Approximately 550 gallons of produced water was sampled from a Oil/Gas Exploration wellsite located in the Cherokee shale formation which lies within the Anadarko Basin. Two totes of water were collected on October 29, 2013 and susequently transported to Colorado Springs. From October 31, 2013 – November 6, 2013 a comprehensive series of Variable Electro Precipitation™ treatments were conducted on the water with various flows, geometries, anodes/cathodes, and voltage settings using a small scale EC system. The pH of the untreated water measured at 7.97.
Treatment goals included the reduction of these contaminants:
A series of 35 different treatment protocols were conducted on the Oil/Gas Exploration, LLC produced water to determine the optimum operating conditions to maximize bacteria removal. The five best treatments in terms of bacteria reduction efficiency are outlined in Table 1 below.
|Table 1 – Bacteria Results - Five Best VEP Treatments on Oil/Gas Exploration Produced Water|
|Sample #||Sample Description||ATP Bacteria (pg/mL)||% bacteria reduction|
|115/125||Raw Water||9690.8 / 6348.6||N/A|
Reduction of Total Suspended Solids (TSS) was also identified a being a priority although the produced water had a relatively low level of TSS when it arrived – 37 mg/L TSS. In addition to the TSS, hardness and metal removal was tested. Two samples were selected to be sent out for independent third party laboratory analysis. The results are shown in Table 2.
Total Dissolved Solids (TDS) was shown to be reduced by 5.2% & 4.4% for the 2 samples that were analyzed.
Total Suspened Solids (TSS) was reduced down to a level of <5.0 mg/L, which represents a reduction of greater than 86.5% for the 2 samples tested. The TSS was analyzed on the treated water after the solids had been allowed to settle and a subsample drawn off from the settled clear portion.
Hardness concentrations for the 2 samples analyzed were reduced by 75.9% and 61.3% respectively.
|Table 2 – Sample Results for TDS, TSS, Hardness and Dissolved Metals on treated Oil/Gas Exploration Water|
|Parameter||Sample#||Sample Description||Raw Sample Result (mg/L)||Treated Sample Result (mg/L)||% Reduction|
|Hardness (as CaCO3)||163||Treated Water||326||78.7||75.9|
|Dissolved Barium||163||Treated Water||0.743||0.207||72.1|
|Dissolved Boron||163||Treated Water||5.56||4.71||15.3|
|Dissolved Iron||163||Treated Water||21.7||<0.007||>99.9|
|Dissolved Sodium||163||Treated Water||3272||3371||N/A|
|Dissolved Strontium||163||Treated Water||18.8||6.86||63.5|
|Dissolved Zinc||163||Treated Water||0.475||0.319||32.8|