Method and apparatus for drilling and working in offshore wells

Claim 1

THE METHOD OF DRILLING AN OFF-SHORE WELL COMPRISING ANCHORING A DRILLING VESSEL ON THE SURFACE OF A BODY OF WATER ABOVE A SUBMERGED WELL SITE, CEMENTING A LENGTH OF CASING VERTICALLY IN THE SUBMERGED EARTH AT SAID WELL SITE WITH THE TOP END OF SAID CASING POSITIONED ADJACENT THE SURFACE OF SAID SUBMERGED EARTH, ATTACHING A FLEXIBLE GUIDING MEANS BETWEEN THE SAID TOP END OF SAID CASING AND THE SAID DRILLING VESSEL, OPERATIVELY CONNECTING A SECTIONAL DRILL STRING INCLUDING A DRILL BIT ATTACHED TO THE LOWER END THEREOF TO A ROTARY MOTOR UNIT WHICH IS WITHIN A MOTOR ASSEMBLY PROPORTIONED TO FIT WITHIN THE UPPER END PORTION OF SAID CASING IN SLIDING RELATIONSHIP, SUSPENDING SAID MOTOR ASSEMBLY FROM SAID DRILLING VESSEL BY LIFTING AND LOWERING LINES WHICH ENABLE SAID MOTOR ASSEMBLY WITH THE SAID DRILL STRING EXTENDING DOWNWARDLY THEREFROM TO BE LOWERED FROM SAID DRILLING VESSEL AND INTO THE SAID TOP END OF SAID CASING AND TO BE RAISED FROM SAID CASING TO SAID DRILLING PLATFORM, CONNECTING SAID ROTARY MOTOR UNIT TO A SOURCE OF MOTIVE POWER THEREFOR ON SAID DRILLING VESSEL BY POWER-TRANSMITTING FLEXIBLE LINES, LOWERING SAID MOTOR ASSEMBLY AND SAID DRILL STRING FROM SAID DRILLING VESSEL AND GUIDING SAID DRILL BUT AND SAID DRILL STRING INTO SAID TOP END OF SAID CASING, CONTINUING LOWERING SAID MOTOR ASSEMBLY AND SAID DRILL STRING FROM SAID DRILLING VESSEL UNTIL SAID DRILL BIT IS IN CONTACT WITH THE SUBTERRANEAN FORMATIONS BELOW SAID CASING AND SAID MOTOR ASSEMBLY IS POSITIONED WITHIN THE UPPER END PORTION OF SAID CASING AND SUPPORTED THEREIN BY SAID LIFTING AND LOWERING LINES, PROVIDING MEANS TO PREVENT A RELATIVE ROTATION BETWEEN SAID MOTOR ASSEMBLY AND SAID CASING, ACTUATING SAID ROTARY MOTOR UNIT BY REMOTE CONTROL FROM SAID SOURCE OF MOTIVE POWER ON SAID DRILLING VESSEL TO ROTATE SAID DRILL STRING AND SAID DRILL BIT, DRILLING A WELL BORE BY LOWERING SAID MOTOR ASSEMBLY WITHIN THE SAID UPPER PORTION OF SAID CASING BY MANIPULATION OF SAID LIFTING AND LOWERING LINES FROM SAID DRILLING VESSEL TO MAINTAIN CONTACT BETWEEN SAID DRILL BIT AND SAID SUBTERRANEAN FORMATIONS WHILE ROTATING SAID DRILL STRING BY SAID ROTARY MOTOR UNIT, LIFTING SAID MOTOR ASSEMBLY AND THE ATTACHED SAID DRILL STRING FROM SAID CASING AND THROUGH SAID BODY OF WATER TO PLACE SAID MOTOR ASSEMBLY AND THE UPPER PORTION OF SAID DRILL STRING AT SAID DRILLING VESSEL, CONNECTING AN ADDITIONAL SECTION TO SAID DRILL STRING BELOW SAID MOTOR ASSEMBLY TO INCREASE THE LENGTH OF SAID DRILL STRING AGAIN LOWERING AND GUIDING SAID MOTOR ASSEMBLY AND THE ATTACHED SAID DRILL STRING INTO SAID CASING TO DISPOSE SAID MOTOR ASSEMBLY WITHIN THE SAID UPPER PORTION OF SAID CASING AND WITH SAID DRILL BIT IN CONTACT WITH THE BOTTOM OF SAID WELL BORE, ACTUATING SAID ROTARY MOTOR UNIT TO ROTATE SAID DRILL STRING AND SAID DRILL BIT WHILE FURTHER LOWERING SAID MOTOR ASSEMBLY BY SAID LIFTING AND LOWERING LINES TO DEEPEN SAID WELL BORE, AND POSITIONING A BLOWOUT PREVENTER ASSEMBLY AT THE OPEN UPPER END OF SAID CASING CONNECTING SAID BLOWOUT PREVENTER ASSEMBLY TO SAID DRILLING VESSEL BY POWER TRANSMITTING FLEXIBLE LIES AND OPERATING SAID BLOWOUT PREVENTER ASSEMBLY FROM SAID DRILLING VESSEL BY REMOTE CONTROL TO PREVENT THE BLWOUT THROUGH SAID CASING OF WELL FLUIDS FROM SAID SUBTERRANEAN FORMATIONS.

Claim 2

THE METHOD OF DRILLING AN OFF-SHORE WELL COMPRISING ANCHORING A DRILLING VESSEL ON THE SURFACE OF A BODY OF WATER ABOVE A SUBMERGED WELL SITE, CEMENTING A LENGTH OF CASING VERTICALLY IN THE SUBMERGED EARTH AT SAID WELL SITE WITH THE TOP END OF SAID CASING POSITIONED ADJACENT THE SURFACE OF SAID SUBMERGED EARTH, ATTACHING A FLEXIBLE GUIDING MEANS BETWEEN THE SAID TOP END OF SAID CASING AND THE SAID DRILLING VESSEL, OPERATIVELY CONNECTING A SECTIONAL DRILL STRING INCLUDING A DRILL BIT ATTACHED TO THE LOWER END THEREOF TO A ROTARY MOTOR UNIT WHICH IS WITHIN A MOTOR ASSEMBLY PROPORTIONED TO FIT WITHIN THE UPPER END PORTION OF SAID CASING IN SLIDING RELATIONSHIP, SUSPENDING SAID MOTOR ASSEMBLY FROM SAID DRILLING VESSEL BY LIFTING AND LOWERING LINES WHICH ENABLE SAID MOTOR ASSEMBLY WITH THE SAID DRILL STRING EXTENDING DOWNWARDLY THEREFROM TO BE LOWERED FROM SAID DRILLING VESSEL AND INTO THE SAID TOP END OF SAID CASING AND TO BE RAISED FROM SAID CASING TO SAID DRILLING PLATFORM, CONNECTING SAID ROTARY MOTOR UNIT TO A SOURCE OF MOTIVE POWER THEREFOR ON SAID DRILLING VESSEL BY POWER-TRANSMITTING FLEXIBLE LINES, LOWERING SAID MOTOR ASSEMBLY AND SAID DRILL STRING FROM SAID DRILLING VESSEL AND GUIDING SAID DRILL BUT AND SAID DRILL STRING INTO SAID TOP END OF SAID CASING, CONTINUING LOWERING SAID MOTOR ASSEMBLY AND SAID DRILL STRING FROM SAID DRILLING VESSEL UNTIL SAID DRILL BIT IS IN CONTACT WITH THE SUBTERRANEAN FORMATIONS BELOW SAID CASING AND SAID MOTOR ASSEMBLY IS POSITIONED WITHIN THE UPPER END PORTION OF SAID CASING AND SUPPORTED THEREIN BY SAID LIFTING AND LOWERING LINES, PROVIDING MEANS TO PREVENT A RELATIVE ROTATION BETWEEN SAID MOTOR ASSEMBLY AND SAID CASING, ACTUATING SAID ROTARY MOTOR UNIT BY REMOTE CONTROL FROM SAID SOURCE OF MOTIVE POWER ON SAID DRILLING VESSEL TO ROTATE SAID DRILL STRING AND SAID DRILL BIT, DRILLING A WELL BORE BY LOWERING SAID MOTOR ASSEMBLY WITHIN THE SAID UPPER PORTION OF SAID CASING BY MANIPULATION OF SAID LIFTING AND LOWERING LINES FROM SAID DRILLING VESSEL TO MAINTAIN CONTACT BETWEEN SAID DRILL BIT AND SAID SUBTERRANEAN FORMATIONS WHILE ROTATING SAID DRILL STRING BY SAID ROTARY MOTOR UNIT, LIFTING SAID MOTOR ASSEMBLY AND THE ATTACHED SAID DRILL STRING FROM SAID CASING AND THROUGH SAID BODY OF WATER TO PLACE SAID MOTOR ASSEMBLY AND THE UPPER PORTION OF SAID DRILL STRING AT SAID DRILLING VESSEL, CONNECTING AN ADDITIONAL SECTION TO SAID DRILL STRING BELOW SAID MOTOR ASSEMBLY TO INCREASE THE LENGTH OF SAID DRILL STRING AGAIN LOWERING AND GUIDING SAID MOTOR ASSEMBLY AND THE ATTACHED SAID DRILL STRING INTO SAID CASING TO DISPOSE SAID MOTOR ASSEMBLY WITHIN THE SAID UPPER PORTION OF SAID CASING AND WITH SAID DRILL BIT IN CONTACT WITH THE BOTTOM OF SAID WELL BORE, ACTUATING SAID ROTARY MOTOR UNIT TO ROTATE SAID DRILL STRING AND SAID DRILL BIT WHILE FURTHER LOWERING SAID MOTOR ASSEMBLY BY SAID LIFTING AND LOWERING LINES TO DEEPEN SAID WELL BORE, AND POSITIONING A BLOWOUT PREVENTER ASSEMBLY AT THE OPEN UPPER END OF SAID CASING CONNECTING SAID BLOWOUT PREVENTER ASSEMBLY TO SAID DRILLING VESSEL BY POWER TRANSMITTING FLEXIBLE LIES AND OPERATING SAID BLOWOUT PREVENTER ASSEMBLY FROM SAID DRILLING VESSEL BY REMOTE CONTROL TO PREVENT THE BLWOUT THROUGH SAID CASING OF WELL FLUIDS FROM SAID SUBTERRANEAN FORMATIONS.