Hydraulic hammer proves out in first deployment off Brazil.

StabFrame, a newly developed subsea pile-stabilizing template, recently saw its first use in the completion of an offshore pile driving installation in the OGX Waimea field in Brazil's Campos Basin. Jointly developed by Large Diameter Drilling Ltd. (LDD) and MENCK GmbH, the StabFrame stabilizes piles in all depths required for underwater pile driving.

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The operation was carried out under a contract awarded to MENCK by Wellstream International Ltd., the main contractor for OGX Petroleo e Gas on the Waimea subsea field development. The contract required MENCK to drive ten 84-inch mooring piles in water depths of up to 140 meters using an MHU 500T hydraulic hammer to accommodate the installation of a mooring system for a Floating Production, Storage, and Offloading (FPSO) vessel in the Waimea Field.

Steered via a work-class remotely operated vehicle (WROV), the StabFrame can stabilize a vertical pile in varying soil conditions. Rather than relying on a release mechanism attached to the pile, the StabFrame's hydraulic release mechanism allows the pile to be driven farther into the seabed, if required, before opening the frame. The StabFrame can adjust to unpredictable and challenging seabed conditions.

Continuous Deployment

Despite strong currents, estimated at times to be more than 3.5 knots, the project finished without incident or injury and ahead of schedule. The companies reported that even with initial low pile penetration (under its own weight), with its hydraulic release mechanism, the StabFrame made stable penetration of the mooring piles possible.

"The operation clearly demonstrated that the StabFrame can reliably accommodate unpredictable soil conditions," said Thorsten Sprunk, project manager for MENCK.

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LDD and MENCK say they are preparing for their next joint pile-driving program which involves 160 monopile foundations at the Gwynt y Mor wind farm off the coast of Wales. www.menck.com; www.lddrill.com.