Sunday, 29 November 2015

BP over a barrel as oil leak estimate hits 60k

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London - The “most likely” flow rate of oil from BP’s damaged Deepwater Horizon subsea well in the Gulf of Mexico is now estimated at between 35,000 and 60,000 barrels per day.

The figures, which are based on updated information and scientific assessment, represent a major hike in previous estimates – the leak was generally reckoned to be around 18,000 b/d, less than a week ago.

The latest flow rate estimate from US authorities is based on a combination of analyses of high resolution videos taken by remote operating vehicles (ROVs), acoustic technologies, and measurements of oil collected by the oil production ship together with pressure measurements inside the top hat. 

In particular, the “improved” estimates are informed by newly available, detailed pressure measurements from within the Deepwater Horizon’s failed blowout preventer (BOP) system taken over the past 24 hours – BP had previously signalled efforts to install pressure sensors in one of the lines being used to inject methanol to prevent the formation of hydrates in a lower marine riser package (LMRP) cap now in place on the BOP.

Scientists have also been able to draw on more than a week of data about the amount of oil being collected through the top hat, added a joint statement by US secretary of energy Steven Chu, secretary of the interior Ken Salazar, and chair of the National Incident Command’s Flow Rate Technical Group (FRTG) Dr. Marcia McNutt, director of the US Geological Survey.

“As we continue to collect additional data and refine these estimates, it is important to realise that the numbers can change,” said US energy secretary Steven Chu.”In particular, the upper number is less certain - which is exactly why we have been planning for the worst case scenario at every stage and why we are continuing to focus on responding to the upper end of the estimate, plus additional contingencies.”

The US government has demanded that BP’s containment capacity reaches 40,000-53,000 b/d by the end of June and 60,000-80,000 b/d by mid-July.

BP has installed two systems to collect oil and gas flowing from the MC252 well and transport them to vessels on the surface.

The LMRP containment cap located on top of the failed blow-out preventer (BOP). This system, which was installed on 3 June, takes oil and gas to the Discoverer Enterprise.

A second system, which started on 16 June, is connected directly to the BOP and carries oil and gas through a manifold and hoses to the Q4000 vessel on the surface. The Q4000 uses a specialised clean-burning system to flare both oil and gas captured by this second system.

The total volume of oil recovered from both the LMRP containment cap system and the Q4000 since they became operational is approximately 249,500 barrels. Officials have previously estimated that the LMRP cap could capture up to 18,000 b/d, and that the Q4000 could expand total leak containment capacity to 20,000-28,000 b/d. 

Work on a first relief well, which started 2 May, continues and has currently reached a measured depth of 15,936 feet. A second relief well, which started 16 May, is at a measured depth of 10,000 feet. Both wells are still estimated to take approximately three months to complete from commencement of drilling.

BP, meanwhile, continues to caution that the LMRP containment cap – an engineered containment device with a sealing grommet – and the Q4000 have never been deployed at these depths (5000ft) and conditions before, and its efficiency and ability to contain the oil and gas could not be assured. Process animation – Click ’back button to return to this page

The success of the LMRP follows a failed bid stop the leak by pumping over 30,000 barrels of heavy mud at rates of up to 80 barrels a minute, and deploying a wide range of different bridging materials, the ’top kill’ operation on the failed BOP did not overcome the flow from the well.

Engineers had previously achieved partial success through the use of an RITT used at the well, which at one stage was drawing off 3000 b/d of oil. The RITT - a five foot long steel pipe with specially designed rubber baffles - was placed in the end of the leaking riser on 16 May, allowing oil and gas to flow up to the drillship Discoverer.

The recovery rate, however, subsequently dropped off due to issues relating to the flow parameters and physical characteristics within the riser in deep sea conditions.

US government investigators continue to interview witnesses regarding the incident. These have reportedly included: a worker on the Deepwater Horizon rig, who alleged that BP had taken risky shortcuts in its drilling procedures prior to the explosion; and another alleging that there were unusually pressure readings coming from the wellhead in the hours before the blast.

The investigation earlier uncovered “significant problems” with the BOP - the supposedly fail safe system installed to cut off the flow of oil and gas to the Deepwater Horizon drill rig.

The BOP has multiple rams that are supposed to slam shut to pinch off any flow around the drill pipe and stop the flow of oil from the well. There are also shear rams in the BOP that are supposed to cut and seal the pipe to
prevent oil and gas from flowing.

“We know that the blowout preventer, the BOP, did not properly engage,” US congressman Bart Stupak, chairman of the House Energy and Commerce Committee’s Subcommittee on Oversight and Investigations, told a hearing to
examine the causes of the incident.

BP was leasing the rig to drill an exploratory well in the Gulf of Mexico.The rig was owned and operated by Transocean, the world’s largest offshore drilling company, and was under contract from BP. Two days after the blast, the rig capsized and sank to the floor of the ocean. The accident resulted in 11 fatalities and oil leaks from three separate locations among the twisted wreckage.

According to Stupak, US investigators have found that the BOP appeared to have a significant leak in a key hydraulic system. This leak was found in the hydraulic system that provides emergency power to the shear rams, which are supposed to cut the drill pipe and seal the well.

A senior official at Cameron, which manufactured the BOP, told investigators that when the remote operating vehicles (ROVs) tried to operate the shear rams, they noticed a loss of pressure. They investigated this by injecting dye into the hydraulic fluid, which showed a large leak coming from a loose fitting, which was backed off several turns.

The leak did not seem to have been caused by the blowout because every other fitting in the system was tight, according to the Cameron official, who believed this was one of several possible failure modes: the leak depriving the shear rams of sufficient power, so that they could not cut through the drill pipe and seal the well.

Secondly, the investigation learnt that the BOP had been modified in potentially significant ways. The device has an underwater control panel. BP spent a day trying to use this control panel to activate a variable bore ram on the BOP, which should seal tight around any pipe in the well.

When BP investigated why their attempts to activate the bore ram failed, they learnt that the device had been modified. A useless test ram - rather then the variable bore ram - had been connected to the socket that was supposed to activate the variable bore ram.

Thirdly, the US team learnt that the BOP was not powerful enough to cut through joints in the drill pipe. They cited a Transocean document that stated: most blind shear rams (BSRs) are “designed to shear effectively only on the body of the drillpipe. Procedures for the use of BSRs must therefore ensure that there is no tool joint opposite the ram prior to shearing.”

“This seemed astounding to us because the threaded joints between the sections of drillpipe make up about 10% of the length of the pipe. If the shear rams cannot cut through the joints, that would mean that this so-called failsafe device would succeed in cutting the drillpipe only 90% of the time,” Stupak told the hearing.

“We asked the Cameron official about the cutting capacity of the blowout preventer on the Deepwater Horizon. He confirmed that it is not powerful enough to cut through the joints in the drillpipe. And he told us this was another possible explanation for the failure of the blowout preventer to seal the well, the congressman added.

A fourth finding was that the emergency controls on the BOP may have failed. The BOP has two emergency controls. One is called the emergency disconnect system (EDS). BP officials told investigators that that the EDS was activated on the drill rig before the rig was evacuated.

“But the Cameron official said they doubted the signals ever reached the blowout preventer on the seabed,” said Stupak. “Cameron officials believed the explosion on the rig destroyed the communications link to the blowout preventer before the emergency sequence could be completed. In other words, the emergency controls may have failed because the explosion that caused the emergency also disabled communications to the blowout preventer.”

Meanwhile, the BOP also has a “deadman switch” which is supposed to activate the shutoff system when all else fails. But, according to Cameron, there were multiple scenarios that could have caused the deadman switch not to activate. One was human oversight: the deadman switch may not have been enabled on the control panel prior to the BOP being installed on the ocean floor. Another is lack of maintenance: the deadman switch won’t work if the batteries are dead.

The deadman switch is connected to two separate control pods on the BOP. Both rely on battery power to operate. When one of the control pods was removed and inspected after the spill began, the battery was found to be dead. The battery in the other pod has not been inspected yet.

Another issue concerns the design. The deadman switch activates only when three separate lines that connect the rig to the BOP are all severed: the communication, power, and hydraulic lines. Cameron believes the power and communication lines were severed in the explosion, but it is possible the hydraulic lines remained intact, which would have stopped the deadman switch from activating.

“These are not the only failure scenarios that could impair the function of the BOP,” said Stupak. “The Cameron official we met with described many other potential problems that could have prevented the blowout preventer from functioning properly. Steel casing or casing hanger could have been ejected from the well and blocked the operation of the rams.

“The drill pipe could have been severed successfully, but then dropped from the rig, breaking the seal. Or operators on the rig could have tried to activate the shear rams by pushing the shear ram control button. This would have initiated an attempt to close the rams, but it would not have been successful. The shear rams do not have enough power to cut drill pipe unless they are activated through the emergency switch or the deadman switch.”

Stupak also revealed an “astonishing document” that Transocean prepared in 2001, when it bought the BOP from Cameron. It said there were 260 separate “failure modes” that “could require pulling of the BOP.” According to this report, “the predominant failures” included “ram locking mechanisms.”

“How can a device that has 260 failure modes be considered failsafe?” the congressman asked.

Problems with the BOP were also found to extend to the procedures for testing the device. The CEO of Transocean, Steven Newman, said in a testimony: “we have no reason to believe that they were not operational - they were jointly tested by BP and Transocean personnel as specified on April 10 and 17 and found to be functional.”

But this assertion seemed to be contradicted by a document prepared by BP on 27 April, one week after the explosion. According to this document, “BOP stack emergency systems are not typically tested once the BOP stack is on the seabed.”

“What this means that while some functions on the BOP may have been tested in the weeks before the explosion, the emergency systems, including the deadman system and the leaking emergency hydraulic system, were unlikely to have been tested,” Stupak concluded.


Readers' comments (12)

  • Same old save money by not following all procedures. Their thinking was that this peice of tech wouldn't fail. If it did, we'll get the oil to stop and fix it. Typical money grubbing logic.

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  • This is another prime example of BP telling us in advance that they have already sabotaged the top-kill strategy, or never expected it to work at all. BP hasn't put forth a single plan aside from this (very poor) one to actually -STOP- the oil leak, but they've put into action a whole bunch of different half-cracked schemes to continue collecting the oil.

    This is not about stopping the oil. The amount they're going to have to pay out at this point is likely at its legislated maximum. At this point they're just trying to pull up enough of the black sticky to help pay for the efforts before it all leaks into the ocean.

    They care far less about the shrimp and fisheries than they do about a cushion for the impact their wallets are about to suffer.

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  • For those of you who think BP is trying to get money from the oil, think again. Lets imagine that BP is lying through their teeth and really they know that the well is leaking at 10 times the estimated rate, that is at 50,000 barrels a day. Further lets imagine that their RITT system can capture 100% of the oil rather than just a fraction.

    Crude is currently around 50 pounds a barrel. So in this extreme case BP would be collecting 2.5 million pounds worth of crude per day. And they are paying a lot more than that in cleanup costs per day!

    Realistically they are collecting between 2 and 3 thousand barrels of crude a day worth 150,000 pounds. They spend more than that every hour on the cleanup effort.

    If they could have stopped the well earlier they would have.

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  • Good Luck on the Kill-Shot!!!!

    I have a concern:

    The Drill-Pipe which was in the Well-Bore at the time of accident is still in the Well-Bore. That Drill-Pipe is hollow and "empty" [unobstructed].

    the other end of Said Drill-Pipe is Laying on the sea-bed and has been capped.

    Two issues: 1. are we certain that said "Cap" can withstand the pressure of the mud you will be pumping. 2. is there some means of anchoring it just incase the caps comes off. If the cap comes off that lose drill-pipe could whip around like a lose water hose and take out a bunch of equipment.

    The thought is like this: If we do manage to pump the heavy mud down to the end of the Drill-Pipe; That same mud might travel up that Drill-Pipe thru the BOP and Riser and to the Capped end of the Drill-Pipe laying on the Sea Bed Floor. If the Pressure is high enough, it could blow the Cap off the Drill-Pipe. this could propel the Drill-Pipe rather like a lose water hose.

    We don't want that!

    We need enough time to double check the Cap on the Drill-Pipe which is laying free on sea-bed floor;

    Something to tie the Drill-Pipe to something, so it can't come lose and damage equipment and your efforts.

    You have all the expertise required.

    To better understand my point: find the BP graphic which has two(2) pictures of the BOP. the one with the Black rectangle in the upper left corner. just below that black rectangle, you can see the Drill-Pipe with the caption: Capped Drill-Pipe. that is what I'm referring too see Link - lower left corner

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  • 50 years in exploration worldwide, or as you may say 50 years of mistakes (including the cigarette lighter, Gassi-Touil Grand Erg Oriental Algeria 1961) of which 30 offshore (20 on semisubs) allow me to say that we do not have all the technical details to "juge" what BP does now. There are undeniable facts leading to believe that wrong prcedures, or Company men decisions were not appropriate, but It is sure that if anyone from BP, Exxon, CVX and others had now a solution, BP will all be glad to apply it immediatly, even non-classic one (as Coots in Gassi-Touil).
    Without being associated with BP I can only pray for them to succeed because if gulf people "demand" after only one week of oil on their beaches that a solution been found NOW, be ready to see what is coming.
    I do not think that BP will outspeed the oil/gas flow and will not succeed (I hope I am wrong). Even if we tailk about 3 1/16" lines, I also think that pumping for too long and as fast as they could with heavy mud, they may have more chance to cut thru the line or an elbow due to the relative abrassivemenes of the baryte (not much but very possible)... But do they have a choice any more as deviated wells are still 60 days away.
    The only secure, garanty thing is that at least this will decrease the flow. .. Except if by "pure luck" they manage to close the weel before plugging (with particles ) or perforating the injection lines.
    In clear it is a disaster of unknown magnitude ...
    if it is not the time now to look for who is responsable, the contracts are 100% clear on that subject, the "company" is sole responsable 100%.
    The unforgatable aspect is that the OIM did not follow what was going on and the day and the night pushers did not react fast enough to protect not only their own rig but mainly their own people (or his life since the night pusher died in the explosion).
    To simplify, the situation is legally very simple; BP rent the semisub as you would rent a car with a driver. If you (as BP) seat on the back seat and order the driver to take a 90 degres curb at 100 miles/hr it is the responsability of the driver (OIM and tool pushers all transocean) to chalenge and refuse to execute... if they knows their jobs....
    It has happen... solved by putting "town" in the loop before riching a non-return point...
    This is Very, very sad and the comedy of the politiciens will not change anything because they do not know ... these ordinary braguards, will never know or comprehend what it is to lead alone by 120 knots wind 65 ft seas heaving 35 ft every 8 sec in North Sea or landing a stack at 5000ft deep in the gulf without been able to see anything while being. .. scared... silently but still facing and controling the situation.

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  • Assuming worst case that nothing can stop the flow, how much oil does this field contain and for how long will it continue to leak into the gulf?

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  • I have design on a dome that might help


    Problematic factors/equations in confining ruptured well

    1. Identify the composition of ocean floor to 100 feet of well head
    2. Create a contour model of ocean floor to 100 feet of well head

    3. Design dome to withstand pressure @ well head depth
    4. Design factors/criteria;

    a. material composition of dome
    b. thickness of material of dome (weight assertion)
    c. curvature of dome (ocean water pressure resistance)
    d. re-enforcement of dome shell (i.e. superstructure framework, shoring)
    e. contour of dome edge fitting ocean floor
    f. length of "toothed edge" @ perimeter of dome to ocean floor
    g. optional additiional spikes to stabilize dome to ocean floor
    h. main spout design (tapered, with seal, flow capacity)
    i. design accessory spouts for relief and access to existing wellhead (servo activated gates)
    j. hydraulic vibrators to embed dome to ocean floor

    5. Capture oil through main spout, other spouts if needed

    6. Drill new "offset" well to relieve all pressure from original well
    7. Cap ruptured well permanently after new well is operational
    8. Monitor work performed

    Teams needed for scope of work;
    1. Pressure design calculations teams (ocean floor stability, composition of floor, water pressure)
    2. Structural engineers for dome design and placement of dome
    3. Petroleum engineers for oil flow piping/containment design
    4. Rough-neck crews for install of piping
    5 Tanker crews for oil retrieval

    Coefficients------ X. water pressure
    Y. composition of dome
    Z. curvature of dome
    W. weight of dome
    Q. volumetric capacity of dome interior
    P. pressure inside of dome @ seal time

    I have a rendering of the dome with its accessories, your site will not let me install picture on this page. Please send me a site or page to which I can attach or paste drawing to.

    Thank you

    Louis Montoya

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  • I've seen reports that it would go on for 20-30 years... that there is 25,000 square miles of oil in this "deposit" which is not a typical deposit-- rather its a transit way for oil down there like an expressway between one deposit area and another. I don't know anything about oil deposits-- that's just what I read somewhere that struck me as worth checking out.

    I've also read that the Russians stopped their out of control underwater wells with small nuclear weapons designed just for that purpose beginning in 1966. Since then, they've had to nuke 7 of their wells... and it worked.... so it's not as if we don't have a possible srategy here. We can't say its off the table.

    It's interesting that the reason we had to allow dangerous deepwater drilling in the first place was a shortage of power generated by nuclear in the first place... and now we'll have to use nuclear energy release with its high heat to seal this thing.

    I'm pretty confident that DOE and Army Corp of Engineers have plans to shut it down this way. It's been done before. The relief wells are unlikely to work because it's hard to hit that target the way they need to and too much oil will leak over the next few months.

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  • The problem with wellhead containment domes is that there is cracking of the seabed floor around the wellhead and somewhat distant from the wellhead. Multiple leaks are occurring--- and to put containment domes over all of them would be tricky indeed... probably impossible. The best overall solution is to use what's worked in the past-- the small nuke used as a peace time tool-- which has a long history in construction projects and -- on the Russian side-- stopping out of control wells.

    This event is going to separate the men from the boys. The use of a nuclear device to save the world has been simulated in the movie Asteroid-- applied in space, rather than underwater of course. But the principle of using nuclear explosive as a tool was the key thing to note.

    Peaceful use of the nuclear explosive takes maturity and reasoning in a culture. It's going to be interesting to see if we "pass the test". He he.

    I think what will have to happen is that Obama is going to have to step down. I hear that Obama (Barry Sotoro) has had several social security numbers-- which means he's illegally holding office as an imposter of some kind. Biden would have to step in and take command and control of the situation under advice from DOD and order the well stopped with a nuclear device.

    The thing has to be stopped... just like that asteroid in the movie. Culture, politics and everything else will have to come to terms with this fact. And we'll see who's who. This is a defining moment in US and world history.

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  • Add a radioactive component to the massive spill, are you insane? How's about B.P. looking into the multitude of suggestions that "they asked the public for"? As an example for collecting the floating oil, Willie Nelson( not the singer ). But a entepenure from Ontario Canada has formulated, a now Canadian Government sanctioned method for collecting oil spilled on water and he's being snubbed by all the arrogant think they know it all's. The same people who told the world 60 day's ago this was son to be capped?!

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