Underwater dual tubing well completion

Claim 1

IN OIL AND GAS WELL COMPLETION OPERATIONS CARRIED OUT FROM AN OPERATIONAL BASE POSITIONED ABOVE THE SURFACE OF WATER, WITH A MARINE CONDUCTOR PIPE STRING EXTENDING FROM SAID BASE AND CONNECTED TO AN UNDERWATER WELL CASINGHEAD, THE METHOD OF INSTALLING DUAL TUBING STRINGS IN A WELL CASING DEPENDING FROM AN UNDERWATER WELL CASING HEAD AND MOUNTING A WELLHEAD ASSEMBLY THEREON, SAID METHOD COMPRISING CLOSING SAID WELL CASING TO FORMATION FLUIDS UNDER PRESSURE, RUNNING DUAL STRINGS OF TUBING SIMULTANEOUSLY FROM SAID BASE ABOVE WATER DOWN THROUGH SAID MARINE CONDUCTOR PIPE AND CASING HEAD AND INTO SAID CASING, ATTACHING A STOP MEMBER AND A RUNNING STRING TO THE TOPS OF SAID TUBING STRINGS, LANDING IN SAID CASINGHEAD SAID STOP MEMBER WITH SAID TUBING STRING DEPENDING THEREFROM AND WITHDRAWING SAID RUNNING STRING, DISCONNECTING FROM SAID CASING HEAD SAID MARING CONDUCTOR PIPE AND WITHDRAWING IT TO THE ABOVE-WATER BASE, LOWERING A TOOL ON A RUNNING STRING AND GUIDING IT WITHIN SAID CASINGHEAD TO ENGAGE SAID TUBING STRINGS, WITHDRAWING THE UPPER ENDS OF SAID TUBING STRINGS TO A POINT ABOVE THE SURFACE OF THE WATER WITH THE LOWER ENDS OF THE TUBING STRING REMAINING IN THE WELL, ATTACHING A WELLHEAD ASSEMBLY TO THE TOP OF SAID TUBING STRINGS, AND LOWERING THE UPPER TO THE TOP OF SAID TUBING STRINGS BACK INTO SAID WELL CASING WITH THE WELLHEAD ASSEMBLY, AND CLOSING THE UPPER END OF SAID CASINGHEAD WITH SAID LOWERED WELLHEAD ASSEMBLY.