The AMSER Science Reader Monthly aims to provide educators with a useful package of information about a particular topic related to applied math and science by combining freely available articles from popular journals with curriculum, learning objects, and web sites from the AMSER portal. The AMSER Science Reader Monthly is free to use in the classroom and educators are encouraged to contact AMSER with suggestions for upcoming issues or comments and concerns at [email protected].
This month's AMSER Science Reader Monthly topic is Unmanned Aerial Vehicles.
Gulf Oil Spill, Deepwater Disaster
Article
by Joel K. Bourne, Jr.
Synopsis and resource annotations by Max Grinnell
On April 20, 2010, the Deepwater Horizon drilling rig explosion set off a massive oil spill in the Gulf of Mexico that lasted three months. The resulting environmental damage was significant, and by the time the wellhead was capped, it was estimated that 4.9 million barrels of crude oil had been released into the Gulf. This thoughtful article by Joel K. Bourne, Jr. appeared in the October 2010 issue of National Geographic Magazine and it takes a close look at the likelihood of future oil disasters and the risks associated with deepwater oil drilling.
The article begins by describing the initial reaction to the Deepwater Horizon incident and then offers a brief summary of the challenges faced by those companies seeking to drill deep into the Gulf of Mexico for oil. Not surprisingly, the obstacles are significant, and they include deep canyons, ocean ridges, active mud volcanoes that are over 500 feet high, and temperatures ranging from near freezing to 400 degrees Fahrenheit.
Deepwater digging in the Gulf was not terribly common for decades, as the costs associated with such projects was prohibitively expensive. In 1995, the U.S. Congress passed a law forgiving royalties on deepwater oil fields leased between 1996 and 2000, and soon new rigs were popping up across the Gulf. By 1997, there were over 1,100 rigs extracting oil. One of the problems with the quick expansion in deepwater drilling was that methods for preventing blowouts and cleaning up spills for these massive new oil exploration projects were not sophisticated enough for the new conditions.
The article goes on to note that, by the early 2000s, scholars became concerned with the increasing reports from the oil industry of the increasing risk of deepwater blowouts and the fallibility of blowout preventers. A 2007 study from the Minerals Management Service (MMS) noted that only 39 blowouts occurred during the drilling of more than 15,000 oil and gas wells in the Gulf, and that few of these released much oil. However, this same report noted that there had been a significant increase in the number of blowouts associated with cementing - a process that involves pumping cement around the steel well casing to fill the space between it and the actual borehole.
This aspect of the report would have a direct bearing on the Deepwater Horizon project, as the article goes on to mention. By early April 2010, the project was six weeks behind schedule and this delay was costing BP more than $500,000 a day. BP had also chosen to drill in the most expeditious fashion, which in this case turned out to involve a "long string." This technique places two barriers between the oil and blowout preventer on the seafloor. One of these barriers was a metal seal, known as a lockdown sleeve, and it had not been installed when the well blew out. Additionally, congressional investigators and other professionals found that BP made significant shortcuts on this cement job; they failed to ensure that the cement had cured and sealed correctly nor did they test to make sure the cement had bonded properly. While each of these decisions may have been legal and cost effective, they each increased the risk of blowout.
The piece moves on to talk about the events on the night of April 20th, when things started to go very wrong at the Deepwater Horizon project site. For starters, a large gas bubble got into the casing and shot straight up. While the blowout preventer should have stopped the bubble from moving upwards, it did not. The device failed to function properly, and subsequent attempts to activate the preventer failed. The article then talks a bit about BP's recent corporate history, which involved the take-over of the companies Amoco and ARCO. After this merger, BP forced thousands of older and more experienced oil workers into early retirement. As a result, BP began to become more dependent on contractors for various areas of engineering expertise. The piece also goes on to note that the drilling operation was regulated by the MMS (which has since been renamed) and that this particular agency had not adequately reviewed BP's spill-response plan for the entire Gulf. Curiously, this plan had made mention of the minimal harm a spill would have to the creatures in the Gulf, such as walruses and sea otters, neither of which live anywhere near this particular body of water. And, just weeks before the spill, the federal government announced that there would be an expansion of offshore drilling. Of course, there was a moratorium placed on such projects after the Deepwater Horizon incident. BP was still in the process of cleaning up the spill as of August 2010 and by that point, the Deepwater Horizon spill had become the largest spill into the ocean, even larger than the Ixtoc I blowout in 1979 in Mexico's Bay of Campeche. The article describes the long-term effects of the Ixtoc spill on fisheries and the economy of the Bay of Campeche. Wes Tunnell, a coral reef expert at Texas A&M University points out that it is still easy to find oil remaining from the 1979 spill. A quote from local fisherman Gustavo Mateos Moutiel is also quite telling: "Urchins gone. Oysters gone. Conch gone. Fish almost all gone. Our families were hungry. The petroleum on the beach was halfway up our knees." It took 15 or 20 years for catches to return to normal, and by then most of the fisherman had found other jobs.
The piece ends with a bit of commentary from Florida State University oceanographer Ian MacDonald. Remarking on the sheer volume of spilled oil, he noted that the long-term effects on many creatures in the region could be tremendous. MacDonald expressed deep concerns about the bluefin tuna population in the region, which spawn only in the Gulf and in the Mediterranean. While only time will tell what will these long-term ramifications of the Deepwater Horizon spill will be for the Gulf's overall environmental health, some people would like to use this event to think about adopting greener and cleaner sources of energy.
Found below is a list of useful resources that will illuminate and enhance understanding of the topics found within this article. The first link will take users to a helpful educational resource created at Kennesaw State University that provides an introduction to the world oil market. The second link will whisk visitors to the P.O.R.T.S. project containing access to real-time oceanographic data. Moving along, the third link will take interested parties to the homepage of the Lophelia II, a ship that has been documenting the Gulf of Mexico over the past few years. The site includes a profile of the ship's investigations in and around the Deepwater Horizon site, which is well worth a look. The fourth link will take users to the website for the Office of Response and Restoration at the NOAA's Ocean Service. The site includes information on historic oil spills, along with photographs and other documentation. The fifth link takes users to a helpful teaching activity that helps students learn about the long-term effects of major oil spills. The final link leads to a resource provided by the WGBH Educational Foundation that uses animations and other materials to help students learn about the effects of oil spills.AMSER Science Reader Monthly is published by Internet Scout at the University of Wisconsin-Madison in conjunction with the National Science Digital Library with funding from the National Science Foundation. If you have questions or suggestions please e-mail us at [email protected].