WO2001033034B1

WO2001033034B1 - An arrangement for drilling and workover of oil and gas wells

Info

Publication number: WO2001033034B1
Application number: PCT/NO2000/000368
Authority: WO
Inventors: Svein Gleditsch; Boerre Fossli; Dicky Robichaux
Original assignee: Mercur Slimhole Drilling And I; Svein Gleditsch; Boerre Fossli; Dicky Robichaux
Priority date: 1999-11-05
Filing date: 2000-11-03
Publication date: 2001-10-11
Also published as: NO995641L; NO995641D0; AU1180901A; WO2001033034A1

Abstract

Arrangement for continuous lowering or hoisting of pipes in pressurized or pressureless wells, wherein a snubbing unit (3) continuously may be fed with pipes while the stepwise hoisting or lowering operation is carried out, such that the snubbing unit does not stop for coupling or de-coupling a new pipe length (17).

Claims

12AMENDED CLAIMS[received by the International Bureau on 23 May 2001 (23.05.01); original claims 1-12 amended (3 pages)]

1. Arrangement for lowering or hoisting of pipe sections, the arrangement comprising at least two feeding devices arranged for alternately grabbing a pipe section (17) and sideways movement along said pipe section, at least one of the feeding devices comprising a rotatory pipe claw for re- leasable coupling to said pipe section, c h a r a c t e r i z e d i n that a lower wedge set (25/26) is arranged to fixedly or rotably grab the string (17a) while a upper wedge set (22a/b) and a related rotation tong (20) is led up to the upper position where they fixedly or rotably grab the upper part of the string (17c) , a pipe manipulator (9b) being arranged to guide a new pipe section (17b) into the rotation tong (20) while the lower wedge arrangement (25/26) releases the string (17c) , said rotation tong (20) and/or pipe manipulator (9b) being arranged to screw the pipe section (17b) into the string (17a) while said string is rotated and/or lowered.

2. Arrangement according to claim 1, c h a r a c t e r i z e d i n that the pipe manipulator (9b) further is arranged to follow the string (17b) downwards until it reaches a lower position, where the pipe manipulator (9b) releases the pipe section (17b) and thereaf- ter brings a new pipe section from a pipe feeder (7b) , while a pipe manipulator (9a) already has brought a new pipe section (17a) from a pipe feeder (7a) and fed it into the rotation tong (20) .

3. Arrangement according to claim 1 or 2 , c h a r a c t e r i z e d i n that the upper wedge set (22a/b) comprises swivels (21/23) and a rotation tong (20) for continuous assembling of pipe sections while the step- wise lowering or hoisting of pipe sections (17) is carried out. 13

4. Arrangement according to one of the previous claims, c h a r a c t e r i z e d i n that a universal snubbing frame (8) is arranged on the deck of a vessel, said universal snubbing frame comprising a snubbing unit (3) enabling work in wells through a production tree (27) .

5. Arrangement according to claim 4 , c ha r a c t e r i z e d i n that a self upholding, single or double pipe handling mast (4) is arranged on top of the universal snubbing frame (8) , the self upholding, single or double pipe handling mast (4) comprising a guiding track for one or more pipe section manipulators (9a/b) .

6. Arrangement according to one of the previous claims, c h a r a c t e r i z e d i n that the pipe manipulators (9a/b) comprise pivotable organs (12a/b) for alternate sideways movement of pipe sections (17a/b) from a hoisting position (33/34) to a drilling centre (11) .

7. Arrangement according to one of the previous claims, c h a r a c t e r i z e d i n that the pipe manipulators (9a/b) comprise a pivotable pipe claw (13a/b) for coupling pipe sections (17a/b) to the pipe manipulator (9a/b) .

8. Arrangement according to one of the previous claims, c h a r a c t e r i z e d i n that the pipe manipulators (9a/b) comprise a hydraulic or electric rotary motor for coupling of pipe sections (12a/b) .

9. Arrangement according to one of the previous claims, c h a r a c t e r i z e d i n that the pipe manipulators (9a/b) comprise circulation pipes and liquid swivels (18a/b) for pumping pressurized liquids through the pipe manipulators (9a/b) . 14

₁₀. Arrangement according to claim 9, c _h a r a c t e r i z e d i n that the pipe manipulators (9a/b) comprise a locking device between the liquid swivel (18a/b) and the pipe connection for thereby coupling a pipe length to the pipe connection of the pipe manipula^¬ tor for circulation of liquid down through the string.

11. Arrangement according to one of the previous claims, c ha r a c t e r i z e d i n that a compensator frame (19) is arranged between the lower wedge set (25/26) on the snubbing unit (3) and the production tree (27) .

12. Arrangement according to claim 10, c h a r a c t e r i z e d i n that the compensator frame (19) comprises compensator cylinders and accumulators (29) in order to carry out snubbing from moving vessels (1) with a constant but adjustable tension between the snubbing unit (3) and the stationary production tree (27) .