Underwater Pipeline Inspection

Challenge

Inspectahire team were tasked with carrying out a subsea water pipe survey at Flotta, in Orkney. The aim of the inspection was to determine the condition of the two pipes which ran from the eastern shore to the west. The brief of the job stated the two pipes were 6m apart, however after carrying out the inspection it was determined they were actually around 60-70m apart.


Solution

A range of inspection technologies and skills were used to carry out the project successfully.

The team deployed a Side Scan Sonar, Towed Subsea Camera and Outlander ROV.

The first stage of the inspection involved locating where the pipes were situated using the side scan sonar. This not only situated the pipes, but gave the first indication of what condition they were in. Small abnormalities in the structure of the pipes could clearly be seen. The Towed Subsea Camera produced a more detailed visual on the condition of the pipes and the areas that had previously been marked for closer inspection by the scan sonar. This ensured that time was not wasted carrying out a detailed inspection in areas which appeared structurally sound. The Towed Subsea camera was used to capture clear and detailed images of the pipes. It constantly provided the team with a picture of the pipeline, when there was a particular area of build up the image was captured.

The towed Subsea Camera images showed areas where the pipes structure may be at risk, at one stage the camera located a large concrete block located very close to the pipeline. The object had previously been identified as an area of interest during the sonar scan.

A submersible ROV was deployed to capture additional images in greater detail. It also allowed the inspection team to reach areas which could not be covered by the towed Subsea camera. The ROV could travel directly along the pipeline and close up images could be viewed. If there were areas of corrosion or damage it was clearly visible.

Result

The use of these technologies ensured the client was provided with detailed results of the inspection. The image was then included in the final report, with information on its exact location being given to the client.