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Use of electric-powered or dual-fuel equipment rather than diesel-powered equipment in the hydraulic fracturing process is a gas operations innovation highlighted in a recent study by the Joint Institute for Strategic Energy Analysis. The use of such equipment can greatly reduce diesel fuel use and emissions, reduce noise levels, and lower operating costs.
In 2013, Cabot Oil & Gas announced that it had used dual-fuel technology in hydraulically fracturing wells in northeastern Pennsylvania using Marcellus Shale field gas. In dual-fuel technology, engines operate on a mix of natural gas and diesel, and can reduce diesel fuel consumption by 70 percent.
Now such innovation is being brought to the Appalachian Basin. CNX Resources and Evolution Well Services in June 2018 announced a three-year agreement to operate a100-percent electric fracturing fleet using natural gas, a first for the industry in this area. Evolution operates six all-electric fleets around the country.
“This has the potential to be the next step change in the efficiency frontier,” said Tim Dugan, CNX chief operating officer, in a press release announcing the deal.
The electric pressure pumping equipment can save dramatically on fuel costs while operating below EPA emissions standards for nitrogen oxides and particulates. The equipment uses turbine generators fueled by the natural gas that is being produced to power-pumping activities where electricity is distributed from the turbine generator to the process equipment.
The Evolution unit began work at its first pad, Morris 42 in Richhill Township, Greene County, in late May. It then moved to a second pad in Greene County. Seven wells at the two pads in Greene were fractured using the technology. The unit then moved on to Ohio, but is set to return to Greene County in August, according to information provided by CNX.
The results have been what CNX hoped for. The use of natural gas to power electric equipment reduces emissions. The electric equipment is also quieter than diesel-powered engines, operating at about 85 decibels compared to 115 decibels for a conventional fracking fleet. In addition, higher-horsepower equipment improves efficiency. Fewer trucks are required to move equipment and deliver fuel.
Safety has also been enhanced. About 50 percent fewer people are needed each shift, and no workers have to be near equipment during the fracturing process, eliminating exposure to high-pressure components. No refueling of hot equipment has to be done, further improving safety.
So far, CNX has seen an 80 percent reduction in fuel costs, faster pad moves, less pump maintenance, and the ability to reduce the footprint of the fracturing operation by about 60 percent.
The technology is also being used in the Permian Basin in West Texas, where operators have seen a surplus in oil and gas production. Instead of flaring, or burning off, billions of cubic feet of natural gas each year that is a byproduct of oil drilling, Baker Hughes in early 2019 unveiled new turbines that will use the excess gas to power hydraulic fracturing equipment.
Baker Hughes estimated that each fleet of diesel-powered fracking equipment uses more than 7 million gallons of diesel fuel each year, emits about 70,000 metric tons of carbon dioxide and requires 700,000 tanker truck trips of diesel to drilling sites.
Photo courtesy of CNX Resources