Oil well that ends well

Closing the BP oil leak was a tremendous feat of engineering
August 19, 2010

The tactless remark made some weeks ago by former BP boss Tony Hayward that, given its size, the ocean would cope with the Gulf of Mexico oil slick, has turned out to be more or less correct. Predictions of devastation haven't come true. Yes, the spill is the worst in the history of the US, in terms of the volume of oil that spewed into the sea. But no, the Gulf shoreline hasn't turned into an oil-drenched mess of the kind we ignore in places like Nigeria. The US Fish and Wildlife Service has recorded fewer than 4,000 bird deaths from the spill. The Exxon Valdez disaster of 1989 may have killed 250,000. Meanwhile, the White House concluded on 4th August that almost three quarters of the oil spilled from the well had either evaporated, been burned, skimmed off, recovered from the wellhead or dispersed using chemicals; and much of the dispersed oil "is in the process of being degraded." By then, the US Environmental Protection Agency had ruled that BP's dispersants were not, as critics had claimed, even more toxic than the oil itself. And the gravity-defying "plumes" of oil said to be moving through the sea, bearing more devastation, haven't materialised, perhaps because they have already dematerialised: scientists cited by the White House say BP's oil is degrading very quickly. BP was lucky. The Exxon Valdez spilled less oil, but its crude oil was heavier, containing sulphur and other nasties, whereas the light, sweet crude which spewed into the Gulf evaporates more quickly and contains more water. The warm Gulf waters are also more conducive both to speedier evaporation of the oil and to the kind of insects that help degrade it. Lastly, the containment efforts after the Exxon Valdez spill were made more difficult by a storm that blew the oil along the Alaskan coastline and up onto its shores. BP, by contrast, faced relatively clement conditions as it deployed nearly 380 miles of booms to stop the oil from reaching beaches, while 830 skimmers scooped oil from the water. This story—of a successful response to a tragic accident—hasn't had as much attention as the earlier one, about big bad oil companies and their reckless ambition to defy nature. Armageddon is sexier. And BP didn't help itself—among other mistakes, it badly underestimated the volume of oil its well was spilling. This explains why we have heard relatively little about the extraordinary engineering feat required to kill the well. Drilling in deep water is difficult enough. But capping a gusher spewing 50,000 barrels a day of oil from a blown well 1,500m beneath the surface was an achievement far greater. At such depth, the pressure is more than 2,000lb per square inch. No human-operated submarine capable of carrying out repairs could descend so far. The "static kill" operation that finally sealed the well at the beginning of August, and the placing of a cap over the blowout preventer (the failure of which caused the accident) a couple of weeks earlier, were carried out using remotely operated vehicles (ROVs). These mini subs, connected by cable to a ship almost a mile above, are controlled by operators whose understanding of three-dimensional space and deep diving is only matched by their abilities with a joystick. Sometimes, BP had more than a dozen ROVs operating at once. And eventually, after weeks of work and many failed attempts, the remote controllers pulled it off, shutting the tap. In another context, the engineers and ROV operators would have been awarded medals. BP has already spent more than $6bn (£3.8bn) on the clean up, suspended a multibillion-dollar shareholder dividend and launched a fire sale of assets to raise cash for a $32.2bn liability fund. And its deep-water operations have become a symbol of an under-regulated, overambitious oil industry, content to take risks and cut corners in its search for black gold. But this view is loaded with hypocrisy. Oil companies operate in deep-water regions such as the Gulf of Mexico because governments sell them licences to do so. Indeed, the White House had opened new waters to the drillers just weeks before the Deepwater Horizon rig went down. The lax rules governing companies' operations in the Gulf weren't just the consequence of the authorities' "corruption," as President Obama described it. They were made lax to encourage oil companies to drill there, instead of spending their cash in another region of the world. And in any case, the companies spend billions of dollars drilling offshore wells because consumers reward them handsomely for the oil they extract.