The water depth of nearly three kilometres (1.9 miles) and isolated location of the Perdido platform posed major challenges to first oil production. So did the dispersed nature of the reservoirs and low pressure in the porous rock that hinders the flow of oil and natural gas.
Cutting deep-water drilling time
Only a few floating rigs can drill down far enough to reach the reservoirs: the Noble Clyde Boudreaux is one of them. Retrofitted specifically for the Perdido project, the Noble Clyde Boudreaux pre-drilled Perdido’s 22 direct vertical access wells to just above the oil and gas layers. This limited the time the crew would spend drilling once the Perdido spar platform was installed, speeding up production. It takes six 13,500-horsepower generators to power the drills on the 29,000-tonne Noble Clyde Boudreaux that soars six storeys above the water.
With two drilling decks instead of one, it operates faster than conventional rigs. It can work on one well and simultaneously drill a new one. Precision drilling at these depths demands great skill — operators on the rig use joysticks to guide the drill-bits below, driving them up to three kilometres (1.9 miles) beneath the seabed to hit a target about the size of a dustbin lid.
The location of the fields, 320 kilometres (200 miles) from the nearest supply port in Galveston, Texas means that every litre of fuel and piece of machinery must be shipped in on a 23-hour journey. Keeping the platform compact and reducing the amount of equipment needed in this isolated location is vital.