Well bore liner hanger

A well liner hanger for supporting a string of well liner from a landing nipple secured in a well bore, said hanger comprising:

• a tubular body mandrel;
• means at the upper end of said body mandrel for releasable engagement of a handling tool with said hanger;
• means provided on a lower end of said body mandrel for connection with the upper end of a string of well liner to be supported from said body mandrel in a well bore;
• an expandable annular seal assembly slidably fitted on said body mandrel for sealing around said hangar within a landing nipple in a well casing;
• means providing an annular operating shoulder on said body mandrel engageable with a first end of said seal assembly for expanding said seal assembly responsive to movement of said body mandrel in said seal assembly toward the opposite second end of said seal assembly;
• an annular latch assembly on said body mandrel at said second end of said seal assembly for locking said body mandrel against movement of said body mandrel toward said first end of said seal assembly and for holding said seal assembly as said body mandrel moves in said seal assembly toward said second end of said seal assembly, said latch assembly including an annular slip retainer ring spaced concentrically around said body mandrel and having an end edge surface engaged with said second end of said seal assembly and an internal annular slip locking surface sloping inwardly toward said body mandrel and second end of said seal assembly, a plurality of slips disposed in circumferential spaced relation around said body mandrel within said slip retainer ring between said locking surface and the outer surface of said body mandrel, each of said slips having a sloping outer arcuate surface mating with and slidable along said slip retainer ring locking surface and an internal cylindrical surface portion provided with arcuate teeth for engaging the outer surface of said body mandrel to hold said body mandrel against movement toward said seal assembly;
• a spring within said slip retainer ring confined between said slips and a shoulder surface provided on said body mandrel for urging said slips toward said locking surface in said retainer ring to bias said slips toward locking engagement with the outer surface of said body mandrel;
• a tubular locking key mandrel supported in slidable relationship on said body mandrel and connected at a first upper end with a lower end portion of said slip retainer ring, said key mandrel having circumferentially spaced windows therein;
• means releasably locking said key mandrel with said body mandrel;
• a radially expandible and contractable locating and locking key disposed in each of said windows of said key mandrel, each of said locking keys having an external locking shoulder for engagement with a locking shoulder in a landing nipple to hold said hanger against movement in a first direction and each of said keys having an external locating profile engageable in a mating profile in a landing nipple in a well bore, said keys being adapted to engage a desired landing nipple along a well bore and lock said hanger against downward movement at said landing nipple in said well bore;
• a spring secured between each of said keys and said body mandrel for biasing each of said keys outwardly on said body mandrel, said keys being mounted on said body mandrel for movement between contracted release positions and fully expanded locking positions on said body mandrel at a first upper position of said body mandrel within said keys;
• said body mandrel being provided with longitudinally spaced external annular locking boss surfaces engageable with upper and lower internal end position surfaces in said keys for locking said keys in expanded locking positions upon movement of said body mandrel within said keys to a second lower position;
• and said keys when expanded in locking relationship at a landing nipple being adapted to hold said hanger against downward movement in said landing nipple and to lock said slip retainer ring against movement for expanding said seal assembly and holding said seal assembly expanded responsive to longitudinal movement of said body mandrel within said seal assembly, said slip locking assembly, and said keys whereby said body mandrel is moved to said second lower position and said keys are locked outwardly, said locking slips are urged against said body mandrel to hold said body mandrel against movement toward said assembly, and a downward force is applied to said seal assembly to hold said assembly expanded in a sealing relation with said landing nipple.