Patent ID: 7934551

Claim:
A method for blending oil-fields produced water with saline water to remove carboxylates and suspended particles and produce a suitable saline stream, said method comprising the steps of: (a) increasing the pH of said oil-fields produced water by adding an amine solvent to enhance the dissociation of said carboxylates; (b) mixing said pH increased oil-fields produced water with said saline water to produce intermediate saline stream and dispersed oily droplets by bonding said carboxylates in said pH increased oil-fields produced water with said suspended particles in said saline water; (c) separating said dispersed oily droplets from said intermediate saline stream by hydrophobic membranes to remove said carboxylates and suspended particles and to produce said suitable saline stream; (d) removing said amine solvent and oxygen from said suitable saline stream by vacuum based unit; (e) injecting said suitable saline stream into subterranean formation for hydrocarbons recovery.