More Nigeria news from SkyTruth

Oil slick near Bonga field. Photo: Shell Oil

Why do we hear so little about spills in the Gulf of Guinea region? Well, there are the officials and companies who don’t (seem to) give a damn. There are the restrictions on the press in a number of countries and the lack of resources for journalists across the region that hamper in-depth reporting. But there’s also the fundamental lack of oversight: we don’t hear much because the governments themselves don’t know much. They don’t have monitoring systems and are — far too often — at the mercy of the oil companies when it comes to getting information about spills and clean-up.

SkyTruth, an organization that seeks to create environmental awareness through the use of satellite imagery (“If you can see it, you can change it”), has been posting regular updates on the recent Bonga spill.

I’m reposting links to the last two pieces from SkyTruth, which get at several crucial points regarding the Gulf of Guinea: No one knows what’s going on because of the lack of monitoring and oil is being spilled or dumped all the time in the region. Remember the spill off the coast of Ghana in November? Was it from the Jubilee operations or a passing tanker? Who knows?

Oil Pollution off Nigeria – Other Sources?

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):

To see the image and continue reading, click here.

 

And the second post:

Shell Oil Spill off Nigeria – How Big?

Shell has declared victory over the major oil spill from their BongaFPSO 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 daysdon’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 thesize 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…).

 

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