Study on Reinjection Technology of Sewage With SO4 in Oilfield

摘要

SO4~(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 SO42" 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 SO4~(2+) and the rate of formation damage is negligible when the pH below the critical of 9.8.