Fluid pressure actuated well packer

Claim 1

A WELL PACKER INCLUDING: A TUBULAR MANDREL CONSTITUTING A FLOW CONDUCTOR; AN EXPANDER SLEEVE MOUNTED ON SAID MANDREL FOR LIMITED LONGITUDINAL MOVEMENT THEREON, SAID SLEEVE HAVING A PORTION SPACED FROM SAID MANDREL TO PROVIDE AN ANNULAR SPACE THEREBETWEEN; CLOSURE MEANS ON SAID EXPANDER SLEEVE AT THE OPPOSITE ENDS OF SAID ANNULR SPACE HAVING SEALING ENGAGEMENT WITH SAID MANDREL TO CLOSE SAID ANNULAR SPACE; PARTITION MEANS RIGIDLY SECURED ON SAID MANDREL IN SAID ANNULAR SPACE DIVIDING SAID ANNULAR SPACE INTO TWO LONGITUDINALLY SPACED CHAMBERS, SAID MANDREL HAVING A PORT COMMUNICATING THE INTERIOR OF SAID MANDREL WITH ONE OF SAID CHAMBERS; VALVE MEANS CLOSING SAID PORT; EXPANDABLE PACKING MEANS CARRIED BY SAID MANDREL AND MOVABLE TO EXPANDED POSITION BY SAID EXPANDER SLEEVE UPON MOVEMENT OF SAID EXPANDER SLEEVE IN ONE LONGITUDINAL DIRECTION RELATIVE TO SAID MANDREL, SAID ONE OF SAID CHAMBERS INCREASING IN VOLUME WHEN SAID EXPANDER SLEEVE MOVES TOWARD EXPANDING POSITION AND THE OTHER OF SAID CHAMBERS DECREASING IN VOLUME, SAID CHAMBERS BEING INITIALLY AT LOW PRESSURE, SAID EXPANDER SLEEVE BEING MOVED BY FLUID PRESSURE INTRODUCED INTO SAID ONE CHAMBER FROM THE INTERIOR OF SAID MANDREL TOWARD SAID POSITION EXPANDING SAID PACKING MEANS WHEN SAID VALVE MEANS IN MOVED TO OPEN SAID PORT.