Industry – Oil Remediation
Fort St. John Frac Flowback Remediation
Date of Project: Summer, 2013
Problem
Opaque, dark water was collected from an open pit frac flowback pond containing some hydrocarbons exhibiting considerable bacterial activity. Testing revealed particulates were in the sub-micron size range and would never respond to conventional gravitational settling or microfiltration (1.0-25.0 micron).
Customer Needs
Massive, growing volume of accumulated frac flowback was being stored in open ponds on customer’s property. The flowback was being slowly consumed in conjunction with fresh surface water to formulate new frac fluid compositions, but decreasing quality of flowback was necessitating increased demand for frac chemicals and lowering the efficacy of the resultant frac. Additionally, bacterial activity in the ponds was creating an H2S hazard.
Solution and Performance
The Fort St. John flowback sample was treated with the Hydro-Pod, a system that utilizes bimetallic electrocoagulation in conjunction with ozone treatment.
The application of caustic for pH control prompted significant precipitation of heavy metal salts. Repeated ozone treatment was required to remove discoloration (likely caused by the presence of Fe2+), crack most of the organic constituents of the flowback, destroy the bacterial infestation, and initiate further precipitation.
The EC treatment stabilized the solid particulates, leading to further particle growth. Addition of polymer further coagulated the solids, causing them to drop to the bottom of the storage tank.
Component | Units | Before | After | % Removal |
---|---|---|---|---|
Fe | mg/liter | 30.5 | 2.2 | 93% |
B | mg/liter | 12.5 | 3.5 | 72% |
Ba | mg/liter | 160 | 25 | 84% |
Ca | mg/liter | 4500 | 2500 | 44% |
Hardness | mg/liter | 12500 | 7500 | 40% |
SO42- | mg/liter | 19.7 | 3.9 | 80% |
Oil & Grease | mg/liter | 4 | 0.5 | 88% |
Additional Hydro-Pod Benefits
• Effective hydrocarbon, heavy metal, and bacterial removal
• Reduced water footprint
• Reduced environmental risk from flowback pond LOC
• At-the-well analytical capabilities
Products/Equipment Used
• Hydro-Pod
• Caustic
• Ozone
• Bimetallic Electrocoagulation
• Polymer