Chevron Oil Spill, Brazil - Small Slick December 6, 2011
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Envisat ASAR radar image taken December 6, 2011. Image courtesy European Space Agency - click for larger version.
We've been getting a few Envisat ASAR radar satellite images of the Campos Basin off the coast of Brazil, covering the Frade field, where Chevron and their contractor Transocean experienced a loss of well control during drilling on November 7 that initiated an oil spill. Apparently "unexpected" reservoir pressure caused drilling mud to back up in the well, allowing highly pressurized oil (and probably some gas) to leak out into the surrounding bedrock. This oil has since been working its way up to the seafloor through faults or fractures in the rock, emerging along a line of unnatural seeps on the seafloor, and floating up to the surface to create visible oil slicks. The well was plugged a week after the spill began, and since then visible slicks have diminished in size.
Chevron may also be required by Brazilian authorities to drill a relief well to inject cement into the well at depth -- an expensive proposition -- to formally abandon the failed well. And a Brazilian federal prosecutor based in Campos has filed a $10.8 billion suit against Chevron and Transocean, and is seeking to have both companies permanently banned from drilling in Brazil.
Meanwhile in Bohai Bay, China, ConocoPhillips has found little environmental damage from their spill earlier this year in the Peng Lai 19-3 field. But they did reveal that their spill, like Chevron's, was caused "due to unexpected pressure encountered while drilling." A mistake like that can lead to a blowout and major spill. I hope all of the technical details from both of these incidents are being disclosed and will be made available to the public and to US regulators.
The radar satellite image above, taken on December 6, 2011, shows a very small slick originating near the location of Transocean's SEDCO 706 drilling rig that was installing Chevron's failed well. The slick is about 7.3 miles long and a few hundred yards wide, comparable to the slicks created by natural oil seeps in the Gulf of Mexico. Wind conditions were good for slick detection at the time, blowing at about 10 knots (5 meters per second). Several other small slicks are visible near a cluster of oil platforms (bright spots) about 50 miles south of the SEDCO 706. This is within the southern Campos Basin, and these slicks may be the result of minor spills or leaks from platforms, pipelines, or vessels operating in one of the many offshore fields in the region.
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Scientists Ask For More Arctic Science Before Drilling
| 573 scientists, including renowned oceanographer and National Geographic explorer-in-residence Sylvia Earle, signed a letter just delivered to President Obama asking him to follow the recommendations of a 2011 US Geological Survey report to fill in gaps in our understanding of Arctic Ocean marine science, before allowing full-blown oil and gas drilling in the Beaufort and Chukchi Seas.
Shell and BP are two of the big players with big drilling plans for the Arctic. Both have caused major oil spills recently, off Nigeria a few weeks ago and of course in our own Gulf of Mexico in 2010. |
Media Highlights - 2011
| Check out SkyTruth's media page for the link to our Media Highlights - 2011 page. The page contains a list of all of SkyTruth's major media hits from 2011, from the Op-Ed piece in the Huffington Post that John co-wrote with Dr. Ian MacDonald of Florida State University, to the Los Angeles Times blog announcing the launch of our SkyTruth Alerts System.You can also read the Associate Press interview with John about the size of the Shell oil spill off the coast of Nigeria. That story was carried in several major media outlets like The Guardian and the New York Times. You can also find the radio interview as well as the television interview with WV Public Broadcasting, and many more media hits so what are you waiting for? Go have a look! |
Blowout off Nigeria?
| Given the sustained intensity of the fire on the K.S. Endeavor drill rig that ignited off the coast of Nigeria yesterday morning, we're starting to think a total loss of well control occurred.
Yep, that would be a blowout. Two workers are still missing.
We assume the rig was drilling Chevron's "Funiwa Deep" natural gas exploration well. Since gas was the target, we hope that means the risk of a major oil spill is low.
What's next? The rig will probably collapse soon from
the intense sustained heat. It's possible that will extinguish the
fire, although the natural gas and/or gas condensate release will continue to pose a serious fire/explosion hazard
until Chevron can plug the leaking well. They'll have to bring in another rig
to drill a relief well.
Depressingly familiar? You bet. See the Montara blowout off Australia in 2009, and BP blowout in the Gulf of Mexico in 2010, for two of the more spectacular drilling failures in recent years. |
Taylor / 23051 Chronic Leak Site in Gulf: Oil Analyzed
| Back on September 15, a team from National Wildlife Federation piled onto a small boat on the Louisiana coast. Their destination: the chronic leak site about 12 miles offshore where a cluster of wells operated by Taylor Energy has been steadily spilling oil into the Gulf since 2004. Check out this aerial video of the site, shot by On Wings of Care on December 9, 2011:
Their objective: to collect samples of the Taylor oil slick for analysis, to see if it's chemically distinguishable from the oil that gushed from BP's infamous Macondo well about 30 miles away. We wanted to know if other samples of oil collected in this region of the Gulf, on beaches and barrier islands and from slicks observed offshore, could possibly be coming from the Taylor site since it's a well-documented source of oil pollution. The NWF team -- coached in advance by Dr. Ed Overton at Louisiana State University on proper collection and sampling technique -- succeeded. Dr. Overton analyzed the Taylor oil samples and in mid-October told us "these were heavily weathered oil with slight differences in the fingerprint pattern from the Macondo oil." (more after the jump....)
Elaborating on this a few days later, Dr. Overton said "the biomarker fingerprint is very similar but it does have significant
differences especially in the 218 and 231 ion plots. Also, the
C2DBT/C2Ph and C3DBT/C3Ph ratios are not consistent with Macondo oil.
The sample we got from Ben Raines [of a small slick one mile from the Macondo well location] was very fresh with almost no
weathering while the Taylor samples were all pretty heavily weathered
with almost no normal hydrocarbons left in the GC data. So, if you know
what you are doing, you should be able to distinguish between Taylor
sheens and other samples especially of the Macondo oils. We really need
samples of nearby seep oils and sheens from these seeps to get a full
picture but so far, we have been able to fingerprint the Macondo oil
fairly accurately (at least in my opinion)."
Here is a graphic Dr. Overton provided us yesterday, illustrating the difference in "weathering" of the Taylor oil samples from NWF compared with fresh Macondo oil samples taken directly from the riser pipe that connected the Macondo well with the Deepwater Horizon platform. Dr. Overton said "While the data shown in the plots are not from the fingerprinting, these
plots clearly show how much the Taylor samples were weathered compared
to the Macondo Riser oil. Getting good samples of all the slicks is a
very daunting task because it requires close collaboration between
surface sampling vessels and airborne observation. None the less, we
still do not have good samples from sheens in the vicinity of the
Macondo well."
Data illustrating difference in weathering between oil samples taken from slicks at the Taylor/23051 chronic leak site, and from the riser pipe containing fresh crude from the Macondo well. Graphic courtesy Dr. Ed Overton, Louisiana State University.
The upshot: oil leaking from the Taylor site should not easily be confused with relatively unweathered oil from the Macondo disaster. But it would be very helpful to collect more and better samples from the slicks being observed in the vicinity of the Macondo well site.
Eventually, as residual Macondo oil gets older and more highly weathered it will become more difficult to differentiate it from Taylor oil. |
Shelling out the Oil in Waters off Nigeria: Radar Satellite Image December 21, 2011
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Envisat ASAR satellite radar image showing large slick (black) from major Shell oil spill off Niger Delta. Image taken December 21, 2011 at 9:30am local time. Image courtesy European Space Agency.
Royal Dutch Shell's Nigerian drilling operations in the highly productive Bonga Field were officially brought to a halt yesterday after "less than 40,000 barrels of oil" (1.7 million gallons) were reportedly leaked during a transfer of crude to a tanker. We've just processed a radar satellite image taken this morning (December 21, 2011) of the field, with the spill clearly visible. Here it is showing the slick outlined in yellow; it is about 70 km (45 miles) long, 17 km (10 miles) wide at it's widest, and covers 923 square kilometers (356 square miles) of ocean:
Envisat
ASAR satellite radar image showing large slick (outlined in yellow) from major oil spill
off Niger Delta. Image courtesy European Space Agency.
Another, much smaller oil slick appears at lower right; this looks like a bilge dump from a passing vessel, not related to the Shell spill.
Located 120 km off the the Nigerian coast, the Bonga Field
is the first deepwater oil exploration and production project for the
country since Shell began offshore drilling there in 2005. Shell's onshore operations in the Delta have a long history of spills.
Map showing location of Bonga Field off Nigeria. Courtesy Marcel De Jong, Shell Deepwater Services Regional Study Team.
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Shell Oil Spill - Moving Toward Nigerian Coast
| Yesterday's MODIS satellite images were a bust, but today's were slightly less cloudy/hazy. Both the Terra and Aqua images show a pale patch of ocean water about 18 kilometers offshore, covering a total area of about 678 square kilometers. But this is a tough call - the image quality really isn't very good. The closest sizable populated area near this part of the coast, according to Google Earth, is the town of Burutu located at top center on this graphic:
MODIS/Terra satellite image taken December 23, 2011 at 10:10am local time. Possible location of oil slick noted. Image data courtesy NASA/MODIS Rapid Response Team.
This fuzzy patch that may or may not be the remnants of the oil slick is located about where we would expect to see it, given the wind speed and direction over the past couple of days (blowing from the south-southwest at 5-10 knots). Radar imagery would give us a better look but we haven't seen any new radar images since December 21.
So far we haven't heard that any oil has come ashore. Shell reports they have mounted a vigorous response, including the use of chemical dispersants to break up the oil slick.
Yesterday Shell also released this photograph showing what purportedly caused the leak - a small crack in a transfer line at their FPSO. Engineers, tell us - how long would it take to spill >1 million gallons of oil from a relatively small break like this? I don't know the diameter of this line; possibly 20" or so?
Photograph reportedly taken by ROV showing crack in transfer line. Photo courtesy Shell.
Let us know if you have any expertise on flow rates through pipelines, and are willing to provide some expert opinion on this. |
Oil Pollution off Nigeria - Other Sources?
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After flying journalists over the remnants of the Bonga FPSO oil spill off Nigeria,Shell pointed out that they are not the only
polluters in this part of the world, and will clean up another small spill in the area not related to any of their operations.
That certainly doesn't excuse their (much larger) mess but they are correct: satellite images of the west coast of Africa, like some other
coastal regions around the world, routinely show signs of oil pollution from other sources, especially bilge-dumping by vessels large and small. We don't know if it's legal in this area; it is not legal in US or Canadian waters. Radar satellite imagery is an excellent tool for detecting bilge-dumping.
This Envisat ASAR image taken on December 18, 2011 shows a 100-mile-long slick caused by bilge dumping from a large vessel that was traveling toward the southeast on a course taking it very close to the Bonga FPSO (we've inferred the location of the FPSO from multiple radar satellite images; if anyone has the exact lat/lon coordinates please pass them along to us):
Envisat ASAR image taken December 18, 2011 showing oily bilge dump from a passing vessel northwest of the Bonga oil field off Nigeria. Image courtesy European Space Agency.
At 1 micron thick this bilge slick holds about 80,000 gallons of oily material. Projecting the vessel track back to the northwest, we land near the city of Aneho on the Togo coast. There is an industrial facility in the area that appears to have an offshore loading system. It could be the point of origin for the suspect vessel, but we really have no way of knowing:
Projecting backward along bilge slick to shore. Envisat ASAR image courtesy European Space Agency.
Here's what it looks like in Google Maps. Does anyone have any information about this facility?
View Larger Map |
Shell Oil Spill off Nigeria - How Big?
| Shell has declared victory over the major oil spill from their Bonga FPSO off Nigeria, claiming the slick was halted 12 miles offshore and has mostly dissipated, thanks to evaporation plus the use of chemical dispersants. Our observations of satellite images over the past few days don't indicate anything to the contrary.
How big was this spill? We think the amount spilled is near the high end of Shell's estimate of "up to" 1.68 million gallons, based on the size of the oil slick observed on December 21 and the photos provided by Shell showing a rainbow sheen. The thickness of "rainbow sheen" is in the 5 to 10 micron range according to the CONCAWE guidelines, and 0.3 to 5 micron range according to the BONN convention.
The overlap -- 5 microns -- would mean a spill of at least 1.2 million gallons (28,571 barrels).
On
their website
Shell reported the slick was "less than a hundredth of a millimeter" thick in
most areas. 1/100th of a millimeter is 10 microns, which would be a
spill of 2.4 million gallons -- 58,000 barrels.
Assuming Shell, like most successful companies, is fanatical about inventory control they should be able to provide an accurate measurement by comparing the amount pumped out of the FPSO with the amount that actually ended up in the shuttle tanker. Flow meters on the pumps and transfer lines, and gauges in the tanks, should allow them to calculate the spill with precision. Let's ask them for those numbers and settle the question.
Regardless of the specific amount spilled, we're left with some troubling questions, most notably: how could up to 1.7 million gallons of oil steadily leak into the ocean before anybody noticed and took action? The crack in one of the transfer lines that Shell blames for this leak looks like it could only divert about 5-10% of the flow through that line. How long would that take to amount to 1.7 million gallons? This is just the latest example of the many mundane, low-tech ways that modern offshore oil production still poses risks -- even when it's being done by one of the biggest, technically accomplished, retail-brand-sensitive multinational oil companies (hmm, that sounds familiar...). |
Satellite Image Shows Heat From Chevron Drill Rig Fire, Offshore Nigeria
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K.S. Endeavor jackup drilling rig burning off Nigeria's coast on January 16, 2012. Photo courtesy Chevron.
We've been following reports of a drill rig on fire off the coast of Nigeria, working for Chevron in the Funiwa field. We've also been collecting satellite imagery of the site. Yesterday's MODIS images had a big data gap right over this area, so we didn't get a chance to see this until today. Here's what it looked like this morning from space, captured by NASA's MODIS sensor on the Terra satellite. Clouds and haze, all too common in this part of Africa, obscure most of the area, and there is little sign of a big problem down below in the standard "true color" rendering:
MODIS/Terra true-color satellite image of Niger Delta region, January 17, 2012. Clouds and haze obscure much of the area.
But let's look again, this time with the 7-2-1 rendering that includes the mid-infrared wavelengths. There is a bright red dot located approximately where we think the rig was working (we could use a more precise location if anyone has it):
MODIS/Terra 7-2-1 infrared composite of Niger Delta region, January 17, 2012. Clouds and haze are minimized, and the burning rig appears as a bright red spot just offshore along the curve in the Delta coastline.
[See zoomed-in images after the jump...]
Geek alert: this indicates strong emission from the middle-infrared part of the spectrum (band 7). At high temperatures the Planck emission function is shifted toward shorter wavelengths. This fire must be at least 1000 degrees Kelvin (1340 degrees Fahrenheit), hot enough to soften steel:
Let's zoom in a bit and compare the true-color image with the 7-2-1 false color infrared composite:
Detail of MODIS true-color image along Niger Delta coastline, January 17, 2012.
Detail of MODIS 7-2-1 infrared image along Niger Delta coastline, January 17, 2012. Bright red spot marks inferred location of the burning K.S. Endeavor jackup drill rig.
Of course, we're continuing to monitor this pollution-plagued part of the world. |
Brazil's Latest Oil Spill - Another FPSO-Related Failure
| According to a SkyTruth volunteer based in Brazil, the vessel involved in this week's spill is the tanker Elka Aristotle.
And according to a handy vessel traffic site she recently stopped off at "Campos Basin P38" which appears to be an FPSO in the Marlim Sul field of the Campos Basin. Check out this excellent, well illustrated and very detailed summary of the Marlim Sul field discovery and development, including the role of the P38 FPSO.
So this spill was most likely related to routine FPSO operations. Something to look forward to soon in the Gulf of Mexico. |
Drilling to Begin Soon in Deep Water Off Cuba
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Say hello to my little friend: Scarabeo-9 arrives to begin deepwater drilling off Cuba. Photo courtesy Shipspotting.com.
The Scarabeo-9, a big semisubmersible drill rig owned by Italian company ENI, just built in China, and currently under contract to the Spanish oil company Repsol, has arrived in the Florida Straits off the north coast of Cuba to begin exploratory oil drilling. The rig will begin its work in exploration block N27 (see map after the jump) just 90 miles from Key West, in water about 6,500' deep. That's 1,500' deeper than the site of the BP / Deepwater Horizon spill in the Gulf in 2010.
[More after the jump...]
Map of offshore oil and gas exploration blocks in Cuban waters. Scarabeo-9 rig will be drilling soon for Repsol in Block N27 in Florida Straits, about 90 miles from Key West. Map courtesy Cuba Standard.
The rig passed an informal US inspection while it stopped over in Trinidad on its trip here from China, and Repsol has voluntarily agreed to comply with to US "environmental requirements" related to offshore drilling (whatever that means). But Floridians are concerned that should a major spill occur, wind and current could push oil into US waters and potentially on to southern Florida islands and beaches that dodged a bullet during the BP / Deepwater Horizon spill.
Making matters worse, the US trade embargo against Cuba prohibits US spill-response companies and oil companies from providing assistance unless they've received a special license from the State Department. Only a few firms have been licensed at this point -- representing only about 5% of the spill-response capacity that was thrown, with minimal effect, at the BP / Deepwater Horizon spill -- but that's not going to stop the Scarabeo-9 from making hole.
On the hook for a rig-rental fee of more than $500,000 per day, Repsol is unlikely to keep the Scarabeo idle while we get our act together. Time is big money in this capital-intensive business.
We'll be monitoring this area, too, using satellite images. We'll publish here when we get our first image showing the rig on location. |
Oil Slicks off Brazil - December 30, 2011
| SkyTruth staff and volunteers have been looking pretty hard at the offshore oil producing areas along the coast of Brazil since Chevron's spill from the Frade field in the Campos Basin, caused when they lost control of a new well being drilled in deepwater back in November. That well had to be plugged and abandoned. But there is a lot going on in Brazil's waters, and there are other sources of oil pollution apparent on radar satellite images taken on November 25 and December 6.
Teri noticed that this NASA/MODIS image from December 30, 2011, shows a moderate-sized apparent oil slick (with a much smaller companion nearby) in deepwater about 225 kilometers offshore. It doesn't have the shape we usually associate with bilge-dumping from a passing vessel; this looks more like the slicks formed by leaks at depth, or from a stationary point source. The slicks cover about 260 square kilometers. We calculate they hold at least 68,000 gallons:
Detail from MODIS satellite image taken December 30, 2011, showing apparent oil slicks off Brazil.
(maps after the jump)
This is far out on the edge of deepwater activity in Brazil, so we're not sure what could be the source. The maps below give the context for these slicks. Actively producing offshore fields are outlined in green; colored dots show exploration and production wells; and yellow rig icons show the locations where rigs were drilling in 2011, based on data we downloaded from ANP yesterday. These data show no rigs in the vicinity, and the nearest well is an exploration well (purple dots) about 17 km from what we infer to be the source end of the larger slick:
Map showing December 30 oil slicks, active offshore oil /gas fields, drill rigs that were working in 2011, and existing wells.
Overview showing December 30 oil slicks and regional offshore oil/gas infrastructure of the Campos and Santos basin areas off Brazil.
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