This blog provides commentary on interesting geological events occurring around the world in the context of my own work. This work is, broadly, geological fluid dynamics. The events that I highlight here are those that resonate with my professional life and ideas, and my goal is to interpret them in the context of ideas I've developed in my research. The blog does not represent any particular research agenda. It is written on a personal basis and does not seek to represent the University of Illinois, where I am a professor of geology and physics. Enjoy Geology in Motion! I would be glad to be alerted to geologic events of interest to post here! I hope that this blog can provide current event materials that will make geology come alive.

Banner image is by Ludie Cochrane..

Susan Kieffer can be contacted at s1kieffer at gmail.com

Monday, November 21, 2011

9,627 feet and counting--Shell sets new deep water drilling record.

Shell Oil has posted this graphic of the Perdido well compared to other
wells in the Gulf of Mexico. Note the progression from shallow to deep over
the past 30 years.
According to the Houston Chronicle, Shell Oil Company has announced that it is producing oil from a well 9,627 feet below the surface, drilling through 8,000 feet of water and another 1,627 feet of sediment and rock. This depth is more than six times the height of the Empire State Building.  The record broke the old record by 271 feet. BP and Chevron also have investment shares in this well (37.5% and 27.5% respectively). The well is 200 miles out in the Gulf from Houston. It serves three fields: Great White, Tobago, and Silvertip). At peak production, it can produce 100 kboe/d, which I assume means 100,000 barrels of oil equivalent per day. The Tobago field, where the record was broken, is the world's deepest subsea completion.

A major part of the Perdido "spar" was constructed in Finland, and it took an 8,200 mile journey to Texas over a three month period in 2008. The spar is 555 feet long, attached to the sea floor.  The drilling and production platform was constructed on top of the spar.  About 270 people live on the platform and an "adjacent floating hotel (a flotel)." There are 22 vertical access wells from the spar.

Equally impressive is that the well is several miles away from the Perdido drilling and production that serves it, and other wells that are up to seven miles away.  The oil has to flow along an incline on the sea floor before being pumped vertically to the platform. Shell says that the reservoir is a low-ressure reservoir which, I assume, means that it's mostly oil and not gas. The low pressure made it necessary for engineers to install a system of electrical pumps in the seabed to help get the oil to the surface, a technology that didn't exist when Shell purchased the lease in 1996.

A bit of an alarm bell went off when I got to the end of the article.  According to Don Van Nieuwenhuise of the University of Houston, producing from this depth is pushing up against the limits of safety equipment which is designed, only recently, to be used in up to 10,000 feet of water.  Well control equipment has been designed or redesigned for this limit in the aftermath of the Deepwater Horizon accident last year.  Ven Nieuwenhuise says "They are getting real close to the limit of what we can do safely." To which, the shell spokesman, Jaryl Strong, replies "There are a number of safety innovations built into the Perdido platform to accomodate the environment it is in, in terms of the great depths and long distance from shore. Safety was the No. 1 priority."

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