The ROV-borne Soil Stinger offers cost-effective shallow soil investigations

April 1, 2005
Soil Stinger, a new tool for environmental and geotechnical soil investigations, will be available from Stinger Technology this year.

Soil Stinger, a new tool for environmental and geotechnical soil investigations, will be available from Stinger Technology this year. The company is on track to perform onshore and offshore trials of a prototype this summer, General Manager Bjarte Langeland reports.

Stinger Technology has designed the Soil Stinger to provide the market with a simple and cost-effective tool for shallow soil surveys compared with current tools that hang from a crane or A-frame. It consists of a neutrally buoyant package, which an ROV carries. A suction skirt carried under the ROV establishes the reaction force. This is positioned on the seabed and the water pumped out, which provides a stable platform for penetrating operations.

A powerful injection unit, the Soil Stinger moves a special coiled pipe continuously into the seabed to the required depth, typically 15 m. In fact the prototype will have a 20 m-long pipe, which in soft soils will be capable of being fully inserted into the seabed, Langeland says.

The Soil Stinger is a new tool for environmental and geotechnical soil investigations.

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The pipe has a 50 mm diameter, enabling it to carry a full-size 37 mm piezo cone, or in very soft soil a 50 mm cone. The Soil Stinger will provide an efficient platform for the collection of high-quality cone penetration test data, as well as for other shallow seabed investigations such as core sampling. It is designed for operation in water depths down to 2,500 m.

Versatile reach

As the system is ROV-borne, it can reach places - beneath platforms or close to pipelines or seabed equipment - where heavy crane-deployed equipment cannot go for fear of causing damage. Neutrally buoyant, it can also be used for tasks such as penetrating the soils on top of a buried pipeline to assess whether the mass of burial material is in accordance with the client’s specification.

Patents are pending for the core technology, the innovative coiled rod. A contractor team will operate the tool. Eidesvik Subsea, in joint venture with Seacore, has chartered MSVKingfisherfor geotechnical operations, while Oceaneering will provide ROV services. Statoil and Innovation Norway, a government agency, are providing the technology development.