Devices and methods for setting a packer inside a wellbore with little appreciable reduction of the useable area of the wellbore. The outer casing or liner of the wellbore contains one or more integrated casing coupler joints having an increased diameter chamber portion. A large bore packing element is carried within the increased diameter chamber portion. The packing element may be selectively actuated to form a seal against an interior tubular member. Because the packing element is located within the chamber portion of the casing coupler, the packer may be set while saving useable cross-sectional area within the casing.