Treatment of Fracturing Returned Fluids:
The major hardware components of the system used for cleanup of returned fracturing fluids consist of an electrocoagulation (EC) unit, two reverse osmosis (RO) units and 3 to 4 tanks. The RO units are not identical. One unit is equipped to process high TDS Fluids (high salt or desalination unit). In our experience with reclaiming water from fracturing treatments in the Barnett Shale, the initially returned water typically contained very low TDS levels. Our EC units require a minimum of 700ppm TDS in order to be effective. The reason for this is, water with low ion concentration has poor electrical conductivity, and as a result, the EC unit is not effective in flocculating materials. As the "Flowback" continues, there is a consistent gradual incline in TDS levels present in the fluids. After Electrocoagulation, PH levels and TDS readings are consistently observed in order to direct the fluid to the RO capable of treating it. Water Cleaning Services has developed effective techniques and procedures that we implement when the "Flowback" reaches its conclusion stages, and TDS is above the RO's threshold. Our objective is to reclaim as much fresh water from the returned frac fluid as our equipment, our process, and knowledge will allow. Our fresh water recovery rates are currently between 75-80 percent per "Flowback" job.