Offshore intervention works is a very important issue with respect to engineering of subsea structures and pipelines. The need for detailed geotechnical evaluations is increasing when the project developments are going into deeper water, where the soil conditions become more difficult and the seabed is uneven. Soft sediments and sloping terrain require comprehensive foundation of subsea equipment and pipeline supports by use of rock dumping, dredging or other solutions. It is important to develop an optimum design, while still maintaining robust solutions that can accommodate all applicable loads and settlement during lifetime.

Work tasks related to offshore intervention works are for instance; evaluation of pipe-soil interaction, design and analysis of seabed preparation, evaluation of slope stability and geo-hazards, together with geotechnical engineering of foundations for pipelines and subsea structures. Seabed preparation/intervention work for subsea pipelines and umbilicals is basically used for free span rectification, expansion control, or for ensuring sufficient stability and protection if necessary. For subsea-to-beach projects, it would be required to perform comprehensive geotechnical evaluations of landfall solutions and pipeline routes in the near shore area together with evaluation installation methods and pipeline trenching and backfilling requirements.