Wednesday, August 04, 2010

Day 107 BP Oil Spill: 75% Of Oil Gone; Static Kill Success

Aug 4: The Federal government has issued a report indicating that the vast majority of the oil from the BP oil spill (i.e. approximately 75 percent) has either evaporated or been burned, skimmed, recovered from the wellhead or dispersed -- much of which is in the process of being degraded. A significant amount of this is the direct result of the robust federal response efforts. The latest government report follows the revised estimate released by the Flow Rate Technical Group (FRTG) on August 2, indicating that 4.9 million barrels of oil were released into the Gulf by the BP leak.
    The new report -- BP Deepwater Horizon Oil Budget: What Happened To the Oil? -- says that a third (33 percent) of the total amount of oil released in the Deepwater Horizon/BP spill was captured or mitigated by the Unified Command (UC) recovery operations, including burning, skimming, chemical dispersion and direct recovery from the wellhead. An additional 25 percent of the total oil naturally evaporated or dissolved, and 16 percent was dispersed naturally into microscopic droplets. The residual amount, just over one quarter (26 percent), is either on or just below the surface as residue and weathered tarballs, has washed ashore or been collected from the shore, or is buried in sand and sediments. Dispersed and residual oil remain in the system until they degrade through a number of natural processes. According to a release, early indications are that the oil is degrading quickly. 
    The estimates were derived by the National Oceanic and Atmospheric Administration (NOAA) and the Department of the Interior (DOI), who jointly developed what's known as an Oil Budget Calculator, to provide measurements and best estimates of what happened to the spilled oil. The calculator is based on the estimated 4.9 million barrels of oil released into the Gulf and more than 25 of the "best government and independent scientists" contributed to or reviewed the calculator and its calculation methods.
    Jane Lubchenco, under secretary of commerce for oceans and atmosphere and NOAA administrator said, "Teams of scientists and experts have been carefully tracking the oil since day one of this spill, and based on the data from those efforts and their collective expertise, they have been able to provide these useful and educated estimates about the fate of the oil. Less oil on the surface does not mean that there isn't oil still in the water column or that our beaches and marshes aren't still at risk. Knowing generally what happened to the oil helps us better understand areas of risk and likely impacts."
   The estimates do not make conclusions about the long-term impacts of oil on the Gulf. Fully understanding the damages and impacts of the spill on the Gulf of Mexico ecosystem is something that will take time and continued monitoring and research. The release indicates that dispersion increases the likelihood that the oil will be biodegraded, both in the water column and at the surface. "While there is more analysis to be done to quantify the rate of biodegradation in the Gulf, early observations and preliminary research results from a number of scientists show that the oil from the BP Deepwater Horizon spill is biodegrading quickly. Scientists from NOAA, EPA, DOE, and academic scientists are working to calculate more precise estimates of this rate." 
   The release explains that it is well known that bacteria that break down the dispersed and weathered surface oil are abundant in the Gulf of Mexico in large part because of the warm water, the favorable nutrient and oxygen levels, and the fact that oil enters the Gulf of Mexico through natural seeps regularly. Residual oil is also degraded and weathered by a number of physical and biological processes.  Microbes consume the oil, and wave action, sun, currents and continued evaporation and dissolution continue to break down the residual oil in the water and on shorelines.
    In additional major news on the BP spill, the company issued a statement on August 3, indicating that based on the results of the injectivity test, it started pumping drilling mud at 15:00 (CDT) [4 PM EDT] as part of the static kill operations. All operations are being carried out with the guidance and approval of the National Incident Commander. The aim of these procedures is to assist with the strategy to kill and isolate the well, and will complement the upcoming relief well operation.

    Today (August 4), BP announced that the MC252 well appears to have reached a static condition -- "a significant milestone." The well pressure is now being controlled by the hydrostatic pressure of the drilling mud, which is the desired outcome of the static kill procedure carried out on August 3. Pumping of heavy drilling mud into the well from vessels on the surface was stopped after about eight hours of pumping. The well is now being monitored, per the agreed procedure, to ensure it remains static. Further pumping of mud may or may not be required depending on results observed during monitoring.

    BP said it will continue to work with the National Incident Commander and other government officials to determine the next course of action, which involves assessing whether to inject cement in the well via the same route. The aim of the procedures is to assist with the strategy to kill and isolate the well, and will complement the upcoming relief well operation, which will continue as per plan. A relief well remains the ultimate solution to kill and permanently cement the well. The first relief well, which started May 2, has set its final 9 7/8-inch casing. Operations on the relief wells are suspended during static kill operations. Depending upon weather conditions, mid-August is the current estimate of the most likely date by which the first relief well will intercept the Macondo well annulus, and kill and cement operations commence.
    Access the release on the Federal report (click here). Access the complete 5-page BP oil spill budget report (click here). Access a release from BP on the current static condition (click here). Access more information on BP activities from the BP response website (click here). Access the Restore the Gulf website for more information (click here). Access the Unified Command website which contains additional information (click here). 

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