Subsea pipelines are fundamental to the global economy, play a particularly important role in the exploitation of offshore oil and gas resources, since they are used to transport products from the production area to the export oil terminal or to a refinery process plant where crude oil is transformed.
To ensure the good conditions of pipes laid on the seabed, the preparation of the bottom is of crucial importance; it must be as flat and regular as possible, otherwise conductors will suffer the risk of overstressing.
Subsea buried pipelines can also suffer damage, from soil loading, internal pressure of the pipe, buckling when soil and surface loads are excessive, construction defects, corrosion.
To avoid damages due to seabed modelling or cave in, it is necessary a planned and periodic inspection and survey activity, in order to detect any change and immediately carry out stabilisation tasks.
Underwater acoustic systems play an important role during survey tasks, they can provide information about seabed surface, near-surface and sub-surface or deep sedimentary layers.
To determine the physical properties of the layers below seabed, Sub-Bottom Profiling (SBP) is used, an acoustic system that works at different transmission frequencies capable of penetrating the seabed to quickly measure sedimentary structures.
SBP is an essential tool to support offshore construction, oil and gas production, the burial of subsea pipelines, decommissioning structure, the detection of UXO.
The Sub-Bottom Profiler Z-Tam system designed by Sonar Tech company uses Chirp technology, it is used for shallow water surveys tasks such as geographical and geohazard surveys, sediment classification, pipeline and cable location, buried object detection (UXO).
Read more in the digital JP Mag – JPmag – October 2021
Paolo Mazzone
SubEng – HSE Adviser
Images of Sub Bottom Profiler by Sonar Tech
