[clim] Deepwater Horizon Mitigation and Impacts-What Can We Learn from Ixtoc I
Alvia Gaskill
IXTOC I
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Behavior of Oil
Bahia de Campeche, Mexico| Subject | Behavior of Oil |
|---|---|
| Posting Date | 1979-Jun-03 |
Prevailing northerly currents in the western Gulf of Mexico carried spilled oil toward the U.S. A 60-mile by 70-mile patch of sheen containing a 300 foot by 500 foot patch of heavy crude moved toward the Texas coast. On August 6, 1979, tarballs from the spill impacted a 17 mile stretch of Texas beach. Mousse patches impacted the shoreline north of Port Mansfield Channel on August 15 and again on August 18. On August 24, mousse impacted shoreline south of Aransas Pass. By August 26, most of North Padre Island was covered with moderate amounts of oil.
As of September 1, all of the south Texas coast had been impacted by oil. A storm lasting from September 13-15 removed the majority of the oil. For the remainder of the response and subsequent study period (through August 1980) only tarmats were observed on the beaches. Some oil escaped around boom barriers protecting the three major inlets. During the September storm, there was washing of oil over the Barrier Islands. Impacts to the estuaries were minor.
http://www.incidentnews.gov/entry/508790
Countermeasures/ Mitigation
Bahia de Campeche, Mexico
| Subject | Countermeasures/ Mitigation |
|---|---|
| Posting Date | 1979-Jun-03 |
In the initial stages of the spill, an estimated 30,000 barrels of oil per day were flowing from the well. In July 1979 the pumping of mud into the well reduced the flow to 20,000 barrels per day, and early in August the pumping of nearly 100,000 steel, iron, and lead balls into the well reduced the flow to 10,000 barrels per day. Mexican authorities also drilled two relief wells into the main well to lower the pressure of the blowout. PEMEX claimed that half of the released oil burned when it reached the surface, a third of it evaporated, and the rest was contained or dispersed. PEMEX contracted Conair Aviation to spray the chemical dispersant Corexit 9527 on the oil. A total of 493 aerial missions were flown, treating 1,100 square miles of oil slick. Dispersants were not used in the U.S. area of the spill because of the dispersant's inability to treat weathered oil. Eventually the OSC requested that Mexico stop using dispersants north of 25°N. In Texas, an emphasis was placed on coastal countermeasures protecting the bays and lagoons formed by the Barrier Islands. Impacts of oil to the Barrier Island beaches were ranked as second in importance to protecting inlets to the bays and lagoons. This was done with the placement of skimmers and booms. Efforts were concentrated on the Brazos-Santiago Pass, Port Mansfield Channel, Aransas Pass, and Cedar Bayou (which during the course of the spill was sealed with sand). Economically and environmentally sensitive barrier island beaches were cleaned daily. Laborers used rakes and shovels to clean beaches rather than heavier equipment which removed too much sand. Ultimately, 71,500 barrels of oil impacted 162 miles of U.S. beaches, and over 10,000 cubic yards of oiled material were removed. On August 8, the United States Fish and Wildlife Service (USFWS) began training volunteers for the handling of oiled birds and implemented beach patrols on South Padre Island. Bird cleaning stations were set up by the USFWS on Mustang and South Padre Islands. An overall decrease in bird population densities due to movement from their regular habitats along the oiled shoreline may account for the fact that only a few dead, oiled birds were ever found. After the beaches were cleaned, population densities increased, but not to expected levels. Contamination of food supplies caused many birds to leave their habitats for the duration of the spill. One thousand four hundred twenty one birds were recovered with oiled feathers or feet. The species suffering the most incidents of oiling were the Royal Terns, Blue-faced Boobies, Sanderlings, Willets, Piping Plovers, Black-bellied Plovers, and Snowy Plovers suffered oiling to their feathers while Great Blue Herons, Black-Crowned Night Herons, Noddy Terns, Cattle Egrets and Snowy Egrets had tarred feet.
http://www.incidentnews.gov/entry/508792
Other Special Interest Issues
Bahia de Campeche, Mexico
Subject Other Special Interest Issues Posting Date 1979-Jun-03 The U.S. government had two months to prepare for the expected impact of the IXTOC I oil on the Texas shoreline. During this time the government realized the importance of coastline mapping in regards to oil sensitivity. This led to a mapping project which resulted in the first Environmental Sensitivity Index (ESI) prepared by Research Planning , Inc. (RPI) under contract to The National Oceanic and Atmospheric Administration (NOAA). Placement of containment boom and other response equipment was done after study of the environmental sensitivity as reported in the ESI. The IXTOC I well blowout was an unusual situation with regard to responsibility for, coordination of, and control and cleanup of the spilled oil. The U.S. government publicly requested compensation from Mexico for damages associated with the spill without first entering into negotiations with the Mexican Government. Mexico denied being financially responsible for damages incurred, and refused to help pay cleanup expenses to the U.S. Officials reported that tourism along the Texas beaches dropped by 60% during the course of the spill.
From Wikipedia, the free encyclopedia
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This article needs additional citations for verification. Please help improve this article by adding reliable references. Unsourced material may be challenged and removed. (May 2010) |
| Ixtoc I | |
|---|---|
 | |
| Location | Bay of Campeche, Gulf of Mexico Campeche, Mexico |
| Coordinates |  19°24′30″N 92°19′30″W / 19.408333°N
92.325°W / 19.408333;
-92.325Coordinates: 19°24′30″N 92°19′30″W / 19.408333°N
92.325°W / 19.408333;
-92.325 |
| Date | 3 June 1979 – 23 March 1980 |
| Cause | |
| Cause | Wellhead blowout |
| Operator | Pemex |
| Spill characteristics | |
| Volume | 3,000,000 barrels (480,000 m3) |
Ixtoc I was an exploratory oil well in the Bay of Campeche of the Gulf of Mexico, about 100 km (62 mi) northwest of Ciudad del Carmen, Campeche in waters 50 m (160 ft) deep. On 3 June 1979, the well suffered a blowout and is recognized as the second largest oil spill and the largest accidental spill in history.[1][2]
Contents[hide] |
[edit] Accident
Mexico's government-owned oil company Pemex (Petróleos Mexicanos) was drilling a 3 km (1.9 mi) deep oil well, when the drilling rig lost drilling mud circulation. The Ixtoc I was being drilled by the Sedco 135, a semi-submersible platform on lease to Pemex. In modern rotary drilling, mud is circulated down the drill pipe and back up the casing to the surface. The goal is to equalize the pressure through the shaft and to monitor the returning mud for gas. Without the counter-pressure provided by the circulating mud, the pressure in the formation allowed hydrocarbons to fill the well column, blowing out the well. The hydrocarbons caught fire and the platform collapsed.
At the time of the accident Ixtoc was drilling at a depth of about 3,600 metres (11,800 ft) below the seafloor.[3] The day before Ixtoc suffered the blow out and resulting fire that caused her to sink, the drill bit hit a region of soft strata. Subsequently, the circulation of drilling mud was lost resulting in a loss of hydrostatic pressure[4]. Rather than returning to the surface, the drilling mud was escaping into fractures that had formed in the rock at the bottom of the hole. PEMEX officials decided to remove the bit, run the drill pipe back into the hole and pump materials down this open-ended drill pipe in an effort to seal off the fractures that were causing the loss of circulation.
During the removal of the pipe the drilling mud suddenly began to flow up towards the surface. Normally, this flow can be stopped by activating shear rams contained in the blowout preventer (BOP). These rams are designed to sever and seal off the well on the ocean floor, however in this case drill collars had been brought in line with the BOP and the BOP rams were not able to sever the thick steel walls of the drill collars leading to a catastrophic blow out.
The drilling mud was followed by a large quantity of oil and gas at an increasing flow rate. The oil and gas fumes exploded on contact with the operating pump motors, starting a fire which led to the collapse of the drilling tower. The collapse caused damage to underlying well structures. The damage to the well structures led to the release of significant quantities of oil in to the ocean.[3]
[edit] Aftermath
In the next nine months, experts and divers (including Red Adair[5]) were brought in to contain and cap the oil well. Approximately an average of ten thousand to thirty thousand barrels per day were discharged into the Gulf until it was finally capped on 23 March 1980.[6] Prevailing currents carried the oil towards the Texas coastline. The US government had two months to prepare booms to protect major inlets. Eventually, in the US, 162 miles (261 km) of beaches and 1421 birds were affected by 3,000,000 barrels (480,000 m3) of oil.[6] Mexico rejected US requests to be compensated for cleanup costs.
The oil slick surrounded Rancho Nuevo, in the Mexican state of Tamaulipas, which is one of the few nesting sites for Kemp's Ridley sea turtles. Thousands of baby sea turtles were airlifted to a clean portion of the Gulf of Mexico to help save the rare species.
HURRICANE IMPACTS?
I was also asked this weekend if a hurricane could carry the oil onto the land in reference to an article where this scenario was posited. My response:
Only from a storm surge. The evaporated water that makes up a hurricane is just that, water only. If a storm formed and came ashore where the majority of the slick is located, some of that oil could be carried inland for a few hundred feet, but it is more likely that the wind-driven waves from the storm would disperse the oil. The idea that the oil could reduce hurricane intensity is also ridiculous for the same reason. It would be dispersed as well by a storm passing through. The area covered by the slick is also too small to prevent or inhibit tropical storm formation in the Gulf of Mexico. You have no doubt seen the ribbons of oil on the surface, so the coverage is not uniform and thus there is ample surface area for evaporation to occur.
Track of Hurricane Bob, first data point is July 9, 1979. Ixtoc I is located SE of the first data point, near the land that is just above the I in Ixtoc. How far the oil sheen had spread at that point is unclear, but it did reach the Texas coastline in August.
Track of Hurricane Henri, September 15-22, 1979. Note that it seemed to wander all over the location of the spill,
Is it true that a hurricane could move the oil spill inland?
By Sherry Mann (about the author) Page 1 of 2 page(s)
opednews.com For OpEdNews: Sherry Mann - Writer
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