June 2013, Vol. 25, No.6

Problem Solvers

 

Achieving fracking-water treatment success

 

Problem : Fracking flow-back containing high levels of salt, chloride, and abrasive solids    

Solution : Install pumps designed to handle highly corrosive material 

  

Obtaining natural gas through reservoir hydraulic fracturing, or fracking, is growing across U.S. production fields, including the Marcellus, Utica, Huron, Haynesville, and Bakken basins. Since water constitutes approximately 90% of the liquid used in fracking, operating companies face the challenges of limited freshwater supplies and an increasing number of environmental and transportation controls. This requires companies to incorporate water treatment and reuse into business models.  

  

Moving into and remodeling a dilapidated facility 

One company decided to move into a facility formerly known as American Video Glass Co. The Mount Pleasant, Pa., facility, which was owned and operated by Sony Corp. (Tokyo), had been in operation for several decades before closing in 2004. It was sold to an ethanol producer in 2006 that closed in 2008. It then became permitted and converted to treat water from the Marcellus Shale fracking fields. The rehabilitated facility opened in April 2010. 

Andy Kicinski, president and chief executive officer of Reserved Environmental Services LLC (RES; Mount Pleasant), worked with Bob Vlah of PCF Sales Corp. (Pittsburgh) to put the necessary equipment together to get the plant up and running. Kicinski had to remediate an abandoned water treatment plant, which had been left without proper decommissioning, into something to treat fracking water for potential reuse. 

“This plant was shut down for half of a decade before Andy took it over,” Vlah said. 

Move-in conditions included rusted machinery and broken pipes, pumps, and instruments, Vlah explained.  

Refurbishment work included installing holding tanks for fracking liquid, large clarifier tanks to chemically treat the liquid for metals and remove other pollutants, and BN 35-12 progressive cavity pumps to move clarifier underflow, or solids, to a proprietary dewatering system that Kicinski designed.  

  

Why a progressive cavity pump? 

Because Kicinski worked with seepex Inc. (Bottrop, Germany) at his first treatment facility in West Virginia, he was familiar with the company’s progressive cavity pumps. The pump consists of a single-helix metal rotor turning inside a double-helix elastomeric stator. The cavities transport fluid without shearing or emulsification. The sealing line between the rotor and stator separates each cavity and handles solids, liquids, gases, or any combination of the three.  

In fracking operations, clarifier underflows often contain highly saline liquids and abrasive solids, such as sand. The RES treatment plant also needed pumps that are chemically resistant to 120,000-ppm chloride content. To meet this need, the rotor and all other wetted parts were made of stainless steel. The pump also has a Hastelloy mechanical seal designed to withstand higher corrosion levels. The rotor is chromium-coated to withstand increased abrasion. Several BN 2-6L pumps also were installed to pump flocculants. 

Progressive cavity pumps, which produce the same pressure as four-stage pumps, are designed to be compact, have uniform walls, and be smaller and less expensive than other similar technology. The pumps can be outfitted to use a standard hydraulic motor to minimize downtime. They also are used on oil and gas completion, water-well drilling, and grouting rigs, as well as to pump explosive emulsions into drill holes for blasting.  

In addition, the company provides onsite support for all pumping aspects of the shale operations, including flow-back and produced water treatment, chemical metering, sludge treatment, sludge feed, solids handling, drilling-mud cleaning, shaker underflow, desanders and desilters (discharge), centrifuge discharge, and grout pumping.  

  

Transitioning into seamless treatment 

“Trucks are arriving from a 60-mi [97-km] radius, but we have had trucks delivering water from as far as 80 miles [129 km] away,” Kicinski said.  

The treatment plant has a 4542-m3/d (1.2-mgd) capacity and a 30-minute unloading and recycle process turnaround time. It also is a zero-liquid discharge facility that returns 100% of the treated water to the shale-gas production field. 

The pumps have provided trouble-free service since April 2010. RES plans on using the pumps for future projects, including in two additional field plants planned, Kicinski said. “The new plants will be smaller than our Mount Pleasant facility and will be located near the gas productions fields,” he said.