Patent ID: 8226832
Filing Date: 2012-07-24
Classification: C02F,Y10T

Abstract:
1. A method for producing and continuously monitoring and controlling a concentration of chlorine dioxide in an aqueous fluid that is present at a well site, which aqueous fluid is adapted hydraulic fracturing, the method comprising: providing at the well site a continuous, pressurized flow of the aqueous fluid through at least one fluid flow line from at least one source of aqueous fluid to at least one frac tank; continuously determining the flow rate of the pressurized flow of the aqueous fluid; continuously determining an initial concentration of the chlorine dioxide within the pressurized flow of the aqueous fluid; continuously determining a treating rate capable of adjusting the initial concentration of the chlorine dioxide to a defined free residual level based upon stoichiometric demand; automatically generating at the well site sufficient chlorine dioxide solution to achieve the defined free residual level; treating the aqueous fluid at the well site by automatically introducing the chlorine dioxide into the aqueous fluid at the determined treating rate at an initial in-line treatment point under conditions conducive to thorough mixing of the chlorine dioxide within the pressurized flow of at least a portion of the aqueous fluid to produce treated aqueous fluid; continuously monitoring a post-treating concentration of the chlorine dioxide within the pressurized flow of the treated aqueous fluid; continuously comparing the post-treating concentration of the chlorine dioxide to the defined free residual level; and selectively adjusting the post-treating concentration at the well site by recirculating at least a portion of the treated aqueous fluid from the at least one frac tank to a point upstream of where the aqueous fluid is treated.