There is no doubt that hydraulic fracturing for oil and gas in shale deposits is a controversial technology — especially when it comes to impacts to water resources. Protecting water is the biggest environmental issue facing the hydraulic fracturing industry today.
“Fracking” consumes vast amounts of water — typically millions of gallons for every well drilled. This can have a huge impact on groundwater resources, especially in arid regions in the western United States, and heavily populated areas in the eastern half of the nation that are already dealing with water issues, including depleted aquifers.
Oil and gas companies also add chemicals to the water they pump down the hole, including lubricants and biocides to kill bacteria. Then there is “flowback water” — naturally occurring water that is contained in the deep rocks below and flows back up to the surface under geologic pressure. This water is often brackish and contains high levels of salts, heavy metals, and sometimes naturally occurring radioactive compounds.
Instead of cleaning up the water on site, most oil and gas companies truck the contaminated water off-site and pump it down disposal wells, or take it to water-treatment facilities. Some companies, however, are now investing millions of dollars in new technologies that treat water on site — not just for environmental reasons or to boost their public image, but also to improve their bottom line.
Trucking water over long distances for disposal is expensive and time-consuming. If the water can be cleaned and re-used on site, less water needs to be taken from nearby resources for drilling, and less water needs to be hauled away — reducing truck traffic, fleet expenses, and fuel costs.
As a result, innovative companies are developing better ways to clean and recycle drilling water on site, as well as manufacturing “greener” drilling solutions that have fewer harmful chemicals. For example, Halliburton is now offering a down-hole drilling solution whose active ingredients are all sourced from the food industry.
Some companies are using ultraviolet light or ozone to kill bacteria in the water, eliminating the need for biocides and other chemicals that eliminate scale build-up. “Our patented Ozonix® (oxidation) technology has been used to treat over three billion gallons of water in the U.S. hydraulic fracturing industry since 2008,” states George Chapas, director of new business development for Ecosphere, a water-engineering firm. This has eliminated the need for more than 1.7 million gallons of harmful chemicals in about 600 drilling projects over the last five years.
Ecosphere Ozonix® water treatment systems being utilized by a customer in the Fayetteville shale region of Conway, Arkansas
Advanced desalination technologies are also being designed to treat contaminated drilling water. GE is developing a technology called membrane distillation to separate pure water vapor from salt water. Once commercialized, this process could reduce water treatment costs by 50 percent. Other companies are using electricity to isolate and remove pollutants. Halliburton’s CleanWave ® system delivers an electrical charge that concentrates pollutants in the water, which then either sink to the bottom to be collected, or float to the surface where they are removed with a surface skimmer. The treated water is then clean enough to be re-used in drilling and production operations.
With the explosion of hydraulic fracturing in the U.S., oil and gas companies are anxious to prove their commitment to the environment by investing in new technologies to protect water resources. These new, cutting-edge approaches to water management will also prove valuable to other water-cleaning projects.