Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

'Problem wells' source of greenhouse gas at unexpected stage of natural gas production

15.04.2014

High levels of the greenhouse gas methane were found above shale gas wells at a production point not thought to be an important emissions source, according to a study jointly led by Purdue and Cornell universities. The findings could have implications for the evaluation of the environmental impacts from natural gas production.

The study, which is one of only a few to use a so-called "top down" approach that measures methane gas levels in the air above wells, identified seven individual well pads with high emission levels and established their stage in the shale-gas development process.


This shows a well pad in southwestern Pennsylvania. A Purdue and Cornell study found high levels of the greenhouse gas methane above shale gas wells during the drilling stage -- a production point not thought to be a significant emissions source.

Credit: (Photo courtesy of Dana Caulton)

The high-emitting wells made up less than 1 percent of the total number of wells in the area and were all found to be in the drilling stage, a preproduction stage not previously associated with significant emissions.

"These findings present a possible weakness in the current methods to inventory methane emissions and the top-down approach clearly represents an important complementary method that could be added to better define the impacts of shale gas development," said Paul Shepson, a professor of chemistry and earth atmospheric and planetary sciences at Purdue who co-led the study with Jed Sparks, a professor of ecology and evolutionary biology at Cornell. "This small fraction of the total number of wells was contributing a much larger large portion of the total emissions in the area, and the emissions for this stage were not represented in the current inventories."

The researchers flew above the Marcellus shale formation in southwestern Pennsylvania in the Purdue Airborne Laboratory for Atmospheric Research, a specially equipped airplane. The aircraft-based approach allowed researchers to identify plumes of methane gas from single well pads, groups of well pads and larger regional scales and to examine the production state of the wells.

"It is particularly noteworthy that large emissions were measured for wells in the drilling phase, in some cases 100 to 1,000 times greater than the inventory estimates," Shepson said. "This indicates that there are processes occurring - e.g. emissions from coal seams during the drilling process - that are not captured in the inventory development process. This is another example pointing to the idea that a large fraction of the total emissions is coming from a small fraction of shale gas production components that are in an anomalous condition."

The bottom-up inventories have been produced from industry measurements of emissions from individual production, transmission and distribution components and then scaling up to create an estimate of emissions for the region. However, with thousands of wells, and a complex processing and transmission system associated with each shale basin, obtaining a representative data set is difficult, he said.

A paper detailing the results will be published in the Proceedings of the National Academy of Sciences on Monday (April 14). The David R. Atkinson Center for a Sustainable Future at Cornell University funded this research.

"We need to develop a way to objectively measure emissions from shale gas development that includes the full range of operator types, equipment states and engineering approaches," Shepson said. "A whole-systems approach to measurement is needed to understand exactly what is occurring."

###

Writer: Elizabeth K. Gardner, 765-494-2081, ekgardner@purdue.edu

Source: Paul Shepson, 765-494-7441, pshepson@purdue.edu

PHOTO CAPTION: A well pad in southwestern Pennsylvania. A Purdue and Cornell study found high levels of the greenhouse gas methane above shale gas wells during the drilling stage - a production point not thought to be a significant emissions source. (Photo courtesy of Dana Caulton)

A publication-quality photo is available at http://www.purdue.edu/uns/images/2014/shepson-wellpad.jpg

PHOTO CAPTION: Researchers used the Purdue Airborne Laboratory for Atmospheric Research, a specially equipped airplane, to measure plumes of methane gas above shale gas wells in southwestern Pennsylvania. (Photo courtesy of Paul Shepson)

A publication-quality photo is available at http://www.purdue.edu/uns/images/2014/shepson-plane.jpg

ABSTRACT

Toward a Better Understanding and Quantification of Methane Emissions from Shale Gas Development
Dana R. Caulton, Paul Shepson, Renee L. Santoro, Jed P. Sparks, Robert W. Howarth, Anthony R. Ingraffea, Maria O. L. Cambaliza, Colm Sweeney, Anna Karion, Kenneth J. Davis, Brian H. Stirm, Stephen A. Montzka, and Ben R. Miller

The identification and quantification of methane emissions from natural gas production has become increasingly important owing to the increase in the natural gas component of the energy sector. An instrumented aircraft platform was used to identify large sources of methane and quantify emission rates in southwestern PA in June 2012. A large regional flux, 2.0-14g CH4 s-1 km-2, was quantified for a ~2,800-km2 area, which did not differ statistically form a bottom-up inventory, 2.3-4.6 g CH4 s-1 km-2. Large emissions averaging 34 g CH4s-1 per well were observed from seven well pads determined to be in the drilling phase, 2 to 3 orders of magnitude greater than US Environmental Protection Agency estimates for this operational phase. The emissions from these well pads, representing ~1% of the total number of wells, account for 4-30% of the observed regional flux. More work is needed to determine all of the sources of methane emissions from natural gas production, to ascertain why these emissions occur and to evaluate their climate and atmospheric chemistry impacts.

Elizabeth K. Gardner | Eurek Alert!

More articles from Ecology, The Environment and Conservation:

nachricht Preservation of floodplains is flood protection
27.09.2017 | Technische Universität München

nachricht Conservationists are sounding the alarm: parrots much more threatened than assumed
15.09.2017 | Justus-Liebig-Universität Gießen

All articles from Ecology, The Environment and Conservation >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Neutron star merger directly observed for the first time

University of Maryland researchers contribute to historic detection of gravitational waves and light created by event

On August 17, 2017, at 12:41:04 UTC, scientists made the first direct observation of a merger between two neutron stars--the dense, collapsed cores that remain...

Im Focus: Breaking: the first light from two neutron stars merging

Seven new papers describe the first-ever detection of light from a gravitational wave source. The event, caused by two neutron stars colliding and merging together, was dubbed GW170817 because it sent ripples through space-time that reached Earth on 2017 August 17. Around the world, hundreds of excited astronomers mobilized quickly and were able to observe the event using numerous telescopes, providing a wealth of new data.

Previous detections of gravitational waves have all involved the merger of two black holes, a feat that won the 2017 Nobel Prize in Physics earlier this month....

Im Focus: Smart sensors for efficient processes

Material defects in end products can quickly result in failures in many areas of industry, and have a massive impact on the safe use of their products. This is why, in the field of quality assurance, intelligent, nondestructive sensor systems play a key role. They allow testing components and parts in a rapid and cost-efficient manner without destroying the actual product or changing its surface. Experts from the Fraunhofer IZFP in Saarbrücken will be presenting two exhibits at the Blechexpo in Stuttgart from 7–10 November 2017 that allow fast, reliable, and automated characterization of materials and detection of defects (Hall 5, Booth 5306).

When quality testing uses time-consuming destructive test methods, it can result in enormous costs due to damaging or destroying the products. And given that...

Im Focus: Cold molecules on collision course

Using a new cooling technique MPQ scientists succeed at observing collisions in a dense beam of cold and slow dipolar molecules.

How do chemical reactions proceed at extremely low temperatures? The answer requires the investigation of molecular samples that are cold, dense, and slow at...

Im Focus: Shrinking the proton again!

Scientists from the Max Planck Institute of Quantum Optics, using high precision laser spectroscopy of atomic hydrogen, confirm the surprisingly small value of the proton radius determined from muonic hydrogen.

It was one of the breakthroughs of the year 2010: Laser spectroscopy of muonic hydrogen resulted in a value for the proton charge radius that was significantly...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

ASEAN Member States discuss the future role of renewable energy

17.10.2017 | Event News

World Health Summit 2017: International experts set the course for the future of Global Health

10.10.2017 | Event News

Climate Engineering Conference 2017 Opens in Berlin

10.10.2017 | Event News

 
Latest News

Terahertz spectroscopy goes nano

20.10.2017 | Information Technology

Strange but true: Turning a material upside down can sometimes make it softer

20.10.2017 | Materials Sciences

NRL clarifies valley polarization for electronic and optoelectronic technologies

20.10.2017 | Interdisciplinary Research

VideoLinks
B2B-VideoLinks
More VideoLinks >>>