BP learned during Top Kill procedure some mud went into formation, the rock outside of well casing, implying problems with well integrity.
Source: http://www.georgewashington2.blogspot.com/2010/06/evidence-points-to-destruction-beneath.html
Below is the picture of well design (Source: www.energy.gov/oilspilldata )
BP issued an update at 8:40pm Saturday, May 29, 2010 regarding their efforts to stop oil flow from the MC252 well in the Gulf of Mexico. Source: http://www.bp.com/genericarticle.do?categoryId=2012968&contentId=7062487
BP started the “top kill” operations to stop the flow of oil from the MC252 well in the Gulf of Mexico at 1300 CDT on May 26, 2010. The procedure was intended to stem the flow of oil and gas and ultimately kill the well by injecting heavy drilling fluids through the blow-out preventer on the seabed, down into the well.
Despite successfully pumping a total of over 30,000 barrels of heavy mud, in three attempts at rates of up to 80 barrels a minute, and deploying a wide range of different bridging materials, the operation did not overcome the flow from the well.
The Government, together with BP, have therefore decided to move to the next step in the subsea operations, the deployment of the Lower Marine Riser Package (LMRP) Cap Containment System.
The operational plan first involves cutting and then removing the damaged riser from the top of the failed Blow-Out Preventer (BOP) to leave a cleanly-cut pipe at the top of the BOP’s LMRP. The cap is designed to be connected to a riser from the Discoverer Enterprise drillship and placed over the LMRP with the intention of capturing most of the oil and gas flowing from the well. The LMRP cap is already on site and it is currently anticipated that it will be connected in about four days.
This operation has not been previously carried out in 5,000 feet of water and the successful deployment of the containment system cannot be assured.
Drilling of the first relief well continues and is currently at 12,090 feet. Drilling of the second relief well is temporarily suspended and is expected to recommence shortly from 8,576 feet.
Methods Tried to Stop Oil Flow and to Contain the Spill
Source: http://www.nytimes.com/interactive/2010/05/25/us/20100525-topkill-diagram.html
Article Summary:
May 26 The Top Kill and Junk Shot: BP is focusing on two operations called the “top kill” and the “junk shot” to stop the gushing oil. In the “top kill,” heavy drilling liquid is pumped into the well until the weight of the liquid overcomes the pressure of the rising oil. The “junk shot” involves injecting objects like golf balls to clog the blowout preventer, the stack of valves at the top of the well.
May 16 Attaching a Tube: After several unsuccessful attempts, BP was able to attach a mile-long tube into the broken riser pipe to divert some of the oil to a drill ship on the surface some 5,000 feet above the wellhead. The tube has been siphoning off an average of 2,000 barrels a day, but this accounts for a small portion of the leak.
May 7 Lowering a Containment Dome: BP constructed a four-story containment dome, intended to control the largest of the leaks. As the dome was lowered, crews discovered that the opening was becoming clogged by an icy mix of gas and water.
April 30 Chemical Dispersants: BP officials began injecting chemical dispersants underwater, near the source of the leaks. The dispersants, usually used on the water surface, is intended to break up the oil before it rises. The full environmental impact of the technique is unknown, but the E.P.A. has directed BP to change to a less toxic chemical than it had originally chosen.
April 25 Repairing the Blowout Preventer: The quickest way to stop the leak would have been to activate the well’s blowout preventer, a valve designed to seal off the well in an emergency. But several efforts to activate the blowout preventer failed.
BP Resumes Effort to Plug Oil Leak After Suspension; Several “junk shot” attempts made since May 27
Source: http://nyti.ms/bdEgyH
Article Summary:
- as of Friday May 28, engineers made little progress in stemming oil flow from the damaged well
- BP suspended heavy fluid pumping operations at 2:30 a.m. Friday after two “junk shot” attempts to plug the leak with rubber and other materials
- engineers tried to plug the well using different weights of mud and sizes of debris like golf balls and tires, and then watching and waiting. Several “junk shots” of debris have been attempted already
- BP said pumping operations resumed around 3:45 p.m. Friday. “Top kill” procedure continued for a third day.
- one of technicians said that despite all the injections, at various pressure levels, engineers were able to keep less than 10 percent of the injection fluids inside the stack of pipes above the well. Significantly more injected fluid required to enter the pipes leading to the well for “top kill” procedure to work
- engineers cannot use brute force because they risk making the leak worse if they damage the pipes leading down to the well
- anticipating that the top kill may not succeed, BP began preparations to place a second containment vessel over the leak. Mr. Suttles said BP was also preparing to replace the damaged blowout preventer (BOP)
BP halted live video feed from Deepwater Horizon MC252 oil well in the Gulf of Mexico as of 5.30pm May 28, 2010. Video feed was off for at least 30 minutes. Currently no additional comments from BP regarding Top Kill procedure progress or whether BP started well cementing.
The video feed source:
http://tinyurl.com/bp-stream
BP update: ‘top kill’ halted at 11.59 pm May 27, results under review. If successful, will commence cementing
Source: http://www.bp.com/genericarticle.do?categoryId=2012968&contentId=7062470
Subsea efforts continue to focus on progressing steps to stop the flow of oil from the well through interventions via the failed Deepwater Horizon blow out preventer (BOP), and to collect the flow of oil from the leak points. These efforts are being carried out in conjunction with industry experts and governmental authorities.
Heavy drilling fluids were pumped under pressure into the BOP starting May 26 at 1300CDT and continued through 2400CDT (midnight) on May 27. The heavy fluid pumping was stopped at midnight (11.59pm) May 27 to evaluate the progress. It is estimated that the full top kill procedure could extend for another 24 to 48 hours.
If the well was successfully ‘killed’, it is expected that cementing operations would then follow. The top kill procedure has never before been attempted at these depths and its ultimate success is uncertain.
In parallel with the ongoing top kill operation, preparations have been made for the possible deployment of the lower marine riser package (LMRP) cap containment system. Deployment would first involve removing the damaged riser from the top of the failed BOP to leave a cleanly-cut pipe at the top of the BOP’s LMRP. The cap, a containment device with a sealing grommet, will be connected to a riser from the Discoverer Enterprise drillship, 5,000 feet above on the surface, and placed over the LMRP with the intention of capturing most of the oil and gas flowing from the well.
The LMRP cap is already deployed alongside the BOP in readiness for potential deployment. If it is decided to deploy this option, this would be expected to take some three to four days.
In addition to these steps, planning is being advanced for deploying, if necessary, a second BOP on top of the original failed BOP.
Drilling of two relief wells began on May 2 and May 16. It is estimated that each of these wells will take three months to complete from the commencement of drilling.
For the top kill procedure we are designing equipment to pump the highest kill rate we can, irrespective of the flow rate of oil from the well, to force a downward flow of mud into the well. This, combined with the heavy drilling fluid is designed to eventually stop the flow. This has never been attempted at these depths. This is very complex – and involves several complex procedures coming together.
Detailed description of the procedureWe have the Q4000 vessel at the surface which has a crane for lifting heavy equipment and is a central part of the surface equipment for this procedure. We also have a number of other vessels: the HOS Centerline, with Halliburton pumping equipment; the HOS Strongline; and the BJ Services Blue Dolphin and Halliburton Stim Star IV pumping boats.
A total of 50,000 barrels of mud will be on location to kill the well – far more than necessary, but we want to be prepared for anything. Pumping capacity on location is more than 30,000 hydraulic horsepower.
The mud will be pumped down the 6-5/8 inch drill pipe (pipe is connected to the Q4000), then through 3-inch hoses, which go through the manifold on the seafloor. Then the mud moves through another set of 3-inch hoses attached to the Deepwater Horizon BOP choke and kill lines.
With the manifold, we can also pump the ‘junk shot’ if necessary to stop too much of the kill mud going out through the top of the BOP rather than going down into the well to stop the flow. By switching valves in the subsea manifold, we can inject the ‘bridging material’ (the junk), which will prevent such losses and enable the top kill to continue.
We’ve been testing the junk shot on-shore, looking at different configurations of what might restrict the flow out of the Deepwater Horizon riser and what types of materials would help shut it off. Materials in a junk shot can include well-known items such as pieces of tires, golf balls, and pieces of rope.
Most of the equipment is on site and preparations continue for this operation.
Subsea efforts continue to focus on interventions via the blow out preventer (BOP).
Source: http://www.bp.com/genericarticle.do?categoryId=2012968&contentId=7062409
A series of diagnostic tests are currently underway on the Deepwater Horizon’s failed BOP to improve understanding of the status and configuration of the BOP and determine whether a ‘top kill’ procedure can be successfully executed. These tests involve pumping drilling fluids into the BOP to measure pressures and validate flow paths. When complete, a decision will be made on the execution of the top kill procedure itself.
This top kill procedure has not been carried out offshore at 5,000 feet water depth before, and its success cannot be assured. It is expected that the entire procedure could take up to two days, and it cannot be predicted how long it will take for the operation to prove successful or otherwise. Should it be necessary, plans and equipment are in place to combine the top kill process with the injection under pressure of bridging material into the BOP to prevent or limit upward flow through the BOP.
BP will continue to provide a live video feed from the seabed through the diagnostic testing and top kill, if undertaken. Throughout the diagnostic process and top kill procedure very significant changes in the appearance of the flows at the seabed will be expected. These will not provide a reliable indicator of the overall progress, or success or failure, of the top kill operation as a whole.
Should the top kill not succeed in fully stopping the flow of oil and gas from the well, BP would then intend to move forward to deployment of the LMRP cap containment system.
Deployment of this system will involve first removing the damaged riser from the top of the BOP to leave a cleanly-cut pipe at the top of the BOP’s lower marine riser package (LMRP). The LMRP cap, an engineered containment device with a sealing grommet, would then be connected to a riser from the Discoverer Enterprise drillship and then placed over the existing LMRP with the intention of capturing most of the oil and gas flowing from the well.
The LMRP cap is already on site and it is anticipated that this option will be available for deployment by the end of May.
Additional options also continue to be progressed, including the option of lowering a second blow-out preventer, or a valve, on top of the failed Deepwater Horizon BOP.
Work on the drilling of two relief wells, begun on May 2 and May 16, continues. Each of the wells is estimated to take some three months to complete from the commencement of drilling.
BP confirmed it will continue to provide live video feeds from the seabed throughout the planned ‘top kill’ procedure – the attempt to stop the flow from the damaged MC252 well by pumping heavy drilling fluids into it. Preparations for this procedure are continuing with the expectation that it could be activated on the morning of Wednesday May 26, 2010. Throughout the extended top kill procedure – which may take up to two days to complete – very significant changes in the appearance of the flows at the seabed are expected. These will not provide a reliable indicator of the overall progress, or success or failure, of the top kill operation as a whole. BP will report on the progress of the operation as appropriate and on its outcome when complete.
