The Financial Times highlights a concern we had raised early on about the effort by BP to drill a relief well to stop the flow of oil into the Gulf. While many analysts have acted as if the BP forecast, that the well would be completed by August, there is no reason to assume the initial effort will succeed, particularly at this depth, which is unprecedented for this effort. We pointed out the last effort to drill a relief for a large leak in the Gulf, at Ixtoc in 1979, took ten month to yield results. The commentary i the story suggests that a delay would not be as severe.
From the Financial Times:
Almost 6,060m below the surface of the Gulf of Mexico and 4,500m below the seabed, BP’s engineers are zeroing in on a narrow target: the 25cm-wide steel casing of its old Macondo well, which has been leaking oil since late April…
While those in the industry believe the relief wells will eventually stop the oil, they note the scale of the challenge. In addition to the depth, the original drilling process suffered several setbacks because of the difficult geology and pressures.
“Drilling a well thousands of feet into rock to hit a target no more than six inches [15cm] wide isn’t exactly a sure thing,” says Guy LeBas, strategist at Janney Capital Markets. “There remains a risk that the leak could continue past August.”
BP, under pressure from Washington, is drilling two relief wells to multiply the chances of success…
The intersection is targeted for a section of the pipe that is less than 10 inches in diameter.
“It may take a couple of tries,” says Jonathan Parry, of consultants IHS CERA and who previously worked as a deepwater engineering advisor for Chevron. “It may take more than one relief well,” Mr Parry says.
Experience suggests that it can take several attempts – and more time than BP has so far admitted…
“It is extremely difficult,” says a geologist. Oil engineers warn that the extra attempts do not require a full, new relief well, however. If BP fails to intersect the well at its first attempt, the engineers will backtrack and use their directional drilling systems, which allow them to move their drill like a snake. Each attempt will take days or weeks, rather than the three months needed to drill a new well, they say
On other fronts, another concern raised early on, that the dispersant used by BP, Corexit, was dangerous and could cause additional harm, appears to be valid. Crops near the Gulf Coast are showing damage consistent with Corexit toxicity. From SFGate (hat tip reader Doc Holiday):
BP’s favorite dispersant Corexit 9500 is being sprayed at the oil gusher on the ocean floor. Corexit is also being air sprayed across hundreds of miles of oil slicks all across the gulf…
Corexit 9500 is a solvent originally developed by Exxon and now manufactured by the Nalco of Naperville, Illinois (who by the way just hired some expensive lobbyists). Corexit is is four times more toxic than oil (oil is toxic at 11 ppm (parts per million), Corexit 9500 at only 2.61ppm).
In a report written by Anita George-Ares and James R. Clark for Exxon Biomedical Sciences, Inc. titled “Acute Aquatic Toxicity of Three Corexit Products: An Overview” Corexit 9500 was found to be one of the most toxic dispersal agents ever developed…
The UK’s Marine Management Organization has banned Corexit so if there was a spill in the UK’s North Sea, BP is banned from using Corexit. In fact Corexit products currently being used in the Gulf were removed from a list of approved treatments for oil spills in the U.K. more than a decade ago. The Environmental Advisory Service for Oil and Chemical Spills at IVL, Swedish Environmental Institute, has, upon request of the Swedish Environmental Protection Agency evaluated Corexit extensively and recommended it not be used in Swedish waters.
The Swedish study concludes: “The studies suggest that a mixture of oil and dispersant give rise to a more toxic effect on aquatic organisms than oil and dispersants do alone… The research on toxicity of oils mixed with dispersants has, however, shown high toxicity values even when the dispersant per se was not very toxic.” A report for the Alaska Department of Environmental Conservation Division of Spill Prevention and Response concluded that Corexit actually inhibits bacterial degradation of crude oil. It may look good on the surface but it will take longer for natural bacteria to eat up the crude oil.
Studies on Corexit and its effects on plants are consistent with the damage sustained in the lower Mississippi area. Check out the table on page 877 of the study. While no one precisely knows, all the signs point to BP’s use of aerosolized Corexit brought inland by the ocean winds or rain.
Yves here. Note the author points out that the link between Corexit and crop damage at this point is “conjecture”. Update 2:30 AM: Reader Kalpa believes the more likely culprit for the plant damage is sulfur trioxide vapors released from the Lucite Chemical plant in Millington, Tennessee, which was shut down by the EPA until the problem was resolved. Back to the original post.
However, other commentators are concerned that evaporating oil and dispersants may be harming clean-up crews and Gulf residents. From the Orlando Independent Examiner (hat tip reader Doc Holiday):
Toxins that are released into the air from evaporating oil and dispersants may pose a greater health risk to clean-up workers and Gulf residents than oily water when the thickest parts of the oil slick wash ashore…
Scientists and researchers, however, are keenly aware of potential health risks to people not only from exposure to oil in the water, but also to fumes in the air. The Institute for Southern Studies (ISS) reported as early as May 10 that, “the latest evaluation of air monitoring data shows a serious threat to human health from airborne chemicals emitted by the ongoing deep water gusher.”…
A report published by the Louisiana Environmental Action Network (LEAN) analyzed data released by the EPA taken from a testing site in Venice, LA between April 26 and May 26 (see chart). The results show unsafe levels of both Hydrogen Sulfide and VOCs in the air.
For instance, on May 3 hydrogen sulfide had been detected at concentrations more than 100 times greater than the level known to cause physical reactions in people. The fluctuations in readings are attributed to many factors such as wind speed and direction, heat index and other atmospheric conditions that vary on a daily basis.
A more recent report published by the Natural Resources Defense Council (NRDC) analyzes offshore air quality data released by BP. The findings replicate conclusions in earlier reports that the level of toxins in the air is unsafe for humans. “Nearly 70% (275 out of 399) of offshore air samples had detectable levels of hydrocarbons and nearly 1 in 5 (73 out of 399) had levels greater than 10 parts per million (ppm), which is an EPA cutoff level for further investigation. 6 samples exceed 100 ppm which in a previous monitoring summary was labeled as the action limit.”
Moreover, there are now reports of BP oil on the US East Coast (hat tip reader emca from Alexander Higgins):
I confirmed that water and oil mixture then does indeed extend to the Florida Keys as shown on the ROFFS map which directly contradicts the statement NOAA has made stating that the Florida Keys and South Florida will be unaffected by the spill.
ROFFS also told me that in addition to the confirmed Jacksonville oil concentration that there are unconfirmed reports of oil in Fort Pierce, Florida which is south of the Jacksonville as well as unconfirmed reports of oil as far north as the Washington D.C and Maryland area.
The post includes a recording and transcript of the call. Higgins also has a cheery report that the mixture of oil and Corexit is damaging boat hulls.
Emca also pointed out that BP is not cooperating with effort to fingerprint the oil, which would enable researchers to be certain that oil sighted is indeed from the Gulf leak.
Needless to say, this is all pretty disheartening.