Hydraulic fracturing (commonly referred to as fracking) has faced increasing scrutiny from the public and regulators alike. On May 2nd, Colorado’s high court repealed a charter that banned fracking in the city of Longmont and also voted down a 5-year moratorium on fracking in Fort Collins. These are the latest developments in a long string of proposed regulatory actions to ban, or at least hinder, fracking. Groups like Keep Tap Water Safe keep an up-to-date list of regulatory actions against the practice. It seems like everyone who is anyone has something bad to say about fracking.
However, most people still use oil & gas as energy sources, and fracking makes these commodities increasingly affordable. Concerns about the practice seem to have had little influence in its rapid expansion. Instead, the industry is developing technologies to mitigate the concerns that people have expressed.
At the forefront of these trepidations is water quality. There is no doubt that fracking consumes and produces a vast quantity of water. The fracturing process itself involves the high-pressure injection of fracturing fluid (a viscous mixture consisting of water, sand, and proprietary thickening and surfactant agents) underground. This fluid creates and holds open cracks within the bedrock foundation, allowing trapped oil & gas pockets to easily migrate to the wellhead where they are pumped out—a process which also releases water from the aquifers trapped along with the oil & gas. According to an article from Scientific American, a single well can use as much as 9.6 million gallons of water. Even more astonishing is that many of these wells are located in arid regions like Colorado and Texas, where demand for freshwater frequently outpaces supply.
Even with the recent downturn in natural gas prices, producers are continuing to frack in dry regions. This leads to issues with both source water and wastewater. The market for obtaining and disposing water is worth billions of dollars, and costs are higher in states with limited freshwater supplies or those with limits on the disposal of wastewater.
There are three main methods of dealing with wastewater in the oil & gas industry. The first (and by far most common) is collecting the water in large tanks offsite and shipping it for disposal in underground injection wells (called Class II wells). The second method is treating the water, either onsite or at a centralized facility, to standards acceptable for surface water discharge. This is not particularly common, as the treatment standards are much more stringent and the cost is somewhat prohibitive. The third option is to treat the water to lesser degrees and reuse it for fracturing fluid.
Wastewater recycling with treatment is becoming increasingly popular as a way to circumvent Class II underground disposal wells and high cost of getting freshwater. Fracking wells produce water primarily in two forms: flowback, which is fracturing fluid returning to the surface; and produced water, which comes from already existing aquifers and can contain high levels of dissolved salts and radiation.
What’s the Catch?
Treating a combination of flowback and produced water can be tricky, especially as the fine points of contamination differ from location to location. Systems have to be designed with a well’s specific water quality in mind, so large centralized treatment plants often do not work well. In addition, the high cost of transporting water means that centralized treatment plants are often as expensive as mobile systems.
Additionally, the cost of treating water is higher than the cost of underground disposal, which ranges from about $4 to $10 per barrel. However, some states are adopting regulations about deep well injection. In Pennsylvania, for example, the U.S. Environmental Protection Agency regulates the permitting of Class II underground disposal wells. There are only seven active disposal wells for oil & gas use in Pennsylvania. Increasing regulation and changes in economic conditions are causing the demand for water treatment to expand rapidly.
Fortunately, many technologies for water treatment are being adapted to this industry. Advanced oxidation, membrane filtration, and reverse osmosis are all becoming common in mobile treatment units. There are a number of companies implementing these treatment solutions, and the cost per barrel is falling as the technology penetrates the market.
The market for water treatment in hydraulic fracturing will continue to expand, especially as the prices of oil & gas recover. Higher profits will result in additional investment in treatment technologies as they will save operating costs in the long run. While the public becomes increasingly wary of hydraulic fracturing, oil & gas companies are developing technologies to reduce the effects of fracking. In the next decade, hydraulic fracturing is expected to have a much smaller footprint, both economically and environmentally.
If you would like to find out more about wastewater treatment in hydraulic fracturing, be sure to check out Navigant Research’s recently published Wastewater Treatment Technologies in Natural Gas Hydraulic Fracturing report. This report forecasts the markets for wastewater treatment and deep well injection in hydraulic fracturing through 2025.