NASA and University of Michigan researchers are out with a new study claiming to identify “more than 250” point sources of methane in the Four Corners region – an area in the San Juan Basin where the borders of Arizona, New Mexico, Colorado, and Utah meet.
The researchers conducted a series of flyovers in the area using methane detecting equipment and coordinated with teams on the ground to spot and identify point sources of methane. But curiously, the study does not provide the data showing exactly what sources produced what volumes of methane. Further, the researchers clearly admit, “there is not a single source explaining most enhancements.”
Yet despite this admission by the researchers, environmental groups have leapt on the study to lay the blame on methane in the area on oil and natural gas producers in their push for new regulations on energy producers.
Here are four things to know about NASA’s latest Four Corners methane research:
#1: Researchers curiously did not provide data on how much methane was released from each of the “more than 250” point sources
One of the strangest aspects of the study is that it finds,
“more than 250 individual methane plumes from fossil fuel harvesting, processing, and distributing infrastructures, spanning an emission range from the detection limit ∼∼ 2 kg/h to 5 kg/h through ∼∼ 5,000 kg/h. Observed sources include gas processing facilities, storage tanks, pipeline leaks, and well pads, as well as a coal mine venting shaft.”
But the researchers do not appear to have released a full list of the sources connected with sites on the ground. Rather, the team only chose to profile eight sites in more detail within the paper. Of those eight, one is a “coal mine venting shaft” while researchers describe a plume detected at another as “sporadic” that was observed “on one particular occasion” after the team flew over the site on “multiple times, usually without plume detection.”
It is certainly very curious that a study setting out to identify what is causing the largest amounts of methane does not include the detailed information about the majority of sites they appear to have identified that are causing the largest amounts of methane.
#2: Researchers admit they could not identify every “point source”
While flyovers are able to detect methane plumes, as EID has pointed out before, part of the difficulty of this type of data collection comes when researchers cannot pin-point the source. This is something they admit in the study:
“Example #7 has been observed multiple times as well, and its origin is unclear, as the site was inaccessible to the ground team. The estimated flux is slightly higher than the venting shaft and is caused by multiple strong plumes, presumably emanating from newly built gas production and processing facilities. This site is only 3.5 km to the east of the coal mine venting shaft and is one example where the in situ aircraft suspected an additional strong source but was unable to trace it back to a specific location. Even without quantitative methane retrievals, the mere detection of individual plumes and the capability to geolocate strong sources to within a few meters is invaluable for source attribution and design of ground-based studies.” (Emphasis added)
As EID has noted on a number of occasions, one of the obvious drawbacks and limitations associated with evaluating methane concentrations from flyovers is that there is often a lot of uncertainty about where exactly the methane is coming from. Evaluating what percentage of the methane originates from oil and gas production versus other sources, such as agriculture, coal production, or natural seeps, often involves complicated modeling exercises and hypothesizing.
#3: Emissions from at least one of the larger emitting natural gas sources were an anomaly — due to permitted maintenance work
In other instances, the presence of methane might be from a scheduled maintenance event or other special circumstance. For example, when Williams Partners L.P. got word that researchers had detected a “significant” methane release at their Ignacio natural gas processing plant near Durango in Southwest Colorado, the company took to their blog to explain that NASA’s findings were actually part of “planned maintenance work.” Williams writes:
“We were working on our molecular sieve regeneration gas system, purging natural gas from equipment on April 20, 2015, the same time as one of NASA’s flyovers,” says Michael Jordan, supervisor of operations at the Ignacio plant.
Williams goes on:
“The equipment finishes de-pressuring in only a couple minutes,” Michael says. “The estimated volume of methane released during the work was 7,040 cubic feet. To put this into perspective, the average U.S. home uses 71,540 cubic feet each year[1].”
As Williams reports, as with “all planned release events,” the April 20 event was “recorded and then used to calculate greenhouse gas emissions from the plant.” While not every site on NASA’s list can be attributed to maintenance, the researchers admit a flyover is a snapshot in time, and will not always portray an average day, a fact that researchers freely admit. Also from the study:
“However, it should be noted that our snapshots in time might only catch periodic emissions that exceed our detection threshold at the time of overpass, resulting in an overestimate for these locations, while others are missed. Imaging thousands of wells across the area should nevertheless provide a statistical sampling and thus a nonbiased regional average. In the future, repeat overflights can further discriminate transient from persistent sources and thereby greatly help to evaluate source mitigation potentials across large geographic areas.”
#4: Researchers don’t have their story straight on well-known phenomenon of natural methane seepage in the San Juan Basin
Press materials for the study released by the University of Michigan offer some more detail on the “point sources” identified by researchers. As their press release states:
“All told, the team identified 250 methane plumes emanating from natural gas processing facilities, storage tanks, well pads, pipeline leaks, a coal mine venting shaft and natural sources. Not all of these plumes can be mitigated, the researchers say.” (Emphasis added)
But the NASA researchers are telling the Durango Herald a different story:
“The argument that most of the emissions are from natural seeps, definitely, we can put that to rest,” said Christian Frankenberg, a research scientist at NASA’s Jet Propulsion Laboratory.
Of course, many researchers in the area disagree with Frankenberg’s assessment. Take for example Colo.-based geologist Ashley Ager, a researcher who has been mapping coal bed methane seams in the area, who addressed the topic earlier this year at the Four Corners Energy Conference. The Farmington Daily-Times reports:
“Our opinion is that (Fruitland seeps) are a significant contributor to the methane ‘hot spot,'” she said. “We can do calculations and say that there is a decent chance that the outcrops, just the (ones documented by her group in La Plata County, Colo.) contribute at least 15 percent of the emissions that the researchers calculated for the methane ‘hot spot.'”
As EID has pointed out before, the San Juan Basin is well-known as a large area of natural seepage – or in other words, when methane emissions are naturally occurring and not the result of energy development. According to a 1999 report from the U.S. Bureau of Land Management (BLM), “Historically documented naturally occurring gas seeps throughout the San Juan Basin existed prior to oil and gas drilling operations.” BLM continues:
“Shallow water wells penetrating Fruitland and Menefee coalbeds around the Basin rim have historically produced methane gas. Especially notable in La Plata County, Colorado, are seeps at the northern and western rim of the San Juan Basin. Known gas seeps include the Carbon Junction area where the Animas River crosses the Fruitland Formation. At this location methane and hydrogen sulfide seeps were commonly recognized as early as the 1930’s (Amoco, 1996). Local residents noted as early as 1920 that a ‘rotten egg smell’ is being emitted from the Carbon Junction Area” (Whitton, personal communication, 1996).” (p. 14-15)
Speaking of hot spots, the BLM goes on to explain:
“Scoria, cinders, clinker beds, and ash remnants bear testimony to pre-historic fires. North of the Colorado-New Mexico State line lie the Cinder Buttes, distinguished by distinctly reddish oxidized and heat-altered clinker. The name attests to the fact that subterranean fires consumed shallow coalbeds. Recent mapping of the Fruitland outcrop along the Basin rim documents numerous sites where theses ash and clinker deposits grade into recognizable coal seams. It is a matter of clear geologic record that coal fires have been an integral part of the geologic history of near-surface coal exposures in the Furitland Formation. Spontaneous combustion can be spawned by fluctuation of water levels within coalbeds.” (p. 16-17; emphasis added)
Conclusion
Without a full accounting of how much methane is emitted from each “point source” researchers identified, the study raises more questions about why that data were not included. While it may be convenient for news outlets to blame fracking, the study simply does not have the data to justify such a claim.