well lower seal retainer 42 which comprises an annular metallic member is positioned within a recess 48 located adjacent the lower end of mandrel 20 the upper mandrel should defined by recess 48 limits upward travel of the lower seal retainer 42 seal retainer 42 has a chamfered shoulder 46 located at its lower outer edge which is cooperable with an upwardly facing shoulder surface 44 located below the packer seal bore surface 16 at the lowermost end of mandrel 20 an outer mandrel collar 50 is attached to the mandrel by means of a conventional threaded connection in the preferred embodiment shown herein mandrel collar 50 is attached not only to the mandrel but to a portion of tubing or tailpipe extending below the anchor seal assembly 6 in those applications in which additional tubing or tailpipe is not necessary mandrel collar 50 could comprise a bottom sub attached to the exterior of mandrel 20 or it could comprise a raised annular shoulder on the lower end of the mandrel the significant factor is that mandrel collar 50 does protrude radially beyond the surface of the mandrel and overlaps the lower portion of seal retainer 42 after the anchor seal assembly 6 has been attached to the tubing string by means of the threaded connections on mandrel 20 the anchor seal assembly can be inserted into the bore of the packer as previously described the latch collet 26 will engage the packer threads 14 to prevent upward movement of the anchor seal assembly the anchor seal assembly 6 will be properly positioned within the packer bore.