Session: 01-01-03 Offshore Platforms-3

Submission Number: 178550

Experimental Investigation of Electro-Osmosis Assisted Spudcan Extraction 

Spudcans are used in the offshore industry as temporary anchors for jack-up rigs, that are penetrated in the seabed to provide vertical bearing and sliding resistance to the rig while in operations. Those temporary anchors are part of the rig, and need to be extracted once drilling is completed and the rig needs to be relocated to another site. Depending on the soil type, this extraction process can be very time-consuming—sometimes taking several weeks—and therefore generates significant downtime costs. Fine-grained soils are particularly problematic, as undrained extraction induces suction at the spudcan base, which greatly slows down the process.

 

Electro-osmosis involves the circulation of electric currents through clayey soils to achieve various objectives such as dewatering or pollution remediation. One effect is the production of hydrogen gas at the cathode due to an electrode reaction. By using the spudcan as the cathode in an electro-osmotic setup, the generated hydrogen gas could create gaps between the soil and the spudcan, thereby reducing suction and facilitating the extraction process.

 

The experiments are conducted using a small calibration chamber placed inside a MicroCT tomograph, using normally consolidated kaolin clay. While previous studies have already demonstrated the possibility of generating gas and form cracks around the spudcan, the present work focuses on experimentally confirming the reduction in suction and extraction forces, as well as identifying optimized parameters for an energy-efficient process.

Presenting Author: Antoine Mertz Port And Airport Research Institute

Presenting Author Biography: I am a postdoctoral researcher at the Port and Airport Research Institute, specializing in experimental investigations in geotechnical engineering. My main expertise lies in the design and implementation of experimental testing devices and protocols. I completed my PhD at Laboratory 3SR, where I focused on soil–structure interaction of buried gas transportation pipelines. My current research explores electro-kinetic phenomena for various geotechnical applications.

Authors:

Yuri Sugiyama Port and Airport Research Institute
Antoine Mertz Port And Airport Research Institute