BP Deepwater Horizon Blowout Summary – Best Current Understanding

Posted: May 31st, 2010 by: h-2

Here’s the latest summary of ROCKMAN’s best current understanding of the events that led up to the BP Deepwater Horizon blowout. As usual, this was embedded deep inside the current theOilDrum.com blowout comment thread, but it is clear and concise enough to give a good overview of the information we now have that seems reasonably solid.

ROCKMAN on May 31, 2010 – 9:11pm Permalink | Subthread | Parent | Parent subthread | Comments top

Winter — I’ll use your question to give a brief summary, with the permission of the editors, for the benefit of the newbies who seem to be showing up hourly.

Above all else this tales goes with a very BIG IF: if we have a accurate picture of how the incident began then here goes: they had run production casing from total depth back up to the well head/BOP. Cement was pumped down the drill pipe to the bottom of this casing and forced back up between the csg and the rock. The reason for this cmt job is to isolate the oil reservoir. This cement seal would be the only barrier preventing the well from “coming in “ (flowing oil/NG up the csg). Prior to pumping the cmt the weight of the drilling mud kept the reservoir from flowing up. The backpressure stopping the flow was a result of an 18,000’ column of heavy drilling mud.

Before temporarily abandoning the well BP was required for safety reasons to set a series of cement plugs in the production csg to ensure the reservoir would not leak to the surface until they were ready to produce the well. To make the eventual re-entry of the well easier BP “displaced” the riser (that 20” tube that connected the well head/BOP to the drilling rig on the surface of the GOM) with seawater and thus removing the heavy drill mud from the well. But they did this before setting the top cmt plug which would have kept any oil/NG from flowing up should the csg cmt fail. This is why testing the validity of the cmt job was extremely critical: the column of seawater could not produce a sufficient backpressure to prevent the oil/NG from rushing to the surface. If the cmt didn’t hold there was a 100% certainty of the well flowing oil/NG. There has been much discussion about the interpretation of the tests conducted on the cmt, the nature of the cmt, who has ultimate responsibility for certifying the cmt job. Likewise the reason for waiting to set the top cmt plug until after displacement has been speculated by others. I’ll leave those debates to others. But a good cmt job wasn’t the last safeguard.

There is a standard procedure for determining if a well is flowing. The same protocol for a cased hole as when drilling. I don’t know for a fact but I wouldn’t be surprised if this procedure had been done more than 100 times as this well was being drilled. The mud pumps on the rig push drilling mud down the drill pipe, which then returns to the surface between the drill pipe and the csg or open hole. Though this will sound simplistic this is the primary method to tell if a well is kicking (flowing): you shut the mud pumps off. For oil/NG to flow to the surface it has to push the mud out of the hole ahead of it. If you turn the pumps off and the mud stops flowing out you have a static well. If the mud continues flowing out the return line the well is coming in and a blow out is on the way unless you stop this flow. In addition to visually seeing the mud flowing out, there are various mud tanks that have the mud flow volume measured automatically.

Again, IF we have the correct story, the mud returns were not being monitored. I’ll leave the details of why they weren’t monitoring the mud returns to others. Why the cmt failed is a separate issue from not monitoring the mud returns. Had they seen the mud flowing they could have shut the well in (closed all the return valves on the rig). The oil/NG might have still flowed all the way up but it would have not escaped to the drill floor and exploded. Killing a shut in well is a standard procedure and practiced often. Once the well was shut in they could have replaced the light seawater with heavy drilling mud via the drill pipe and stopped the flow of oil/NG from the reservoir. But they did not become aware of the well coming in until it as too late.

The failure of the BOP to stop the blow out is a completely separate issue I’ll let others expand upon. Likewise with the various efforts to stop the blow out and collect the oil spill.

As usual the rest of the TODers are free to add, modify and adjust this summary. My hope was to reduce some of the redundency required to bring our new memebers up to speed.
GregTX on May 31, 2010 – 10:10pm Permalink | Subthread | Parent | Parent subthread | Comments top

What strikes me about all those issues is apparently no one raised an issue with the cure time or the lack of a CBL or number of centering devices, etc. They all trusted that they had the well under control. Disagreement apparently was around the negative test, but it was done. I agree that all of these decisions may have been tragic errors. I’m still not convinced there was anything criminal or negligent about them.

ROCKMAN on May 31, 2010 – 10:41pm Permalink | Subthread | Parent | Parent subthread | Comments top

Greg — I agree with your sentiment in general. But IMHO opinion not checking for mud flow is always negligent. And I would deem it so even if it weren’t a critical stage. When I’m drilling I make sure flow is checked even when we stop pumps to connect a new joint of drill pipe. Even if there’s nothing to be concerned about. I’m not the only one. But attitudes vary. The most important take away about checking for flow is that it costs nothing to do. CBL’s, pressure tests, BOP tests, etc all cost rig time and thus cost money. Checking for flow while displacing would have taken one hand watching the mud pits. You know I like simplistic examples: checking for flow is no different then clicking your seat belt when you get into your car. Might seldom need it but when you do there is no substitute.

GregTX on May 31, 2010 – 10:57pm Permalink | Subthread | Parent | Parent subthread | Comments top

I’m still unclear if they noticed mud returns and were initially unconcerned, failed to watch excessive mud returns or were watching mud returns, saw what was happening and tried to reverse the seawater displacement and then something happened (why did the mud pumps stop?) and then they were hosed?

In any case, assuming they were not watching mud returns, I guess you have to distinguish between best practice (before the accident) and ordinary practice (before the accident) and base their judgement not on what the most conservative practices were, but what the most reasonable liberal practices were to determine negligence (I could be persuaded to believe simple negligence in not following best practice, but would be very skeptical about going after them for gross negligence let alone criminal gross negligence if industry failed in general to see the critical importance of watching mud returns during the plugging stage).

I would expect that this is a wake up call to industry to change their minimal practices (if that is what BP was doing), but nailing the first one caught with an excessive penalty and letting the rest slip by would do no one any favors. Find and fix the root cause rather than just fight the symptom.

I wish I was able to watch all of the interviews and understand what happened. Has the site posted a link to archived videos of the MMS Invetigation? I’ve missed about half unfortunately (damn job getting in the way).

ROCKMAN on May 31, 2010 – 11:14pm Permalink | Subthread | Parent | Parent subthread | Comments top

Greg — the story line is that they were distracted with shuting down ops and offloading mud. To be honest that has been total supposition as far as I can tell. But I know what it’s like on a rig at that point and it is plausible. I think we’ll have to wait for the formal investigation to get confirmation. But I would readily bet you lunch that checking flow is being beaten into every drill crew in the USA on every rig every day. But it’s SOP for some of us. I mentioned the other day about an 18,000’ well in the La. bayous last January. I had flow checked on every connection. And double-checked b a second hand. And then had it triple checked personally by the company man. I’ll confess I’m not perfect. But I try to be.
Mad Dog on May 31, 2010 – 10:51pm Permalink | Subthread | Parent | Parent subthread | Comments top


My understanding (third hand from inside BP) is that the plan was to run the CBL with the completion rig. If true, this would not be unusual as there is normally a specialist switch from open hole logging to cased hole logging and for better or worse (much worse in this case) this is normal in many cases. I wasn’t there but if there were any doubts as to the cement job, pressure tests, etc. it would be a no brainer to fix the problem before T&A. I noted in a previous post my suspicions concerning why they ran a tapered string and not simply a 7″ liner and tieback. (I suspect it was perceived to be a more cost efficient method.) The small volume of cement and long trip down the hole plus a less than ideal cement plug arrangement that had to wipe both casing sizes is more apt to allow mud to bypass and contaminate this small volume in the 9 7/8″ casing. The ECD would have all been reduce thereby reducing losses, etc. etc. In addition you could have run a liner top packer for an extra barrier to flow. The engineering just cascades.

Apologies for the lengthy snippets, but this answers the questions quite well.

But overall, I’m glad at least one person in this discussion has the ability to question these events on a more macro level, because the macro level is where this problem originates:

wilis_newton on May 31, 2010 – 9:43pm Permalink | Subthread | Parent | Parent subthread | Comments top

No, you do not ROCK. Sorry, I am sure they work hard and master a lot of skills but people who deserve our admiration work for change and the future, in my opinion and RISK things like their livelihood and reputation when they stand up to power and demand that corners not get cut. I think when we learn more it may be possible that there were some, like possibly men from Schulumberger who tried to make a stand but in the end it was “the BP way or the highway” and they wisely choppered off the DWH after objecting to the lack of testing that was going on as BP rushed to complete the well.

Jimmy Harrell of transocean objected in a meeting to the bad drilling practice but ultimately bowed to pressure. Had he not, I am sure he felt he would have been replaced anyway. This is the current culture at which the oil and gas industry works, and it is a bad culture. It led directly to this disaster, and the supposed live cam you are impressed with is showing to me proof that things are rotten down there and topsides, too. We know already from sworn testimony that plenty of people screwed up bigtime. I won’t get into it here, but you need to realize that MAJOR mistakes were made and they were human error and BAD drilling practice. It’s been written about elsewhere.

Yes, the ROV people have skills. Too bad they are not applying them for science, instead of mitigating man made disasters of biblical proportions caused by greed and stupidity.

As for reputations, one BP company man has already pled the fifth and the other called in sick when asked to testify by the coast guard. If I had to characterize thier reputation I would have to use words you can’t print in a newspaper, and end with the words incompetent and cowardly. I could list their names, they are a matter of public record but it is their bosses that are ultimately culpable. Criminal charges can and should be filed here and these people and their bosses (especially their bosses) deserve a day in court to defend themselves but also deserve justice in the form of lengthy prison terms if it is proven that they did the things they are already admitting to, more or less.

Don’t get me started on the culture of the regulatory side of the industry either, it is almost suppertime and I might get sick.

Please explain further what is unfair about BP’s reputation being ruined. I don’t see it. A fish rots from the head.

Yes indeed. Maybe it’s time to take a closer look at that greed, which would be the primary and sufficient cause of the ensuing stupidity, so I see little need to focus on anything other than the greed part in this case. And maybe also consider just why we have come to think that it’s OK to destroy our only ecosystem, with barely a thought about it as we engage full speed ahead, pausing only when utterly shocked by some extreme event like BP Deepwater Horizon or Chernobyl or Three Mile Island. Or the Santa Barbara blowout. Or the Ixtac blowout… oh, wait, that list is pretty long, and that’s only the biggest events.

Or check out Clouds of Undersea Oil Drifting Through Gulf May Cause Oxygen `Dead Zones’ from our friends at Bloomberg.com.

“There is great, great concern of the subsurface nature of this event, of the amount of dispersants and what this means to the entire ecosystem,” Roger Helm, Chief of the U.S. Fish and Wildlife Service Division of Environmental Quality, said at a press conference. “This is going to be groundbreaking science.”

A government team appointed by the Coast Guard estimates oil has been spilling from the well at a rate of 12,000 to 19,000 barrels a day. That could increase as much as 20 percent when BP makes its next attempt to control the leak by sawing off a damaged pipe. Within the week, BP plans to reconnect the pipe and funnel oil to a ship on the surface.
The millions of gallons of oil leaking from a broken well a mile under the Gulf of Mexico may create oxygen-depleting dead zones below the ocean, killing sea life and upsetting the region’s ecology for decades, scientists say.

Oops. You know, I have to admit, I always prefer using financial media sources because then people reading this will have a harder time denying reality by the typical knee-jerk ‘oh that’s a liberal media outlet’ pavlovian response… and of course, for those who think Fox news is news, well, pretty much everything rational is going to seem like a liberal conspiracy, so there’s not much point in trying to learn or discuss facts when ranting and fantasy seems to be so much more satisfying.

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