Emissions are unmeasured, affect debate over proposed EPA regulations
As debate roils over EPA regulations proposed this month limiting the release of the potent greenhouse gas methane during fracking operations, a new University of Vermont study funded by the National Science Foundation shows that abandoned oil and gas wells near fracking sites can be conduits for methane escape not currently being measured.
The study, to be published in Water Resources Research on October 20, demonstrates that fractures in surrounding rock produced by the hydraulic fracturing process are able to connect to preexisting, abandoned oil and gas wells, common in fracking areas, which can provide a pathway to the surface for methane.
A recent paper published in the Proceedings of the National Academies of Science showed that methane release measured at abandoned wells near fracking sites can be significant but did not investigate how the process occurs.
"The debate over the new EPA rules needs to take into account the system that fracking operations are frequently part of, which includes a network of abandoned wells that can effectively pipeline methane to the surface," said the new paper's lead author, James Montague, an environmental engineering doctoral student at the University of Vermont, who co-wrote the paper with George Pinder, professor of environmental engineering at the university.
The study focused on an area in New York State underlain by the Marcellus Shale formation, which had been fracked until a ban went into effect in the state in the summer of 2015.
The formation, composed of layers of shale and hydrocarbons, is beneath land that has been the site of conventional oil and gas drilling since the 1880s, when American oil companies first began operating.
About 40,000 existing wells in New York, 30,000 of them located within the footprint of the Marcellus formation, are documented by the state's Department of Environmental Conservation. But the department estimates that 70,000 wells in all have been drilled.
Because the location of so many wells is not known - a common phenomenon in many regions where fracking takes place - the study uses a mathematical model to predict the likelihood that the hydraulically induced fractures of a randomly placed new well would connect to an existing wellbore.
The model put the probability that new fracking-induced fractures in the Marcellus formation would connect to an existing well bore at between .03 percent and 3 percent.
But industry-sponsored information made public since the paper was published vastly increased assumptions about the area impacted by a set of six to eight fracking wells known as a well pad - to two square miles -- increasing the probabilities cited in the paper by a factor of 10 or more.
While all fracking sites are different, most have a similar enough hydrocarbon profile that they attracted conventional oil and gas drilling in the past and most, like the Marcellus, have a large number of abandoned wells, many with unknown locations.
Not all abandoned wells provide a pathway to surface for methane. Only those that are damaged, largely when the concrete that buffers the well from the surrounding earth loses integrity, can act as a conduit.
But even a small percentage of damaged wellbores, given the large number of abandoned wells, can potentially pose an environmental risk, Pinder said.
Jeff Wakefield | EurekAlert!
Climate satellite: Tracking methane with robust laser technology
22.06.2017 | Fraunhofer-Gesellschaft
How reliable are shells as climate archives?
21.06.2017 | Leibniz-Zentrum für Marine Tropenforschung (ZMT)
An international team of scientists has proposed a new multi-disciplinary approach in which an array of new technologies will allow us to map biodiversity and the risks that wildlife is facing at the scale of whole landscapes. The findings are published in Nature Ecology and Evolution. This international research is led by the Kunming Institute of Zoology from China, University of East Anglia, University of Leicester and the Leibniz Institute for Zoo and Wildlife Research.
Using a combination of satellite and ground data, the team proposes that it is now possible to map biodiversity with an accuracy that has not been previously...
Heatwaves in the Arctic, longer periods of vegetation in Europe, severe floods in West Africa – starting in 2021, scientists want to explore the emissions of the greenhouse gas methane with the German-French satellite MERLIN. This is made possible by a new robust laser system of the Fraunhofer Institute for Laser Technology ILT in Aachen, which achieves unprecedented measurement accuracy.
Methane is primarily the result of the decomposition of organic matter. The gas has a 25 times greater warming potential than carbon dioxide, but is not as...
Hydrogen is regarded as the energy source of the future: It is produced with solar power and can be used to generate heat and electricity in fuel cells. Empa researchers have now succeeded in decoding the movement of hydrogen ions in crystals – a key step towards more efficient energy conversion in the hydrogen industry of tomorrow.
As charge carriers, electrons and ions play the leading role in electrochemical energy storage devices and converters such as batteries and fuel cells. Proton...
Scientists from the Excellence Cluster Universe at the Ludwig-Maximilians-Universität Munich have establised "Cosmowebportal", a unique data centre for cosmological simulations located at the Leibniz Supercomputing Centre (LRZ) of the Bavarian Academy of Sciences. The complete results of a series of large hydrodynamical cosmological simulations are available, with data volumes typically exceeding several hundred terabytes. Scientists worldwide can interactively explore these complex simulations via a web interface and directly access the results.
With current telescopes, scientists can observe our Universe’s galaxies and galaxy clusters and their distribution along an invisible cosmic web. From the...
Temperature measurements possible even on the smallest scale / Molecular ruby for use in material sciences, biology, and medicine
Chemists at Johannes Gutenberg University Mainz (JGU) in cooperation with researchers of the German Federal Institute for Materials Research and Testing (BAM)...
19.06.2017 | Event News
13.06.2017 | Event News
13.06.2017 | Event News
26.06.2017 | Life Sciences
26.06.2017 | Physics and Astronomy
26.06.2017 | Information Technology