Abstract: A completion system is provided for completing downhole wells, comprising an upper polished bore receptacle incorporated into an intermediate casing of the downhole well and formed with a honed inner bore. A bottom packer for supporting a completion string within the intermediate casing has a first sealing assembly for sealing engagement against the inner bore of the upper polished bore receptacle. A lower polished bore receptacle is further incorporated into the intermediate casing and formed with a honed inner bore. A flow control hanger in the form of a hollow mandrel hangs a production liner in the intermediate casing and has a second sealing assembly for sealing engagement against an inner bore of the lower polished bore receptacle. A further completion system is provided comprising a polished bore receptacle (PBR) and a latch down packer having a lower end to which the PBR is connected.