Geopolymerization is a green innovative technique for the synthesis of inorganic membrane using fly ash as a raw material. In this work, fly ashes from thermal power plant were used as a source material for the synthesis of sintering-free, self-supported geopolymeric membrane. Geopolymeric slurry was obtained by chemical activation (Na 2 SiO 3 /NaOH = 2.5 and 15 M) of fly ashes (Si/Al = 2.8) after mixing of 30 min with 120 rpm. Compressive strength of 18.5 MPa was achieved after curing and hydrothermal treatment at 90°C for 24 h with the average pore size of 0.4-0.3 µm. Flux of different range 10, 14, 20, 26, and 29 L h-1 m-2 was obtained at driving pressure of 2, 3, 4, 5, and 6 bar respectively. Flux decline for produced water through prepared membrane were investigated after 60 s. Parametric studies of produced water from oil and gas production facility were also investigated before and after treatment.