Experimental research of waste acidizing fluid for reinjection treatment in oilfield

摘要

In view of the problem that waste acidizing fluid composition is complicated and its dealing is difficult, "Neutralization-Oxidation-Coagulation-Filtration" processing technique has been proposed by regulating the pH value during the process and the removal of total iron, suspended matter and other contaminants on the basis of analyzing the main pollution components of waste acidizing fluid. The objective of this work is to investigate the effects of process conditions on the removal of pollutants, such as chemicals type, chemicals dosage and the processing time, and the process parameters were optimized as follows: the mass ratio of NaOH and CaO was 3:1, c(H_2O2)=4000mg/L, oxidation time was 20min, c(PAC)=800mg/L, c(PAM)=10mg/L. The results showed that the waste acidizing fluid in oilfield under such treatment could meet the standards of reinjection (SS<10mg/L, oil content<30mg/L, pH=6~9, corrosion rate<0.076 mm·a~(-1)). Furthermore, this paper provided basis of theoretical and guidance for the reinjection requirements, experiment basis for design and implementation of disposing of wasted acidizing fluid treatment devices.