BP / Gulf Spill – 172 Million Gallons of Oil, 11.6 Billion Cubic Feet of Natural Gas

Scientists vehemently disagreed with the brief report issued by the federal government on August 4 that some interpreted as evidence that most of the oil spilled from BP’s Macondo well was…gone. Researchers at the University of Georgia issued their own report yesterday, claiming that nearly 80% of the oil spilled remains in the ecosystem, subject to evaporation and biodegradation but at unknown rates, meanwhile doing damage in a variety of different ways.

And natural gas, mostly methane, was released in great quantities during this spill. Some scientists have estimated that as much as 40% of the flow from the Macondo well was natural gas, mostly methane (CH4) that dissolved rather than floating to the surface and escaping into the atmosphere. At 80 cubic meters of methane per barrel of oil, with a total spill of 4.1 million barrels (172 million gallons) of oil, we calculate 328 million cubic meters – 11.6 billion cubic feet (BCF) – of methane were injected into the Gulf.

Researchers from Texas A&M University, the University of Georgia, and the University of California – Santa Barbara have measured levels of dissolved methane thousands of times above normal, thousands of feet below the surface. The microbial degradation of methane will consume oxygen from the water, possibly slowing biodegradation of the oil, particularly at deeper levels, and leading to the formation of additional oxygen-deficient dead zones devoid of fish, marine mammals, and much of the typical Gulf fauna.

Dr. Ian MacDonald of Florida State University will testify to Congress about this and the lingering impacts of this spill tomorrow morning. You can download his testimony here. A preview:

The Unified Command has made no mention of this gas, but it should not be ignored. Because the discharge occurred at 5000 ft depth, all the material rising toward the surface or drifting in subsurface plumes is in the ocean for hours, days, or months and can have a significant chemical and biological effect. So the hydrocarbon gas meets the OPA definition of “discharged.” The hydrocarbon gas is highly soluble in the deep, cold waters of the Gulf. Based on previous measurements, much of the gas released at depth will dissolve before it reaches the surface. Microbes degrading this material will compete for nutrients (like oxygen) with those attacking oil and will significantly affect the overall degradation process held to be so important by NOAA and DOI. Fish exposed to concentrated methane have exhibited mortality and neurological damage. The hydrocarbon gas was a major component of the total pollution load discharged from the BP well.

BP / Gulf Oil Spill – Curb Your Enthusiasm, Part 3

Yesterday the federal government weighed in on a complex topic: what happened to all the oil that spilled into the Gulf of Mexico from BP’s blown-out Macondo well? The joint report by NOAA and USGS lead some, including White House energy adviser and former EPA director Carol Browner, to make the claim that most of the oil that spewed into the Gulf this summer — an estimated total of 206 million gallons — is gone. Collected, burned, biodegraded or otherwise destroyed. Scientists have raised serious objections.

OK, let’s take a look at the actual report. According to the “Oil Budget Chart” above (Figure 1 in their report), NOAA estimates only 25% of the oil has been diverted, collected or otherwise definitively destroyed. The remaining 75% is still on or below the water’s surface or buried in marsh and beach sediments (26%); or it evaporated or dissolved (25%), was naturally dispersed (16%), or was chemically dispersed (8%).

Evaporation probably has moved a lot of the hydrocarbon out of the water and into the air. But “dissolved” and “dispersed” are not the same thing as “gone.” (Try drinking a nice tall glass of tea with a few spoonfuls of salt dissolved in it, and you’ll get what I mean.) NOAA is assuming rapid biodegradation of the dispersed and dissolved oil, which may be reasonable in relative terms — i.e., biodegradation in the hot Gulf is quicker than biodegradation in the frigid Arctic. But with no data provided on the actual rates of biodegradation, we don’t have any way of knowing just how much of the oil has naturally biodegraded at this point. We also don’t know what the intermediate breakdown products are, and what they do in the environment, and how long they last. Pesky but very important questions that can’t be answered quickly, or without a dedicated research effort that hopefully (??) is underway.

Total up the categories NOAA describes as “currently being degraded naturally” and you get 50% of the spilled amount, a whopping 103 million gallons (2.45 million barrels) of oil. That’s almost 10 times the size of the official Exxon Valdez spill.

Take the report at face value, agreeing that “only” 26% of the oil remains active in the environment, and you’re still talking about 50+ million gallons, almost 5 Exxon Valdez spills.

BP / Gulf Oil Spill – Static Kill Deemed a Success

Die, dragon, die!

The “static kill” operation has apparently succeeded, and cement is now being pumped into BP’s deadly Macondo oil well in the Gulf of Mexico. Work will continue on the nearest relief well to ultimately intercept Macondo at depth and complete the job, pumping cement in from the bottom of the failed well in a “bottom kill” operation that should provide a redundant measure of assurance that the Macondo dragon is well and truly dead.

When that finally happens it will be time to breathe a sigh of relief, and to think again about those who were killed and hurt, and their families and friends.

Then take a good hard look at exactly what happened, what the short-term damages are, and what the long-term consequences – environmental and economic – will be from this massive oil spill, the biggest unintentional oil spill in history. And hopefully learn the lessons, act on the harsh education we’ve all just been given (again), and get a lot smarter about how we produce and use energy in the future.

BP / Gulf Oil Spill – Static Kill Begins

Just heard that the “static kill” operation – pumping mud, possibly followed by cement, into the Macondo well via one of the valves on the blowout preventer – is now under way.

BP / Gulf Oil Spill – How Much Oil Underwater?

The new spill-rate estimate provided by government scientists yesterday got us thinking:

  1. How much of the oil, spilled 5,000′ down at the seafloor from BP’s Macondo well, never floated up to the surface, or sank back below the surface after being sprayed with dispersant?
  2. How much oil may remain in Gulf waters, possibly thousands of feet below the surface?
  3. What are the impacts of that “unseen” oil, and how long will it have toxic effects?

Time for some math: SkyTruth’s estimate of the spill rate (26,500 barrels per day), calculated way back at the end of April with help from Dr. Ian MacDonald at Florida State University, was based entirely on the oil we could see and measure at the ocean’s surface (8.9 million gallons, based on a Coast Guard map of the oil slick for April 28, 8 days into the spill).

Our spill-rate estimate is 43% of the 62,000 barrels-per-day rate that scientists now claim for the early days of the spill. But surely some of the “missing oil” in our estimate was consumed in the fire that raged on the Deepwater Horizon rig before it sank on April 22; so let’s optimistically say 2 days worth of flow from the well was totally burned up, bumping SkyTruth’s estimated daily flow rate up to 35,317 barrels per day – 57% of the new government rate. No oil was being diverted from the well at that time, and skimming operations probably weren’t collecting much at that point either, but dispersants were being used to break up the slick.

This suggests that at least 43% of the oil that leaked from the well remained under water or was driven back under water by dispersants, out of sight to satellite images and Coast Guard observers. Given a total spill of 172.2 million gallons, if we extrapolate from that first week we can conclude that at least 43% of that oil – 74 million gallons – may still be lurking beneath the surface in the Gulf.

That’s our attempt at answering the first question. As for the second question, biodegradation should be steadily breaking down this oil, but we don’t know at what rate, or what the byproducts of that breakdown might be. And we have no idea how to answer the third question.

Getting these answers will require a concerted, sustained, publicly transparent science effort. So we can be better prepared the next time something like this happens, and make better-informed plans for how we use our nation’s ocean resources in the future.