Abandoned wells can be ‘super-emitters’ of greenhouse gas

One of the wells the researchers tested; this one in the Allegheny National Forest. -  Princeton University
One of the wells the researchers tested; this one in the Allegheny National Forest. – Princeton University

Princeton University researchers have uncovered a previously unknown, and possibly substantial, source of the greenhouse gas methane to the Earth’s atmosphere.

After testing a sample of abandoned oil and natural gas wells in northwestern Pennsylvania, the researchers found that many of the old wells leaked substantial quantities of methane. Because there are so many abandoned wells nationwide (a recent study from Stanford University concluded there were roughly 3 million abandoned wells in the United States) the researchers believe the overall contribution of leaking wells could be significant.

The researchers said their findings identify a need to make measurements across a wide variety of regions in Pennsylvania but also in other states with a long history of oil and gas development such as California and Texas.

“The research indicates that this is a source of methane that should not be ignored,” said Michael Celia, the Theodore Shelton Pitney Professor of Environmental Studies and professor of civil and environmental engineering at Princeton. “We need to determine how significant it is on a wider basis.”

Methane is the unprocessed form of natural gas. Scientists say that after carbon dioxide, methane is the most important contributor to the greenhouse effect, in which gases in the atmosphere trap heat that would otherwise radiate from the Earth. Pound for pound, methane has about 20 times the heat-trapping effect as carbon dioxide. Methane is produced naturally, by processes including decomposition, and by human activity such as landfills and oil and gas production.

While oil and gas companies work to minimize the amount of methane emitted by their operations, almost no attention has been paid to wells that were drilled decades ago. These wells, some of which date back to the 19th century, are typically abandoned and not recorded on official records.

Mary Kang, then a doctoral candidate at Princeton, originally began looking into methane emissions from old wells after researching techniques to store carbon dioxide by injecting it deep underground. While examining ways that carbon dioxide could escape underground storage, Kang wondered about the effect of old wells on methane emissions.

“I was looking for data, but it didn’t exist,” said Kang, now a postdoctoral researcher at Stanford.

In a paper published Dec. 8 in the Proceedings of the National Academy of Sciences, the researchers describe how they chose 19 wells in the adjacent McKean and Potter counties in northwestern Pennsylvania. The wells chosen were all abandoned, and records about the origin of the wells and their conditions did not exist. Only one of the wells was on the state’s list of abandoned wells. Some of the wells, which can look like a pipe emerging from the ground, are located in forests and others in people’s yards. Kang said the lack of documentation made it hard to tell when the wells were originally drilled or whether any attempt had been made to plug them.

“What surprised me was that every well we measured had some methane coming out,” said Celia.

To conduct the research, the team placed enclosures called flux chambers over the tops of the wells. They also placed flux chambers nearby to measure the background emissions from the terrain and make sure the methane was emitted from the wells and not the surrounding area.

Although all the wells registered some level of methane, about 15 percent emitted the gas at a markedly higher level — thousands of times greater than the lower-level wells. Denise Mauzerall, a Princeton professor and a member of the research team, said a critical task is to discover the characteristics of these super-emitting wells.

Mauzerall said the relatively low number of high-emitting wells could offer a workable solution: while trying to plug every abandoned well in the country might be too costly to be realistic, dealing with the smaller number of high emitters could be possible.

“The fact that most of the methane is coming out of a small number of wells should make it easier to address if we can identify the high-emitting wells,” said Mauzerall, who has a joint appointment as a professor of civil and environmental engineering and as a professor of public and international affairs at the Woodrow Wilson School.

The researchers have used their results to extrapolate total methane emissions from abandoned wells in Pennsylvania, although they stress that the results are preliminary because of the relatively small sample. But based on that data, they estimate that emissions from abandoned wells represents as much as 10 percent of methane from human activities in Pennsylvania — about the same amount as caused by current oil and gas production. Also, unlike working wells, which have productive lifetimes of 10 to 15 years, abandoned wells can continue to leak methane for decades.

“This may be a significant source,” Mauzerall said. “There is no single silver bullet but if it turns out that we can cap or capture the methane coming off these really big emitters, that would make a substantial difference.”


Besides Kang, who is the paper’s lead author, Celia and Mauzerall, the paper’s co-authors include: Tullis Onstott, a professor of geosciences at Princeton; Cynthia Kanno, who was a Princeton undergraduate and who is a graduate student at the Colorado School of Mines; Matthew Reid, who was a graduate student at Princeton and is a postdoctoral researcher at EPFL in Luzerne, Switzerland; Xin Zhang, a postdoctoral researcher in the Woodrow Wilson School at Princeton; and Yuheng Chen, an associate research scholar in geosciences at Princeton.

Mercyhurst, Vanderbilt research targets supervolcanoes

The National Science Foundation has awarded Mercyhurst and Vanderbilt universities a $354,000 grant to engage students in researching one of Earth’s rarest yet deadliest acts — the eruption of a supervolcano.

The Research Experience for Undergraduates (REU) three-year project will take 10-12 students per year into northwest Arizona to study an extinct supervolcano. Students will select their own research pursuit, follow up with lab work at either Mercyhurst or Vanderbilt and, ultimately, present their findings at a national conference.

“The emphasis of this project is to engage students in scientific research, which is consistent with Mercyhurst’s commitment to hands-on learning,” said principal investigator Nick Lang, Ph.D., an assistant professor of geology at Mercyhurst. His project colleague at Vanderbilt is Lily Claiborne, Ph.D.

Lang said the research initiative targets students from diverse backgrounds. “We are looking for talented students, with a particular emphasis on returning veterans, first-generation college students and minorities who will do original research and contribute to the large body of work on supervolcanoes,” he said.

Comprehending what led to supereruptions in the past is essential to understanding and predicting similar events. A supereruption, Lang said, is a volcanic explosion that erupts a volume of material greater than 1,000 km3. This can be about a thousand times larger than normal volcanic eruptions. The deadly 1980 Mount St. Helens explosion, for instance, ejected only 1 cubic km3 of volcanic material, Lang said.

The 10-12 students chosen to participate in each of the three years will hone their geology field skills by investigating the Silver Creek caldera, which produced the Peach Spring Tuff (PST) supereruption nearly 19 million years ago. The PST is exposed over 32,000 km² of western Arizona, southeastern California and southern Nevada.

Students studying the region’s geologic record will guide their research around questions like: What does a supervolcano look like before it erupts? How and why do large magmatic systems change over time? How does supereruptive magmatism (ex., PST) compare with typical-scale magmatism (ex., Mt.St. Helens)?

Lang said he is eager to get started on the research, which will begin in late December or early January in Arizona followed by another field session in the summer. Students will also complete their lab work during the summer, attending either Mercyhurst or Vanderbilt.

“This is an exciting opportunity for us because these grants (National Science Foundation) are difficult to obtain,” Lang said. “The success rate for a project to be funded is 20 to 25 percent.”

Water was present during birth of Earth

New research by The University of Manchester and the Carnegie Institution of Washington is to make scientists rethink their understanding of how Earth formed.
New research by The University of Manchester and the Carnegie Institution of Washington is to make scientists rethink their understanding of how Earth formed.

New research by The University of Manchester and the Carnegie Institution of Washington is to make scientists rethink their understanding of how Earth formed.

The team have found that volatile elements – most likely to include water – were present during the violent process of the Earth’s birth between 30 and 100 million years after the solar system was created – a minute period in geological terms

The findings mean that comets and asteroids were unlikely to have brought the bulk of volatile elements to Earth – as commonly thought.

Lead scientist Dr Maria Schonbachler from The University of Manchester, publishes her research in Science, the prestigious weekly American journal today.

The scientist based at the University’s School of Earth, Atmospheric and Environmental Sciences hit upon the findings by using high precision equipment to measure abundances of Silver isotopes contained in rocks.

The readings show that the moderately volatile element Silver was present in relatively large amounts towards the final stages of the Earth’s formation.

The radioactive isotope Palladium 107 decays to Silver 107, which was present during the formation of the solar system.

The decay of Palladium 107 creates anomalies in the abundances of Silver isotopes, which can be measured and used for dating, even though Palladium 107 is no longer present on Earth.

The findings give a new boost to a 30 year old model, which suggests that volatile elements were already present in the final stages of the Earth’s birth.

How much of these elements were lost during impacts like the one that formed the moon, however, is still not well known.

Dr Schonbachler said: “The sensitive equipment we use works in much the same way as when you might carbon date a rock or artifact – but on a scale which enables us to go back billions of years.

“And those measurements allow us to detect a transition from volatile-depleted to volatile-enriched building blocks as the accumulation of Earth proceeded.

“Because we know what happened to the moderately volatile Silver, it’s very likely that the same thing happened to the highly volatile water.

“Though I accept that about 85 per cent of the Earth’s mass was built without volatile elements the rest of it was- and that’s quite an important difference in our understanding of the Earth’s geological history.”

“We don’t now need any theories about how water came to Earth – such as comets and asteroids – it was most likely here almost from the beginning. And water is, what made Earth habitable for life. “

New translation reveals ancient metals and minerals

New GSA Special Paper 467, 'Mining and Metallurgy in Ancient Peru,' is a translation of a 1970 publication by Georg Petersen. Translator William E. Brooks notes that many of the ancient Andean mining and metallurgical techniques described in this book precede those known in Europe. -  The Geological Society of America
New GSA Special Paper 467, ‘Mining and Metallurgy in Ancient Peru,’ is a translation of a 1970 publication by Georg Petersen. Translator William E. Brooks notes that many of the ancient Andean mining and metallurgical techniques described in this book precede those known in Europe. – The Geological Society of America

In 2009, Perú was the world’s leading producer of silver, the second leading producer of copper, and the leading producer of gold in Latin America. But this isn’t something new. Perú’s leadership in mining and metallurgy extends for centuries into the past. This Special Paper from The Geological Society of America documents the use in ancient Perú of minerals, metals, and mineral resources for pigments, industrial stone, aesthetics, and art.

The GSA volume is a translation of a 1970 publication by the Instituto de Investigaciones Antropológicas, in Lima, Perú, written by Georg Petersen. Translator William E. Brooks notes that many of the ancient Andean mining and metallurgical techniques described in this book precede those known in Europe.

The volume also provides forward-thinking analytical data on metals, artifacts, and alloys. A detailed pyrite mirror, featured on book’s cover, symbolizes the spectacular workmanship and blending of utilitarian craft and mineral resources in ancient Perú.

Chapters cover minerals, gems, and pigments; ornamental and industrial stone; specific occurrences of gold, silver, copper, iron, mercury, tin, lead, and platinum in Perú, Bolivia, and Colombia; gold, silver, copper, and mercury metallurgy; Inca mining from 1533 to 1534 in the Altiplano, as documented by the Spanish explorers; and even a forensic description of the Chuquicamata Mummy, the remains of an ancient copper miner killed during an earthquake.