Four-year study finds no link between methane in water wells outside Fort Worth and natural gas operations in the Barnett Shale.
Researchers at the University of Texas at Austin and the University of Michigan issued the fifth and final study of groundwater wells in the Barnett Shale, stating no link was found between methane in water wells in the Fort Worth area from shale gas production in the Barnett Shale. The study did determine that the methane appears to be migrating from the shallower Strawn formations. The study is important as methods were developed that can be applied to other situations in determining methane origination in the environment.
Lead research associate Toti Larson with the Bureau of Economic Geology, a research unit of the UT Jackson School of Geosciences stated, “Protecting groundwater quality is a fundamental requirement for sustainable energy development. It is important to develop tools that can be used to monitor ongoing gas exploration and production activities.”
From the over 450 wells studied in twelve counties, a cluster of eleven wells near the Parker-Hood County line had methane levels above 10 milligrams per liter of water, requiring venting to prevent flammable gas from accumulating to hazardous levels. Approximately 85% of the wells had very low levels (<0.1 milligrams/liter) of methane in the groundwater.
The latest study used dissolved nitrogen to estimate stray gas infiltration into the groundwater. Stray methane gas in the water wells had higher levels of nitrogen than found in the Barnett Shale, with levels being more typical of the levels measured in the Strawn Group. These findings were consistent with the previous four studies.
“Nitrogen is another line of investigation,” said J.P. Nicot, a research scientist at the bureau. “This team has developed a method that can be used to monitor fugitive natural gas in groundwater.”
The study, “Monitoring Stray Natural Gas in Groundwater with Dissolved Nitrogen. An Example from Parker County, Texas” can be found in the Water Resources Research, an AGU Journal. The study was funded by Research Partnership to Secure Energy for America, a program authorized by the U.S. Energy Policy Act of 2005.