Method for degrading guanidine gum in waste fracturing fluid under coupling of potassium ferrate and ultrasonic intensification

Abstract

The invention relates to the technical field of waste fracturing fluid, in particular to a method for degrading guanidine gum in waste fracturing fluid under the coupling of potassium ferrate and ultrasonic intensification. The method includes the following steps that firstly, the waste fracturing fluid is separated after standing to obtain clear fluid; secondly, absolute ethyl alcohol is added into the clear fluid for purification; thirdly, an alkali regulator is added into the purified guanidine gum solution to regulate the pH value; fourthly, a potassium ferrate aqueous solution is added, meanwhile external-field ultrasonic intensification and oxidization are carried out, and qualified flowback fracturing fluid is obtained. According to the method of deeply oxidizing guanidine gum in the waste fracturing fluid with potassium ferrate under external-field ultrasonic intensification, guanidine gum is deeply oxidized under the coupling of the oxidizing agent and the external-field acting force, and the CODCr value and viscosity of the waste fracturing fluid are effectively reduced; meanwhile, secondary pollution is not generated in the treating process as potassium ferrate serves as the oxidizing agent and is environmentally friendly, and the chroma of the flowback fluid is increased as ferric hydroxide generated after potassium ferrate is reduced has the flocculation and precipitation effect.

Description

technical field

[0001] The invention relates to the technical field of fracturing waste liquid, and relates to a method for degrading guar gum in fracturing waste liquid by using potassium ferrate and ultrasonic intensified coupling. Background technique

[0002] The waste fluid produced during the fracturing process of oil and gas wells is mainly the waste fluid discharged to the ground after the fracturing operation is completed, suspended oil particles in the liquid and a variety of water-soluble polymers that are difficult to remove, including guar gum and many organic Additives, mainly including polycyclic aromatic hydrocarbons and benzene-derived compounds, are extremely stable, highly toxic, and contain chloride ions and heavy metal ions mainly iron. The fracturing flowback waste fluid has high viscosity and high COD Cr value, high oil content, high chroma and high content of suspended solids. If these waste liquids are discharged directly without treatment, it w...