Retrievable hydrostatically set subsurface well tools

Claim 2

IN APPARATUS ADAPTED TO BE SET IN A WELL BORE: BODY MEANS; NORMALLY RETRACTED MEANS ON SAID BODY MEANS ADAPTED TO BE EXPANDED OUTWARDLY INTO ENGAGEMENT WITH THE WALL OF THE WELL BORE; HYDRAULICALLY OPERABLE MEANS FOR HAVING A HIGH PRESSURE SIDE AND LOW PRESSURE SIDE; AND HAVING A HIGH PRESSURE SIDE AND A LOW PRESSURE SIDE; MEANS FOR PREVENTING THE HYDROSTATIC HEAD OF FLUID IN THE WELL BORE INTERNALLY AND EXTERNALLY OF SAID BODY MEANS FROM ACTING ON SAID HIGH PRESSURE AND LOW PRESSURE SIDES; MEANS FOR SHIFTING A PORTION OF SAID PREVENTING MEANS TO A POSITION PERMITTING ACTION OF SAID HYDROSTATIC HEAD OF FLUID ON SAID HIGH PRESSURE SIDE, BUT NOT ON SAID LOW PRESSURE SIDE, TO CAUSE SAID HYDRAULICALLY OPERABLE MEANS TO EXPAND SAID NORMALLY RETRACTED MEANS; AND MEANS FOR SHIFTING A PORTION OF SAID PREVENTING MEANS TO A POSITION PERMITTING ACTION OF SAID HYDROSTATIC HEAD OF FLUID ON SAID LOW PRESSURE SIDE TO SUBSTANTIALLY EQUALIZE THE HYDROSTATIC HEAD ACTING ON SAID HIGH AND LOW PRESSURE SIDES SAID ENABLE SAID NORMALLY RETRACTED MEANS TO BE RETRACTED FROM ITS OUTWARDLY EXPANDED POSITION.

Claim 3

IN APPARATUS ADAPTED TO BE SET IN A WWLL BORE: BODY MEANS; NORMALLY RETRACTED MEANS ON SAID BODY MEANS ADAPTED TO BE EXPANDED OUTWARDLY INTO ENGAGEMENT WITH THE WELL OF THE WALL BORE; FIRST PASAGE MEANS FOR CONSAID BODY MEANS OPERATIVELY CONNECTED TO SAID NORMALLY RETRACTED MEANS TO EXPAND SAID NORMALLY RETRATED MEANS OUTWARDLY; SAID CYLINDRICAL AND PISTON MEANS HAVING A HIGH PRESSURE SIDE AND THE A LOW PRESURE SIDE IN WHICH A GASEOUS MEDIUM IS CONFIGURED INTERNALLY; FIRST PASSAGE MEANS FOR CONDUCTING THE HYDROSTATIC HEAD OF FLUID IN THE WELL BORE TO SAID HIGH PRESSURE SIDE OF SAID CYLINDRICAL AND PISTON MEANS TO EXPAND SAID NORMALLY RETRACTED MEANS OUTWARDLY SECOND PASSAGE MEANS FOR CONDUCTING THE HYDROSTATIC HEAD OF FLUID IN THE WALL BORE TO SAID LOW PRESSURE SAID OF SAID CYLINDER AND PISTON MEANS TO ENABLE SAID NORMALLY RETRACTED MEANS TO RETRACT FROM ITS OUTWARDLY EXPANDED POSITION; FIRST MEANS INITIALLY CLOSING SAID FIRST PASSAGE MEANS; SECOND MEANS INTERIALLY CLOSING SAID SECOND PASSAGE MEANS TO CONFINE THE GASEOUS MEDIUM IN SAID LOW PRESSURE SIDE AND PREVENT ENTRY THROUGH SAID SECOND PASSAGE MEANS OF THE HYDROSTATIC HEAD OF FLUID IN THE WELL BORE INTO SAID LOW PRESSURE SIDE; MEANS FOR SHIFTING SAID FIRST CLOSING MEANS TO OPEN POSITION; AND MEANS FOR SHIFTING SAID SECOND CLOSING MEANS TO OPEN POSITION.

Claim 4

IN APPARATUS ADAPTED TO BE SET IN A WWLL BORE: BODY MEANS; NORMALLY RETRACTED MEANS ON SAID BODY MEANS ADAPTED TO BE EXPANDED OUTWARDLY INTO ENGAGEMENT WITH THE WELL OF THE WALL BORE; FIRST PASAGE MEANS FOR CONSAID BODY MEANS OPERATIVELY CONNECTED TO SAID NORMALLY RETRACTED MEANS TO EXPAND SAID NORMALLY RETRATED MEANS OUTWARDLY; SAID CYLINDRICAL AND PISTON MEANS HAVING A HIGH PRESSURE SIDE AND THE A LOW PRESURE SIDE IN WHICH A GASEOUS MEDIUM IS CONFIGURED INTERNALLY; FIRST PASSAGE MEANS FOR CONDUCTING THE HYDROSTATIC HEAD OF FLUID IN THE WELL BORE TO SAID HIGH PRESSURE SIDE OF SAID CYLINDRICAL AND PISTON MEANS TO EXPAND SAID NORMALLY RETRACTED MEANS OUTWARDLY SECOND PASSAGE MEANS FOR CONDUCTING THE HYDROSTATIC HEAD OF FLUID IN THE WALL BORE TO SAID LOW PRESSURE SAID OF SAID CYLINDER AND PISTON MEANS TO ENABLE SAID NORMALLY RETRACTED MEANS TO RETRACT FROM ITS OUTWARDLY EXPANDED POSITION; FIRST MEANS INITIALLY CLOSING SAID FIRST PASSAGE MEANS; SECOND MEANS INTERIALLY CLOSING SAID SECOND PASSAGE MEANS TO CONFINE THE GASEOUS MEDIUM IN SAID LOW PRESSURE SIDE AND PREVENT ENTRY THROUGH SAID SECOND PASSAGE MEANS OF THE HYDROSTATIC HEAD OF FLUID IN THE WELL BORE INTO SAID LOW PRESSURE SIDE; MEANS FOR SHIFTING SAID FIRST CLOSING MEANS TO OPEN POSITION; AND MEANS FOR SHIFTING SAID SECOND CLOSING MEANS TO OPEN POSITION.