| Shale gas is a kind of unconventional oil and gas resources in our country and is developed by multi stage hydraulic fracturing technology in horizontal wells.A lot of fracturing fluid is required in the fracturing process,so the fracturing fluid flowback with a large number of high COD,high suspended solids,high turbidity and high salinity will be produced in the end of the fracturing process.The components of fracturing flowback fluid in Chongqing Fuling shale gas development zone were analyzed and compared with other development zone at home and abroad in the paper,and the characteristics of the fracturing fluid flowback in Fuling zone were discussed.Then the treatment technology of the fracture fackflow was studied by chemical flocculation,electrocoagulation and Cathode in situ Fenton electrochemical oxidation process.The results show that chemical flocculation can be used for treatment of fracturing fluid flowback in different period,the removal rate of COD and the turbidity was up to88%,but the sludge yield is more than 37%;the removal of fracturing fluid COD and the turbidity in electrocoagulation process were above 92%and 96%respectively,sludge production is less than 30%.The COD and turbidity removal efficiency of electrocoagulation process are better than that of chemical flocculation,but the fluid flowback treatment cost is relatively higher than chemical flocculation;In cathode in situ Fenton electrochemical oxidation process,the yield of H2O2 can reach 85.2 mg/L in optimized conditions,the removal rate of COD is up to 40%,it is a promising fackflow wastewater treatment technology. |
PDF Full Text Request