CCS EXPERTS DOWNPLAY INDUCED SEISMICITY CONCERNS

Tamar Hallerman
GHG Monitor
06/29/12

Proponents of carbon capture and storage this week argued that the industry already has protections in place limiting the potential for the technology to spur seismic events such as earthquakes, a fact they say weakens many of the conclusions presented in two recently published papers on the topic. Two high-profile reports published last week by the National Research Council and the journal Proceedings of the National Academy of Sciences, and amplified at a subsequent Senate Energy and Natural Resources Committee hearing, link the geologic storage of CO2 with the potential to induce seismic events. But in written responses this week and interviews with GHG Monitor, many in the CCS community said that some of the arguments made in the reports are moot given that current industry best practices and federal regulations aim to identify and root out any causes and effects of seismic events early through thorough site characterization and monitoring.

Several experts pointed to the Environmental Protection Agency’s Underground Injection Control program and Department of Energy and industry-developed best practices as reasons why the public should not be concerned about the potential for CCS projects to induce earthquakes.  “[The Proceedings study] is kind of attempting to whistle-blow something that’s already strongly overseen by regulations,” Susan Hovorka, a senior research scientist at the University of Texas at Austin’s Bureau of Economic Geology, said in an interview this week. “The Environmental Protection Agency’s Safe Drinking Water Act of 1974 and its new Class VI rules call out a very strong requirement to assess, avoid, manage and mitigate any negative geomechanical effects. So what’s the fuss? This paper warns us not to do something that’s already forbidden.”

Characterization, Monitoring Work Root Out Many Problems, Proponents Say

In particular, CCS proponents said that proper site characterization and monitoring, as required by DOE and EPA, is designed to help root out most potential causes for induced seismicity stemming from CCS operations early on. “If the upfront characterization work for the site is properly done, this would give us a very good understanding of the site geology, so the risks should be low for any potential induced seismic activity,” Victor Der, the Global CCS Institute’s chief representative for North America who previously worked as acting Assistant Secretary for Fossil Energy at DOE, told GHG Monitor this week.

Julio Friedmann, chief energy technologist at Lawrence Livermore National Laboratory, said that while he agrees with most of the fundamental technical observations from the Proceedings paper, its conclusions “misrepresent” many accepted practices within the sequestration community. He said that the paper underestimates the ability for sequestration site operators to adjust procedures if signs of seismic events are spotted. “The analysis assumes that you’re going to sort of start injecting and then close your eyes and do nothing for 60 years,” he said in an interview. “It puts forward no allowances for your ability to intervene or intercede and do something else, and there is no case where that would never be as so. There is no case in which you would just start injecting and then have an irreversible problem that you couldn’t map, anticipate or manage.”

Brian McPherson, an associate professor of Civil and Environmental Engineering at the University of Utah, said that other industry best practices—such as injecting CO2 through multiple wells for enhanced oil recovery operations instead of through a single, high-pressure injection point—also lower the likelihood of operations inducing seismic events. He criticized the reports for examining high injection rates as the only path forward for CO2 storage operations. “If a high injection rate approach is taken, then yes, induced seismicity will be a major concern, and I don’t disagree with anything they say in that respect. But I think that in itself is the flaw in the model,” he told GHG Monitor. “We’ve got 40 years of very successful enhanced oil recovery operations with CO2 injection, which takes place primarily over many wells with lower injection rates, not single wells with massive volumes going in.”

Supporters Underscore Need for More Data, Demonstration Work

Nearly all CCS experts interviewed by GHG Monitor pointed to a passage in the National Research Council study that said that more demonstration work is needed to fully understand CCS’ potential to induce seismic events and that few solid conclusions can be made at this point in time given the limited data available. While the Proceedings paper argued that lack of data and uncertainties related to induced seismicity are substantial enough to largely abandon the technology as a commercial-scale CO2 mitigation effort, others said that the same reason is enough to continue moving forward on CCS research. “It’s simply premature to make much of this before we do anything,” Friedmann said. “In a few years we will have a handful of large projects in the country and a bunch of data that we can assess from that. That’s an appropriate time, I think, for public and stakeholders to get exercise one way or another, but at this point we’re not talking about anything that exists.”

DOE Assistant Secretary for Fossil Energy Chuck McConnell said that the uncertainties surrounding CCS and induced seismicity are also enough to continue demonstration work. “We can get into debates in the press with people hypothetically talking about a lot of things. At the end of the day, what you see by executing the demonstrations, is being able to point to the realities of what the demonstrations display, not getting into some intellectual debate about what if or what could happen, but actually being able to point to [the results],” McConnell told reporters late last week on the sidelines of a National Coal Council meeting. “That’s why it’s so important that we continue with the demonstration projects that we have and we continue to get the support to do that.”

Deluge of Industry Responses Follow Studies’ Release

The flood of industry responses was sparked in part by the fear that public backlash could ultimately harm the future of CCS, one that was increased after the two reports garnered a flurry of media reports on the topic. Fears of a worst-case scenario of public opposition discontinuing projects—on par with what ultimately helped kill Germany’s only remaining CCS project, Vattenfall’s Janschwalde, last winter and propelled the Dutch government to ban all onshore CCS projects in early 2011—began to resurface for many in the industry. A hearing on the reports last week also appeared to raise concerns from some senators, suggesting that a broader debate on the safety of the technology in Congress or among the general public could be possible.

The National Research Council study, which was peer-reviewed, concluded that CCS “may” have the potential for causing “significant induced seismicity,” particularly because it requires the continuous injection of liquids into the subsurface at high pressures without a subsequent withdrawal of fluid from wells in order to balance pore pressure levels. The study also emphasized that risk is “currently difficult to accurately assess” given that there is not much field data available on the technology and that more work is needed before broader conclusions can be made.

The Proceedings paper, written by Stanford geophysicists Mark Zoback and Steven Gorelick, came largely to the same conclusions but took a harder line in terms of language. The pair said that there is a “high probability” that small to moderate-sized earthquakes will be triggered by the injection of large volumes of CO2 into the brittle rocks commonly found in the country’s continental interiors, often considered ideal sites for long-term CO2 storage, given their “critically stressed nature.” The two said that while induced seismicity stemming from CCS operations is of worry, even more principal a concern is that small to medium-sized quakes generated could threaten the seal integrity of the CO2 storage formation, potentially causing CO2 leaks. “Because even small- to moderate-sized earthquakes threaten the seal integrity of CO2 repositories, in this context, large-scale CCS is a risky, and likely unsuccessful, strategy for significantly reducing greenhouse gas emissions,” the paper said.

No Formal Response From DOE

Notably absent from the debate this week was DOE, which through its National Risk Assessment Program and regional sequestration partnerships has helped fund much of the landmark research on CCS and induced seismicity to date. There have been talks recently within the high ranks of DOE’s Office of Fossil Energy about drafting an official Department response, GHG Monitor confirmed, but nothing has surfaced as of press time. McConnell on June 22 said that DOE continues to be “mindful” the issue and said only that he did not have a department response “today.” “We’re not leaving any geological rock unturned, if you will, because it’s important for us to understand all the aspects of [the potential for induced seismicity],” McConnell said. “We continue to be mindful of it, and will do so as we continue with the demonstrations.”

Detailed rebuttals, though, were not hard to find among industry stakeholders. Bruce Hill of the Clean Air Task Force was among the first to respond last week, as was the Natural Resources Defense Council’s George Peridas, who said that he was worried about the Proceedings report in particular sparking “undue alarm” in the media. The reaction also crossed international borders, with the U.K.-based industry group the Carbon Capture and Storage Association publishing a page on its website this week examining whether the injection of CO2 can lead to earthquakes. The Regina-based Petroleum Technology Research Centre, which manages the IEAGHG Weyburn-Midale CO2 Monitoring and Storage Project in Saskatchewan, also issued a response comparing some of the points made in the Proceedings paper to their experiences at Weyburn. “In most respects, the opinions expressed by Drs. Zoback and Gorelick—about the importance of selecting safe sequestrations sites and the use of seismic and monitoring methods to assure the safety of such sites—have been anticipated and carried out by the Weyburn-Midale Project. None of the anticipated potential problems, however, have been observed,” PTRC CEO Malcolm Wilson said in his response.

Can Industry Ride Out the Storm?

McPherson said he expects the storm surrounding CCS and the potential for induced seismicity will soon blow over in the minds of the public and politicians. “I think the public will react more on results from actual testing than from speculation, even educated speculation, because it is speculation based on very little data, frankly, at this stage,” he said. Both McPherson and Peridas said that the studies and surrounding media firestorm reminded them of another paper published in 2010 in the Journal of Petroleum Science and Engineering. That report, written by Michael Economides and Christine Ehlig-Economides concluded that there is likely not enough storage capacity available for the safe geologic sequestration of CO2, leaving CCS to be a “profoundly non-feasible option for the management of CO2 emissions.” While some predicted a subsequent death for the CCS industry, that report was intensely refuted by people in the CCS community and ultimately did not lead to the destruction of the technology. 

Peridas, however, said that there is still a need for people in the scientific community to speak up if they do not agree with reports such as the NRC or Stanford papers. “What we need here is for the scientific community to read and digest what was published, to make their views known,” he told GHG Monitor. “I think it’s no good if scientists silently discredit things that were written but don’t make their views known.” Overall, Peridas said that it is important for CCS proponents to be open and honest with the public about the issue of induced seismicity. “I think the best communications strategy, frankly, is to be 100 percent honest. I don’t think we should be defending CCS in a way that portrays that we have no remaining doubts—I think that would be wrong,” Peridas said. Hovorka said that she ultimately does not expect the topic of induced seismicity to lead to extended anxiety for proponents looking to sell the technology to the public. “I think the important thing for CCS practitioners, the industry and DOE to say is ‘right, seismicity is a very important issue. It’s in our laws, we have various tools to characterize, monitor and mitigate the issue and we don’t need to change course. We need to go forward,” she said.