 Fig. |
Both missions has been aiming for Corrosion control of welded joints of pipelines operating in deep waters and carrying hydrocarbons (Gas).First mission was to make several radiographic shots of a weld on the 20" export pipeline from the TOGI Template carrying Gas from the TROLL field to the Oseberg field for injection into the Oil producing layers at the Oseberg. The TOGI Template is installed on 350 meters depth and is therefore out of reach for normal diving operations.
The second mission was to make several shots of a complex weld on a 10" production pipe on a template at the Frigg field. This weld is joining two lines of Black Carbon Steel to a Duplex steel pipe. Wall thickness of these pipes was of special concern as the Duplex pipe has walls of 39 mm while the Carbon steel was only 29 mm.The isotope and film carrier was specially designed to encircle the pipe and place the Isotope container opposite to the film. The film used was standard film in double pack version wrapped in a water sealed envelope.
Both missions was success' and the result gave excellent film images. The operations also proves that radiography may be performed underwater by remote operated systems.
Present Isotope container has been tested for 735 meters of seawater and ROY's may operate to 3000 metres water depth and beyond allowing the technique to be operated to any waterdepth subject to increased qualification of the isotope container.
Picture shows the Isotope container from OIS pie mounted on the SCS launching tool. The film is carried by the tool under the pipe. The exposure is controlled by hydraulic from the ROV.
Abstract Source:
Book of Abstracts, 7th European Conference on Non-Destructive Testing, 26-29 May 1998, ISBN: 87-986898-0-00
Full-Text Source:
Proceedings of the 7th European Conference on Non-Destructive Testing, 26-29 May 1998, ISBN:
Publication Contact:
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