Treatment technology of flowback fluid from the acidizing in oil well and injection well

The flowback fluid from the acidizing in oil well and injection well was difficult to be treated due to its complex components. In this study, on-site treatment was proposed and achieved near the wellhead. A treatment process of "sedimentation-multifunctional system-filtration" was designed on the basis of analyzing flowback fluid samples from 11 oil wells and injection wells. Besides, the neutralization agent, oxidant, flocculants and sludge conditioners were optimized for the field tests. Finally, a skid-mounted treatment equipment was developed and further applied in the following field tests for 15 times. The treated flowback fluid could meet the oilfield reinjection requirements (pH 6-8, oil contents < 10 mg/L, and SS < 10 mg/L), and on-site reinjection was realized.