The Perdido Spar, The Deepest Offshore Rig In The World
The race to discover new sources of oil continues even as the price of crude has fallen. That race is leading companies like Shell Oil into even deeper waters in search of valuable deposits.
Shell oil has towed the Perdido Star semi submersible into almost 10,000 feet of water in the area known as the Perdido Foldbelt. The rig, seen in the illustration above, is almost as tall as the Eiffel tower and weighs more than 10,000 family cars. It will serve as home to 150 oil rig workers and support personnel including cooks, and housekeeping workers.
The upper deck of the rig will feature a one of a kind heliport capable of landing two Sikorsky S93 long range helicopters at the same time. Each helicopter will ferry 24 crew at a time from the distant mainland. The Perdido Spar will be the farthest oil rig operating in the Gulf of Mexico at the edge of United States territorial waters 220 miles from Galveston.
Shell geologists expect that the wells drilled by the Perdido Star will produce over 130,000 barrels a day. The cost to extract those barrels is staggering.
The Perdido Spar was built by Technip in Pori Finland and towed across the Atlantic to Ingleside Texas. It began it’s long journey to the Gulf Of Mexico in May of 2008. It is the largest structure of it’s kind ever placed into operation in the Gulf of Mexico.
Engineering Challenges:
Building and moving the massive deepwater drilling rig is only part of the engineering challenge. Once the wells are drilled over 180 miles of pipe will be laid on the seafloor. ROV’s or remote operated vehicles will be used to do much of the work. Tasks like underwater welding and connecting pipes will be done using underwater robots controlled from the surface. Since the pressure of the oil coming out of the well will not be sufficient to force it all the way to the surface, a series of truck sized pumps will be located in stages along the riser that extends to the seafloor.
A pipeline over two hundred miles long will be laid along the bottom of the seafloor to transport oil and gas from the Perdido field to the mainland. The Perdido Star offshore rig is truly an amazing feat of modern engineering however even it may be dwarfed by mega projects already being planned for deeper waters.
