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PollutionEngineering August 2012 : Page 26

Analytical Method Provides Safe Hydraulic Fracturing While fracking is now a part of the public’s lexicon, it is time to get serious about ensuring safe oil in water levels. By SANDRA RINTOUL, President of Wilks Enterprise Inc. ydraulic fracturing to release natural gas is get-ting positive and negative attention in the news. On the positive side, a less expensive domestic fuel source is a plus for many industries. A recent newspaper article heralded the abundant natural gas from hydraulic fracturing as the clean-est fuel available for big rigs on top of a one third savings on fuel costs [1] . On the cautionary side, some reporters worry that groundwater, surface water and drinking water sources for families and livestock risk contamination from drilling chemi-cals, gas leaks and radioactive elements released from the shale. On-site analytical testing can both help the well operators keep systems operat-ing optimally as well as assure concerned citizens that appropriate environmental efforts are being taken. In A White Paper Describing Produced Water from Production of Crude Oil, Natural Gas and Coal Bed Methane for the U.S Department of Energy [2] , the authors wrote, “Oil and grease are the constituents of produced water that receive the most attention both in onshore and offshore operations, while salt content (expressed as salinity, conductivity or total dissolved solids) is also a primary constituent of concern in onshore operations.” Oil in water testing can be a benefit at several different stages in the handling of water generated during hydraulic fractur-ing. It is a test that can also conveniently be done at the well location. Hydraulic fracturing requires a large amount of water. According to EPA esti-mates, approximately 35,000 wells are fractured each year with an annual water H Above is a photo of the Wilks InfraCal TOG/TPH Analyzer that can be used in the field to provide operators with total oil and grease or total petroleum hydrocarbon analysis in minutes. usage of 70 to 100 billion gallons [3] . Some calculate as much as five million gallons of water is used per well. Most of the injected water for fracturing comes back to the sur-face as flowback water. Flowback water is a mix of the fluid used to facture the shale and water from the formation. It contains solids, metals, salts, chemical additives and trace amounts of oil. Once the well is operating, naturally occurring water from the shale formation flows to the surface as produced water. Produced water contains high levels of total dissolved solids (TDS): minerals such as barium, calcium, iron and magnesium that are leached out of the shale along with dissolved hydrocarbons [4] . Water management options include 26 Pollution Engineering AUGUST 2012

Analytical Method Provides Safe Hydraulic Fracturing

Sandra Rintoul

While fracking is now a part of the public’s lexicon, it is time to get serious about ensuring safe oil in water levels.<br /> <br /> Hydraulic fracturing to release natural gas is getting positive and negative attention in the news. On the positive side, a less expensive domestic fuel source is a plus for many industries. A recent newspaper article heralded the abundant natural gas from hydraulic fracturing as the cleanest fuel available for big rigs on top of a one third savings on fuel costs[1]. On the cautionary side, some reporters worry that groundwater, surface water and drinking water sources for families and livestock risk contamination from drilling chemicals, gas leaks and radioactive elements released from the shale.<br /> <br /> On-site analytical testing can both help the well operators keep systems operating optimally as well as assure concerned citizens that appropriate environmental efforts are being taken.<br /> <br /> In A White Paper Describing Produced Water from Production of Crude Oil, Natural Gas and Coal Bed Methane for the U. S Department of Energy[2], the authors wrote, “Oil and grease are the constituents of produced water that receive the most attention both in onshore and offshore operations, while salt content (expressed as salinity, conductivity or total dissolved solids) is also a primary constituent of concern in onshore operations.”<br /> <br /> Oil in water testing can be a benefit at several different stages in the handling of water generated during hydraulic fracturing.It is a test that can also conveniently be done at the well location.<br /> <br /> Hydraulic fracturing requires a large amount of water. According to EPA estimates, approximately 35,000 wells are fractured each year with an annual water usage of 70 to 100 billion gallons[3]. Some calculate as much as five million gallons of water is used per well. Most of the injected water for fracturing comes back to the surface as flowback water. Flowback water is a mix of the fluid used to facture the shale and water from the formation. It contains solids, metals, salts, chemical additives and trace amounts of oil.<br /> <br /> Once the well is operating, naturally occurring water from the shale formation flows to the surface as produced water.Produced water contains high levels of total dissolved solids (TDS): minerals such as barium, calcium, iron and magnesium that are leached out of the shale along with dissolved hydrocarbons[4].<br /> <br /> Water management options include Collection and removal to an offsite treatment facility, evaporation ponds, injection into disposal wells, recycle and reuse for hydrofracking and treatment to allow surface discharge. Whether the flowback water is contained and transported offsite for disposal or treated onsite for reinjection, it is a large amount of contaminated waste to handle. Each waste management option has maximum levels of free or dissolved oil that will be accepted. As one of the first steps in the various options for water treatment is hydrocarbon removal, testing the oil in water can help reduce problems for subsequent procedures.<br /> <br /> For example, if the flowback or produced water is going to be recycled and reused for fracturing after the concentration of petroleum hydrocarbons are lowered to the desired level, polymer additives and inorganic scale-forming compounds are removed, followed by disinfection of bacteria and microorganisms that could sour the well.<br /> <br /> TDS removal may be included for either reuse or potential surface discharging.<br /> Typically, either membrane or thermal technologies are used to lower TDS levels.<br /> Membrane technologies require the removal of oil in order to prevent fouling of the membrane surfaces. Thermal evaporation and crystallization systems also benefit by reducing potential fouling agents, which include free and dissolved oil.<br /> <br /> In arid areas, where evaporation ponds are used for produced water disposal, the amount of oil in the water must be controlled to avoid an oil film, or sheen, as it will reduce the evaporation efficiency. If the wastewater disposal option is a public treatment plant, they too need to control the amount of oil and grease in order to not overwhelm their system.<br /> <br /> Onsite oil in water measurements can ensure that the oil/water separation system is removing the oil to the required limits.Infrared oil in water analyzers such as Shown in photo 1, have been used in the oil industry on offshore oil rigs for more than 40 years. The same technology can be used for testing the amount of oil in wastewater from hydraulic fracturing. The analysis can be done at the well site in less than 15 minutes, thus avoiding the cost and delay Of laboratory analysis. Infrared analysis can also be used for TPH in soil if a spill or pond leak occurs to determine the extent of contamination. An added benefit is that the procedure does not require a trained laboratory technician to do the test.An onsite infrared oil and grease measurement provides operators at a well site a useful tool for optimizing treatment procedures, maximizing evaporation pond efficiency, complying with offsite disposal requirements, or for assessing contamination.<br /> <br /> Sandra Rintoul is the president of Wilks Enterprise Inc., Norwalk, Conn. She can be reached by email at srintoul@wilksir.com or by telephone at 203-855-9136 for additional information.<br /> <br /> 1 Scientific American, Cheap Fracked Gas Could Help American Keep on Truckin’, April 23, 2012, www.scientificamerican.com/ article.cfm?id=natural-gas-as-alternativetransportation- fuel <br /> <br /> 2 Veil, John A.; Puder, Markus G,; Elcock, Deborah; Redweik, Robert J. Jr; A White Paper Describing Produced Water from Production of Crude Oil, Natural Gas and Coal Bed Methane, prepared for U.S Department of Energy National Energy National Energy Technology Laboratory Under Contract W-31-109-Eng-38, January 2004.<br /> <br /> 3 United States Environmental Protection Agency, Draft Plan to Study the Potential Impacts of Hydraulic Fracturing on Drinking Water Resources, EPA/600/D-11/001/ February 2011/www.epa.gov/research. <br /> <br /> 4 Shramko, Andrea; Palmgren, Tor; Gallo, Daniel; Dixit, Rahul; M-I SWCO, Analytical Characterization of Flowback Waters in the Field, 16th Annual Petroleum & Biofuels Environmental Conference (IPEC), Houston, Nov 2009.

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