TITLE: AUV PIPELINE INSPECTION
AUTHOR: SEAN P. COMISKEY* AND JAMES WHEELER*
COMPANY: OCEANEERING INTERNATIONAL INC.
ABSTRACT
Regular inspection is a part of pipeline integrity management for keeping these assets in the best condition possible. Previously, Remote Operated Vehicles (ROVs) were the primary platform used to perform pipeline inspection.
The use of Autonomous Underwater Vehicles (AUVs) is relatively new to the pipeline inspection survey scene. Oceaneering International Inc. (OII) has developed an AUV that is equipped with a Voyis laser bathymetry system and a high-resolution camera in addition to the Kongsberg EM2040 multibeam echosounder, Edgetech side scan sonar, and a subbottom profiler. Utilizing the ultra-high resolution laser bathymetry and multibeam data in EIVA’s pipeline inspection software, pipelines can be fully inspected with hazard identification that would impact pipeline integrity. The addition of pipe tracking technology and the usage of the EIVA software package, the overall efficiency of the AUV pipeline inspections has increased significantly.
As part of these inspections, damage, wreckage, debris, buried or partially buried sections, free-spans, carbonate sediments, pipeline crossings, pipeline movement and vertical or lateral buckling can all be identified. In addition, basic components such as anodes, field joints, inline SLEDs, mattresses and other methods for stabilization are analyzed.
The survey via AUV consists of a series of steps:
· Identification of pipelines and its location in the company’s database.
· Reconnaissance (high-pass) survey with the AUV determining the as-found location of the pipeline using side scan sonar and multibeam.
· Inspection (low-pass) survey with high-definition laser, camera, and multibeam.
The preliminary results are exceptional due to the high quality, resolution, and incredibly high precision of the sensors. Utilizing the EIVA software package, the data is cleaned and a finished Digital Terrain Model (DTM) is generated for both the laser and multibeam. From these DTMs, the pipeline, adjacent seabed and mean seabed levels are parameterized at a given interval. The still images are geolocated in the NaviModel software and events determined from all the various data sets.
