Well packers

Claim 1

A HYDRAULICALLY SET PACKER FOR INSTALLATION ON THE LOWER END OF A STRING OF TUBING THROUGH WHICH PRODUCTION IS DELIVERED IN A WELL HAVING CASING EXTENDING DOWN THE WELL BELOW THE PACKER, SAID PACKER COMPRISING A TUBULAR MANDREL WITH A CENTRAL OPENING EXTENDING THERETHROUGH, SAID TUBULAR MANDREL HAVING A SUBSTANTIALLY UNIFORM INNER DIAMETER THROUGHOUT ITS LENGTH, A RING OF DEFORMABLE MATERIAL MOUNTED ON THE OUTER SURFACE OF THE MANDREL TO FORM A PACK OFF ELEMENT ADAPTED TO ENGAGE THE CASING WHEN THE PACKER IS SET, A SLIP CONE SLIDABLY MOUNTED ON THE OUTER SURFACE OF THE MANDREL ABUTTING THE LOWER END OF THE PACK OFF ELEMENT, SAID MANDREL HAVING AT ITS LOWER END A SECTION OF ENLARGED OUTER DIAMETER, A SLEEVE SLIDABLY MOUNTED ON THE MANDREL BETWEEN THE SECTION OF ENLARGED OUTER DIAMETER AND THE SLIP CONE, THE SLEEVE AND SECTION OF LARGE OUTER DIAMETER BEING CONSTRUCTED AND ARRANGED TO FORM A PRESSURE CHAMBER BETWEEN THE SLEEVE AND THE MANDREL, SEALING RINGS ENGAGING THE SLEEVE AND MANDREL AND COOPERATING WITH THE SLEEVE AND MANDREL TO PREVENT FLOW OUTWARDLY FROM THE PRESSURE CHAMBER, A PORT EXTENDING INWARDLY THROUGH THE MANDREL FROM THE PRESSURE CHAMBER, SLIPS EXTENDINGLY UPWARDLY FROM THE SLEEVE TO A POSITION ADJACENT AND BELOW THE SLIP CONE WHEN THE PACKER IS IN CONDITION FOR RUNNING INTO THE WELL AND ADAPTED TO MOVE UP OVER THE OUTER SURFACE OF THE SLIP CONE AS THE SLEEVE IS MOVED UPWARDLY ON THE MANDREL ON THE APPLICATION OF HYDRAULIC PRESSURE IN THE PRESSURE CHAMBER, A NARROW SHOULDER EXTENDING INWARDLY AROUND THE INNER SURFACE OF THE MANDREL AT A POSITION BELOW THE PORT TO FORM A VALVE SEAT, AND A VALVE ELEMENT HAVING A DIAMETER SMALLER THAN THE INNER DIAMETER OF THE MANDREL AND ADAPTED TO REST ON THE SHOULDER TO CLOSE THE LOWER END OF THE MANDREL WHEREBY A HYDRAULIC PRESSURE TO SET THE PACKER CAN BE APPLIED TO THE MANDREL ABOVE THE SHOULDER.