Abstract: A gravel packing system in which the gravel screen and attached packer are anchorable in a well bore. A cross-over tool has an indicator device which cooperates with the gravel screen to provide surface indications of the downhole tool positions and the operation of a gravel valve. A setting tool can be used with the cross-over tool to set the packer and is releasable by hydraulic pressure. The setting tool and packer are releasably and co-rotatively coupled permitting right hand rotation while going in the well bore. The cross-over tool has a float valve which permits reverse circulation in low pressure wells. The packer has a release system for permitting retrieval of the packer.