The Deepest Offshore Drilling Rig In The World
An Offshore Engineering Marvel In The Gulf Of Mexico
In the search for more sources of oil to fuel the world economy Shell Oil along with partners have built the deepest operating drilling rig and production platform in the world. The Perdido Spar stands nearly as high as the Eiffel Tower.
Earlier this year the massive rig was towed from Ingleside Texas to an area about 200 miles south of Galveston known as the Perdido Foldbelt. The Perdido foldbelt is a rich discovery of crude oil and natural gas that lies in waters over 2400 meters or nearly 8000 feet deep. This will shatter the previous record for deepest operating offshore rig by 2200 feet. The wells drilled will be in excess of 10,000 feet according to Shell Press Releases
The Challenges Of Pumping Oil From The Deepest Offshore Rig
The oil that will be extracted lies another 6000 feet below the surface, making it one of the most complex drilling projects in the history of the industry. Remote operated vehicles or ROV's will be operated by technicians from the surface to do everything from connecting pipelines and welding. Massive pumps, large as an SUV, will be staged in the riser leading to the seafloor to help the low pressure oil to reach the surface.
"It will be the first application of wet tree direct vertical access (DVA) wells from a spar.
Using a DVA configuration allows a larger number of subsea completions to be accessed by the facility’s rig drilling, resulting in significant savings in the drilling and completions programs for these wells.
The wet tree DVA system will use a single high pressure drilling and completion riser suspended from the host to access 22 subsea trees directly below the host. The configuration will allow the use of a surface blow-out preventer (BOP) for the drilling, completion and later sidetracking of wells." Source. Shell Website
A Very Long Way From Land
The deepest offshore rig in the world will also be one of the most distant from land. The Perdido Foldbelt lies at the edge of United States Territorial waters, next to Mexico's territorial claim.
The trip from Galveston by boat can take several days. Crews of 24 will be ferried back and forth on two large Sikorsky S93 ultra long range helicopters a staggering cost per trip. Crews will most likely work thirty day on and thirty off rotations due to the huge expense of transportation.
The Perdido Spar, when completed will provide living quarters for over 150 oilfield workers and support personnel. What's at stake and the reason for the massive expenditure (cost is undisclosed) is 130,000 barrels of crude oil production a day when completed.
The cost to extract those barrels is staggering. Pipelines, will have to be laid all the way to the mainland and over 190 miles of gathering lines will have to be laid on the seafloor, along with all the manifolds and equipment to connect those lines. The work done by ROV will be some of the deepest yet done.
The Perdido Spar was constructed by the Finnish company Technip and made the long journey across the Atlantic to Ingleside Texas where it was prepared for operation. It is thus far the largest man made object in operation in the Gulf Of Mexico and the deepest operating oil drilling rig / platform in the world. How long that record stands remains to be seen. Other milestones can be seen in the illustration below.
Below is a map of the location of the Perdido Spar, the deepest operating offshore oil rig in the world.
Image From Shell Website