Full bore set down tool assembly for gravel packing a well

A tool assembly 10 provides a housing 12 attached to a packer 7 in a wellbore 1 and aligned with the production zone. A service tool 14 of the tool assembly 10 is attached to a tubing string 8 extending to the surface and is adapted for selective, removable attachment 48 (Fig 2d) and positioning within the housing 12. The tool assembly defines a downstream flow path 40 and a return flow path 42 when the service tool 14 is attached to the housing 12. A ball valve 80 that is selectively shiftable from the surface opens and closes the return flow path 42 to define a circulate position and a squeeze position. The tool assembly 10 facilitates gravel packing of the annulus 9 between the wellbore casing 2 and the service string 3.