Factors leading to instability of extra-low permeability oilfield produced water by water characteristic analysis

The unstable treatment of produced water was one of the puzzles for the exploitation of extra-low permeability oilfield. This work was to give a comprehensive estimation for the characteristic of the extra-low permeability oilfield produced water. For this purse, the produced water samples were collected from the produced water treatment plant located in Daqing. The physical, chemical and microbiological compositions of the produced water were investigated. The main factors leading to instability of the wastewater were analyzed though advanced treatment, which is dissolved organic compounds and microbiologically influenced corrosion. This also demonstrated that the conventional physical-chemical methods could not meet the stable re-injected water requirements. The biological treatment on the extra-low permeability oilfield produced water was recommended.