Well drilling method

Claim 1

A METHOD OF DRILLING AN UNDERWATER WELL FROM A FLOATING DRILLING VESSEL AT THE SURACE OF A BODY OF WATER, SAID VESSEL HAVING A ROTARY TABLE ABOVE AN UNOBSTRUCTED PASSAGE TO THE SURFACE OF THE WATER AND MEANS FOR SUPPORTING A DRILL STRING BELOW SAID ROTARY TABLE, SAID METHOD COMPRISING THE SEQUENTIAL STEPS OF (A) POSITIONING SAID VESSEL AT A SELECTED DRILLING LOCATION, (B) LOWERING FROM THE VESSEL INTO CONTACT WITH THE FORMATION BENEATH THE BODY OF WATER A DRILL STRING HAVING A KELLY AT THE UPPER END THEREOF, (C) INSERTING THE KELLY IN THE ROTARY TABLE, (D) DRILLING A HOLE IN THE FORMATION BY APPLYING A ROTATING FORCE TO THE KELLY TO ROTATE THE DRILL STRING, (E) SUPPORTING ON SAID FLOATING DRILLING VESSEL AT A LEVEL BELOW THE ROTARY TABLE THE UPPER END OF THE DRILL STRING AT A POINT BELOW THE KELLY, WITH THE LOWER END OF THE DRILL STRING BEING FREELY SUSPENDED FOR VERTICAL UP AND DOWN MOVEMENT IN THE DRILLED HOLE, (F) DISCONNECTING THE KELLY FROM THE TOP OF THE DRILL STRING, (G) COUPLING A SECTION OF DRILL PIPE TO THE TOP OF THE DRILL STRING AND CONNECTING THE KELLY TO SAID PIPE SECTION, AND (H) ROTATING THE DRILL STRING TO DRILL MORE HOLE.

Claim 2

A METHOD OF DRILLING AN UNDERWATER WELL FROM A FLOATING DRILLING VESSEL AT THE SURACE OF A BODY OF WATER, SAID VESSEL HAVING A ROTARY TABLE ABOVE AN UNOBSTRUCTED PASSAGE TO THE SURFACE OF THE WATER AND MEANS FOR SUPPORTING A DRILL STRING BELOW SAID ROTARY TABLE, SAID METHOD COMPRISING THE SEQUENTIAL STEPS OF (A) POSITIONING SAID VESSEL AT A SELECTED DRILLING LOCATION, (B) LOWERING FROM THE VESSEL INTO CONTACT WITH THE FORMATION BENEATH THE BODY OF WATER A DRILL STRING HAVING A KELLY AT THE UPPER END THEREOF, (C) INSERTING THE KELLY IN THE ROTARY TABLE, (D) DRILLING A HOLE IN THE FORMATION BY APPLYING A ROTATING FORCE TO THE KELLY TO ROTATE THE DRILL STRING, (E) SUPPORTING ON SAID FLOATING DRILLING VESSEL AT A LEVEL BELOW THE ROTARY TABLE THE UPPER END OF THE DRILL STRING AT A POINT BELOW THE KELLY, WITH THE LOWER END OF THE DRILL STRING BEING FREELY SUSPENDED FOR VERTICAL UP AND DOWN MOVEMENT IN THE DRILLED HOLE, (F) DISCONNECTING THE KELLY FROM THE TOP OF THE DRILL STRING, (G) COUPLING A SECTION OF DRILL PIPE TO THE TOP OF THE DRILL STRING AND CONNECTING THE KELLY TO SAID PIPE SECTION, AND (H) ROTATING THE DRILL STRING TO DRILL MORE HOLE.

Claim 3

A METHOD OF INITIALLY STARTING THE DRILLING OF AN UNDERWATER WELL FROM A FLOATING DRILLING VESSEL AT THE SURFACE OF A BODY OF WATER, SAID VESSEL HAVING A ROTARY TABLE ABOVE AN UNOBSTRUCTED PASSAGE TO THE SURFACE OF THE WATER, SAID METHOD COMPRISING THE SEQUENTIAL STEPS OF (A) POSITIONING THE VESSEL AT A SELECTED DRILLING LOCATION, (B) LOWERING FROM THE VESSEL INTO CONTACT WITH THE FORMATION BENEATH THE BODY OF WATER A DRILL STRING HAVING A BIT AT THE LOWER END THEREOF AND HAVING A KELLY AT THE UPPER END THEREOF POSITIONED IN A ROTARY TABLE DURING DRILLING OPERATIONS, (C) DRILLING A HOLE IN THE FORMATION BY ROTATING THE DRILL STRING, (D) CARRYING OUT SAID DRILLING OPERATION OVER A PERIOD WHERE A DROP IN TIDE TAKES PLACE WHICH IS SUBSTANTIALLY GREATER THAN ANY RISE IN TIDE WHICH MAY OCCUR RESULTING IN A DECREASE IN THE DISTANCE BETWEEN THE FORMATION AND THE VESSEL AND A CORRESPONDING INCREASE IN THE DEPTH OF THE HOLE DRILLED IN THE FORMATION, (E) RAISING THE DRILL STRING AN AMOUNT SUFFICIENT TO SUSPEND IT FROM THE VESSEL WITHOUT THE LOWER END OF THE DRILL STRING LOSING CONTACT WITH THE HOLE, (F) ADDING A FIRST NEW SECTION OF DRILL PIPE BETWEEN THE KELLEY AND THE TOP OF THE DRILL STRING, (G) INSERTING THE DRILL STRING BACK TO THE BOTTOM OF THE HOLE, AND (H) CONTINUING DRILLING OPERATIONS.

Claim 4

A METHOD OF INITIALLY STARTING THE DRILLING OF AN UNDERWATER WELL FROM A FLOATING DRILLING VESSEL AT THE SURFACE OF A BODY OF WATER, SAID VESSEL HAVING A ROTARY TABLE ABOVE AN UNOBSTRUCTED PASSAGE TO THE SURFACE OF THE WATER, SAID METHOD COMPRISING THE SEQUENTIAL STEPS OF (A) POSITIONING THE VESSEL AT A SELECTED DRILLING LOCATION, (B) LOWERING FROM THE VESSEL INTO CONTACT WITH THE FORMATION BENEATH THE BODY OF WATER A DRILL STRING HAVING A BIT AT THE LOWER END THEREOF AND HAVING A KELLY AT THE UPPER END THEREOF POSITIONED IN A ROTARY TABLE DURING DRILLING OPERATIONS, (C) DRILLING A HOLE IN THE FORMATION BY ROTATING THE DRILL STRING, (D) CARRYING OUT SAID DRILLING OPERATION OVER A PERIOD WHERE A DROP IN TIDE TAKES PLACE WHICH IS SUBSTANTIALLY GREATER THAN ANY RISE IN TIDE WHICH MAY OCCUR RESULTING IN A DECREASE IN THE DISTANCE BETWEEN THE FORMATION AND THE VESSEL AND A CORRESPONDING INCREASE IN THE DEPTH OF THE HOLE DRILLED IN THE FORMATION, (E) RAISING THE DRILL STRING AN AMOUNT SUFFICIENT TO SUSPEND IT FROM THE VESSEL WITHOUT THE LOWER END OF THE DRILL STRING LOSING CONTACT WITH THE HOLE, (F) ADDING A FIRST NEW SECTION OF DRILL PIPE BETWEEN THE KELLEY AND THE TOP OF THE DRILL STRING, (G) INSERTING THE DRILL STRING BACK TO THE BOTTOM OF THE HOLE, AND (H) CONTINUING DRILLING OPERATIONS.