Few associate the EPA’s “3-R’s” mantra with the upstream oil and gas industry. However, the industry has begun to think differently about their high water usage concerning their hydraulic fracturing operations that unlock unconventional oil and gas in shale formations. While laboratories are working on innovative fluids and materials to replace the use of water during “fracking,” these solutions are decades away. In an effort to use less water, companies are beginning to recycle and reuse frack water, resulting in considerable savings and a possible huge impact on the environment.
The practice of hydraulically fracturing shale wells involves the heavy use of water. Drillers use anywhere from three to eight million gallons of water per well mixed with sand, lubricants, and other chemicals to pump down the well at high pressures to break open shale thousands of feet below the surface. A largely contested issue involves how the flowback water, or the water that comes back up after fracturing the rock, is disposed.
Flowback water, which can be up to 40% of the water sent down the well, contains salts, carcinogens like benzene, harmful chemicals, and naturally-occurring radioactive elements such as radium. About three barrels of flowback water is produced for every barrel of oil produced. The wastewater is stored in a pond at the drilling site and often is disposed of in two ways: reinjection into old wells or treatment at a plant. Wastewater reinjection has been associated with earthquake tremors, interstate tensions, and even civil unrest. Wastewater treatment brings along another set of difficulties when potentially partially-untreated frack water is released into local surface water. These issues have sparked debate over public health and safety, and rightly so. In the face of these challenges, a new industry has grown and begun to develop methods to treat and recycle frack water for additional drilling operations.
So how is the frack water recycled? Several companies, including oilfield services giants Schlumberger and Halliburton, have developed frack water recycling technology. Halliburton’s CleanWave system is a mobile trailer that can be brought next to the wastewater pond that treats as much as 26,000 bbls of water a day. The technology, shown in the graphic below, uses an electric coagulation unit that uses anodes and cathodes within a tank to separate various weights of particles that are skimmed off the top or fall to the bottom. Dangerous bacteria are treated as well. This treatment allows much of the flowback water to be used for another fracking operation at another site.
The benefits of recycling frack water seem to appease oil and gas operators and local residents. The technology is being used more and more by the industry mostly because it saves money. Several companies claim that their technology solutions can save operators 25-50% of the cost of traditional disposal methods. In addition, recycled frack water decreases the amount of freshwater needed from local sources. In North Dakota’s Bakken shale, water rights typically cost $0.10-0.14 per gallon. On top of this, less transportation fuel is required for the whole drilling process because the recycled frack water can be transported directly to the next site. These variables can add up to some serious savings for operators. In addition, residents are pleased with less local water source strain and truck traffic.
So far, the technology seems promising. In 2012, about 14% of the wells fracked in shale-rich Pennsylvania utilized frack water recycling. Chesapeake Energy, one of the largest natural gas exploration and production companies in the US, reportedly recycles all of their flowback water in Northern Pennsylvania fracking operations. Increasing reuse trends in other parts of the state are promising, but only time will tell if the water treatment systems will be used more in other drilling-rich areas of the country.
One of the most encouraging things about this emerging technology is that it seems to be a win for many parties. Operators and local residents work together more easily. Risk decreases of environmental contamination. A new industry could create more jobs. While this technology still has challenges and needs to be implemented on a larger scale, we seemingly can continue to produce natural gas that can power our immediate energy future while reducing burdensome water use.