(1) the oily water temperature (40-60 ℃) and formation temperature is near, is beneficial to oil displacement, water absorbing capacity of water injection interval also increases.
(2) oily wastewater is sodium bicarbonate type water with large alkalinity. It has a good oil washing effect when injected into the oil layer.
(3) oily wastewater contains naphthenic acid and demulsifying agent added in the process of electrochemical dehydration, with high surface activity and good oil washing and oil displacement capacity, which is conducive to the improvement of water absorption in formation.
(4) high salinity of oily wastewater can inhibit the expansion of clay particles in low permeable vehicle oil layer and improve water absorption index in favorable low permeability oil layer.