HomeLatest ThreadsGreatest ThreadsForums & GroupsMy SubscriptionsMy Posts
DU Home » Latest Threads » Forums & Groups » Topics » Environment & Energy » Environment & Energy (Group) » Statistical methods for t...

Sun Jan 31, 2016, 11:21 AM

Statistical methods for the eternal monitoring of carbon dioxide waste dumps.

Right now the world's largest, pretty much to the exclusion of all others, carbon dioxide dump is the planetary atmosphere. The failure to address climate change by humanity is obviated that the increase in planetary carbon dioxide concentrations in this dump, according to preliminary figures at the Mauna Loa carbon dioxide observatory, for the first time exceeded 3 ppm in a single year, setting an all time record.

Obviously all strategies to address the issue have failed miserably. We are now drilling more gas, more oil, and mining more coal than ever before, and basically the politically popular strategies for addressing the issue have all failed miserably.

One often discussed approach to dealing with the dangerous fossil fuel waste carbon dioxide is to "sequester" it in abandoned oil and gas fields after all of the dangerous fossil fuels in them have been mined and burned. Each year the amount of carbon dioxide dumped into the atmosphere is more than 30 billion tons; in 2012, according to the table on page 93 of the 2014 World Energy Outlook report, the world emissions were 31.6 billion tons. Undoubtedly the figures for 2013, 2014, and 2015 were significantly worse.

Twelve years ago, an overly optimistic and much discussed paper about "stabilization wedges" was published by two Princeton University faculty members, the famous Pacala and Socolow paper. (Science 13 Aug 2004: Vol. 305, Issue 5686, pp. 968-972)

One may note that many of the "suggestions" in this paper describing technologies that were allegedly "already available" in 2004 are extremely dubious, for two obvious examples being substituting wind energy and solar energy for coal; coal plants have capacity utilization factors of approximately 70 to 80 percent, whereas wind plants are lucky to approach 40% and solar facilities 20%, and I'm probably being overly generous with both of these figures. If one shuts a coal plant down for the four hours when lots of solar energy is available near the summer equinox for example, one will be required to waste huge amounts of energy since coal boilers are not perfectly thermally isolated, and extra energy will be required to return the boilers to operational levels, much as a kettle on a stove requires significant heat before the water boils.

(Solar and wind energy are therefore useless as alternatives to coal; and in fact, they are completely dependent on dangerous natural gas to exist at all, with all the fracking and other risks gas dependency requires.)

One of the "stabilization wedges" discussed was carbon dioxide capture and sequestration sites designed to collect and store dangerous fossil fuel waste when, um, the wind wasn't blowing and the sun wasn't shining. In Pacala and Socolow's paper, in table 1 on page 970 this is described as "building 3500 Sleipners."

A "Sleipner" in case one doesn't know, refers to a program proposed by the Norwegian dangerous fossil fuel company Statoil to put lipstick on its offshore oil and gas drilling pig by injecting carbon dioxide into the Sleipner oil field for "sequestration" which Statoil liked to imply was "eternal sequestration." After much hulaboo, the Sleipner program was abandoned on the grounds that it was, um, "too expensive" compared to dumping carbon dioxide waste directly into the existing and "economic" dump, the planetary atmosphere.

The number of "Sleipners" built since 2004 is uncomfortably close to zero; nearly one hundred percent of all carbon dioxide injected into oil and gas fields today is designed for "EOR," the euphemistically named "enhanced oil recovery" scheme, where the plan is to drive even more dangerous fossil fuels out of the ground so the waste can be dumped in the atmosphere.

But one may ask: Suppose that there really were significant carbon dioxide waste dumps built on the scale that Socolow and Pacala suggested were "already available" in 2004, what then?

A recent paper in the scientific journal Environmental Science and Technology discusses some of the issues that are grotesquely ignored in what I regard as this "sweep it under the rug and let future generations worry about it" scheme: The possibility that these dumps for containing a dangerous gas might, um, leak.

The paper is here: Environ. Sci. Technol., 2015, 49 (2), pp 12151224

The title is: Quantifying the Benefit of Wellbore Leakage Potential Estimates for Prioritizing Long-Term MVA Well Sampling at a CO[sub]2[/sub] Storage Site.

Here's some of the introductory text from the paper:

In an effort to mitigate concentrations of carbon dioxide (CO2)in the atmosphere that are caused by stationary anthropogenic inputs, the United States Department of Energy (DOE) is pursuing carbon capture and sequestration (CCS) as one approach in a portfolio of greenhouse gas (GHG) reduction strategies. CCS involves (1) separating CO2 from an industrial process, (2) transporting the CO2 to a storage location, and (3)injecting and sequestering the CO2 in a geologic reservoir furlong-term isolation from the atmosphere.1 Through the Carbon Sequestration Program, the DOE is working with seven Regional Carbon Sequestration Partnerships (RCSPs) to identify feasible sites within the U.S. and portions of Canada for large-scale (i.e., one million tons of CO2 or greater) CO2geologic sequestration.2 The DOE is pursuing three primary types of geologic systems for long-term CO2 storage: (1)depleted oil and gas fields; (2) unconventional formations such as gas shales, coal seams, and basalts; and (3) salineformations.3

One of the potential risks associated with the injection and long-term storage of CO2 into geologic reservoirs is leakage of stored CO2 from geologic containment and into the near surface or surface environment. A potential leakage pathway in depleted oil and gas fields is associated with legacy exploration and production wells.4−6 These legacy wells provide a potential conduit through low-permeability cap rock formations that would otherwise act as a seal to retain CO2 in the storage reservoir. Extensive work has been conducted in Alberta, Canada over the past decade to assess the potential CO2leakage risk of legacy wells by drawing inferences from well completion and abandonment information. This work has, in part, been performed as part of the DOE Regional PartnershipPlains CO2 Reduction (PCOR) Partnership...

The paper then explores the "statistical power" of sampling a subset of drilled wells to determine the probability that more are leaking.

...A well leakage potential scoring approach like the one developed by Watson and Bachu8 provides a quantitative means for ranking the increased probability of CO2 leakage at specific well because of SCVF and/or GM. Applying this scoring methodology to the legacy wells that are located within particular region provides a screening-level risk assessment approach for identifying potential geologic CO2 storage sitesareas with a high incidence of high-ranking wells would represent locations that are not favorable to long-term geologic storage of CO2, while areas with a low incidence of highrankingwells may be suitable future CO2 injection and storage.In addition, once a geologic CO2 storage site has beenidentified, then such a well ranking approach also informs themonitoring, verification, and accounting (MVA) sampling planfor the site, as higher-ranking wells would take priority overlower-ranking wells...

There's no mention at all of what it might cost future generations to monitor these dumps for...um, um, um...eternity, but if that bothers you, don't worry, be happy: You can be reasonably assured that these dumps, not twenty "Sleipners" never mind 3500 of them, will not be built. It's far more convenient and, um, "economic" to use the "traditional" dump, the planetary atmosphere.

Enjoy the remainder of your Sunday.

0 replies, 642 views

Reply to this thread

Back to top Alert abuse

Reply to this thread