Brazilian drillship upgrade completed

Totalling 247,235 man hours for the 600-plus workforce, the contract was one of the largest offshore oil and gas projects for the UK-based company. The upgrade encompassed accommodation, cranes, steelwork (for which 250 tons of steel were supplied); major pipe renewal in excess of 3,200m of piping; painting; and the removal and replacement of transformers and motors; and four major electrical tasks along with many smaller electrical tasks. Activity was split between dry dock and alongside.

“DODI tasked us with locating a dry dock, suitable for this project,” said Harris Pye managing director Mark Prendergast. “Arsenal de Marinha do Rio de Janeiro proved ideal for this project. Timing was all-important. Ocean Clipper was in Brazilian waters, on charter to Petrobras, and was being released for a set number of days for this major contract to be undertaken. We were awarded the contract on a turnkey basis, and manned this project with our Brazilian workforce from our base in Macaé, Rio de Janeiro, backed up by members of our European team, and a small number of specialist sub-contractors in order to complete the project within the stipulated timeframe.”

Major work carried out included:

• Hydro blasting and painting of the outside hull, sponson tanks ballast tanks, mud tanks and moonpool area, and various other areas around the vessel
• Structural conversion of the existing flume tanks to mud pits, including installation of agitators, mud mixing and transfer pumps, new mud pipelines; and fabrication and installation of a new mud gas separator
• Fabrication of new crane pedestals and crane boom rests, and the removal of old cranes and installation of replacements
• Hull removals of the sponson tanks in order to remove old electrical transformers, and install new transformers. This included removal, repair and re-installation of the main propulsion motors
• Removal, overhaul by 3rd party and re-installation of vessel thrusters motors
• General dry docking works such as propeller works, tail-shaft works, rudders, sea valve overhauls, and anode renewals
• Fabrication and installation of stainless steel pipework for new hydraulic pressure unit and upgrade of ancillary equipment
• Steel renewals and modifications in all relevant areas such as sponson tanks, main deck, rig floor, ballast tanks, flume tanks and accommodation modules
• Piping fabrication and renewals/installation of high pressure piping systems, and sea water cooling systems
• Accommodation refurbishment of the mess room, cabins, and alleyways
• HVAC (heating, ventilation, air conditioning) upgrades that included the removal of old, and installation of new, air handling units
• Management and co-operation with third party suppliers.

The electrical tasks included:

• New watertight door status indication panels
• Power supplies to two new mud transfer pumps
• Change out of galley transformers (additional to other transformer tasks)
• Switchboard cleaning
• New power supply to bow crane
• New power supply and communications to Seatrax crane
• Power supply to new accommodation module
• Disconnection and re-connection of several HVAC units
• Installation of transformers and distribution boards for the new electrical room (again in addition to other transformer task)
• Installation of mud agitator panels, associated junction boxes, level sensors and all power and control cabling
• Modifications to wiring of A/C compressor and air handler cabling
• Disconnection and re-connection of all four propulsion motors

Originally built by Mitsubishi in 1977, Ocean Clipper has a rated drilling depth of 25,000ft. She currently has a five-year commitment to Petrobras.