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Recycling Fracking Wastewater

13 fall fracking 1A butterfly valve (red handle) and a ball valve (blue valve) on the sump pump take waste out of the frack waterAmerica is the largest consumer of energy in the world—energy production is pivotal to the economy, balance of trade, deficits and domestic stability. That’s why new oil and gas well completion techniques, including horizontal drilling and hydraulic fracturing (fracking) are critical: Many Americans believe fracking is the road to becoming oil independent, creating jobs and improving the U.S. economy.

However, as with many great things in the business world, challenges exist. One of the major ones with fracking involves the copious amounts of water needed for the process. According to Chesapeake Energy, the company’s current typical oil well fracking process consumes about 5 million gallons of fresh water per well. With the many new oil and gas wells being drilled across America, we can expect billions of gallons of fresh water to be used, contaminated, and then discarded.

As water conservation becomes a larger issue, and fracking takes on even more significance, the oil and gas industry has come face to face with this dilemma. Adding to the problem is the reality that, in many of the areas where fracking is taking place (e.g., Texas and Oklahoma, which constitute 57% of the nation’s rig count), there is serious drought. Fresh water taken from community reservoirs and environmental ground waters in these drought-ridden regions has those regions concerned. What’s more, about 30% of the water used in a typical fracturing process comes back to the surface soon after it is completed, a process known as flow back water. This water can create concerns with the local drinking and agricultural water supply.

Faced with the growing issues, operators will increasingly turn to alternative ways of obtaining and reusing frack water.

A SOLUTION

One solution to this ever-increasing water problem is the $9 billion industry of water recycling. Firms from traditional industrial wastewater companies, as well as energy service companies, have recently developed technologies to address the critical needs of sourcing water and disposal issues. Some of the firms have built physical plants requiring trucks to haul the water to a location for processing, while others have sought on-site mobile systems.

This oilfield water recycling industry segment is a young and rapidly growing market. Many of these companies have heavily invested time and money into developing and commercializing effective water recycling systems. The cost of sourcing fresh water, transferring it to a frack site, then disposing of the end result are driving new solutions such as reverse osmosis, evaporation, electro-coagulation and chemical coagulation (CC). Most experts agree that the water to be recycled varies significantly in different parts of the United States; therefore, many believe technologies should not be selected solely by operating costs, but also by efficacy to certain types of water.

13 fall fracking 2Scrapers remove solids on top of the unit where bubbles are formed.One proven system that benefits from the fact it’s a mobile service with relatively low operating costs for the on-site processing is CC, along with dissolved air floatation (DAF). The CC/DAF system can take the contaminated flow back water created by the frack process, eliminate most of the suspended solids and kill about 99% of the bacteria, producing on-site reusable frack water. Since most flow back water can be recycled through the process, operators can then use this recycled water instead of relying on local water supplies. The process not only conserves water, it can create significant economic savings to oil and gas operators. This can range from $100,000 to $500,000 when taking into consideration the amount of water fracking needs, the cost of transport and the disposal of flow back water.

THE PROCESS

The CC/DAF water recycling system uses a two-step process: It coagulates and flocks with chemistry the larger particles found in the water, which fall to the bottom of a large frack tank-size container, then it pushes the remaining water through an air flotation process (dissolved air flotation treatment) to clean and disinfect wastewater.

The first step in this water recycling system is to filter contaminated flow back water through 6-inch butterfly valves into the blending unit. At this stage, the chemicals are added to bind and coagulate the suspended solids. Based on the specific makeup of the environmental water of the fracking site, different chemicals are added to treat different types of contaminated water. That means the system is conveniently compliant to the site’s specific location with no negative impact on existing ecosystems in the treated areas.

The next step is the water leaving the blending unit through multiple

4-inch gate valves, then traveling through several 4-inch ball valves to the DAF unit. Here, millions of nano-sized bubbles are introduced into the water, floating the suspended solids to the surface of the water. This allows the system to scrape off suspended solids that once contaminated the water, leaving clean fracking water at the bottom.

Finally, the water leaves the DAF unit through a 6-inch butterfly valve, entering the disinfecting unit. Here, the total suspended solids-free water is disinfected against 99% of the remaining bacteria. This eliminates concerns of local water resource depletion as well as concerns about negative effects on the local environment from disposal.

A good water recycling system can provide a realistic solution for water conservation in the oil and gas industry. With each system recycling upwards of 20,000 to 30,000 barrels of frack water per day, an operator can save roughly $1 to $2 per barrel. At a rate of using 5 million gallons of water per well, the savings adds up quickly.

On-site recycling systems also eliminate the cost of transporting and buying millions of gallons of fresh water. By lessening the use of community and environmental water and using recycled flow back water, impact on local sources of fresh water and their ecosystems are greatly lessened.


Brent Mulliniks is a petroleum engineer and president of AES Water Solutions, a U.S.-based frack water services company. Reach him at This email address is being protected from spambots. You need JavaScript enabled to view it..

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