This summer the emission of smog-forming compounds from Barnett Shale gas producer activities in North Texas could exceed on-road motor vehicle emissions in the area, according to a study by Southern Methodist University (SMU) that was commissioned by the Environmental Defense Fund. However, Texas producer groups refute the findings and say the research is based on data that doesn’t reflect Barnett Shale production.

The research was done by Al Armendariz of the SMU Department of Environmental and Civil Engineering. It sought to “develop an emissions inventory of air pollutants from oil and gas production in the Barnett Shale area and to identify cost-effective emission control options,” Armendariz wrote in his research report summary. The pollutants considered are nitrogen oxides (NOx) and volatile organic compounds (VOC), greenhouse gases and air toxic chemicals.

The research categorized emissions as coming from point sources — such as compressor engine exhaust and oil/condensate tanks — and fugitive/intermittent sources, including those from production equipment, well drilling and hydraulic fracturing engines, well completions, gas processing and transmission.

“For 2009, emissions of smog-forming compounds from compressor engine exhaust and tanks were predicted to be about 96 tons/d on an annual average, with peak summer emissions of 212 tons/d,” the research report said. Summer emissions are greater because of the effects of temperature on VOC emissions from storage tanks, it noted.

Emissions of smog-forming compounds from all oil and gas sources were estimated to be about 191 tons/d on an annual average, with peak summer emissions of 307 tons/d. “The portion of those emissions originating from the five counties in the DFW [Dallas-Fort Worth] metropolitan area with significant oil and gas production was 165 tons/d during the summer,” the report said.

“For comparison, 2009 emission inventories recently used by state and federal regulators estimated smog-forming emissions from all airports in the DFW metropolitan area to be 16 tons/d. In addition, these same inventories had emission estimates for on-road motor vehicles (cars, trucks, etc.) in the nine-county DFW metropolitan area of 273 tons/d. The portion of on-road motor vehicle emissions from the five counties in the DFW metropolitan area with significant oil and gas production was 121 tons/d, indicating that the oil and gas sector likely has greater emissions than motor vehicles in these counties.”

However, Texas Independent Producers and Royalty Owners (TIPRO) and the Texas Oil & Gas Association (TXOGA) claim that Armendariz used production data from outside the Barnett Shale where produced gas is much wetter, having more condensate and making it a greater contributor to smog. “Different types of natural gas emit differently, yet the study assumes all natural gas production is the same,” they said.

With regard to the emissions of VOCs, the producer groups said the study uses a VOC emissions factor for condensate storage tanks to arrive at its peak summer estimate that is five times higher than the factor used to estimate annual emissions. “Using gas analysis from samples actually collected in the Barnett Shale would result in VOC emissions six to 10 times lower than those reported in the study,” they said.

Adam Haynes, TIPRO executive vice president, told NGI that much of the basis of the report is flawed from a scientific perspective, even though some of TIPRO’s member companies had contacted the researcher to provide input on their concerns about the methodology.

For his part, Armendariz has sought to refute the refutation of his work. “Frankly, I have doubts that the Texas Oil and Gas Association took the time to carefully read the report,” he wrote in a recent memo to state Rep. Lon Burnam (D-Fort Worth), who has introduced several bills to regulate producer and gas gathering activities. “The unsophisticated level of understanding, sophomoric statements and errors of fact are even more numerous and glaring than I would have expected from one of our state’s regulatory agencies.” (TIPRO and TXOGA are not regulatory agencies but rather groups representing the interests of oil and gas producers.)

In his memo Armendariz said the assertion that he “assumes all natural gas production is the same” is incorrect. “In fact, a fair amount of work was performed to account for the varying composition across the regions, including variation within individual counties,” Armendariz wrote. “Geologic maps provided by Barnett Shale oil and gas producers themselves were some of the tools used to account for the varying composition of the natural gas.”

He further asserts that “every bit of data used to calculate” emissions from storage tanks was collected in the Barnett Shale area. “The annual average tank emission factors were provided to me by one of the largest gas producers in the state of Texas, based on numerical computer analysis that they themselves performed on a series of their Barnett Shale tanks. They themselves indicated in phone calls with me that they would expect significantly higher emissions during the summer.”

Regardless of the accuracy of the research, the industry boom times in the Barnett Shale are still inspiring legislation that would curtail development, even though lower gas prices have slowed activity. One piece of legislation proposed by Burnam that would remove eminent domain power from “captive utilities” would “shut down the industry,” according to Texas Pipeline Association Executive Director Patrick Nugent, as reported by the Fort Worth Star-Telegram.

Last December Fort Worth enacted a new gas drilling ordinance in response to all of the Barnett Shale activity (see Daily GPI, Dec. 16, 2008). Last summer some Fort Worth residents were moved to seek a moratorium on gas drilling in their midst due to traffic, compressor noise and the prospect of gas pipelines crossing their property (see Daily GPI, Aug. 11, 2008). That effort never got anywhere.

However, tension between the gas industry and residents is not likely to go away as more than 7,700 wells have been drilled and another 4,700 wells are pending in the Barnett Shale as of June 2008, according to Armendariz.

©Copyright 2009Intelligence Press Inc. All rights reserved. The preceding news reportmay not be republished or redistributed, in whole or in part, in anyform, without prior written consent of Intelligence Press, Inc.