Friday 26 May 2017

James Fisher Subsea Excavation (JFSE) has completed a challenging project for underwater services company Seatek in the Kandla Gujarat region of northwest India.

Experts deployed its shallow water Twin R2000 tool for post-lay trenching and backfilling of an HDPE pipeline with concrete sinker blocks over a distance of 5km. The pipeline was trenched to 1.5m top of pipe in an intertidal zone with 7m tidal variation over a distance of 7.5km.

Following attempts with alternative methods by other contractors, JFSE provided a proven solution that would cope with the conditions and requirements at the beach site with the stability and shallow water capabilities of the equipment.

The challenge of keeping stress levels to a minimum on the plastic pipeline while slowly lowering the concrete sinker blocks in an area where there was often no water meant that the stability and shallow water capabilities of the Twin R2000 were essential.

Added complications included the geophysical properties of the soil, the long intertidal zone and the blocks being asymmetrical to allow for long-term burial. The combination of these factors meant JFSE’s was the only method capable of burying the pipeline.

JFSE’s operations team had successfully completed four similar projects prior to travelling to Kandla Gujarat and have another two scheduled in the coming months.

Delzad Karani, director at Seatek, said: “This was a very challenging element of our overall project and it was essential we found a solution. JFSE's understanding of complex excavation requirements and ability to improvise to suit the site conditions was imperative to the success of our post-lay trenching and backfilling requirements.”