with incompatible salinity is absorbed as the water fills the spaces between the stacked silicate layers another important factor in saline water injection and 4 are rarely found separately and usually are mixed not only with other clays but also with sub microns particles of quartz feldspars and carbonates due to dissociation of their hydroxyl groups finely dispersed clay 39 s particles e g 0 01 to 0 1 u03bcm are very critical since the attractive forces between them are considerably less than the repelling forces of their electric charges thus they are nearly immune to any traditional water treatment steps such as coagulation flocculation and filtration if such dispersed clay 39 s particles are kept in the aquifers water without removal or further dispersion or sufficient stabilization before injection they are destined to cause blockages or plugging at the pore throats of the oil reservoir the resultant decline in permeability can severely impair the productivity of oil wells the typical acid treatment in sandstone oil reservoirs for example is very complex to reverse clays plugging and the global success rate of such a treatment is very discouraging lt 30 oil content and tss are critical in oil fields produced water since 1 dispersed and dissolved oil residues remain in produced water 2 produced water.