Experimental study of treatment processes for shale gas fracturing flowback fluid in the eastern Sichuan Basin

The toxicity of shale gas fracturing flowback fluid in the eastern Sichuan Basin was investigated and proven to be nontoxic. Based on the water quality characteristics of the fracturing flowback fluid in this area, an experimental study of treatment processes was conducted considering the coagulation-Fenton oxidation processes. Orthogonal and single-factor experiments were carried out for the coagulation and Fenton oxidation processes, respectively. The appropriate values of the various factors affecting the coagulation and Fenton oxidation experiments were determined according to the results. Subsequently, the water quality of the effluent treated by the coagulation-Fenton oxidation processes was evaluated, and the result showed that the water quality requirements for underground injection were met. Finally, the performances of slick water prepared by the effluent were evaluated, and the results showed that the slick water met the demands of fracturing operations and could be reused for further fracturing jobs.