Room for everyone when it comes to recycling water in Barnett Shale

by Erin Rice

With thousands of natural gas well locations permitted for future drilling in the Barnett Shale, each requiring anywhere from one to four million gallons of water to start producing, the issue of water use in the region is ever-growing.

By Flickr user Mike Austin

Drilling companies employ a process called hydraulic fracturing ("fracing"), in which a water mixture is pumped into a well to fracture the shale underneath, stimulating gas production. Fracing a typical horizontal well* requires 3 to 4 million gallons of water, a number that fluctuates depending on the location and thickness of the shale. The water enters the ground containing "friction reducer, biocides, scale inhibitor, and surfactants," coming back with high concentrations of salt. Most companies drilling in the Barnett Shale truck the flowback** and the produced water to a disposal well, where the unusable water is pumped over a mile and half into the ground.

The debate rages as to whether such disposal wells are safe (some fear that a faulty disposal well could contaminate groundwater supplies). What’s not debatable is that once disposed of, that water is forever removed from the hydrological cycle. A recent study by the Texas Water Development Board found that in 2005, about 60% of water used for Barnett Shale development was groundwater from the Trinity and Woodbine Aquifers, which made up 3% of their total use that year. The study estimates that by 2025, Barnett-related groundwater use in the area could increase to 7% to 13%. Predominantly rural North Texas counties, where groundwater use outweighs surface water use, would be most affected. (Barnett-related water use from all sources amounts to one percent of total use, a figure that is also predicted to increase.)

Considering the increasing percentage of water use projected, pumping it into the ground to never be seen again seems, at the very least, wasteful. Acting on this line of thought, two companies are currently treating water used to frac wells in the Barnett Shale. Employing entirely different technologies, with seeming success, they provide a sliver of hope that one day it will be common practice among gas drilling companies to recycle and reuse flowback and produced water. And, one day, maybe even return it to the people.

Aqua-Pure Ventures, Inc.

When Jake Halldorson sold off the last bits of Colt Engineering, a company he created in the early seventies, he could have taken his retirement in any number of picturesque mountain retreats in Canada. But, as the current CEO of Aqua-Pure Ventures, Inc. (AQE) admitted, “I don’t think my golf game was going to get that much better. I needed something to do that was interesting and this is a real challenge.” So five years ago, Halldorson jumped on board with the Calgary-based wastewater treatment company, which at the time was treating landfill leachate.

The idea to apply their technology to frac water developed when Delzon Elenburg, who had been helping his son gain permits for disposal wells, decided there must be a better way to handle the water. Elenburg, Halldorson, and Aqua-Pure president Harold Lauman realized there was a business in such recycling and in 2005, through its local subsidiary Fountain Quail Water Management, teamed up with Devon Energy. After a trial run, the companies signed a three-year agreement to continue their partnership.

The Technology

Aqua-Pure employs mechanical vapor recompression (MVR) to boil the brine (very salty water), recover the steam, and condense it to create distilled water. MVR is not a new technology, but the wide-gap plate evaporator exchangers the company uses, as opposed to a traditional shell-and-tube evaporator, is what sets it apart. According to Halldorson, they’re adapted from heat exchangers originally used by Alfa Laval to concentrate fruit juice and can be opened up and cleaned on site when the system inevitably fouls. Aqua-Pure currently has nine systems in operation under Devon, each a modular unit called a NOMAD that is approximately 60’ in length and 20’ tall at its highest point.

aqua-pure.com

After the salt and other undesirables in the flowback are removed, the distilled water is sent back to Devon for reuse in a future frac job. Despite the high temperatures that must be reached to boil the brine, the system recovers 97% of the energy it uses in distillation.

At the moment, Aqua-Pure recycles nearly 80% of the flowback water it receives from Devon, producing roughly 588,888 gallons of distilled water everyday.

Parker County Water Supply Pipeline

Still in the engineering phase, Aqua-Pure plans to begin construction on the Parker County water supply pipeline later this year. They’ve partnered up with the Weatherford wastewater treatment plant to pipe treated water to well sites in Parker County, where there’s limited groundwater available for drilling, meaning high costs and lots of trucks hauling water in and out. “The economic benefits to Weatherford [include] the revenue from selling their effluent, which otherwise would go down the creek for nothing,” says Halldorson. The company will purchase two million gallons of treated water from the plant per day.

In addition to piping Weatherford’s water to drilling sites, the pipeline system would allow for frac water to be piped from the well site to a central recycling facility/reservoir where Aqua-Pure will treat it in a process similar to that of their NOMADs. Via the pipelines, they will be able to process all the frac water that comes back throughout the life of the well, the flowback and produced water.

“The whole idea is to distribute water by pipeline, bring it back by pipeline, and hopefully make the environment a little easier to live in,” says Halldorson, “So people aren’t dodging water trucks, and so on, on the highways.” A recent press release predicts that the Parker County water supply pipeline will remove 220,000 water truck round trips per year from local roads.

Ecosphere Technologies, Inc.

Though newer to the Barnett Shale, Ecosphere Technologies (ESPH) is not new to water treatment. A source of great pride to CEO Dennis McGuire was the work his company did in Waveland, Mississippi. After Hurricane Katrina struck the gulf coast in 2005, Waveland’s municipal water supply was contaminated. Ecosphere deployed its mobile emergency filtration system, providing purified drinking water to the town for six weeks. A CNN special that aired abroad can be found here.

Among Ecosphere Tech’s first “clean technologies,” developed around 10 years ago, was a system to filter hazardous waste water created when toxic combinations of metals, oils, and salts are cleaned off the bottoms of ships. “It just so happens it’s a very similar waste stream as that in the petroleum industry,” says McGuire.

The Technology

The Ecosphere Ozonix Water Treatment Process “combines ozone generation and ultrasound technology in a pressure compensated reaction tank” to recycle water. The introduction of ozone and ultrasonic vibrations combine with a phenomenon called sonoluminescence to break down metals and kill bacteria, before the (now just salty) mix is pushed through a filter that can produce about three parts clean water for every one part chemical-free brine.

The Ozonix operation fits into a tractor trailer that can be rigged up and rigged down in a matter of hours. Given the mobility of the systems, frac water water can be filtered at a well site, reducing the need for water trucks. In the current pilot program operating through Devon Energy, Ecosphere is concentrating on treating the pilot site's produced water. McGuire cites that the project can process about 200 gallons of water per minute, day and night.

Ecosphere Technologies recently announced two additional pilot projects soon to begin operation. The Williams Energy Services pilot will take place at a well site in the Barnett Shale. The third pilot is through Newfield Exploration working in Oklahoma’s Woodford Shale, set to start in November.

*Horizontal drilling is being used in urban areas of the Barnett Shale as the technology has improved over the last several years.

**"Flowback" is the term applied to water that comes back in the first week or two after a well has been hydraulically fractured, amounting to 15-20% of the total water used in the frac job. The 80-85% of the water that comes back gradually after the well has started producing is referred to as "produced" water.

Full discosure: Erin became interested in Barnett Shale water recyling through a pre-existing friendship with an Aqua-Pure employee.