Potential release of additives used in the hydraulic fracturing process into the atmosphere

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Flaring is often used in the energy and petrochemical sectors to dispose of unwanted flammable gases. Flaring is preferred to simply venting gases since the global warming potential of CO2 is much lower than that of methane. It has been estimated that 122 billion m3 of gas was flared or vented worldwide in 2008, while in Alberta approximately 1.14 billion m3 was flared or vented in the upstream sector in 2008. Fracturing fluids have been successfully used for many years in the oil and gas industry to increase well-site productivity. However, in recent years the general public and government regulators have voiced concerns about the possible effects these fluids might have on ground water and air quality. The separation processes at upstream battery sites can potentially create scenarios where some droplets of liquid can enter the flare stack. This liquid is mostly water but can contain other substances like salt and fracturing fluid. The proposed research project will investigate the effects of diluted flowback fracturing fluids on flares. A two-pronged approach will be used. Firstly, the Carleton Flare Facility will be used to measure flaring efficiency and emission factors when such fluids are entrained in the fuel. Secondly, a laboratory-sized quiescent flame at the University of Alberta will be used to complete a detailed study of the chemical and physical properties of the gas and particle-phase emissions emitted by flames with fracturing additives. In this laboratory flame, the sampling system will be designed to sample gases and particulates throughout the combustion process (i.e., pre-combustion fuel/fluid mixture, the flame region, and post-combustion products). In the case of both flames, the diluted fracturing fluids tested will be chosen based on an extensive review of fracturing fluid databases and other resources.