Device for a Pipe Handling Unit and Method of Inserting and Withdrawing a Pipe String in/from a Borehole

A method of inserting and withdrawing a pipe string in/from a borehole by the use of a pipe-handling system, the pipe string being moved continuously in the axial direction of the borehole, wherein the method comprises:

• a) hanging a first pipe or pipe section off in a rotationally rigid manner in a lower rotary unit or an upper rotary unit of a first pipe-handling unit;
• b) wherein the first pipe-handling unit moves the first pipe/pipe section down the center axis of the borehole;
• c) hanging a second pipe or pipe section off in a lower rotary unit or an upper rotary unit of a second pipe-handling unit;
• d) wherein the second pipe-handling unit is moved downwards towards the first handling unit, bringing the second pipe or pipe section to connect to the first pipe or pipe section by the second pipe or pipe section being rotated to be screwed together with the first pipe or pipe section;
• e) disengaging said rotary unit of the first pipe-handling unit from the pipe string as the pipe string has been hung off in a rotationally rigid manner in said rotary unit of the second pipe-handling unit;
• f) wherein the first pipe-handling unit is moved upwards after the lower and upper rotary units (23, 23′) have been moved away from the centre axis of the borehole;
• g) repeating the steps b)-f) until the pipe string is complete;
• and
• h) reversing the steps a)-g) until the pipe string has been disassembled.

A method of joining together or disassembling a pipe string by the use of a pipe-handling system, the pipe string being moved continuously in the axial direction of the borehole, wherein the method comprises:

• a) hanging a first pipe off in a rotationally rigid manner in a rotary unit of a lower pipe-handling section;
• b) wherein the lower pipe-handling section moves the first pipe down the center axis of the borehole;
• c) placing an upper pipe-handling section in its upper position in which a second pipe is hung off in a rotary unit of the upper pipe-handling section;
• d) wherein the upper pipe-handling section is moved downwards towards the lower pipe-handling section, bringing the second pipe to connect to the first pipe by the second pipe being rotated to be screwed together with the first pipe;
• e) disengaging the rotary unit of the lower pipe-handling section from the pipe string as the pipe string has been hung off in a rotationally rigid manner in the rotary unit of the upper pipe-handling section;
• f) wherein the upper pipe-handling section and the pipe string are moved downwards;
• g) wherein the lower pipe-handling section is moved upwards towards the upper pipe-handling section;
• h) wherein the lower pipe-handling section is moved downwards at a rate equal to the rate of the upper pipe-handling section while the rotary unit of the lower pipe-handling section is being connected to the pipe string;
• i) releasing the upper pipe-handling section the pipe string;
• j) repeating the steps b)-i) until the pipe string is complete;
• and
• k) reversing the steps a)-j) until the pipe string has been disassembled.