July 20th, 2010
02:15 PM ET

BP’s trial & error: What’s worked and what hasn’t

[Updated 10:25 a.m., Aug. 6]

With oil gushing into the Gulf of Mexico for almost three months, every attempt to stop the leak has failed, or fallen short - until now. Oil finally stopped gushing from the well on July 15. We look back at how we ended up here: what BP has tried and done so far.

July 20, 2010

Solution: Static Kill
Scientists are weighing a new option called  "static kill” for permanently sealing it. The "static kill" would involve pumping mud into the well to force oil back into the reservoir below. This is similar to the "top kill" method that failed earlier (see below), except that now the oil isn't flowing - hence the word "static."

Read more on static kill at Time.com

Engineers are proceeding with the relief wells that eventually will pump concrete into the well bore to kill it from the bottom. A static kill, if pursued, would hit it from the top.

BP noted that the option could succeed where other similar attempts have failed because pressure in the well is lower than expected. Geologist Arthur Berman tells CNN's "American Morning" the relative simplicity of the static kill makes it an attractive option for BP.

BP finished pouring cement down the well on Aug. 6, completing the job earlier than expected. The process took six hours. Retired Coast Guard Adm. Thad Allen said the cementing phase of the "static kill" operation is not the end of the process, "but it will virtually assure us there's no chance of oil leaking into the environment."

July 10, 2010

Solution: New better-fitting containment cap
BP said it was going to remove the old containment cap, replacing it with another that has a better fit. Robots removed six giant bolts from the apparatus July 11 so the new cap could be positioned.

Scientists will then be able to gauge the pressure inside the well and determine whether the cap is holding in the oil or if crews will need to continue siphoning oil.

BP says it will conduct a “well integrity test,” which involves closing the stack end and stemming the flow coming from the well.

If it works, oil collection via the vessels, Q4000 and Helix Producer, will cease. BP will then close in on the perforated pipe. This process, which will be done in collaboration with U.S. government officials, could take up to 48 hours.

In the best-case scenario, the containment cap would have the ability to actually close down the valves and slowly contain all the oil – not plug the well.

If oil collection was still necessary, over the next two to three weeks, 60,000 to 80,000 barrels (2.52 million to 3.36 million gallons) a day could be collected as part of the containment process, BP Senior Vice President Kent Wells said. That's because the containment cap would allow four collection ships to access the well, rather than the maximum of three allowed by the old cap.

The oil giant said earlier as well that the cap "should improve containment efficiency during hurricane season by allowing shorter disconnect and reconnect times."

Coast Guard Adm. Thad Allen said he approved the cap-switch plan to take advantage of favorable weather predicted for coming days and because, once the switch is complete, the resulting capacity to contain oil "will be far greater than the capabilities we have achieved using current systems." Allen also stressed that once the capping device is on, "we would get the most accurate flow rate to date."

The oil stopped gushing out on the afternoon of July 15 -  the first time BP has been able to gain control since the the Deepwater Horizon rig exploded three months ago and triggered the catastrophe.

The "well integrity test" began on July 15 after two days of delays, first as government scientists scrutinized testing procedures and then as BP replaced a leaking piece of equipment known as a choke line.

BP cautioned that the oil cutoff, while welcomed, isn't likely to go beyond the 48 hours. Valves are expected to open after that to resume siphoning oil to two ships on the surface, the Q4000 and Helix Producer, as government and BP officials assess the data and decide what to do next.

As of July 19, testing on a capped oil well in the Gulf of Mexico continues as the federal government says BP has addressed questions about a seep near the well. Retired Coast Guard Adm. Thad Allen, the federal government's response manager for the oil spill, says that a federal science team and BP representatives discussed the seep during a conference call, including the "possible observation of methane over the well."

See progress on relief wells

June 16, 2010

Solution: Second containment system
BP said Wednesday it has started collecting oil gushing into the Gulf through a second containment system attached to the ruptured well. The new system is connected directly to the blowout preventer and carries oil up to a second ship, the Q4000. The Q4000 uses a specialised clean-burning system to flare oil and gas captured by this second system. The Q4000 uses a specialised clean-burning system to flare oil and gas captured by this second system.

This second system supplements the lower marine riser package (LMRP) cap containment system, which remains in operation, BP said. The new system is connected directly to the blowout preventer and carries oil and gas through a manifold and hoses to the Q4000 vessel on the surface.

Oil and gas collected from the blowout preventer reached the Q4000 at approximately early on June 16. Operations continue to stabilise and optimise the performance of the second containment system.

See progress on the relief wells

June 3, 2010
Solution: An altered version of "cut and cap"
BP went back to the drawing board June 3 and planned to cut away the remains of the damaged riser pipe with a robotic-arm shearing device. A containment dome would then be put over the blowout preventer's lower marine riser package, but the larger, less precise shearing device will have left a rougher cut than what the diamond wire cutter was supposed to offer.

The more primitive cut means that a rubber seal will not be as tight as previously hoped, so the dome may capture less of the oil. Nevertheless, the hope is that a good amount of the oil can be captured and brought to the surface until August, when BP is expected to be ready to use a relief well to seal the leaking well for good.Outcome
BP sliced off the remains of the damaged riser June 3, and Adm. Thad Allen, the federal government's response manager, called the news "extremely important." Robot submarines steered the new cap to the well later that evening. The cap placed over the top of the well funnels oil and gas to a surface ship, though oil is still spilling out from the cap and the valves.

On June 7, BP says that it has closed one of four vents on top of the cap, and that the process is working well. The company says it may not close all four of the valves because engineers think the valves may be releasing more gas than oil.

On June 10, scientists said as much as 40,000 barrels of crude are gushing into the sea every day. The previous estimate by researchers, made two weeks ago, was 12,000 to 19,000 barrels per day.

BP has collected about 73,300 barrels (about 3 million gallons) of oil since it placed a containment cap on its ruptured well, the company said.

June 1, 2010
Solution: "Cut and cap"

BP plans to send marine robots that will cut the "lower marine riser package,” or LMRP, on the well. This is a set of pipes that connect the oil well’s blowout preventer to the damaged pipe. After that, a diamond-cut saw will be used to make a "clean cut," preparing the way for a custom-made cap to be fitted over the package. One of a number of caps that BP has available, depending on the cut, will be placed over the package to bring the oil and gas to the surface.

The operation represents the first of three containment steps that BP plans to take. After the cap is on, a second operation will create a second flow through the blowout preventer, meaning there will be two channels of oil leaking to the surface.

When asked about his level of confidence in the capping procedure, given the fact that other operations aimed at stopping the spill have failed, BP Managing Director Bob Dudley said the company has learned a lot from previous attempts. For instance, warm water will be pumped down in an effort to combat the formation of hydrates, or crystals, that blocked a previous containment vessel.

While the engineering has never been attempted at a depth of 5,000 feet, Dudley said, it is "more straightforward" than that used in previous operations. The cap "should be able to capture most of the oil," Doug Suttles, chief operating officer of BP's global exploration and production business said. However, he cautioned that the new cap will not provide a "tight mechanical seal."

If successful, the procedure will allow BP to collect most, but not all, of the oil spewing from the well. The cutting that precedes the cap placement carries with it a risk of increasing the oil flow, Dudley acknowledged. But "even with increased flow rate, this cap will be able to handle this." However, the BP statement said, "systems such as the LMRP containment cap have never been deployed at these depths and conditions, and their efficiency and ability to contain the oil and gas cannot be assured."

BP's effort to slice off a damaged riser pipe stalled after the blade of a diamond wire saw got stuck June 2. The diamond wire cutter plan was dumped after the device got stuck midway through the pipe. It was freed and taken to the surface.

May 28, 2010
Solution: “Junk shot”
This method involves debris such as shredded tires, golf balls and similar objects being shot under extremely high pressure into the blowout preventer in an attempt to clog it and stop the leak. Engineers at BP used this technique along with the top kill.

What was expected
"Each of these [materials] has been proven to fill various-sized spaces in the blowout preventer until the flow is stopped," BP says in a statement on its website. "While there is no known perfect 'recipe,' a number of combinations of materials will be used." More drilling mud would follow the junk shot, with the hope that the two methods together would stop the oil long enough for cement to be poured into the well. BP’s Suttles compared the operation to stopping up a toilet.

Did it work?
This one failed, too. The process was carried out "a number of times" with the U.S. Coast Guard before the oil giant admitted that the experiment had failed, BP press officer Sheila Williams said. Engineers first used the junk shot to quell the 1991 Kuwait oil fires, but never at such depths. "I don't think we'll be using golf balls again," Williams said.

May 25, 2010
Solution: "Top kill"
The top kill involves pumping heavy drilling fluid into the head of the leaking well at the sea floor. The manufactured fluid, known as drilling mud, is normally used as a lubricant and counterweight in drilling operations. The hope is that the drilling mud will stop the flow of oil. Cement then would be pumped in to seal the well. The first round of pumping began May 26.

Top kill has worked on above-ground oil wells in the Middle East but has never been tested 5,000 feet underwater. BP Chief Executive Officer Tony Hayward has given the maneuver a 60 percent to 70 percent chance of success.

A team of experts will examine conditions inside the five-story blowout preventer to determine how much pressure the injected mud will have to overcome. The company then performs diagnostic tests to determine whether the procedure can proceed.

Three days of work involving three separate pumping efforts and 30,000 barrels of mud – along with what Hayward described as "16 different bridging material shots" – just didn't do the trick.

"We have not been able to stop the flow," a somber Suttles told reporters. " ... Repeated pumping, we don't believe, will achieve success, so we will move on to the next option." Suttles and other officials said that the top kill attempt to stop the flow did so – but only as long as they were pumping. When the pumping stopped, the oil resumed its escape.

May 14, 2010
Solution: Riser insertion tube
The riser insertion tube tool is a temporary solution that involves inserting a 4-inch-diameter tube into the Deepwater Horizon’s rise, a 21-inch diameter pipe, between the well and the broken end of the riser on the sea floor.

The insertion tube connects to a new riser to allow hydrocarbons to flow up to the Transocean Discoverer Enterprise drill ship. The oil will be separated and shipped ashore.

This seems to be the most successful effort thus far in containing some of the spill. The system was able to capture some of the leaking oil and pipe it aboard a drill ship, burning off some of the natural gas released in the process, according to a statement from the joint BP-Coast Guard command center leading the response to the oil spill.

The flow rate from the tube reached 3,000 barrels of crude (126,000 gallons) and 14 million cubic feet of gas a day as of May 20. BP’s Suttles said the company is "very pleased" with the performance of the tube. However, Gov. Bobby Jindal of Louisiana says the efforts haven't stopped oil from reaching his state's coastline.

May 12, 2010
Solution: Second containment dome or “top hat”
The "top-hat" cofferdam is a 5-foot-tall, 4-foot-diameter structure that weighs less than 2 tons and would be injected with alcohol to act as an antifreeze and keep its outlet clear.

BP built the smaller dome after the containment vessel, designed to cap the larger of two leaks in the well, developed glitches. The new device would keep most of the water out at the beginning of the capping process and allow engineers to pump in methanol to keep the hydrates from forming, BP's Suttles said. Methanol is a simple alcohol that can be used as an antifreeze.

BP abandoned the idea of using the “top hat” and opted to proceed with an insertion tube technique instead. It wasn’t clear why BP made that choice.

May 7, 2010
Solution: First containment dome
BP lowered a massive four-story containment vessel over the well to cap the larger of two leak points. The hope was that the container would collect the leaking oil, which would be sucked up to a drill ship on the surface.

"If all goes according to plan, we should begin the process of processing the fluid and stop the spilling to the sea," Suttles said. But the method had not been done at such depths before.

The plan was thwarted after ice-like hydrate crystals formed when gas combined with water to block the top of the dome and make it buoyant. The dome was moved off to the side of the wellhead and is resting on the sea floor, Suttles said. He declined to call it a failed operation but said, "What we attempted to do ... didn't work."

May 4, 2010
Solution: Drilling a relief well
The second well joins the failed well at the bottom, in rock 13,000 feet below the ocean. Once contact is made, drilling fluid and concrete will be put into the first well.

This will lower the pressure on the failed well, enough to allow a concrete plug to be placed into it and permanently shut it down. The relief well could also be used for future oil and gas production. BP began drilling the second well this month, but it will take three months to complete. Weather conditions could prolong the process, Beaudo said.

The well is expected to be completed by August. It would be a permanent solution to cap the leaking well.

End of April
Solution: Robots to shut blowout preventer
The rig’s blowout preventer, a 48-foot-tall, 450-ton apparatus that sits atop the well 5,000 feet underwater, failed to automatically cut off the oil flow after the April 20 explosion of the Deepwater Horizon rig. BP attempted to use remote-controlled submarines with robotic arms to reach access portals and activate the valve.

The highly complex task was to take 24 to 36 hours, said Doug Suttles, chief operating officer of BP's global exploration and production business.

Failed. "We've tried many different ways. Some things have showed promise; some haven't," BP spokesman Daren Beaudo said. "We don't know why the remote-operated shutdown systems haven't worked."

Testing on a capped oil well in the Gulf of Mexico continues for another day as the federal government says BP has addressed questions about a seep near the well. Retired Coast Guard Adm. Thad Allen, the federal government's response manager for the oil spill, says that a federal science team and BP representatives discussed the seep during a conference call, including the "possible observation of methane over the well."

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Filed under: BP • Gulf Coast Oil Spill
soundoff (303 Responses)
  1. Robert

    reIf the relief drill is the only long term solution, I think time has come to force oil companies to always drill a relief drill at the same time they drill a production drill, just in case this nightmare happens again. And in the mean time, why not to start driling relief drills for each production drill already in operation? Cost vs. benefits is the rule.

    June 3, 2010 at 8:35 am | Report abuse |
  2. Frank

    If doing a clean cut at the top or the riser is the beginning of a solution and pressure is making the blade stuck, why don't trying to cut through the bolts of the joint instead?

    June 3, 2010 at 9:16 am | Report abuse |
  3. John Zeffer

    If they can drop a tube down into the pipe to pump in "mud", why can't they use the Stent/Bladder ideas to pump the mud into an inflatable sack or airbag type container to seal off the pipe from the inside as far down as they can get it. Then back the bag-plug with concrete? Or perhaps an umbrella type design that would expand proportionally against the pressure pushing up from below and against the insides of the pipe. Then back it up with the concrete or cement.

    June 3, 2010 at 9:19 am | Report abuse |
  4. Chris

    Reading through the many solutions people have proposed I really see issues with almost all of them. The biggest thing to consider is this is all being done a mile underwater, using robots. I have heard many say crimp the pipe , I doubt this would work cause the pressure would just blow it out somewhere else. Inserting things into the riser isn't feasible either, try sticing a balloon into your garden hose while it is on and blowing it up...now try that by remote control a mile under the ocean ! I think the reason they are trying to siphon off the oil is they have to relieve the pressure, if they were to sheer off the well at the ocean floor it would leave nothing but a hole and even more difficult problem. I am sure BP has some very smart people who have more expereince then most anyone else ( other then some of the other oil companies and even those people are talking to their friends at other companies) . As a System Engineer I understand complex issues and I also know you reach out to others in quiet ways for ideas and help. FYI: I do not have any affliation with the oil companies, drilling companies or the industry in any way.

    June 3, 2010 at 9:34 am | Report abuse |
  5. Steve

    Some of the above people don't get it: The well is gushing at over 10,000 PSI about a mile down under the ocean. To build a device to simply plug the leak is more than a challenge. Also, the riser pipe is about 21" thick and is mangled and broken in several different places. If you pinch off the pipe, it willl still leak anyways around other cracks and breaks.

    June 3, 2010 at 9:38 am | Report abuse |
  6. Stuart Davis

    Cutting the riser pipe seeems risky on two counts.

    Firstly the 20% estimate in flow increase depends upon the current flow resistance provided by the crimp in the riser pipe and the orifice restriction at the leaks, both of which will be eliminated when the pipe is cut. I doubt if there is accurate data on either of these parameters so that the actual flow increase could easily exceed the 20% estimate. When the riser pipe is cut and the discharge has a more regular shape, estimates of the flow will be more accurate but BP can defend their 20% increase estimate because we have so much uncertainty in the present discharge rate.

    The second risk in cutting the pipe is that it eliminates any options having to do with the riser pipe itself eg crimping it or inserting it into a larger diameter pipe leading to the surface. There is no turning back after the riser pipe is cut and I would think that this solution falls into the category of last resort.

    I smell desperation in the air.

    June 3, 2010 at 9:50 am | Report abuse |
  7. Matt

    For all it's worth, there's something else wrong with the well. Not just that the BOP failed, but clearly there's worry from BP that the problem lies deeper down the well, and they've yet to determine or announce what caused the explosion in the first place. Either the pressures are too high at that depth of drilling for standard BOP & kill techniques, or there's way more nat gas in the mix than expected, or something else that BP either does not know about or is holding back on. At this point they'd kill the well and drill again elsewhere to access this deposit, if they didn't fear something.

    June 3, 2010 at 10:44 am | Report abuse |
    • Joe Architect

      ^^^Excellent point. True that. In order to solve this problem, we first need to state exactly what the problem is in detail. We all know there's an out of control gushing well. As you said, we don't know what caused the initial explosion nor the status of the pipe below the BOP nor the amount of natural gas there. I guess that's why it's called Exploration...

      June 9, 2010 at 12:48 pm | Report abuse |
  8. Tnperera

    The Automatic Remote Control Sustems for closing the Valves of all the Blowout Priventors in all the Oilrigs under the oceans should be checked from time to time in future. Prevention is better............

    June 3, 2010 at 10:44 am | Report abuse |
  9. Alex

    Don't count on success of the relief well either: remember it needs to meet the failed well at the 13,000 feet depth, which is not a guarantee, I don't think.

    June 3, 2010 at 12:39 pm | Report abuse |
  10. OilUser

    The continued leak is NOT BP trying to save their oil. If they stopped the leak the day after this event occurred, then they would just drill a new well to get the oil. An oil reserve will commonly have many wells drilled into it for various reasons, so drilling a new one is NOT a problem. In fact, having the oil leak into the open water is causing them to lose oil and money. BP’s greed being the reason they are not capping the leak is the most ridiculous idea.

    Besides, do not blame BP for their inability to stop the leak. This problem is an industry wide problem and could have happened to any deep-water drilling company. If Exxon, Shell, Halliburton, BJ Services, etc. know how to stop this leak, then they would gladly share this information with BP. Those companies are already releasing resources such as those underwater robots for BP to utilize. This event will not just hurt BP, but the entire oil industry, as new regulation will affect all of them. They all want BP to stop the leak.

    The difficulty cleaning the spilled oil is also an industry wide problem. The same technology BP is using to trap the oil floating on the ocean and hitting our shores is the same technology any other company would be using if they had a major spill in the gulf. I am simply saying this is not a BP only problem and to direct your energy at all the organization involved in oil production. Call on all of them to develop better technology.

    And the America population, do not think you have no blame on yourself for the oil. We all use oil, even if you do not own a car. Have any plastic items in your house? They came from oil. Vehicles using fuel from oil transport almost every product you buy. Drive on Asphalt roads? Yep, oil in that too! Our thirst for oil is what makes these companies billions in profits every year and causes them to go to great lengths to get to the oil.

    Go look back in history; hitting an oil reserve when drilling was a nuisance before we found a large use for it (cars). After everyone in the US was using oil it became what it is today, Black Gold!

    BTW, do not think boycotting a BP gas station will hurt the company at all as you will only be hurting the people who own the BP station, which are most probably local resident in your community.

    June 3, 2010 at 1:19 pm | Report abuse |
  11. engineer

    To stop the oil: Drill a hole 50 feet deep at a distance of 10 feet from the blowout preventers. Fill the hole with ~200 to 500 pounds of high explosive this will most likely cause the well pipe to close and stop the leak. You can see how it can be done here: http://www.youtube.com/watch?v=uuJETgpozOw

    June 3, 2010 at 2:24 pm | Report abuse |
  12. Stephanie & Jason Riojas

    BP could have stopped the leak immediately at ANYTIME by using dinamite. The dinamite blows up the pipe/well causing it to cave in. This is a permanent fix. Therefore had BP used this method, they would NOT be able to tap this well again and they WOULD NOT profit from the large amount of oil it's producing. All of the previous methods show that BP's #1 concern/priority right now is NOT our ocean, but their financial gain!!

    June 3, 2010 at 3:46 pm | Report abuse |
    • OilUser

      What is dinamite? Oh, you mean Dynamite?

      Drilling and setting off an explosion in an attempt to crush the pipe or collapse the well would be the riskiest project BP could possibly undertake. There would be no guarantee it would work and it could create a worse situation, one where oil finds other routes through the seafloor to leak through. If that did happen, then there would be no way to stop the leak besides the even more risky idea suggested elsewhere of using a nuclear device.

      June 3, 2010 at 5:46 pm | Report abuse |
  13. Dan

    They may have the brightest scientists attempting to stop it, but they have the dumbest managers to try and prevent it.

    June 3, 2010 at 4:30 pm | Report abuse |
  14. Carl

    Call Joe the Plumper

    June 3, 2010 at 5:48 pm | Report abuse |
  15. K

    BP is looking completely incompetent. Any company that doesn't have effective safety procedures in place and doesn't know how to handle a spill or emergency should not be allowed to drill for oil anywhere. Get them out of the gulf and let companies who actually know what they are doing drill.

    June 3, 2010 at 6:05 pm | Report abuse |
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