With the Deepwater Horizon rig six weeks behind schedule and millions over budget, BP made a number of decisions with the Gulf well that saved money, saved time, and set the stage for the disaster, according to an investigation by The Wall Street Journal.
Weeks ago, in Congressional hearings that President Obama called a "ridiculous spectacle," BP blamed the failed blowout preventer owned by Transocean, and Transocean blamed the cementing process performed by Halliburton.
But according to the Journal article, BP made several cost-cutting and time-saving decisions in its choice of well design, its preparation for cementing, its testing of the well after the cementing process was complete, and its decision to proceed with a risky method of finishing the well even after a pressure test revealed signs of "a very large abnormality," as described by a BP investigator's findings in a Congressional memo released earlier this week.
We've asked BP representatives for a response to each of these points and will update when we hear back. BP spokesman Andrew Gowers told the Journal that "safe and reliable operations remain a priority regardless of how much a well is behind schedule or over budget."
Bea, as part of the Deepwater Horizon Study Group, released a preliminary report summarizing his findings and listing several factors that led to the disaster. Among them: improper well design; improper cement design; early warning signs not properly detected, analyzed or corrected; and removal of drilling mud.
The Journal has more on each of these points.
On BP's cheaper well design:
The cement job was especially important on this well because of a BP design choice that some petroleum engineers call unusual. BP ran a single long pipe, made up of sections screwed together, all the way from the sea floor to the oil reservoir.
Companies often use two pipes, one inside another, sealed together, with the smaller one sticking into the oil reservoir. With this system, if gas tries to get up the outside of the pipe, it has to break through not just cement but also the seal connecting the pipes. This more typical design provides an extra level of protection, but also requires another long, expensive piece of pipe.
BP told the Journal that the company's engineers "evaluate various factors" to determine well design, and that this well design was not unusual.
On BP's preparation before cementing:
Halliburton, the cementing contractor, advised BP to install numerous devices to make sure the pipe was centered in the well before pumping cement, according to Halliburton documents, provided to congressional investigators and seen by the Journal. Otherwise, the cement might develop small channels that gas could squeeze through.
In an April 18 report to BP, Halliburton warned that if BP didn't use more centering devices, the well would likely have "a SEVERE gas flow problem." Still, BP decided to install fewer of the devices than Halliburton recommended -- six instead of 21.
BP told the Journal that it's still investigating how cementing was done.
On cutting short a "best practice" procedure, pre-cementing:
Before doing a cement job on a well, common industry practice is to circulate the drilling mud through the well, bringing the mud at the bottom all the way up to the drilling rig. This procedure, known as "bottoms up," lets workers check the mud to see if it is absorbing gas. If so, they can clean the gas out of the mud before putting it back down into the well to maintain the pressure. The American Petroleum Institute says it is "common cementing best practice" to circulate the mud at least once.
Circulating all the mud in a well of 18,360 feet, as this one was, takes six to 12 hours, say people who've run the procedure. But mud circulation on this well was done for just 30 minutes on April 19, drilling logs say, not nearly long enough to bring mud to the surface.
BP told the Journal that the amount of time spent circulating mud is "one of many parameters considered when designing a successful cement job," and that it's still investigating how cementing was done.
On skipping another test, post-cementing:
BP also didn't run tests to check on the last of the cement after it was pumped into the well, despite the importance of cement to this well design and despite Halliburton's warning that the cement might not seal properly.
BP told the Journal that the tests weren't run because cementing seemed to go smoothly, and the tests were only needed if the cement job showed signs of trouble. The Journal points out, however, that BP officials told congressional investigators on Tuesday that there were signs of problems with cementing.
And finally, as we've pointed out, in moving to finish the well, BP also -- after overruling Transocean workers and managers -- made the call to remove heavy drilling mud and displace it with seawater. It was a move that Transocean managers equated to "taking shortcuts," according to witness statements reported by The Associated Press.
The second half of the Journal's investigation ran today, focusing on the mayhem on the rig during the actual accident. It also features a slideshow at the bottom with a little about each of the Deepwater Horizon's 11 victims. It's worth checking out to remember the human cost of the accident, amid all the attention paid to the environmental.