Study On Reinjection Technology of Sewage With SO 4 2+ in Oilfield

摘要

SO 4 2- rich in reinjection sewage combined with Ca 2+ , Mg 2+ in formation water to form precipitate which results clogging in the formation pore. Ion exchange method was chosen to remove SO 4 2- in reinjection sewage and the anion exchange resin with OH - is selected as the exchange medium. It is necessary to evaluate alkali sensitivity of the formation rock due to the reinjection of sewage containing excess OH - . The results indicate that ion exchange method can remove more than 90% of the SO 4 2+ and the rate of formation damage is negligible when the pH below the critical of 9.8.