Stabilising marine or fluvial sediments exposed to erosion - by depositing grout comprising e.g. clay and gravel, protecting structures in e.g. submarine petroleum fields

摘要

A method of stabilising an erodable marine or fluvial sediment consists of depositing directly on the sediment a grout comprising a pasty or colloidal non-hardening material, pref. mud or clay, incorporating particles of a solid material, pref. gravel. The group is brought to the required position above the sediment by forcing it through an under-sea tube fitted with a mobile delivery head which spreads the group over the sediment. The invention eliminates the inconveniences of existing processes. These include using concrete, an inverse filter, rock or gravel, synthetic material, plants or bitumen plates. They are in general different to apply and costly and may not be always reliable or compatible with the environment. The method according to the invention protects under-sea structures. e.g. pipes or the feet of stands in petroleum drillings against damages produced by undermining caused by waves and currents in the sea. It supports sections of piping which have been undermined, is compatible with the environment and the bed is stable for a long period. It can be applied with precision from a ship without supervision by divers.