The unconventional revolution in North America has provided lessons for industry throughout the world – from technology to geology, operators look to precedents set in the United States to decide best practices and procedures.
The trend holds true especially with regard to resistance from environmental and community groups.
The recent AAPG-SEG International Conference and Exhibition (ICE) in Melbourne, Australia, provided a unique opportunity to learn about that precedent in the sessions dedicated to environment, regulation and social license to operate.
Ian Duncan, a native of New South Wales, returned to his home country to share research from his work at the Bureau of Economic Geology at the University of Texas in Austin. He brought a poster and delivered a lecture on the scientific data intended to inform public debates over coalbed seam gas (CSG) extraction and hydraulic fracturing.
Duncan’s poster, “Accuracy of Facts Supporting Justice-Based Social License-to-Operate Arguments for CSG Development: Information From Four Decades of CBM Production in North America,” provided a review of environmental impact statements and models published before coalbed methane (CBM) extraction and compared them with case studies conducted by state agencies and consultant reports to see what actually happened.
Duncan, who presented the poster with Andrew Garnet, director of the Center for Coal Seam Gas at the University of Queensland, said his research helps address concerns that have risen in Australia surrounding CSG.
“Australia with CSG is where the United States was 20-25 years ago with stages of development,” he said. “Australia can learn about getting gas out of coal by looking at the track record in the United States.”
Prediction and Reality
Duncan’s analysis in Melbourne addressed two primary concerns raised by CSG extraction: water table reduction and land subsidence.
“Because operators have to pump water out of coal beds in order for gas to come out, farmers and environmentalists are concerned that they will get all the water out of the area and it will be gone,” he said.
Duncan noted that when CBM extraction first started in the United States, numerous hydrological and computer models predicted massive amounts of water would be extracted. After projects were completed, the total extraction was much less than predicted.
The difference between prediction and reality comes from challenges associated with geologic modeling and modeling consultants’ hesitancy to underestimate the impact of CSG development.
“Modelers tend to be conservative,” he said. “Extracting more water is bad; less water is good. No one wants to be seen as having a rosy scenario. The conservative choice is to have the highest permeability.”
Duncan added that areas with coal seam gas tend to have low permeability rocks, which are very challenging to model.
He also noted that Australian land models are very similar to models used in the United States 20-25 years ago.
“The models tend to create a grid spacing of 10-15 square meters,” he said. “That includes a number of different types of geology, so they have to average them and create rocks that don’t actually exist.”
Another question raised throughout the world is how much the land surface will sink as a result of CSG extraction.
“In Australia, there are suggestions in the Surat Basin, the land will sink up to two meters,” Duncan said, noting that these claims do not fit with his subsidence studies following decades of CBM extraction in the Rattan Basin in New Mexico.
Analysis measured subsistence as small as a fraction of a millimeter, but in most cases measurements in the basin reached scales of one to two centimeters. The largest subsistence was six centimeters spread out over several kilometers.
“There’s no evidence of large scale subsidence,” he said, “Even if you had a house there, you wouldn’t notice.” Duncan said he hopes his CSG presentation helped to inform geoscientists and encouraged them to respond to news coverage and discussions in which “exaggerated claims are made.”
“We’re trying to get the information out to geologists first,” he said, “because geologists are the ones who tend to understand.”
The Court of Public Opinion
Providing scientific answers in response to media reports was a primary focus of Duncan’s second ICE lecture, “Evaluating the Veracity of Scientific Reports Used to Argue Against a Social License to Operate for CSG: The Curious Case of the Pavilion Wyoming Deep Monitoring Well Study.”
The lecture featured an analysis of data collected following the 2009 Environmental Protection Agency (EPA) study in Pavilion, Wyo., a rural farming area located within the Wind River Indian Reservation.
The EPA conducted the study following resident complaints that local water wells had been polluted by natural gas drilling.
Duncan described Pavilion as “probably geologically the worst place to look for pollution of water wells and gas wells.”
He pointed out that, in addition to the minimal environmental regulation on the Indian Reservation, there is almost no seal between the coalbed layer and the aquifer.
“People were drilling water wells in the gas surface,” he said.
The EPA aimed to test pollution allegations by drilling two deep monitoring wells at 1,000 feet each. Duncan noted that the producing gas wells were located at 1,400 feet.
The EPA collected samples and produced a large number of analyses, and the agency’s preliminary report, published in 2011, showed the presence of hydraulic fracturing chemicals in wells that the EPA drilled.
International newspapers published articles claiming the EPA found definitive evidence that hydraulic fracturing has contaminated water wells, and frac’ing opponents like “Gas Land” director Josh Fox claimed victory.
Representatives from field operator Encana Corporation disputed EPA claims and hired consultants to show what the agency had done wrong while drilling. Allegations included drilling at depths not previously specified and having paint on well casings, which would skew the results.
The debate reached the U.S. Congress, and the U.S. Secretary of the Interior Ken Salazar directed the U.S. Geological Survey (USGS) to go to Pavilion and resample the wells that the EPA drilled.
In 2012, the USGS produced two reports full of data. The problem with the data, Duncan stated, was “there was no interpretation at all … not a sentence.” Shortly after the USGS data was published, the EPA withdrew its report – an action that, according to Duncan, caused both sides of the hydraulic fracturing debate to claim victory.
“One group says the EPA found frac water contamination and was forced out by political pressure. The other group says, ‘No they weren’t. The USGS data was contrary to the EPA data,” Duncan said. “Frac’ing opponents say that the EPA wells were the best proof that contamination occurred. Supports say, ‘No the well wasn’t completed properly, so the study doesn’t prove anything.’”
Following the debate, the geochemist and geologist decided to go back and see what actually happened. He restudied all of the EPA and USGS data and reviewed the original chemical analyses.
“I screened, plotted and analyzed. I’ve come up with a new interpretation of what happened that no one has heard,” he said.
Duncan said he was intrigued by claims made by construction consultants hired by Encana to study the EPA wells.
“Consultants said that when the EPA grouted the well they put too much water in the cement, so the cement was watery. Seven hundred gallons of cement went out into the sand layer that the EPA later sampled,” he said.
He noted that watery cement and incorrect plotting of hydrogen and oxygen isotope data caused misinterpretation of the findings.
“(The EPA) misplotted points in 2011, so it looked like there was no pattern,” he said. “If plotted correctly the isotopes pointed to a meteoric water line.”
Duncan noted that the local reservoir displayed isotopes matching those present in the river water used to source the city’s water supply. This same city water was mixed with the cement used to grout the EPA well.
The first sample taken out had 80 percent river water. The second had 60 percent river water. The third and fourth samples had 40 and 30 percent respectively. As the amount of river water decreased, the amount of contaminants decreased as well. “(The EPA) flushed watery cement into low permeability aquifer,” Duncan said. “Pollution goes down as there is less and less river water and more surface water present.”
Duncan also noted that several contaminants present in EPA samples, glycols, 2BE and phenols, are found in frac fluids, but they also are added to cement to improve grindability. An isotope of hydrogen tridium, produced during atomic testing in the 1950s, was also found in the city water supply.
Hydrogen tridium levels, like the other contaminants, decreased when there was less city water and more surface water present.
Duncan compiled his findings into a report, which he submitted to the journal Science and is awaiting word on publication.
“I was out to show that most of the chemicals that the EPA claimed were contaminants from frac’ing actually were contaminants from the watery cement they introduced into the aquifer,” he said.
Duncan has not yet heard from the EPA, but he expects some kind of communication when the article is published.
“There were good scientific reasons for them to drop the study based on my work,” he said, “and I’m imagining that they might have been thinking the same thing.”
Why He’s Talking
Duncan said he hopes his Pavilion study will provide insight to organizations involved with the hydraulic fracturing and water contamination debate in Australia.
“Earlier this year, one of the farmers from Pavilion went to Queensland to talk about how polluted their water was. There’s a direct connection,” he said.
“With the Internet and social media, everything is connected. If some paper gets published in the United States, people in Australia are on to it straight away,” he said.
Duncan said he hopes his findings will help other geoscientists understand the hydraulic fracturing debate is not as simple as some industry representatives, environmentalists or community groups imply.
“The general public gets info chemicals found in water wells caused by frac’ing. Often it’s because someone found a water sample and found something,” he said. “In the Pavilion case, there were
thousands of samples gathered, two federal agencies and hundreds of millions of dollars involved. It’s very difficult to find out what these data mean, and sometimes they don’t mean anything.”
Other Causes of Contamination
Duncan also noted that while advancing technology improves the ability to detect chemicals, it may also cause undue alarm.
“Sometimes you have to ask the question, ‘What’s the significance of finding one part in a trillion of something?” he said.
Duncan said it is also important to recognize other causes of contamination. He noted one of the items on EPA’s contaminants list is 2BE, a chemical found in common household cleaning products.
“The average person probably has several bottles of 2BE sitting under their sink,” he said. “In rural areas, if you wash your floor and have a bucket of water, what are you going to do with it? Are you going to take it to a toxic disposal facility or dump it outside?”
He also noted that nitriles found in water, including in the Pavilion water, often from the nitrile gloves people use while conducting testing.
Duncan said there are ways to do testing, using ultra distilled water and seal blanks. This testing is time consuming and expensive, and strict procedures are not always followed.
Ultimately, the issues are not as simple as newspaper headlines may imply, he said.
“We have to be really careful jumping to conclusions with water testing. People overreact,” he said. “I am not saying not to test anything. But we’re in a whole new era.”