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Categorized under: Super Pollutants

Curb Methane Emissions

For several weeks now the public and the media have cast increasing attention on Arctic oil and gas drilling, specifically regarding the plans of Shell to explore in the Arctic waters off the coast of Alaska. This is, pardon the pun, only the tip of the iceberg when it comes to Arctic oil and gas development. Around the Arctic, efforts are ramping up in Russia, Norway, Greenland and Canada to stake a claim to one of the last great reserves of undiscovered oil and gas. According to the United States Geological Survey, the Arctic holds one-fifth of the world’s undiscovered, recoverable oil and natural gas; 90 billion barrels of oil and 1,669 trillion cubic feet of natural gas.

With Shell’s imminent entrance into Arctic waters, the debate is turning from “if we drill in the Arctic,” to “how and where we drill in the Arctic.” The discussion to date has primarily revolved around the key questions of oil spills and impacts to marine ecosystems. However, it is also critically important to remember that this debate starts and ends with climate change.

The melting of the Arctic due to global warming is what set off the race for Arctic oil and gas. Now, it is incumbent upon the countries and the companies that intend to develop the Arctic to make sure that it is done in the least damaging way possible, and this includes paying very close attention to the global warming pollutants coming from the production: methane, black carbon and carbon dioxide. Pointing the way forward in a new report: (www.catf.us/resources/publications/view/170),

Clean Air Task Force has laid out the primary climate risks and mitigation strategies of drilling in the Arctic. Here is a summary of some of the key findings of that report:

While oil production is the primary focus of current exploration and production activities due to high oil prices, natural gas is almost always produced along with oil, posing the problem of what to do with it. Crude oil usually contains some amount of “associated” natural gas that is dissolved in the oil or exists as a cap of free gas above the oil in the geological formation. In some cases, this represents a large volume of gas. For example, nearly 3 trillion cubic feet (Tcf) per year of gas is produced in association with oil in Alaska. The largest (but by no means only) potential source of methane pollution is from the leaks or outright venting of this “associated” natural gas. Flaring, the typical way to dispose of this “stranded” gas, is much better than venting, but it releases a tremendous amount of CO2. Worldwide, about 5 trillion cubic feet of gas is flared each year. That’s about 25 percent of the US’s annual natural gas consumption. This leads to the release of about 400 million tons of CO2 per year globally, the equivalent to the annual emissions from over 70 million cars.

Black carbon is also emitted from flares, although measurements are lacking to fully understand the potential burden from flaring. What we do know is that the black carbon that flaring will release in the Arctic is particularly harmful, since it is so likely to settle out on snow or ice, where the dark pollutant rapidly warms the white frozen surface.

Many technologies and best practices exist to reduce the impact of oil and gas production both to the Arctic and the global climate. If we are going to extract the oil from the Arctic, we need to do it in a way that does not exacerbate the very real problem that climate change is already posing there. In order to do so, the US must take the lead in ensuring that only the best practices are acceptable when it comes to Arctic exploration and drilling. The technologies and practices below can dramatically reduce the emissions associated with oil and natural gas, in some cases by almost 100%.

First, we need better characterization of emissions in the region, and better monitoring and reporting information. Our current estimates of methane and black carbon emissions from oil and natural gas production are very rough, and may not apply at all for Arctic operations. Establishing standardized monitoring and reporting protocols, backed by legislation, is essential to quantifying these emissions and then adopting the best mitigation techniques.

Second, we must deal with the CO2, methane and black carbon from oil and gas production. Put simply, we must use it, store it or, as a last resort, flare it as cleanly as possible:

  • Wherever possible, all associated gas that is brought to the surface must be used beneficially. Gas should be sent to consumers through pipelines or consumed on-site or locally (for power generation, thermal or feedstock uses). Liquefying gas for transport to distant markets is another productive use, but it comes at a very large energy (CO2 emissions) cost and may also have higher methane emissions from boil-off of LNG. Other technologies to chemically transform stranded gas to liquids should also be investigated.
  • When the gas cannot be used locally or piped, the best option will often be reinjection of the gas into underground reservoirs, where geologically feasible. In addition to preventing methane or CO2 emissions, this serves to both store the gas for potential future use and also to maintain pressure in the geologic formation. Associated gas has been re-injected at large scale on Alaska’s North Slope for over 30 years.
  • When there is no reasonable alternative to flaring, operators must use effective flares. Efficient flares can destroy nearly all the methane in the gas, and should have very minimal releases of black carbon, however, as stated above, they will remain a very large source of CO2. Producers must pay royalties on any gas they flare off, too – every incentive must be brought to bear to push producers to find ways to avoid flaring.

Next, we need to deal with vented and fugitive methane emissions. Here we need vapor recovery units on storage, process tanks and floating production, storage and offloading units. Operators must use compressed air or electric control systems rather than pneumatic controllers, mitigation of methane emissions from all dehydrators and piston compressors must be required, and the use of wet seal compressors without gas capture systems must be prohibited. To detect leaks and equipment failures, aggressive inspection and maintenance programs must be in place for all facilities operating in the Arctic.

Finally, for the mitigation of black carbon emissions, we should require ultra low sulfur diesel fuel (ULSD) and Diesel Particulate Filters (DPF) for all diesel engines and diesel-powered ships – either new or retrofit. And we should push to establish International Maritime Organization requirements for BC emission reductions for international shipping affecting the Arctic.

The opening of the Arctic to increased oil and gas development is a cause for concern. The Arctic is already being hammered by climate change and other environmental impacts. If we are on the verge of an Arctic oil and gas rush, this will only add to the issues facing this fragile environment. If we implement the above policies domestically, and pressure our other Arctic neighbors to do the same, we will reduce, but certainly not eliminate, the air and climate impacts of oil and gas development in the Arctic.