BP oil rig’s sinking and gushing crude raise questions

Many involve failed blowout preventer and how to stem unchecked flow of oil

Around 10 p.m. local time on April 20, the Deepwater Horizon — a floating oil-drilling platform leased to British Petroleum — suffered an explosion and fire about 40 miles off the Louisiana coast. While the aftermath of that devastating accident is now being observed and chronicled in painful detail, even the most basic features of what triggered it remain sketchy.

The platform belonged to Swiss-based Transocean, which bills itself as “the world’s largest offshore drilling contractor.” The huge floating facility had a crew of 126 at the time of the accident. Eleven men perished in the catastrophic blowout, including nine Transocean employees. A tragedy, by any measure.

The event also set in motion what may evolve into an epic environmental tragedy — one with huge costs measured in thousands of jobs, poisoned wildlife, an imperiled food supply, a setback for the Obama/industry plan to boost offshore drilling and a pervasive distraction from other pressing issues of the day. Clearly, plenty of people want to know what went wrong — not the least of which is why a failsafe “blowout preventer” system failed to do its job.

Next week, Congress will have its chance to grill oil-industry officials, when a House Energy and Commerce subcommittee investigates the companies’ safety measures and emergency responses. But a number of people within the industry are themselves speculating widely about the accident as well.

Among them: Mike Miller, chief executive officer and senior well-control supervisor at Safety Boss. Headquartered in Calgary, Alberta, his half-century old Canadian company specializes in fighting oil-well fires, blowouts, pipeline ruptures and processing-facility fires. He’s curious why BP rushed to put out the rig’s fires.

“At least while the rig was burning, all of the effluent from the well was coming to the surface and burning at the surface,” Miller notes. Indeed, burning oil — even on the sea surface — is an accepted spill-mitigation technique. So he’s puzzled why water boats were deployed to dowse the burning platform.

A mile down and out of sight
“What they did was fill the rig up with water. At which point it sunk,” Miller says — a full 5,000 feet to the seabed. And that, he maintains, violated “the first rule in offshore fire-fighting, which is not to sink the ship.” The reason: As soon as the rig submerged, it took down the riser pipe, which in this case was a 5,000-foot-long tethered straw through which the oil was gushing up from a reservoir 13,000 feet below the seafloor.

This riser didn’t just break loose and fall down when the platform sank: It crumpled. And where it suffered acute bends, it weakened, opening up at least two secondary gushers. So instead of having the oil coming out as a single fountain at the Gulf’s surface — one that people could reach — it’s now spewing from multiple holes in a damaged pipe nearly a mile beneath the surface.

Attempting to stem the flow from the seafloor plume by activating the malfunctioning blowout preventer “is like doing open-heart surgery at 5,000 feet [down] . . . in the dark, with robot-controlled submarines.” Or at least that’s the colorful picture BP America chairman and president Lamar McKay offered on ABC’s May 2 edition of This Week.

Also in that interview, McKay speculated that the accident had been triggered by some equipment malfunction. He was referring to that blowout preventer. Interestingly, Tony Hayward, BP’s group chief executive, was quoted in news accounts saying this device had been tested — and performed as expected — just days before the explosion.

Rep. Henry Waxman (D-Calif.), chairman of the House Energy and Commerce Committee, and Bart Stupak (D-Mich.), chairman of the House Subcommittee on Oversight and Investigations, jointly asked McKay and Transocean president Steve Newman in April 29 letters to “provide a copy of these inspection reports, as well as any reports of other inspections at the Deepwater Horizon rig, including all inspections of the blowout preventer.”

The congressmen also asked McKay and Newman to send along any documents, including internal memos, to explain why the Deepwater Horizon didn’t have a backup safety system called a remote-controlled acoustic shutoff switch for the drilling pipe. That backup is commonly used outside the Gulf, the congressmen say.

Notes Miller, offshore drilling in deep water — anything 1,000 feet and deeper — is a fairly new business. But as most known shallow oil deposits already have been tapped, oil-exploration operations have moved increasingly to more challenging sites. Some offshore wells are being developed to operate from platforms floating almost two miles above the seafloor. “There is a question of doing this now,” Miller argues, “simply because [these deepwater and ultra-deepwater wells] are so difficult to work on when things go wrong.”

If the blowout preventer valve can’t be activated, McKay has said BP will invest in an expensive pipe to drill into the bore hole that the Deepwater Horizon had been using. Mud and cement would be pumped into the hole plug the line and stop the gushers. It could take between two and three months to fabricate the line, get it to the site and insert it.

In the mean time, BP has promised to implement a temporary fix: the insertion of a “containment dome” over the major leak. It’s a huge conical device with a hole on top. Oil collected in it would be pumped to the surface.

In his This Week interview, McKay said the dome has already been fabricated, and efforts are underway to “get that mobilized and deployed. That will probably be in six to eight days.”

A fact sheet prepared for the official Deepwater Horizon Joint Information Center, a collaborative enterprise run by the federal government and industry, indicates that the heart of this collection system will be a 125-ton conical device that will be lowered over the largest source of gushing oil. A new riser pipe will connect the top to a surface ship — the Deepwater Enterprise. There, the extracted oil will be separated from water and natural gas. And then stored on that floating platform or an adjacent barge.

According to the fact sheet, this system “could collect as much as 85 percent of oil rising from the seafloor.” However, it also notes, “This is the first time this system will be used at this water depth.”

Even in shallower areas, such devices have a habit of underwhelming people, Miller says. “I’d be very surprised if they get even a minor percentage — say 10 percent — of the oil”

But we’ll all hope for the best because a lot of people and acreage stand to suffer mightily in coming months if these oil-containment measures don’t meet expectations.

Janet Raloff is the Editor, Digital of Science News Explores, a daily online magazine for middle school students. She started at Science News in 1977 as the environment and policy writer, specializing in toxicology. To her never-ending surprise, her daughter became a toxicologist.