Hydraulic pressure-set liner hanger

Claim 1

IN A HYDAULIC PRESSURE-SET LINER HANGER, AN ANCHOR ASSEMBLY COMPRISING A TUBULAR MANDREL CONNECTIBLE TO A LINER TO BE RUN INSIDE A WALL CASING, A SLIP EXPANDER MOUNTED ON THE MANDREL, ANCHOR SLIPS SLIDABLY SUPPORTED ON THE MANDREL BELOW THE SLIP EXPANDER FOR MOVEMENT UPWARDLY RELATIVE THERETO TO ENGAGE THE WELL CASING, A RUNNING ASSEMBLY COMPRISING A TUBULAR BODY CONNECTIBLE TO A TUBULAR OPERATING STRING AND INCLIDING MEANS FORMING A RELEASABLE CONNECTION BETWEEN THE RUNNING ASSEMBLY AND THE ANCHOR ASSEMBLY ACTUATABLE BY RELATIVE ROTATION L BETWEEN THE TUBULAR BODY AND THE ANCHOR ASSEMBLY TO RELEASE THE RUNNING ASSEMBLY FROM THE ANCHOR ASSEMBLY, SLIP-ACTUATING MEANS COMPRISING A CYLINDER SLEEVE CONNECTED TO THE SLIPS AND SLIDABLY DISPOSED ABOUT THE EXTERIOR OF THE MANDREL, LONGITUDIALLY SPACED UPPER AND LOWER ANNULAR PISTONS CARRIED BY SAID SLEEVE IN SLIDABLE SEALING ENGAGEMENT WITH THE EXTERIOR OF THE MANDREL, THE LOWER PISTON HAVING GREATER PRESSURE-ACTUATABLE AREA THAN THE UPPER PISTON, BARRIER MEANS EXTENDING FROM THE MANDREL INTO SAID SLEEVE FORMING A PARTITION IN SAID SLEEVE DEFINING UPPER AND LOWER PRESSURE CHAMBERS FOR THE RESPECTIVE PISTONS, CONDUIT MEANS INCLUDING LONGITUDINALLY SPACED UPPER AND LOWER PORT MEANS AND SAID MANDREL RERANGED TO DIRECT PRESSURE FLUID FROM THE INTERIOR THEREOF SEPARATELY TO THE RESPECTIVE PRESSURE CHAMBERS, THE GREATER PRESSURE-ACTUATABLE AREA OF SAID LOWER PISTON BEING OPERATIVE TO URGE SAID SLIPS DOWNWARDLY TO NON-ACTUATED POSITION RELATIVE TO THE SLIP EXPANDER, SAID PLUGGING MEANS INSERTABLE IN SAID MANDREL TO CLOSE OFF THE BORE OF THE MANDREL BETWEEN SAID PORT MEANS WHEREBY TO DIRECT PRESSURE FLUID SOLELY TO SAID UPPER PISTON T ACTUATE THE ANCHOR SLIPS.