OceanTools C-Scan Case Study Caisson Internal · PDF fileOceanTools Ltd OceanTools House...
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OceanTools Ltd OceanTools House Claymore Drive Aberdeen AB23 8GD t: +44 1224 709 606 e: [email protected] www.oceantools.co.uk OceanTools C-Scan Case Study Caisson Internal Inspection
Transcript of OceanTools C-Scan Case Study Caisson Internal · PDF fileOceanTools Ltd OceanTools House...
OceanTools Ltd
OceanTools House Claymore Drive Aberdeen AB23 8GD
t: +44 1224 709 606 e: [email protected]
www.oceantools.co.uk
OceanToolsC-Scan Case StudyCaisson Internal Inspection
OceanTools Ltd
OceanTools House Claymore Drive Aberdeen AB23 8GD
t: +44 1224 709 606 e: [email protected]
www.oceantools.co.uk
OceanToolsC-Scan Case StudyCaisson Internal Inspection
Executive SummaryA global oil and gas major with numerous assets in operation within the watersof the UK Continental Shelf contacted OceanTools to request specialisttechnical assistance with part of their offshore asset integrity program.OceanTools responded with an innovative technical solution that was agreedupon and implemented to notable effect.
Identified ProblemOceanTools’ customer had previously suffered a seawater lift caisson failure,resulting in a Dropped Object situation and the significant HSE concerns andoperational losses associated with it. Suspicion was quickly drawn to a secondcaisson of similar condition and a rapid reaction program of inspection andrepair was immediately put into place.
Technical BriefOceanTools was requested to perform a remote visual surface inspection of aspecific area on the inside of a 930mm internal diameter water lift caisson, andto present a record of that inspection for the purposes of measurement,analysis and the subsequent implementation by the customer of the necessarycorrective measures.
Technical SolutionOceanTools’ Optical 3D Laser Scanning technology, C-Scan, was deployed intothe caisson in question and gravity-fed to a heat-affected zone (HAZ) around aparticular weld suspected of containing numerous defects. A bespoke deploymentand centraliser frame was designed and built to allow the unit to pass through aseries of retaining bars and to maintain a steady central attitude for accurate andeffective scanning at the assigned location.
Due to the limited available space within the caisson, the C-Scan systemrequired substantial modification prior to mobilisation. A bespoke solution wasengineered involving the use of mirrors, specially mounted at precise angleswithin the deployment frame itself. This allowed the laser line emitter anddetector to operate in a linear configuration, thereby minimising the system’soverall width from standard.
ResultsA visual record of the targeted internal profile of the caisson was produced,extracts of which are shown on the following pages. Surface defects werehighlighted and measured in three-dimensions and a comprehensive visual reportwas issued to the customer for remedial action.
SummaryThe rapid, clear and accurate results generated by the C-Scan system and its on-site operator enabled OceanTools’ customer to design and implement a focusedrepair program ensuring that the asset’s fitness for purpose was restored toregulatory levels and that all issues relating to HSE were satisfied in a costeffective, timely and safe manner.
Project LocationNorth Sea (UK)
OceanTools Ltd
OceanTools House Claymore Drive Aberdeen AB23 8GD
t: +44 1224 709 606 e: [email protected]
www.oceantools.co.uk
OceanToolsC-Scan Case StudyCaisson Internal Inspection
Centraliser deployment system designed to fit through limited space. Note the mirrors used to turn the laser and detector through 90°.
OceanTools Ltd
OceanTools House Claymore Drive Aberdeen AB23 8GD
t: +44 1224 709 606 e: [email protected]
www.oceantools.co.uk
OceanToolsC-Scan Case StudyCaisson Internal Inspection
Analysing the data: in this example, there is a 5.8mm (dZ) displacement of the caisson on the weld between the selected points, indicating that the caisson is not properly aligned.
OceanTools Ltd
OceanTools House Claymore Drive Aberdeen AB23 8GD
t: +44 1224 709 606 e: [email protected]
www.oceantools.co.uk
OceanToolsC-Scan Case StudyCaisson Internal Inspection
All specifications are subject to change without notice. E&OE. Version 4 (11.11.2015)
In this software screengrab, the measurements show, from left to right:- the depth of an anomaly (1.47mm)- the distance of the area cleaned before inspection (90.4mm)- the size of an anomaly (26.0mm) - and the width of the weld (9.8mm).
