Approximately 250 gallons of shale produced water from the hydraulic fracturing of the Piceance Basin near Debuque, Colorado was collected on May 7, 2013 and delivered to Colorado Springs, Colorado on May 8, 2013. The pH of the water measured at 7.05. Twelve different Variable Electro Precipitation™ treatments were conducted on the water with various flows, geometries, anodes/cathodes, and voltage settings.
Treatment goals included the reduction of these contaminates:
Table 1 below reflects the best treatment of the twelve different bench scale procedures used. This most successfully geometry/anode type would be used in a pilot test and/or production unit.
The best results were from run #COS-017 on May 14, 2013, and are summarized as follows:
TABLE 1. Variable Electro Percipitation of Colorado Shale Produced Water
|TREATMENT OF COLORADO SHALE HYDRAULIC FRACTURING PRODUCED WATER TREATMENT BY VARIABLE ELECTRO PRECIPITATION™
Colorado Springs, Colorado - May 14, 2013
|Beach Unit Run #144 (1.5 gpm)|
|Parameter||Raw||Treated||% Removal (Unit #)|
|Sulfur Reducing Bacteria (CFU/mL)||Not Available||Not Available||-----|
|Acid Producing Bacteria (CFU/mL)||Not Available||Not Available||----|
|Silica (as SiO2, mg/L)||17||5.2||69.4|
|Total Dissolved Solids||74,000||62,100||16.1|
Figure 1. Colorado Produced Water; Raw and Variable Electro Precipitated™ Treated Samples
Treatment of the shale produced water was successful in reducing suspended solids, silicone, and divalent ions associated with scaling and plugging of shale formations. Unfortunately, testing for acid producing and sulfate reducing bacteria was requested but, was not carried out due to communication problems with the analytical laboratory. The treatment was also successful in reducing heavy metals including Arsenic and Lead. The Variable Electro Precipitation™ treatment resulted in the contaminants settling out of solution and leaving a clear more usable water.
Above, is a photograph of the raw and treated water, along with the analysis of the raw and treated water. It is recommended that an on-site pilot plant be set up to treat fresh produced water to confirm these excellent results.