Steam generation system with subcooled water spray for wellbore steam injection

A steam supply system having a wet steam source and a steam separator disposed to separated wet steam into dry saturated steam and a saturated condensate. The dry saturated steam is heated in a superheater to produce superheated steam, while the saturated condensate is cooled in a subcooler to produced subcooled condensate with a target temperature selected to prevent immediate evaporation of the subcooled condensate when mixed with the superheated steam. The subcooled condensate is sprayed into a stream of superheated steam using spray nozzles and gradually evaporates downstream of the spray nozzles to produce process steam of a desired % quality. A cooling fluid passing through the subcooler is utilized to cool the saturated condensate. The flow rate of the cooling fluid through the subcooler can be utilized to achieve process steam of a desired % quality.