Gulf oil spill update: Top kill maneuver

A frame grab, taken from a BP live video feed, shows activity during the
A frame grab, taken from a BP live video feed, shows activity during the "top kill" procedure to stop the flow of oil from the Gulf of Mexico oil well May 26, 2010. BP Plc launched an ambitious deep sea operation to choke off a gushing oil leak in the Gulf of Mexico on Wednesday, but President Barack Obama cautioned Americans there was no guarantee it would work. (Reuters)

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Greg McCormack
Director, Petroleum Extension Service, University of Texas
Thursday, May 27, 2010; 1:00 PM

The top kill is underway, success uncertain. BP engineers are pumping mud at a furious rate into the damaged blowout preventer that sits on the uncapped well at the bottom of the Gulf of Mexico. The hazardous-but-high-reward maneuver comes five weeks into the oil spill crisis amid an intensifying atmosphere of political recrimination that has spread from the Gulf Coast to the White House and Congress.

Photo Gallery: Oil spills throughout history

Greg McCormack, director of the Petroleum Extension Service at the University of Texas at Austin, was online Thursday, May 27, at 1 p.m. ET to discuss the latest attempt to cap the well and whether he thinks it will work.


Greg McCormack: Hi I am Greg McCormack, Director of the Petroleum Extension Service the University of Texas we are following the activities in the Gulf of Mexico and I am here to explain the Top Kill Operation.

Greg McCormack: Publish


Silver Spring, Md.: Soaking up oil: Whenever I am changing my oil in my car I make certain that I have a bucket of sawdust around (I am a woodworker). When I knock over the old oil from my car, I just throw a few scoops of sawdust on it. It is immediately soaked up the oil and then I scoop it up with a dust pan -- problem resolved. It works. There are millions of cubic yards of sawdust available from lumber mills, furniture makers, etc. Has anybody suggested this. If interested, I can demonstrate or just try it yourself. This oil/sawdust could be disposed of by incinerating or easily hauled away.

Greg McCormack: The sawdust will absorb water as well as oil so it is not as effective as the synthetic material that preferentially absorb oil.


Denver, Colo.: I'm trying to understand the logic behind the complaints that BP isn't doing enough. This is such a major PR disaster for them -- their name is going to be associated with Oil Spill for decades to come, like Exxon. What possible business reason would there be for them not to be doing everything possible to stop the leak and clean stuff up?

Greg McCormack: I think that we all agree that this is a major disaster. BP mobilized a very large task force of technical people from around the world from every major oil company. They are trying very hard to come up with a solution without making it worse. They are analyzing, constructing and deploying at an amazing rate.


Baltimore, Md.: I find it a bit amusing that once it was announced that the "top kill" had worked, all the live camera feeds that a multitude of Web sites were showing live, suddenly ceased. At least I can't find one anywhere to save my soul. So what is this: some "conspiracy" to divert attention from what could be an incomplete success, or just a stupid media mindset of "no drama? Nothing to see here, move along, folks...."????

Greg McCormack: There are multiple web sites showing the live feed. Because it is streaming they occasionally go down or stop showing the video.

I wouldn't say that the top kill is a success. we wont know that for at least another day.


Downingtown, Pa.: I'm unclear on how extensive the cement plug will be. Will it extend from near the sea floor to deep below? Or will it be at the base of the drill casing and extend upward? Perhaps a related question: How significant is the risk that hydrocarbons will bypass the plug and find a way to the sea floor?

Greg McCormack: The plug will extend down from the blow out preventers to some point in the well. BP will have to be very careful during this time that they do not cause the well to flow again.


Newport Beach, Calif.: Why are U.S. deep water drillers not required to drill a relief well at the same time the drill the initial well? I understand this is a requirement in other countries including Canada. Wouldn't that have prevented much of this disaster?

Greg McCormack: I am not aware of any countries that require a relief well be drilled concurrently with the proposed producing well. Which well is then likely to blow out?


Bowie, Md.: Without human intervention, what will ultimately happen to the oil that's been spilled? Will it eventually evaporate; dissolve; sink to the bottom?

Greg McCormack: Oil in the Gulf Of Mexico will be ultimately degraded by the weather, processed by naturally occurring bacteria which live on organic matter and some will sink to the sea floor. There are approximately 500,000 to a 1,000,000 bbls of oil a year natural "seeping" into the Gulf of Mexico which have allowed carbon loving bacteria to thrive and grow.


Laurel, Md.: The United Kingdom produces a lot of petroleum from the North Sea. Is it BP doing that, too? If their environmental practices are consistent, is that region at as much risk as our Gulf?

Greg McCormack: The North Sea is in production decline and there is not a lot of drilling underway. I believe that when all of the facts are known changes will be made in deep water drilling to make it safer. The industry right now is under tremendous scrutiny and all safety issues are being emphasized and re-emphasized.


Arlington, Va.: It sounds to me like BP is just grasping at straws. They want to appear to be doing something, but they really know that the oil is going to continue to flow for several more months until the alternate well is drilled.

Greg McCormack: The technical challenges that BP are faced with today have never been faced with before. While it looks like they are trying fixes that don't work they have to be very careful not to make the situation worse.


Rockville, Md.: Our popular image of a land-based oil well is that it starts with a gusher spraying out the top of a rig. How are offshore wells initially dug in order not to leak in the first place?

Greg McCormack: If you have a gusher you have a blow out and that is not good. Oil wells both on land and on water rely on the weight of the drilling mud to keep the oil and gas within the rock formation until the well is completed and then put in production.


Brooklyn, N.Y.: One thing I have never understood about the spill is that it is apparently an 'exploratory' well. It seems to be an awful lot of oil for a non-production well. Did they just hit too much oil that had more pressure than the well could handle?

If this were a full production well that had ruptured how much worse would the disaster be?

Greg McCormack: Exploratory only means that this is the first well in that particular formation. When they find enough oil they will change the well to a production well.


Arlington, Va.: In the news you often read that the cement would plug the well "permanently."

How permanent is "permanently"? Won't the cement crack and deteriorate over time just like with any structure? Are there any long-range estimates of how long this plug is designed to last?

Greg McCormack: The well will be cemented and capped meaning a seal will be placed on the top of the well. many wells are plugged and abandoned (PA). There is a well documented requirement that must be followed to PA a well.


Washington, D.C.: What do you think about President Obama's halt to offshore drilling for six months? Does offshore drilling have a future? If not, where do we get the oil?

Greg McCormack: It is a societal issue for the US as to whether we drill in the Gulf of Mexico. The US uses approximately 25% of the worlds oil. We depend heavily on imported oil. The world with the growth of the emerging economies will require all of the sources of energy just to keep up with growth in demand. How much are we willing to pay for gasoline and what areas of the world will we get oil and gas from?


Arlington, Va.: What happened to 4-story cofferdam they tried lowering over the leak originally? Is it going to be left on the seafloor or did they raise it back up and recover it?

Greg McCormack: It is still on the sea floor it will be recovered when it is decided that it will not be needed in the future.


Palo Alto, Calif.: A little technical information is always interesting, and your guesses would be nice if you lack the actual data: What was the pressure at the wellhead prior to the start of the top kill, what pressure might have been imposed by the kill mud pumping, and what flow rates down hole might have been achieved in the first hour, and then say at hour 12? Thanks.

Greg McCormack: I will guess that the formation pressure was between 8,000psi and 10,000psi therefore the pressure near the top of the well will be below that since it is not shut in. The kill mud obviously needs to be higher than that. The initial flow rates of the mud were in excess of 2000 gallons per minute. 7,000 bbls of mud were pumped in the first few hours. I don't have access to the well bore pressures so I am unable to estimate the amount that is going downhole and the amount that is going up the BOP stack.


Centreville, Va.: Mr. McCormack, it has been widely reported that for the northern drilling Canada does require a relief well be drilled simultaneously with the production well. The reason this isn't going to cause a 2nd blowout is that the relief well taps into the original well drill hole and plugs it. The relief well doesn't actually drill into the oil reservoir.

Greg McCormack: I will certainly look into this. The relief well must intersect the flowing well just above the producing zone so that enough vertical distance of drilling mud can give the right amount of weight or pressure to kill the well.


Willis, Mont.: Why aren't they using a compound like drylock fastplug? It will solidify under water.

Greg McCormack: The cement that they are using will harden in the presence of other fluids.


Metairie, La.: Why would BP, realizing this is an unprecedented disaster with an unprecedented need, not go outside of their company to have a national summit -- to confer with the top engineers of the country (even competitors like Chevron, Shell, etc.) to help solve this issue and work for the good of the whole industry?

Greg McCormack: They did and they are constantly in contact with technical and operating staff world wide.


Washington, D.C.: Hi Greg, my question is could this attempt to plug the well with mud have been done at the start? I don't know whether it's true, but I've heard that BP avoided it because they wanted to have the well available to them again in the future and didn't want to lose a moneymaker, so they tried other ways first. In that case, they've been looking out for their interests instead of the country's, and that's when the government should have forced them to action on this earlier. Your thoughts on that? Thanks.

Greg McCormack: BP announced very early that they were going to plug and abandon this well and never produce from it. The top kill has some risk in that it may make the leak worse. the containment vessels did not have that risk.


Houston, Tex.: If the professionals do not know to fix this, why do people think blaming Obama will help? Does the president have some skills here beyond what the pros have?

Greg McCormack: Blame does not help this situation, only solutions that everyone should be helping with and focused on.


Hook 'em: The technical challenges that BP are faced with today have never been faced with before.

If innovations in cleanup and stopping oil flow are not hand in hand with innovations in drilling sites and techniques then maybe the oil companies should not be drilling at such depths. Your thoughts?

Greg McCormack: I can see a complete rethinking of disaster preparedness for the future. Both in prevention and preparedness for, if it does occur


Panama City, Fla.: I'm curious about what we see continuing to escape the riser? It does not appear as black as before but the volume of gas would seem to have increased, if it is in fact gas (Methane)

Greg McCormack: We are seeing a lot of drilling mud escaping through the riser. It is changing the color of the plume. The gas flow will vary.


Washington, dc: If the mud and cement plug is successful, is there a chance that it could produce pressure build-up elsewhere in the well's pipes, causing other leaks?

Greg McCormack: There is one other channel to the surface other than the production casing that could potentially leak. I anticipate that they will cement that as well.


Richmond, Va.: It looks as if pumping this heavy mud into the well is resulting in a substantial reduction in the amount of oil flowing from the leak(s). If this is the case why not just keep injecting the heavy mud into the well to keep the oil out of the water? Isn't the mud non-toxic?

Greg McCormack: The idea is to keep injecting mud until all oil and gas flow stops and BP will know that from pressure readings on the well when that happens. Then the well is killed.


Washington, D.C.: If a major hurricane were to hit the Gulf this hurricane season, how would that affect the oil that has already spilled? I'd imagine that it would aid in its devastating spread.

Greg McCormack: If the hurricane makes landfall on the Louisiana coast that could make an already huge problem worse.


Katy, Tex.: Seems to me nobody on the rig was watching the flowback of mud into the tank when swapping it out with Seawater. When this is all said and done, how is the interaction between service companies and producers going to be affected? I see more service requirements, but with greater oversight from the oil companies, and this time hopefully with a competent "Company Man."

Greg McCormack: There is a saying in well control 7-11. That is there are usually seven to eleven events that lead up to a blowout. what you describe is one of those events. I believe that there will be more accountability for safety on the rig. There is a huge problem in the Oil & gas industry with the retirement of experience people and a gap in experience behind them.


Rockville, Md.: Can you recommend a book with a chapter about the technical side of offshore drilling, suitable for an informed citizen to understand?

Greg McCormack: Introduction to offshore operations. You can find it on the PETEX web site.


Exton, Pa.: Is there a technical reason not to immediately proceed with the junk shot if the top shot seems to be gaining ground on the blowout ?

Greg McCormack: There was a fear that it would make the leak worse.


Omaha, Neb.: Is freezing anything an option? Could it help with the current efforts at all?

Greg McCormack: Liquid Nitrogen (to freeze) in water causes an immense pressure surge equivalent to an explosion.


Rockville, Md.: I work as a safety professional, so my job is to always examine worst case scenarios. Can BP really say with a straight face that they, and virtually every other oil company on the planet, never thought a blowout preventer could fail in this manner?

Just reading the few details about the incident, this seems like a 0.01 percent possibility, and certainly something worth investing some time and money into thinking about preventing or at least coming up with an efficient response plan. I just cannot believe engineers have been flying by the seat of their pants on this response and that NOBODY ever considered that something like this could happen and came up with a way to fix it.

Greg McCormack: They will in the future. This disaster scenario will be part of well planning offshore going forward.


Rutherford, N.J.: How wide is the opening of hole on the ocean floor and does it get bigger or smaller towards the surface. Also, does oil in most wells rise due to pressure or pumped to the surface?

Greg McCormack: The conductor casing is 32 inches the production casing is almost 10 inches. The hole is smaller at the bottom than the top. Think of a telescope with the big end at the ocean floor the small end at the bottom of the hole.


Arlington, Va.: Must BP pay royalties on the oil that is spilled?

Greg McCormack: Don't know, but that is the least of there costs.


Anonymous: Can the well be plugged using conventional weaponry such as torpedo? How about nukes?

Greg McCormack: No


Flower Mound Texas: Why did BP representatives, over strenuous objections of the crew on board, decide to replace the drilling mud that held the gas down in the well? Isn't that heavy mud supposed to be there all the time? What was it replaced with?

Greg McCormack: I cannot answer why he did it. The drilling mud does indeed hold back the oil and gas. It would have been eventually replaced by seawater since it was an oil based mud and therefore a pollutant. This is best done when the well is plugged .


Cleveland, Ohio: I realize BP does not want to raise expectations. But given that it has now been almost 24 hours, about how long should we expect to wait before hearing that the flow has been stopped?

Greg McCormack: If the top kill worked I expect that the next word from BP is that they will start cementing.

_______________________ This concludes our discussion with Greg McCormack. Thank you for joining.


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