Colmar Italia has been contracted for an underwater vertical inspection in Qatar.
The contractor is a major oil company which needed to inspect pipeline and installation pressurized with (MEG) in the Persian Gulf.
The inspection technique used has been the vertical inspection mode.
Two ALD teams, including personnel and equipment, has been engaged.
In order to speed up operations the two teams have operated simultaneously to rapidly verify the integrity of the network.
ALD-Acoustic Leak Detector Inspection technique: VERTICAL
The ALD sensor is lower underneath the survey vessel by mean of a wire line kept vertical by a clump weight (CW). The CW keeps the wire line vertical and the sensor oriented downwards. The POD is also fixed to the clump and data reaches the surface trough a soft cable fixed to the wire line.
This technique allows an accurate inspection of pipelines, flanges or valves without the need of divers or ROV. It is recommended for conditions where depth and current make critical the navigation of the towed fish. Suitable for a depth range of 30-150m. The vessel shall be equipped with a dynamic positioning system and a USBL.
The system is mainly composed by a sensor to acquire and pre-process the acoustic data, a POD for pre-processing and digital conversion, a transmission line to take them on the vessel, a receiver for hardware processing and an PC based software to analyze and display the results.