Investigations

BP Canceled a $128,000 Safety Test on the Well to Save Time. Eleven Hours Later, It Blew Out and Killed Eleven Men.

At around 11:15 a.m. on April 20, 2010, a Schlumberger logging crew packed up its equipment and left the Deepwater Horizon by helicopter. BP had flown them out to the rig four days earlier to run a cement bond log, the only test that could confirm whether the cement sealing the bottom of the Macondo well had actually worked. Running it would have cost BP roughly $128,000 and taken nine to twelve hours. Canceling it, and paying Schlumberger a standby fee instead, cost about $10,000. BP canceled it.

Eleven hours later, at approximately 9:49 p.m., the Macondo well blew out. Gas roared up the riser and ignited on the rig floor, killing 11 of the 126 people aboard and injuring 17 more. The Deepwater Horizon burned for 36 hours before it capsized and sank on April 22, rupturing its riser pipe on the way down and opening a wound at the seafloor that would empty an estimated 4.9 million barrels of oil into the Gulf of Mexico over the next 87 days — the largest marine oil spill in history. The well belonged to BP. The rig belonged to Transocean. The cement belonged to Halliburton. All three companies had made decisions, documented in writing, that a subsequent presidential investigation would trace directly to the blowout.

The Cheaper Well Design

BP had a choice of how to finish the Macondo well. It could run a "long string" of steel casing straight from the bottom of the well to the wellhead — cheaper, faster, and requiring fewer barriers between the reservoir and the rig. Or it could use a liner tied back to the wellhead, which added a mechanical barrier but cost more and took longer to install. BP chose the long string.

Halliburton, hired to cement that casing in place, recommended using 21 centralizers to keep it positioned evenly in the wellbore, warning that fewer risked channels forming in the cement that gas could later travel through. BP had only six centralizers of the correct type on hand and decided not to fly out the other 15. A BP drilling engineer, Brett Cocales, wrote in an internal email on April 16 — four days before the blowout — that using six instead of 21 "will probably be fine," adding: "who cares, it's done, end of story, will probably be fine." Another BP email that week described Macondo as "a nightmare well which has everyone all over the place."

The well was, at the time of the blowout, 43 days behind schedule — costing BP an estimated $21 million in rig leasing fees alone.
Halliburton's own internal testing in February 2010 had found the specific nitrogen-foam cement slurry planned for Macondo was unstable. It was used anyway.
BP's well team believed, incorrectly, that the 15 additional centralizers sent to the rig were the wrong model, and discarded that option rather than resolve the confusion.

The Test Nobody Ran, and the One Nobody Read Right

The cement bond log wasn't the only checkpoint that went badly on April 20. Later that evening, the crew ran a negative pressure test, designed to confirm the well was sealed by simulating the pressure it would face once drilling mud was removed. The test produced a result nobody could explain away cleanly: pressure on the drill pipe read as high as 1,400 to 1,500 psi, when a successful test should have shown zero. Rig personnel and a BP well site leader eventually accepted an explanation — a "bladder effect" in an auxiliary line — that let them declare the test a success and move on. Neither the on-duty crew nor the site leaders checked the rig's own blowout preventer pressure sensors, which independently showed the same anomaly.

The National Commission on the BP Deepwater Horizon Oil Spill and Offshore Drilling later concluded that the well could have been shut in safely at multiple points that day, including after this test, had the anomalous readings been correctly interpreted.

A Blowout Preventer That Did Not Prevent the Blowout

The Deepwater Horizon's last line of defense was a stack of valves on the seafloor called a blowout preventer, built to shear through the drill pipe and seal the well in an emergency. When the crew triggered it during the blowout, it failed. A later forensic analysis, commissioned as part of the investigation, found the drill pipe had buckled off-center under the force of the surging gas and fluid, placing it outside the reach of the blind shear ram meant to cut it. The device's control system also relied on a single 27-volt battery to power redundant control channels that were supposed to be independent of each other.

Eleven men died on the rig floor and in the accommodations block that night: Jason Anderson, Aaron Dale Burkeen, Donald Clark, Stephen Curtis, Gordon Jones, Roy Wyatt Kemp, Karl Kleppinger Jr., Blair Manuel, Dewey Revette, Shane Roshto, and Adam Weise. None of their bodies were recovered.

Eighty-Seven Days, 4.9 Million Barrels

With the blowout preventer inoperable and the riser severed, oil and gas flowed unchecked from the seafloor for nearly three months. BP tried a top hat, a top kill, and a containment dome before a capping stack finally shut in the well on July 15, 2010. A relief well intercepted Macondo in September, and on September 19, 2010, federal officials declared the well "effectively dead" after cement pumped through the relief well sealed it permanently.

The federal government's final estimate put the total discharge at 4.9 million barrels, with roughly 800,000 barrels captured directly at the wellhead before reaching open water.
Responders applied 1.84 million gallons of Corexit dispersant — 1.07 million gallons sprayed on the surface and 771,000 gallons injected directly at the wellhead, the first time dispersant had ever been applied at that depth. It remains the largest dispersant application in U.S. spill history.
A federally funded study of cleanup workers later found that those with heavier exposure to oil and dispersant reported higher rates of coughing, wheezing, and skin and eye irritation than those with less exposure.

"I'd Like My Life Back"

BP's chief executive, Tony Hayward, spent the summer of 2010 narrating the spill in ways that did not go over well. Asked about the disaster by American television in late May, he said: "There's no one who wants this over more than I do. I'd like my life back." He later apologized, calling it "a hurtful and thoughtless comment," and said he was "appalled" when he read it back.

Three weeks later, on June 19, with oil still gushing into the Gulf, Hayward was photographed at the JP Morgan Asset Management Round the Island Race off England's south coast, aboard his 52-foot yacht, named Bob, which finished fourth in its class. That same week, BP's chairman, Carl-Henric Svanberg, emerged from a White House meeting with President Obama and told reporters, "We care about the small people." He later apologized for the phrasing.

BP announced on July 27, 2010, that Hayward would step down "by mutual agreement." He was succeeded by Bob Dudley on October 1 and moved to a post at BP's Russian joint venture, TNK-BP.

The Bill

BP's stock fell 55 percent between April 19 and June 25, 2010, wiping out roughly $90 billion in market value, and the company suspended its dividend that June. It took a $40.9 billion charge against 2010 earnings and posted a $3.7 billion annual loss, against a $16.6 billion profit the year before.

In November 2012, BP pleaded guilty to 14 criminal counts, including 11 felony counts of manslaughter, one felony count of obstructing Congress, and environmental crimes, agreeing to pay $4 billion in criminal fines and penalties — at the time the largest criminal resolution in U.S. history. Transocean pleaded guilty to a Clean Water Act violation in 2013 and paid $1.4 billion in combined civil and criminal penalties. Halliburton pleaded guilty to destroying evidence — deleting results of its own post-spill cement tests — and paid the $200,000 statutory maximum fine for that misdemeanor, separately settling private claims for $1.1 billion. In 2015, BP agreed to pay $20.8 billion to resolve federal and state civil claims, the largest environmental settlement in U.S. history. BP's own accounting put its total spill-related costs at roughly $65 billion by 2018.

BP's two on-site well site leaders, Robert Kaluza and Donald Vidrine, were indicted on manslaughter charges in 2012. A judge later dismissed most of the counts against them; prosecutors dropped the remaining charges against Vidrine, and Kaluza was acquitted at trial in 2016. No individual has served prison time in connection with the 11 deaths.

What the Commission Found

The National Commission, in its January 2011 final report, wrote that the Macondo blowout was not the result of one company's isolated mistake but of "a series of identifiable mistakes made by BP, Halliburton, and Transocean that reveal such systematic failures in risk management that they place in doubt the safety culture of the entire industry." It found industry management was, on the whole, more concerned with cost and schedule than with the risks it was managing, while federal regulators had largely deferred to the industry rather than independently verify its judgment. The blowout, the Commission concluded, was preventable.

BP's 2010 annual report, published the following spring, described the company's priority as always having been "no accidents, no harm to people." The cement bond log that would have tested that priority against $128,000 sat unrun in a report BP never had to write, on a well BP's own engineer had already called a nightmare.

Filed from public reporting:

BP Canceled a $128,000 Safety Test on the Well to Save Time. Eleven Hours Later, It Blew Out and Killed Eleven Men.

The Cheaper Well Design

The Test Nobody Ran, and the One Nobody Read Right

A Blowout Preventer That Did Not Prevent the Blowout

Eighty-Seven Days, 4.9 Million Barrels

"I'd Like My Life Back"

The Bill

What the Commission Found

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