Reconnaissance ship drilling machine lifting device with rear-mounted drill string compensation and rope winding method thereof

Abstract

The reconnaissance ship drilling machine lifting device comprises a derrick, a drill column compensation cylinder is arranged in the middle of the rear side of the derrick, a compensation cylinder pulley which moves up and down along the rear side of the derrick is arranged at the top of the drill column compensation cylinder, and a top pulley block is arranged at the top of the derrick. A top drive walking up and down along the front side of the derrick is hung on the lower portion of the top pulley block through a lifting steel wire rope passing through a movable pulley, and the lifting steel wire rope sequentially passes through the movable pulley on the top drive, the top pulley block and a compensation cylinder pulley from the top pulley block, then sequentially returns to the top pulley block and the movable pulley on the top drive and finally is fixed to the top of the derrick. The requirements for lifting operation and wave compensation of a drilling machine of a marine floating drilling ship are met, and the technical problems that in the prior art, corollary equipment is complex in structure, occupies the internal space of a derrick, is high in operation gravity center and is not beneficial to safe operation are solved.

Description

Technical Field

[0001] The invention belongs to the technical field of marine drilling equipment, and in particular relates to a drilling rig lifting device for a survey ship with drill string compensation. The invention also relates to a rope winding method for the drilling rig lifting device for a survey ship with drill string compensation. Background Art

[0002] my country's marine mineral resources, especially deep-sea mineral resources, are extremely rich. Using marine survey ship drilling rigs to conduct marine geological surveys and marine oil and gas resource exploration is an important means of marine mineral resource development. The drilling rig lifting system with drill string compensation function is the core component of the survey ship drilling rig. It is used to lift and lower downhole equipment such as the drill string, and meet the requirements of offshore wave heave compensation, thereby ensuring that the drill bit maintains a constant drilling pressure during downhole drilling. Different types of drill string compensation devices and their settings have a significant impact on the safety of marine operations. The existing technologies are:

[0003] The document "Research and Application of Fully Hydraulic Marine Geological Drilling System" (published in Petroleum Machinery Vol. 47, No. 12 in 2019) discloses a fully hydraulic marine geological drilling system, which is mainly composed of a lifting system (gantry derrick, direct-drive compensation system, top drive, hydraulic elevator and lifting cylinder), a pipe string handling system, an integrated dual driller control system, a seabed base plate retraction and underwater control system, etc. The drill string compensation of this drilling system adopts a direct-drive compensation system. The direct-drive compensation system is set up along the inner side of the derrick with an upper and lower frame with a top drive to move up and down, so as to realize the lifting and lowering of equipment such as the drill string, and meet the requirements of offshore wave heave compensation. The direct-drive compensation system (drill string compensation device) is connected to the top drive and installed on the inner side of the derrick. It occupies the internal space of the derrick in the height direction, which greatly increases the overall height of the derrick. In particular, when the direct-drive compensation system moves to a high position, the center of gravity of the system increases significantly, which is not conducive to the safety of offshore drilling operations of the survey vessel. The direct-drive compensation system has a complex structure and a large weight, and the increase in the height of the derrick also increases its own weight, which increases the weight of the drilling system, thereby affecting the loading capacity of the survey vessel. Summary of the invention

[0004] The purpose of the present invention is to provide a drilling rig lifting device for a survey ship with a drill string compensation rear-mounted, thereby solving the problem that the drill string compensation equipment in the prior art is not conducive to safe operation.

[0005] Another object of the present invention is to provide a rope winding method for a drilling rig lifting device of a survey ship with a drill string compensation rear arrangement.

[0006] The first technical solution adopted by the present invention is: a drilling rig lifting device for a survey ship with a rear drill string compensation, including a derrick, a drill string compensation cylinder is arranged in the middle of the rear side of the derrick, a compensation cylinder pulley that moves up and down along the rear side of the derrick is arranged on the top of the drill string compensation cylinder, and a top pulley block is arranged on the top of the derrick. The top drive that moves up and down along the front side of the derrick is suspended on the lower part of the top pulley block through a lifting wire rope via a movable pulley. The lifting wire rope is from the top pulley block, passes through the movable pulley on the top drive, the top pulley block and the compensation cylinder pulley in turn, and then returns to the top pulley block and the movable pulley on the top drive in turn, and is finally fixed on the top of the derrick.

[0007] The first technical solution of the present invention is also characterized in that:

[0008] The derrick comprises a left column, the top of the left column is connected with the right column through an upper crossbeam, and the rear middle and lower parts of the left column and the right column are connected through a middle crossbeam and a lower crossbeam.

[0009] The drill string compensation cylinder includes an outer cylinder tube, the upper end of the outer cylinder tube is fixed to the middle cross beam, a cylinder rod with its upper end extending outward is arranged inside the outer cylinder tube, a pulley frame is arranged on the top of the cylinder rod, the compensation cylinder pulley is rotatably connected in the pulley frame, a left compensation cylinder pulley guide is arranged on the rear side of the upper half of the left column, a right compensation cylinder pulley guide is arranged on the rear side of the upper half of the right column, the left and right sides of the pulley frame are respectively slidably matched in the left compensation cylinder pulley guide and the right compensation cylinder pulley guide, and a compensation device buffer air bag is symmetrically arranged on the left and right sides of the rear side of the upper cross beam.

[0010] Rollers I and II with V-shaped cross sections are arranged at the contact point between the pulley frame and the left compensation cylinder pulley guide rail. Track I is arranged longitudinally near the center side of the wellhead on the left compensation cylinder pulley guide rail. Track I is a square steel pipe and one edge of the track is opposite to the center of the V-shaped opening.

[0011] Rollers III and IV with V-shaped cross sections are arranged at the contact point between the pulley frame and the right compensation cylinder pulley guide rail. Track II is arranged longitudinally near the center side of the wellhead on the right compensation cylinder pulley guide rail. Track II is a square steel pipe and one edge of which is directly opposite to the center of the V-shaped opening.

[0012] A left top drive guide rail is arranged along the height direction on the left column near the center line of the wellhead, and a right top drive guide rail is arranged along the height direction on the right column near the center line of the wellhead. The left and right sides of the top drive are respectively slidably fitted in the left top drive guide rail and the right top drive guide rail, and a top drive buffer air bag is symmetrically arranged on the left and right sides directly below the upper cross beam.

[0013] The top pulley group includes a rope entry pulley, which is coaxially connected to a left rear pulley on one side of the rope entry pulley close to the center line of the wellhead, a left front pulley is arranged on the same working plane at the front end of the left rear pulley, a right front pulley is symmetrically arranged on the other side of the left front pulley with the center line of the wellhead as the axis, and a right rear pulley is arranged on the same working plane at the rear end of the right front pulley.

[0014] The movable pulley on the top drive comprises a left top drive pulley and a right top drive pulley respectively arranged on the left and right sides of the top of the top drive.

[0015] The diameters of the rope entry pulley, the left rear pulley, the left front pulley, the right front pulley, the right rear pulley, the left top drive pulley and the right top drive pulley are the same, and the spacing between the left front pulley and the right front pulley, the spacing between the left rear pulley and the right rear pulley, the spacing between the left top drive pulley and the right top drive pulley and the diameter of the compensation cylinder pulley are all the same.

[0016] The second technical solution adopted by the present invention is: a rope winding method for a drilling rig lifting device of a survey ship with a rear-mounted drill string compensation, comprising: introducing the lifting wire rope from a rope entry pulley, bypassing the rope entry pulley and obliquely downward to the left top drive pulley on the side of the wellhead center line, bypassing from the bottom of the left top drive pulley and then upward to the left front pulley, from the upper part of the left front pulley through the left rear pulley downward to the compensation cylinder pulley, bypassing from the bottom of the compensation cylinder pulley and then upward to the right rear pulley, bypassing from the right front pulley downward to the right top drive pulley, and finally fixed to the dead rope anchor point on the derrick.

[0017] The beneficial effects of the present invention are as follows: the drilling rig lifting device and the rope winding method of the survey ship with the drill string compensation rear-mounted of the present invention solve the problems in the prior art that the supporting equipment has a complex structure, the drill string compensation device is arranged above the top drive on the inner side of the derrick, and occupies a large space on the derrick, which increases the total height of the derrick, thereby causing the drilling rig lifting system to have a high center of gravity and is unsafe for the operation of the floating drilling ship; by arranging a pulley frame on the top of the drill string compensation cylinder and arranging a guide rail on the rear side of the derrick, the problems such as the top pulley of the drill string compensation cylinder being overloaded and turned when moving up and down, thereby causing the lifting wire rope to twist and break, etc., ensure the safety and reliability of the operation; by arranging a top pulley group with reasonable arrangement and appropriate spacing on the top of the derrick, the problems such as the lifting wire rope swinging back and forth during the working process, thereby causing the lifting process to be shaky and the rope to be tangled, etc., are solved. The requirements of the offshore floating drilling ship drilling rig lifting operation and wave compensation are met. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 It is a structural schematic diagram of a drilling rig lifting device for a survey ship with a drill string compensation rear-positioned according to the present invention;

[0019] Figure 2 It is a schematic diagram of the drill string compensation cylinder of the drilling rig lifting device of the survey ship with the drill string compensation rear-positioned according to the present invention in the retracted state;

[0020] Figure 3 It is a schematic diagram of the drill string compensation cylinder of the drilling rig lifting device of the survey ship with the drill string compensation rear-positioned according to the present invention being in the extended state;

[0021] Figure 4 It is a structural schematic diagram of the guide rails of the compensation cylinder pulley frame in the drilling rig lifting device of the survey ship with the drill string compensation rear-positioned according to the present invention;

[0022] Figure 5 It is a schematic diagram of the connection between the pulley frame of the drill string compensation cylinder and the pulley guide rail of the left compensation cylinder in the drilling rig lifting device of the survey ship with the drill string compensation at the rear of the present invention;

[0023] Figure 6 It is a schematic diagram of the connection between the pulley frame of the drill string compensation cylinder and the pulley guide rail of the right compensation cylinder in the drilling rig lifting device of the survey ship with the drill string compensation at the rear of the present invention;

[0024] Figure 7 It is a top view of the top pulley block in the drilling rig lifting device of the survey ship with the drill string compensation rear-positioned according to the present invention;

[0025] Figure 8 It is a schematic diagram of the dispersed structure of the top pulley block in the drilling rig lifting device of a survey ship with a rear-placed drill string compensation according to the present invention.

[0026] In the figure, 1. drilling platform, 2. derrick, 3. lifting winch, 4. drill string compensation cylinder, 5. top pulley block, 6. top drive, 7. lifting wire rope, 8. support rod, 9. rope entry pulley, 10. left rear pulley, 11. left front pulley, 12. right front pulley, 13. right rear pulley, 14. compensation cylinder pulley, 15. left top drive pulley, 16. right top drive pulley, 17. left front column, 18. right front column, 19. pin shaft, 20. upper crossbeam , 21. Middle crossbeam, 22. Lower crossbeam, 23. Left top drive guide rail, 24. Right top drive guide rail, 25. Left compensation cylinder pulley guide rail, 26. Right compensation cylinder pulley guide rail, 27. Top drive buffer airbag, 28. Compensation device buffer airbag, 29. Roller I, 30. Roller II, 31. Cylinder outer tube, 32. Cylinder rod, 33. Pulley frame, 34. Dead rope anchor point, 35. Track I, 36. Track II, 37. Roller III, 38 Roller IV. DETAILED DESCRIPTION

[0027] The present invention is described in detail below with reference to the accompanying drawings and specific embodiments.

[0028] Example 1

[0029] The present invention provides a drilling rig lifting device for a survey ship with a drill string compensation rear position, such as Figure 1 As shown, it includes a drilling platform 1, on which a derrick 2 and a lifting winch 3 are arranged, a drill string compensation cylinder 4 is arranged at the middle position of the rear of the derrick 2, a compensation cylinder pulley 14 is arranged on the top of the drill string compensation cylinder 4, a top pulley block 5 is arranged on the top of the derrick 2, a top drive 6 is suspended at the lower part of the top pulley block 5 through a lifting wire rope 7, a support rod 8 is arranged at the rear of the derrick 2, and the support rod 8 is connected to the drilling platform 1 through a pin shaft, and the lifting wire rope 7 is led out from the lifting winch 3, through the top pulley block 5 to the top drive 6, to the compensation cylinder pulley 14 on the top of the drill string compensation cylinder 4, and then back to the top pulley 5 to the top drive 6, and finally fixed on the top of the derrick 2.

[0030] like Figure 1 , Figure 2 As shown, the derrick 2 includes a left column 17, the top of the left column 17 is connected to the right column 18 through an upper crossbeam 20, and the rear middle and lower parts of the left column 17 and the right column 18 are connected through a middle crossbeam 21 and a lower crossbeam 22. There is no other connecting beam in the middle along the height direction of the derrick 2, so that the derrick 2 has sufficient strength and rigidity, and there is space for the top drive 6 to move up and down. The lower parts of the left column 17 and the right column 18 are connected to the drilling platform 1 through a pin shaft 19 respectively. The left column 17 is provided with a left top drive guide rail 23 along the height direction near the center line of the wellhead, and the right column 18 is provided with a right top drive guide rail 24 along the height direction near the center line of the wellhead. The two sides of the top drive 6 can cooperate with the left top drive guide rail 23 and the right top drive guide rail 24 so as to move up and down along the left top drive guide rail 23 and the right top drive guide rail 24. A top drive buffer airbag 27 is symmetrically arranged directly below the upper cross beam 20 of the derrick 2, one on each side, to prevent the top drive 6 from colliding with the upper cross beam 20 when it rises to a high position, play a buffering role, and reduce the collision load. A compensation device buffer airbag 28 is symmetrically arranged at the rear of the upper cross beam 20 of the derrick 2, one on each side, to prevent the compensation cylinder pulley 14 from colliding with the upper cross beam 20 when it rises to a high position, play a buffering role, and reduce the collision load.

[0031] like Figure 2 , Figure 3 As shown, the drill string compensation cylinder 4 includes a cylinder outer tube 31, the upper end of the cylinder outer tube 31 is fixed to the middle cross beam 21 of the derrick 2 by bolt connection, and a cylinder rod 32 for telescopic movement up and down is arranged inside the cylinder outer tube 31, and a pulley frame 33 is arranged on the top of the cylinder rod 32, and a compensation cylinder pulley 14 is arranged in the middle of the pulley frame 33. The left compensation cylinder pulley guide 25 for the pulley frame 33 to move up and down is arranged at the rear of the upper half of the left column 17 of the derrick 2, and the right compensation cylinder pulley guide 26 for the pulley frame 33 to move up and down is arranged at the rear of the upper half of the right column 18. When the cylinder rod 32 of the drill string compensation cylinder 4 is raised or lowered, the pulley frame 33 can move up and down along the left compensation cylinder pulley guide 25 and the right compensation cylinder pulley guide 26, which effectively ensures that the cylinder rod 32 moves in a straight line, and ensures that the lifting wire rope 7 works normally in the rope groove of the pulley 14.

[0032] like Figure 4 , Figure 5 As shown, the left compensation cylinder pulley guide 25 is provided with a track Ⅰ35 near the center of the wellhead. The track Ⅰ35 is a square steel pipe and is arranged at an angle of 45 degrees. The contact between the pulley frame 33 and the left compensation cylinder pulley guide 25 is provided with V-shaped rollers Ⅰ29 and rollers Ⅱ30. When the pulley frame 33 is raised and lowered, the rollers Ⅰ29 and rollers Ⅱ30 can just move up and down along the track Ⅰ35 arranged at an angle of 45 degrees, which can effectively ensure that the left side of the pulley frame 33 does not deviate from the preset track.

[0033] like Figure 4 , Figure 6 As shown, similarly, a track II36 is arranged near the center of the wellhead on the right compensation cylinder pulley guide 26. Track II36 is a square steel pipe arranged at an angle of 45 degrees. V-shaped rollers III37 and IV38 are arranged at the contact point between the pulley frame 33 and the right compensation cylinder pulley guide 26. When the pulley frame 33 is lifted up and down, rollers III37 and IV38 can just move up and down along the track II36 arranged at an angle of 45 degrees, which can effectively ensure that the right side of the pulley frame 33 does not deviate from the preset trajectory.

[0034] like Figure 7 , Figure 8 As shown, the top pulley block 5 includes a rope entry pulley 9, a left rear pulley 10 is arranged at the right end of the rope entry pulley 9, the rope entry pulley 9 and the left rear pulley 10 share a rotating shaft, a left front pulley 11 is arranged at the front end of the left rear pulley 10, the left rear pulley 10 and the left front pulley 11 are in the same working plane, a right front pulley 12 is arranged at a symmetrical position of the left front pulley 11, a right rear pulley 13 is arranged at the rear end of the right front pulley 12, the right front pulley 12 and the right rear pulley 13 are in the same working plane, and the rope entry pulley 9, the left rear pulley 10, the left front pulley 11, the right front pulley 12 and the right rear pulley 13 are all fixed pulleys. The left and right sides of the top of the top drive 6 are respectively provided with movable pulleys, a left top drive pulley 15 and a right top drive pulley 16, which move up and down synchronously with the top drive 6, and in addition, the compensating cylinder pulley 14 is also a movable pulley that moves up and down synchronously with the pulley frame 33. The diameters of the rope entry pulley 9, the left rear pulley 10, the left front pulley 11, the right front pulley 12, the right rear pulley 13, the left top drive pulley 15 and the right top drive pulley 16 are the same, the spacing between the left front pulley 11 and the right front pulley 12 is the same as the spacing between the left top drive pulley 15 and the right top drive pulley 16, the spacing between the left rear pulley 10 and the right rear pulley 13 is the same as the spacing between the left front pulley 11 and the right front pulley 12, and the diameter of the compensation cylinder pulley 14 and the spacing between the left front pulley 11 and the right front pulley 12 need to be matched in design, so as to effectively ensure that the lifting wire rope 7 can work normally when wound in all pulleys.

[0035] Example 2

[0036] The rope winding method of the drilling rig lifting device of the survey ship with the drill string compensation rear-positioned of the present invention is specifically as follows:

[0037] Step 1, calculate the length of the lifting wire rope 7. According to the height of the derrick 2 and the length of the wire rope reserved for the drum of the lifting winch 3 when the top drive 6 descends to the low-level drilling platform 1, calculate the total length of the lifting wire rope 7. Then wind the calculated lifting wire rope 7 on the drum of the lifting winch 3.

[0038] Step 2: Wind the rope. Figure 3As shown, the movable end of the lifting wire rope 7 is introduced from point a, bypasses the rope entry pulley 9 to the left top drive pulley 15, exits from point b, then to the left front pulley 11, passes through the left rear pulley 10, to the compensation cylinder pulley 14 at the top of the drill string compensation cylinder 4, exits from point c, then to the right rear pulley 13, passes through the right front pulley 12, to the right top drive pulley 16, and finally to the dead rope anchor point 34.

[0039] Example 3

[0040] The working process of the drilling rig lifting device for survey vessels with post-drill string compensation of the present invention is as follows:

[0041] During the normal drilling process, due to the influence of wave heave, when the survey ship rises with the waves, the lifting system will bring the drill string in the well up with the ship. In order to keep the front end drill bit of the drill string suspended at the lower end of the top drive 6 of the lifting system in contact with the bottom of the well and have a constant drilling pressure, the lifting system descends under the gravity of the drill string in the well, and the left top drive pulley 15 and the right top drive pulley 16 of the top drive 6 descend accordingly. Then the drill string compensation cylinder 4 works, the cylinder rod 32 extends, and the top compensation cylinder pulley 14 moves upward to compensate for the change in the length of the lifting wire rope 7 in the rope system caused by the descent of the top drive pulley, effectively ensuring that when the ship moves upward with the waves, the top drive 6 in the lifting system remains in a constant position relative to the bottom of the well, and the drilling pressure of the drill bit remains unchanged, thereby ensuring normal drilling operations.

[0042] When the survey ship sinks with the waves, the lifting system will descend with the ship. In order to keep the front end drill bit of the drill string suspended at the lower end of the top drive 6 of the lifting system in contact with the bottom of the well and have a constant drilling pressure, the lifting system rises under the reaction force of the drill string in the well, and the left top drive pulley 15 and the right top drive pulley 16 of the top drive 6 rise accordingly. Then the drill string compensation cylinder 4 works, the cylinder rod 32 retracts, and the top compensation cylinder pulley 14 moves downward to compensate for the change in the length of the lifting wire rope 7 in the rope system caused by the rising of the top drive pulley, effectively ensuring that when the ship moves downward with the waves, the position of the top drive 6 in the lifting system relative to the bottom of the well remains unchanged, and the drilling pressure of the drill bit remains unchanged, so as to maintain normal drilling operations.

Claims

1. A drilling rig lifting device for a survey ship with a drill string compensation rear position, characterized in that: The invention comprises a derrick (2), wherein a drill string compensation cylinder (4) is arranged at the middle of the rear side of the derrick (2), a compensation cylinder pulley (14) which moves up and down along the rear side of the derrick (2) is arranged at the top of the drill string compensation cylinder (4), a top pulley block (5) is arranged at the top of the derrick (2), a top drive (6) which moves up and down along the front side of the derrick (2) is suspended at the bottom of the top pulley block (5) through a lifting wire rope (7) via a movable pulley, and the lifting wire rope (7) is passed from the top pulley block (5) in sequence through the movable pulley on the top drive (6), the top pulley block (5) and the compensation cylinder pulley (14), and then returns to the top pulley block (5) and the movable pulley on the top drive (6) in sequence, and is finally fixed to the top of the derrick (2).

2. The drilling rig lifting device for a survey ship with a drill string compensation rear position as claimed in claim 1, characterized in that: The derrick (2) comprises a left column (17), the top of the left column (17) is connected to a right column (18) via an upper crossbeam (20), and the rear middle and lower parts of the left column (17) and the right column (18) are connected via a middle crossbeam (21) and a lower crossbeam (22).

3. The drilling rig lifting device for a survey ship with a drill string compensation rear position as claimed in claim 2, characterized in that: The drill string compensation cylinder (4) includes a cylinder outer tube (31), the upper end of which is fixed to the middle cross beam (21), a cylinder rod (32) with its upper end extending outward is arranged inside the cylinder outer tube (31), a pulley frame (33) is arranged on the top of the cylinder rod (32), the compensation cylinder pulley (14) is rotatably connected to the pulley frame (33), a left compensation cylinder pulley guide rail (25) is arranged on the rear side of the upper half of the left column (17), a right compensation cylinder pulley guide rail (26) is arranged on the rear side of the upper half of the right column (18), the left and right sides of the pulley frame (33) are respectively slidably matched in the left compensation cylinder pulley guide rail (25) and the right compensation cylinder pulley guide rail (26), and a compensation device buffer air bag (28) is symmetrically arranged on the left and right sides of the rear side of the upper cross beam (20).

4. The drilling rig lifting device for a survey ship with a drill string compensation rear position as claimed in claim 3, characterized in that: The contact point between the pulley frame (33) and the left compensation cylinder pulley guide rail (25) is provided with a roller I (29) and a roller II (30) with a V-shaped cross section. The left compensation cylinder pulley guide rail (25) is provided with a track I (35) along the longitudinal direction near the center of the wellhead. The track I (35) is a square steel pipe and one edge of the track is directly opposite to the center of the V-shaped opening.

5. The drilling rig lifting device for survey vessels with post-drill string compensation as claimed in claim 3, characterized in that: The contact point between the pulley frame (33) and the right compensation cylinder pulley guide rail (26) is provided with a roller III (37) and a roller IV (38) with a V-shaped cross section. The right compensation cylinder pulley guide rail (26) is provided with a track II (36) along the longitudinal direction near the center of the wellhead. The track II (36) is a square steel pipe and one edge of the track is directly opposite to the center of the V-shaped opening.

6. The drilling rig lifting device for a survey ship with a drill string compensation rear position as claimed in claim 2, characterized in that: The left column (17) is provided with a left top drive guide rail (23) along the height direction on the side close to the wellhead centerline, and the right column (18) is provided with a right top drive guide rail (24) along the height direction on the side close to the wellhead centerline. The left and right sides of the top drive (6) are respectively slidably fitted in the left top drive guide rail (23) and the right top drive guide rail (24), and a top drive buffer air bag (27) is symmetrically provided on the left and right sides directly below the upper cross beam (20).

7. The drilling rig lifting device for a survey ship with a drill string compensation rear position as claimed in claim 1, characterized in that: The top pulley block (5) comprises a rope entry pulley (9), a left rear pulley (10) is coaxially connected to the rope entry pulley (9) on one side close to the wellhead centerline, a left front pulley (11) is arranged on the same working plane at the front end of the left rear pulley (10), a right front pulley (12) is symmetrically arranged on the other side of the left front pulley (11) with the wellhead centerline as the axis, and a right rear pulley (13) is arranged on the same working plane at the rear end of the right front pulley (12).

8. The drilling rig lifting device for a survey ship with a drill string compensation rear position as claimed in claim 7, characterized in that: The movable pulley on the top drive (6) comprises a left top drive pulley (15) and a right top drive pulley (16) respectively arranged on the left and right sides of the top of the top drive (6).

9. The drilling rig lifting device for a survey ship with a drill string compensation rear position as claimed in claim 8, characterized in that: The diameters of the rope entry pulley (9), the left rear pulley (10), the left front pulley (11), the right front pulley (12), the right rear pulley (13), the left top drive pulley (15) and the right top drive pulley (16) are the same, the spacing between the left front pulley (11) and the right front pulley (12), the spacing between the left rear pulley (10) and the right rear pulley (13), the spacing between the left top drive pulley (15) and the right top drive pulley (16) and the diameter of the compensation cylinder pulley (14) are all the same.

10. The rope winding method for the drilling rig lifting device of a survey ship with a drill string compensation rear position as claimed in claim 9, characterized in that: include: The lifting wire rope (7) is introduced from the rope entry pulley (9), bypasses the rope entry pulley (9), and obliquely downwards to the left top drive pulley (15) toward the side of the wellhead center line, bypasses the bottom of the left top drive pulley (15), and then goes upwards to the left front pulley (11), from the upper part of the left front pulley (11) through the left rear pulley (10) to the compensation cylinder pulley (14), bypasses the bottom of the compensation cylinder pulley (14), and then goes upwards to the right rear pulley (13), passes through the right front pulley (12), and then bypasses the right top drive pulley (16), and finally is fixed to the dead rope anchor point (34) on the derrick (2).

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