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On 16 April, 2010, a BP manager emailed, ‘Who cares, it’s done, end of story, will probably be fine.’ He was talking about the decision to cut corners when cementing shut the newly drilled pipe into a deep undersea oil reserve beneath the Gulf of Mexico, ready for later opening. He was utterly wrong. It was the start of the story, it was not fine, and a lot of people care very much.
The huge pressures in the oil reserve proved too much for the skimped back-up systems. On 20 April, methane gas powered its way up the pipe to BP’s Deepwater Horizon drilling rig and exploded catastrophically, killing 11 people.
Soon oil was pouring out from the seabed. First estimates suggested that it was 1,000–5,000 barrels a day. But as attempt after attempt to cap the gush failed, and other experts chipped in with advice, BP were forced to revise the figure upwards dramatically. By mid-September, when the crisis was finally ended with the drilling of a relief well to take the pressure off an emergency cap dropped into place in June, over 4 million barrels may have gushed out – 13 times as much as the 1989 Exxon Valdez disaster in Alaska. Although the surface oil quickly dispersed, it had already had a devastating effect on Louisiana coastal communities and marine life.
oil at Sea
The irony was that, a few weeks previously, US president Barack Obama, bowing under pressure to satisfy America’s voracious need for cheap oil, had given the go-ahead for further drilling in the Gulf, saying, ‘oil rigs today generally don’t cause spills.’
When his words came back to haunt him, it is no wonder he was enraged. Yet he was partly right; until recently, oil rigs were involved in only a few spills. Most major spills are from oil tanker groundings or broken pipelines – although even these account for only a tiny portion of oil leaking into the ocean (see page 90). Tighter regulations and the wider use of double hulls to prevent breaching in case of accidents have actually been bringing down the number of bad spills dramatically. In the 1970s, there were more than 25 major spills a year, but in the last decade there were barely three. In 2008 there was just one, and in 2009 there were none at all.
Yet, just as tanker spills are declining, so the unstoppable demand for oil pushes companies to drill offshore in evermore extreme conditions. The risk of blowouts like the Deepwater Horizon may be increasing. In 2009, Australia suffered one of its worst oil disasters at the Montara rig in the East Timor Sea. There is also a concern that if, in the aftermath of Deepwater Horizon, drilling in the Gulf is restricted, oil companies will satisfy demand for oil by drilling out of sight of the media in places such as Nigeria, where lack of regulation mean the oil industry has already brought human and ecological tragedy. after the Spill
When oil is spilled from tankers at sea, most floats out in a slick that thins to a rainbow-coloured sheen as it spreads. Creatures that touch the surface – birds and mammals – are the most obvious victims. The oil gets in birds’ feathers, for h After the explosion on the Deepwater
Horizon rig on the 20th April 2010 which claimed the lives of 11 men, firefighters battled to put out the fire for more than a day before the rig finally sank.
151 g This brown pelican was just one of the many bird victims of the Gulf oil
spill along the Louisiana coast. Even if the bird was cleaned by rescue workers, it would soon have died from ingesting the toxic oil.
instance, making it impossible for them to fly. Worse still, as they try to get clean, they ingest the oil and toxic substances and this causes fatal liver failure. After an oil spill, desperate attempts are made to clean oiled birds, but most cleaned birds die from the toxins within a few days of being released.
The clean-up process may be more damaging than the oil itself. After the Exxon Valdez disaster, the worst damage to shore life was caused by steamcleaning the shore, effectively rendering it sterile. Similarly, chemical dispersants may appear to clean the sea by breaking the slick into globules that sink out of sight, but they add toxic chemicals to the water, which can do more harm than the oil. With the Gulf spill, 3 million litres (800,000 gallons) of dispersant were poured on and into the sea in an attempt to stop oil reaching the surface and the shore. Dispersants have never been used in this volume before, and they include Corexit 9527, which is toxic to marine life.
Ten Worst Oil Spills At Sea
Disaster Location Date Volume in barrels
Gulf War oil spill Persian Gulf 19–28 January, 1991 6,000,000–8,000,000 Deepwater Horizon Gulf of Mexico, uSA 20 April, 2010– 15 July, 2010 4,100,000–4,300,000 Ixtoc I Gulf of Mexico, uSA 6 June, 1979– 23, March 1980 3,329,000–3,520,000 Atlantic Empress Trinidad and Tobago 19 July, 1979 2,105,000
Nowruz field Platform Persian Gulf, Iran 4 february, 1983 1,907,000
ABT Summer Angola, offshore 28 May, 1991 1,907,000
castillo de Bellver South Africa, Saldanha Bay 6 August, 1983 1,848,000
Amoco cadiz france 16 March, 1978 1,635,000
Haven Italy 11 April, 1991 1,056,000
Odyssey canada, off Nova Scotia 10 November, 1988 968,000
The combination of coagulated oil globules from dispersed oil and gushing oil held underwater by deep-water pressures is thought to have created underwater plumes and clouds. These may be devastating for huge numbers of marine creatures that swim into them, or seabed life as they settle in the water. Also, plankton and shrimp coated in oil and the toxic chemicals will be eaten by fish, thereby passing the effect up the food chain. Worryingly, these plumes fell on fish spawning grounds at a crucial time, and might be the death knell for the endangered Atlantic bluefin tuna, which spawns exclusively in the Gulf.
There is a temptation to blame corporate greed and carelessness for oil spills, and it is true that the treatment of the environment by the big oil companies around the world has often been shockingly cavalier – especially out of sight of the world’s scrutiny in the world’s poorer countries. But maybe ultimately the problem lies just as much with our unquenchable thirst for cheap oil.
The oil from the Deepwater Horizon spread far and wide over the waters of the Gulf. The floating surface oil actually dispersed quickly but it remains to be seen what effect the denser oil below the surface will have.
fLOrIDA Tampa St. Petersburg
Jacksonville
240 km (150 miles)
Oil on surface Extent of oil Panama city
Source of leaking oil
G u l f o f M e x i c o