Abstract: A system for treating a produced water stream to separate the water into a final concentrated brine stream and a final distillate stream includes a first flash vessel for separating the produced water stream into a first distillate stream and a first concentrated brine stream, a second flash vessel connected to the first flash vessel separates the first concentrated brine stream into a second distillate stream and a second concentrated brine stream, a third flash vessel connected to the second flash vessel separates the second concentrated brine stream into a third distillate stream and a final concentrated brine stream, a first pre-heater heat exchanger for heating the produced water stream by the final distillate stream of combination of the first distillate stream from the first flash vessel, the second distillate stream from the second flash vessel and the third distillate stream from the third flash vessel, a second pre-heater heat exchanger connected to the first pre-heater heat exchanger, for heating t