Study On The Processing Technology Of The Deep Oxidation Of The Melon Gum In The Oilfield Fracturing Waste Liquid

Fracturing technology is the aim of improving the productivity of oil and gas wells,creating a channel of high percolation in the ground,so as to further liberate the productive capacity of low permeability zone.At present,the technology has been widely used in the world's major oil fields.In order to reduce the damage to the formation,the fracturing fluid should be drained to the maximum extent.Because the fracturing waste liquid has the characteristics of high COD value,high viscosity,high oil content,and the liquid containing additives such as melon gum,formaldehyde,polyacrylamide and suspended solids.Without treatment,direct discharge will cause great damage to the surrounding environment,especially surface water system and crops.So it is a hot research topic to properly deal with the waste liquid of oilfield fracturing.This experiment is based on the COD value of the waste liquid of the fracturing back row in an oil production plant in Daqing,with the content of guar gum solution of 0.2% simulated oilfield fracturing waste as the processing object.Combined with the existing processing methods,to reduce the COD value as the main goal of the simulation of waste liquid treatment.First of all,analysis the components of the fracturing waste liquid,determination of solid suspended solids,crude oil and some of the major organic pollutants as the main source of pollution,the COD value of the fracturing fluid is seriously overweight.With COD removal rate and viscosity index,using sodium hypochlorite pre oxidation,coagulation,Fenton reagent oxidation,electrochemical method of fracturing waste processing,and to determine the optimum conditions of each process: Optimum conditions of sodium hypochlorite pre oxidation for dosage 4m L,stirring rate 160r/min,initial p H=6,ultrasonic time of 30 min,stirring time was 80min;The optimum condition of coagulation is the addition of the polymeric aluminum chloride 1200mg/L,cationic polyacrylamide plus 50mg/L,the stirring time of 25 min,the initial p H=9;The best condition of Fenton reagent method is 3m L hydrogen peroxide solution,3m L ferrous sulfate solution,initial p H=3,reaction time 120min;The optimal conditions for the electrochemical depth oxidation are the voltage 3V,the reaction time 60 min,the initial p H=3,the stirring rate is300r/min.After the process combination treatment,the fracturing waste liquid water is clear,p H values between 6.5 to 7.3,COD removal rate of up to 92.87%,viscosity decreased from 4.3cp to 1.24 cp,suspended from 289mg/L to 31.4mg/L,and reached the national level two emission standards.