This is a follow-up to my post last night regarding the enormous methane hotspot over the Four Corners area in the Southwest.
The EPA estimates of methane emissions from oil and gas drilling are compiled using the industry’s own measurements of emissions at well sites. Using those numbers, the EPA extrapolates total methane emissions for an entire region without actually measuring emissions throughout the area. The EPA determined that methane emissions from natural gas extraction operations, including hydrofracking operations, amounted to slightly less methane emitted than from agricultural sources. Some studies supported the EPA’s estimates of methane leakage from methane extraction. However, many of those those studies were not solely focused on methane emissions that occur during the initial drilling process. Those studies (e.g., this study by the University of Texas)primarily examined methane primarily methane leaks from “completion flowbacks, equipment leaks, and pneumatic pumps and controllers …”. Studies of methane in the atmosphere above drill sites during the drilling process were typically not done.
Now, a new study by Purdue and Cornell researchers, which measured emissions of methane in the atmosphere above drilling sites strictly during the drilling process itself, found much higher levels of emissions than previously believed possible.
[A] study published Monday adds to the growing evidence those escaping gases, called “fugitive” emissions, are numerous, especially methane emissions while a well is being drilled, a phase of well development previously thought to emit little if any methane. […]
The study shows that during drilling, as much as 34 grams of methane per second were spewing into the air from seven natural gas well pads in southwest Pennsylvania — up to 1,000 times the EPA estimate for methane emissions during drilling, Purdue atmospheric chemistry professor and study lead author Paul Shepson said in a statement.
“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,” he said.
To determine emissions rates at natural gas fields in Pennsylvania’s Marcellus shale gas fields, the researchers used emissions data gathered from an airplane that flew over natural gas wells in southwest Pennsylvania in June 2012, some of which were in the process of being drilled.
None of the wells in the area were being fracked at the time, and none were in the “flowback” stage, according to the study.
Why haven’t the companies, the EPA and/or other scientists looked at emissions during the drilling process before? Because as the one of the scientist who worked on the study stated, “No one goes out and measures methane emissions while they’re drilling.” The EPA and state regulators simply assumed that the drilling process did not produce a significant amount of methane “leakage” into the atmosphere. Unfortunately, they may be very, very wrong about that. The Purdue and Cornell study’s conclusion that methane emissions from drilling sites is much higher than previously estimated is supported by a study of atmospheric methane releases into the atmosphere above drilling sites in Colorado whose lead scientist is Gabriell Petron, “an atmospheric scientist with NOAA’s Cooperative Institute for Research in Environmental Sciences at the University of Colorado Boulder.”
During two days of intensive airborne measurements, oil and gas operations in Colorado’s Front Range leaked nearly three times as much methane, a greenhouse gas, as predicted based on inventory estimates, and seven times as much benzene, a regulated air toxic. Emissions of other chemicals that contribute to summertime ozone pollution were about twice as high as estimates, according to the new paper, accepted for publication in the American Geophysical Union’s Journal of Geophysical Research: Atmospheres.
The new paper provides independent confirmation of findings from research performed from 2008-2010, also by Petron and her colleagues, on the magnitude of air pollutant emissions from oil and gas activities in northeastern Colorado. In the earlier study, the team used a mobile laboratory—sophisticated chemical detection instruments packed into a car—and an instrumented NOAA tall tower near Erie, Colorado, to measure atmospheric concentrations of several chemicals downwind of various sources, including oil and gas equipment, landfills and animal feedlots. [..]
In May 2012, when measurements for the new analysis were collected, there were about 24,000 active oil and gas wells in Weld County. The new work relied on a different technique, too, called mass-balance. In 2012, Petron and her colleagues contracted with a small aircraft to measure the concentrations of methane and other chemicals in the air downwind and upwind of the Denver-Julesburg Basin. On the ground, NOAA wind profilers near Platteville and Greeley tracked around-the-clock wind speed and wind direction.
Further support for the claim that the EPA and the Oil and Gas Industry has underestimated the amount of methane released into the atmosphere from drilling operations and hydrofracking comes from research that looked at satellite data. Scientists at the University of Bremen and the University of Maryland examined data from an orbiting European satellite to find that the methane released from drilling operations in the shale formations is likely underestimated.
In the past decade, there has been a massive growth in the horizontal drilling and hydraulic fracturing of shale gas and tight oil reservoirs to exploit formerly inaccessible or unprofitable energy resources in rock formations with low permeability. In North America, these unconventional domestic sources of natural gas and oil provide an opportunity to achieve energy self-sufficiency and to reduce greenhouse gas emissions when displacing coal as a source of energy in power plants. However, fugitive methane emissions in the production process may counter the benefit over coal with respect to climate change and therefore need to be well quantified. Here we demonstrate that positive methane anomalies associated with the oil and gas industries can be detected from space and that corresponding regional emissions can be constrained using satellite observations. On the basis of a mass-balance approach, we estimate that methane emissions for two of the fastest growing production regions in the United States, the Bakken and Eagle Ford formations, have increased by 990 ± 650 ktCH4 yr−1 and 530 ± 330 ktCH4 yr−1 between the periods 2006–2008 and 2009–2011. Relative to the respective increases in oil and gas production, these emission estimates correspond to leakages of 10.1% ± 7.3% and 9.1% ± 6.2% in terms of energy content, calling immediate climate benefit into question and indicating that current inventories likely underestimate the fugitive emissions from Bakken and Eagle Ford.
The Bakken formation is primarily in North Dakota and Canada Texas. The Eagle Ford formation is primarily in Texas North Dakota.
This, of course, comes on the heels of the revelation of the massive methane “hotspot” over the Four Corners area where drilling in coal bed formations to extract methane occurred. As one Penn State scientist, Terry Engelder who was quoted about this completely unexpected discovery said in an email: “That is immense.” Indeed the authors of the study that revealed this massive amount of atmospheric methane in the Four Corners region were so surprised and dubious regarding their findings that they they “waited several years and then used ground monitors to verify what they saw from space …” according to “lead author Eric Kort, a University of Michigan atmospheric scientist.”
What is becoming clearer by the day is that the Oil and Gas firms’ own calculations regarding methane releases from their natural gas extraction operations, whether from hydrofracking or other drilling processes, vastly underestimates the amount of uncaptured methane filtering up into the atmosphere. And methane is a far more powerful driver of global warming than carbon dioxide in the near term:
Over a 20-year time frame, each pound of methane is between 72-105 times more powerful at increasing atmospheric heat retention, known as Global Warming Potential (GWP), than the same amount of CO2, and over a 100 year timeframe [sic], methane’s GWP is between 25-33.
Yet, the EPA continues to rely on the Oil and Gas Industry’s own estimates of methane leakage from their extensive drilling operations for natural gas all over our nation and around the world. Maybe it is time for the agency that is supposed to regulate this industry, and is obligated to minimize the release of dangerous greenhouse gases, to stop lying in bed with the same people who have a clear motivation to downplay the danger of the methane releases into our atmosphere from their own drilling operations.
