Another company has taken advantage of the abundant supply of natural gas in the US, becoming more efficient in the process, this time by using field gas to fuel pumps as part of hydraulic fracturing operations. EQT Corp. and Green Field Energy Services reached a milestone in the Marcellus shale play with the successful completion of multifracturing stages using field-gas-fueled pumps, the two companies said in a Sept. 16 news release. The pumps used on the EQT-operated well were powered 100% by gas from its nearby Marcellus natural gas well. Green Field shared insight about the technology behind the process in the August 2013 edition of E&P. The company’s turbine fracturing pump (TFP) technology uses military-grade turbine engines to power the pumps. Use of natural gas in rig fleets is a step in the right direction when it comes to reducing emissions. “When compared to conventional fracturing equipment, the TFPs emit 87% less nitrogen oxide and carbon monoxide, which passes the [Environmental Protection Agency] Tier IV standard when powered by diesel,” Green Field said in the article. “When using fuel sources such as 100% LNG, 100% compressed natural gas [CNG], or 100% field gas, these emissions are reduced further and are found in trace amounts.” If all operators opted for this method of operation, the overall environmental benefits would be even greater. “We are excited to be one of the first to utilize a technology that allows us to power our equipment from one of our producing natural gas wells. We’re continually exploring ways to minimize impact to the environment by making our operations cleaner, greener, and more efficient,” Steve Schlotterbeck, senior vice president and president, EQT E&P, said in the release. “By eliminating diesel and using 100% field gas, we’re able to reduce emissions of carbon monoxide, [CO2], nitrogen, and sulfur oxides as well as decrease the amount of truck traffic on local roads." Rick Fontova, president of Green Field, added, “Our turbine frac pump technology is unique in that it is capable of running on 100% natural gas, where others require the use of diesel. In addition, our proprietary turbine frac pumps meet all of the current EPA Tier IV level emissions standards.” EQT took steps toward using cleaner burning fuels in its operations in 2012 when it began a pilot program aimed at converting drilling rigs from diesel to natural gas and LNG. Since then, four rigs have been commissioned as part of the program, according to the release. Three of these rigs operate on natural gas produced on site, and the fourth runs on LNG. However, EQT is not the only company using field gas as part of drilling operations. Seneca Resources Corp., for example, also has a couple of rigs that run on natural gas. In November 2012 Seneca Resources and Ensign Drilling announced they had installed two of GE’s Jenbacher gas engines to power the first LNG-fueled drilling rigs of their kind in the Marcellus shale. Contact the author, Velda Addison, at vaddison@hartenergy.com.