Exploration and Production Technologies


Development and Validation of an Acid Mine Drainage Treatment Process for Source Water Last Reviewed 6/30/2015

DE-FE00 14066

The goal of this project is to research and optimize a Floatation Liquid-Liquid Extraction (FLLX) water treatment system to process and repurpose water of lesser quality, i.e., acid mine drainage (AMD water) for use in hydraulic fracturing (HF) operations and assess the feasibility of using the system byproducts for flowback water processing. The objectives of this project are to (1) develop an innovative treatment process to support the use of AMD water for HF, (2) to evaluate the use of the (FLLX) process byproducts in flowback water treatment processes and (3) determine the environmental, regulatory, and commercial implications of using treated AMD as source water during HF.

Battelle, Columbus, OH 43201

Persistent pressure on public water resources and an increase in drought conditions in the U.S. have underscored the need for a novel technology to remediate and repurpose a non-potable water source to meet requirements for HF applications. Well injection for an HF application requires around five million gallons of fresh water. The increasing yearly demand on the public water system and the unconventional gas industry’s continued focus on reducing their environmental footprint have made producing a commercial technology capable of reducing potable water consumption essential to the continued success of unconventional resource development. The U.S. Department Of Energy (DOE) is also interested in increasing the effectiveness of flowback water treatment processes because conventional water treatment technologies such as chemical treatment, filtration, reverse osmosis, distillation, etc., must be adapted to treat a range of flowback water chemistries and have disadvantages such high cost, significant energy consumption, and low efficiency.

The research under this award will be performed to optimize a 3,400-bpd water processing system to provide freshwater from AMD sources for HF. The immediate outcome will be a commercial-ready system operated by a water services company at a throughput volume useful for HF operations and an optimized technology ready for deployment at additional sites. More than 30 billion gallons of freshwater have been used for HF since 2011 in efforts to recover the estimated 293 trillion cubic feet of gas trapped in unconventional deposits. Because the development of these unconventional resources is still in its early stages, it can reasonably be assumed that the demand for fresh water will increase in the coming years, taxing local supplies and creating demand for commercial-ready alternative technologies to reduce fresh water usage.

Providing an alternative hydraulic fracturing technology designed to cost-effectively treat environmentally hazardous AMD water will help reduce the use of and strain on fresh water resources. The technology developed during this project will provide a new freshwater source for HF operations in the unconventional resource development industry and concurrently assist in mitigating AMD, a legacy source of pollution.

Accomplishments (most recent listed first)
A source water stakeholder committee was established and provided preferences for the quality of water to be used in hydraulic fracturing operations. The project team anticipates that the HydroFlex platform will be capable of meeting the water quality parameters for reuse in oil and gas operations based on completed laboratory and bench-scale tests.

Current Status (June 2015)
Analytical data from the AMD source has shown that the sulfate concentration has declined to approximately 600 mg/L.  NETL and Battelle have concluded that this concentration is not elevated to a concentration that can demonstrate system efficacy.  Recent field studies have revealed that a second AMD mine pool existing in a shallower coal seam has sulfate concentrations of 1,100 mg/L which is adequate to demonstrate efficacy. NETL is anticipating making piping changes to the source water so that this sulfate rich AMD source can be put into the treatment system. The proposed approach is to temporarily suspend the second test campaign and redirect the finances to the piping changes. Once the results of the first test campaign are complete, NETL will judge whether the technology should be further tested in a second test campaign. This additional testing would require additional DOE funding.

Project Start: October 1, 2013
Project End: December 31, 2015

DOE Contribution: $900,000.00
Performer Contribution: $225,000.00

Contact Information:
NETL –  David Cercone (David.Cercone@netl.doe.gov or 412-386-6571)
Battelle – Anne Lane (LaneA@battelle.org or 614-424-3266)

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