of signals, and signal analysis has been developed to cope for this. Challenges related to using ultrasound is discussed.