A rope-type continuous film-forming and coring device for drilling

Abstract

The present invention belongs to the field of rock science drilling technology, and particularly relates to a rope-type continuous film-forming and coring device while drilling. The present invention includes a drill string, in which a drill string slot is provided; further includes a coring rope, the coring rope is connected to a center rod of section A, a locker is connected to the center rod of section A through a shear pin, a block is rotatably connected to the locker, a pre-compressed spring is connected between the block and the locker, a bayonet brake is sleeved on the center rod of section A, a transmission rod is rotatably connected between the block and the bayonet brake, a bayonet is connected to a side of the bayonet brake facing the center rod of section A through a pre-compressed spring, and a bayonet locking groove is provided in the middle of the center rod of section A; further includes an A liquid storage cylinder, a B liquid storage cylinder, a center rod of section B and a core claw assembly. During the process of drilling down the drill string of the present invention, the processes of lowering the corer, coring, film-forming and lifting the corer can be realized, and the film-forming device while drilling is not lowered with the drill string, and multiple film-forming and coring while drilling can be realized in the target formation downhole.

Description

Technical Field

[0001] The invention belongs to the technical field of rock science drilling, and in particular relates to a rope-type continuous film-forming and coring device while drilling. Background Art

[0002] The key to exploring the laws of deep earth science is to obtain research samples that truly reflect the deep in-situ state, so as to directly obtain accurate physical and mechanical parameters and resource endowment conditions. It is the only way to achieve mineral exploration, safe construction of major projects, and solve scientific mysteries. However, the existing conventional coring process lacks effective protection for the core during the entire process of core drilling, transfer, and testing. The core is in direct contact with drilling fluid or sealing fluid, and it is difficult to avoid the diffusion and loss of materials in the core pores, which will lead to distortion of core analysis results. Therefore, it is necessary to develop deep in-situ quality preservation, moisture retention and light preservation coring technology. Deep in-situ quality preservation, moisture retention and light preservation coring technology has been designed and developed. This technology uses a film-forming fluid to cover the surface of the core during the dynamic process of drilling, and evenly grows a layer of dense polymer solid film with high barrier properties on the surface of the core. This film can preserve the volatile oil and gas components in the core, maintain the humidity stability inside the core, and maintain the in-situ dark and lightless environment, so as to truly obtain core samples that preserve the deep in-situ true state. The chemical reagents that produce the curing reaction in the film-forming liquid are divided into two components, which are pre-stored in a self-isolated manner and mixed in situ at a deep location to form the film-forming liquid.

[0003] The previous film-forming while drilling device can only be lowered with the drill string, and each trip can only be used to core once, which consumes a lot of time and manpower. It is necessary to design a rope-type continuous film-forming while drilling coring device to achieve multiple film-forming while drilling coring in the target formation downhole, greatly improving the efficiency of obtaining deep in-situ fidelity cores. Summary of the invention

[0004] In order to solve the above problems existing in the prior art, the purpose of the present invention is to provide a rope-type continuous film-forming and coring-while-drilling device to realize multiple film-forming and coring-while-drilling in the target formation downhole, greatly improving the efficiency of obtaining deep in-situ fidelity cores.

[0005] The technical solution adopted by the present invention is:

[0006] A rope-type continuous film-forming coring device for drilling, comprising a drill string, a drill string slot being arranged in the drill string; and a coring rope, the coring rope being connected to a center rod of section A, a locker being connected to the center rod of section A via a shear pin, a clamping block being rotatably connected to the locker, a pre-compressed spring being connected between the clamping block and the locker, a bayonet brake being sleeved on the center rod of section A, a transmission rod being rotatably connected between the clamping block and the bayonet brake, a bayonet being connected to a side of the bayonet brake facing the center rod of section A via a pre-compressed spring, and a bayonet locking groove being provided in the middle of the center rod of section A;

[0007] The lower end of the locker is connected to the A liquid storage cylinder, the center rod of section A extends into the A liquid storage cylinder, and an A liquid isolation chamber for storing A liquid is formed between the center rod of section A and the A liquid storage cylinder; the lower end of the A liquid storage cylinder is connected to the B liquid storage cylinder, the lower end of the center rod of section A is connected to the center rod of section B, the center rod of section B extends into the B liquid storage cylinder, and a B liquid isolation chamber for storing B liquid is formed between the center rod of section B and the B liquid storage cylinder; an A liquid migration channel connected to the A liquid isolation chamber and a B liquid migration channel connected to the B liquid isolation chamber are provided in the center rod of section B, and both the A liquid migration channel and the B liquid migration channel are provided with a one-way valve, and a merging channel is also penetrated at the lower end of the center rod of section B, and the A liquid migration channel and the B liquid migration channel are respectively connected to the merging channel; a core claw assembly for clamping the core is provided at the lower part of the B liquid storage cylinder.

[0008] The coring device is lowered into the drill string through the wellhead ground winch and the coring rope. The shear pin can withstand the shear force generated by the net weight of the entire coring device. When the coring device is lowered to the bottom of the drill string, the locking device is located in the drill string slot.

[0009] Lock the ground winch and drive the top drive or drill disc to rotate the drill string and the coring drill bit downward to drill the core. The center rod of section A is axially stationary, and the block is pushed downward by the drill string slot, causing the shear force on the shear pin to exceed its strength limit and be sheared off. The A liquid storage cylinder and the B liquid storage cylinder only move downward without rotation. The center rod of section A and the center rod of section B respectively move relative to the A liquid storage cylinder and the B liquid storage cylinder, causing the pressure of A liquid and B liquid to increase, exceeding the initial sealing force of the one-way valve, and being discharged from the A liquid migration channel and the B liquid migration channel respectively, and merged at the confluence channel to form a film-forming liquid with a certain delayed solidification ability.

[0010] The core is generated during the drilling process. After entering the B fluid storage cylinder, the core claw assembly clamps the core, and the film-forming fluid enters the film-forming space around the core at the top, side, and bottom of the core. The film-forming fluid wraps the core in real time, does not invade and pollute the core pores, and prevents foreign fluids from invading the core pores, achieving initial isolation and protection of the core.

[0011] After the predetermined coring depth is completed, the bayonet locking groove in the middle of the center rod of section A moves to the position of the bayonet brake. The bayonet is inserted into the bayonet locking groove under the thrust of the spring. The center rod of section A drives the bayonet brake to move upward. Under the action of the transmission rod, the trigger block shrinks inward, unlocking the rope-type lowering mechanism.

[0012] The film-forming fluid undergoes a chemical reaction in a short period of time, changing from liquid to solid. The solid sealing film has good barrier properties, wrapping the surface of the core, isolating the core from the exchange of external substances, and protecting the original material information in the core pores in situ. Then the coring device is lifted to the wellhead by a winch, and the coring is completed. When the bottom of the well returns to the initial state, another set of coring devices can be lowered again to carry out continuous film-forming coring while drilling.

[0013] In summary, during the drilling process of the drill string of the present invention, the processes of lowering the coring device, coring, film forming and pulling out the coring device can be realized. The film forming device while drilling is not lowered with the drill string, and multiple film forming and coring while drilling can be realized in the target formation downhole, which greatly improves the efficiency of obtaining deep in-situ fidelity cores and reduces labor costs.

[0014] As a preferred solution of the present invention, the lower part of the center rod of section A is a piston block of section A, which seals the lower part of the isolation chamber of liquid A, and a passage connecting the isolation chamber of liquid A and the migration channel of liquid A is provided in the piston block of section A. The piston block of section A can seal the lower part of the isolation chamber of liquid A to prevent leakage of liquid A.

[0015] As a preferred solution of the present invention, a through communication hole is provided at the lower part of the A-liquid storage cylinder. When the A-section piston block moves to the bottom to contact the B-liquid storage cylinder, the upper surface of the A-section piston block is higher than the communication hole. After the A-section piston block moves upward relative to the A-liquid isolation chamber, the space between the drill string and the A-liquid storage cylinder is connected to the lower space of the A-section piston block, thereby preventing the formation of a vacuum in the lower space of the A-section piston block.

[0016] As a preferred solution of the present invention, the lower part of the central rod of section B is a section B piston block, which seals the lower part of the B liquid isolation chamber, the A liquid migration channel extends into the section B piston block, and the B liquid migration channel and the confluence channel are arranged in the section B piston block. The section B piston block can seal the lower part of the B liquid isolation chamber to prevent leakage of B liquid.

[0017] As a preferred solution of the present invention, when the bayonet is engaged in the bayonet locking groove, the A-section piston block contacts the upper side of the A-liquid isolation chamber and the B-section piston block contacts the upper side of the B-liquid isolation chamber. When the bayonet is engaged in the bayonet locking groove, the A-liquid storage cylinder and the A-section center rod, and the B-liquid storage cylinder and the B-section center rod no longer move relative to each other. At this time, the A-liquid and the B-liquid have been completely drained, thereby preventing the A-liquid and the B-liquid from remaining.

[0018] As a preferred solution of the present invention, a static mixer is arranged in the converging channel. Under the action of the static mixer, liquid A and liquid B are uniformly premixed to form a film-forming liquid with a certain delayed curing ability.

[0019] As a preferred embodiment of the present invention, the core claw assembly includes an upper core claw and a lower core claw, a short core claw groove and a long core claw groove located below the short core claw groove are provided at the lower part of the center rod of section B, the upper core claw sleeve is provided in the short core claw groove, and the lower core claw sleeve is provided in the long core claw groove; the short core claw is provided with a film-forming liquid flow channel connecting the short core claw groove and the long core claw groove.

[0020] When the drill string is drilled and the coring rope is fixed and the bayonet has not yet engaged in the bayonet locking groove, the core is generated during the drilling process. When entering the B liquid storage cylinder, the upper core claw and the lower core claw are opened, and the upper core claw and the lower core claw are moved to the highest point of the short core claw groove and the long core claw groove respectively through friction. The annular gap between the side of the core and the inner wall of the B liquid storage cylinder is the film-forming space on the side of the core. During the coring process, the core enters the cylinder while drilling, and the film-forming liquid is dynamically generated while drilling.

[0021] After the bayonet is engaged in the bayonet locking groove, the ground winch is driven to lift the corer. During the lifting process of the corer, the core claw will tighten and break the core under the friction force with the core. As the corer is lifted, a fracture appears in the core between the upper core claw and the lower core claw. Further lifting the corer will make the lower core claw reach the fully contracted stroke, and the core will be pulled out again. As the upper core claw and the lower core claw pull out the core successively, the core and the bottom sealing rock block are formed respectively. The gap between the core and the bottom sealing rock block is the film-forming space at the bottom of the core. The film-forming liquid can further fill this space, and the bottom sealing rock block can prevent the leakage of the film-forming liquid.

[0022] As a preferred embodiment of the present invention, from top to bottom, the short core claw groove and the long core claw groove are gradually inclined toward the center of the drill string; a limiting step for limiting the upper core claw is provided on the upper side of the short core claw groove, and a limiting step for limiting the lower core claw is provided on the upper side of the long core claw groove.

[0023] As a preferred embodiment of the present invention, the axial length of the long core claw groove is greater than the axial length of the short core claw groove. Since the axial length of the short core claw groove is shorter, the stroke used for the upper core claw to be fully tightened is shorter, and the core will be first broken within a shorter lifting distance. Since the axial length of the long core claw groove is longer, the lower core claw has not yet reached the full tightening stroke at this time. Therefore, as the corer is lifted, a fracture will first appear in the core between the core claw and the lower core claw. Further lifting the corer will make the lower core claw reach the full contraction stroke, and the core will be pulled off again. Since the upper core claw and the lower core claw successively pull off the core, a core and a bottom sealed rock block are formed respectively. The gap between the core and the bottom sealed rock block is the film-forming space at the bottom of the core.

[0024] As a preferred solution of the present invention, the drill string slot is gradually inclined toward the center of the drill string from top to bottom, and a limiting step for limiting the blocking block is provided on the upper side of the drill string slot.

[0025] The beneficial effects of the present invention are:

[0026] 1. During the drilling process of the drill string of the present invention, the processes of lowering the corer, coring, filming and pulling out the corer can be realized. The film-forming device while drilling is not lowered with the drill string, and multiple film-forming and coring while drilling can be realized in the target formation downhole, which greatly improves the efficiency of obtaining deep in-situ fidelity cores and reduces labor costs. Compared with the previous film-forming coring device while drilling, the steps of installing the film-forming coring device while drilling and the time of drilling and drilling can be greatly simplified, saving costs. At the same time, multiple groups of fidelity core samples of continuous formations can be obtained for comparative analysis, which can greatly enhance the scientific significance of in-situ fidelity coring.

[0027] 2. The present invention innovatively designs a double-center-rod isolated liquid storage and drainage while drilling structure, which utilizes the center rod and the annulus of the liquid storage cylinder to store liquid, and has a large liquid storage capacity. The drainage while drilling ratio of liquid A and liquid B can be adjusted by changing the inner diameter of the liquid storage cylinder, so that the ratio of liquid A and liquid B can be arbitrarily adjusted, greatly enriching the selection of liquid A and liquid B. In addition, the mechanical structure is relatively simple, easy to install, and has higher operational stability, which greatly improves the feasibility in actual engineering applications.

[0028] 3. The present invention innovatively develops a double core claw type core bottom sealing structure, which can innovatively utilize rock blocks as bottom sealing barriers. Since the rock blocks are overall cylindrical and fit the shape of the core claws and the cylinder, they have a better effect in blocking the film-forming liquid and can improve the bottom film-forming quality. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 It is a schematic diagram of the structure of the present invention when the coring device is lowered into the drill string as a whole;

[0030] Figure 2 yes Figure 1 A partial enlarged view of the middle A;

[0031] Figure 3 It is a schematic diagram of the structure of the present invention after the coring device is lowered to the bottom end of the drill string;

[0032] Figure 4 yes Figure 3 A partial enlarged view of point B in the middle;

[0033] Figure 5 yes Figure 3 A partial enlarged view of point C in the middle;

[0034] Figure 6 It is a schematic diagram of the structure of the present invention when the coring drill bit is rotating and drilling;

[0035] Figure 7 It is a schematic diagram of the structure of the present invention after completing the predetermined coring footage;

[0036] Figure 8 yes Figure 7 A partial enlarged view of point D in the middle;

[0037] Fig. 9 yes Figure 7 A partial enlarged view of point E in the middle;

[0038] Fig.10 It is a schematic diagram of the structure of the present invention when the coring device is lifted up;

[0039] Fig.11 yes Fig.10 A partial enlarged view of the F in the middle;

[0040] Fig.12 yes Fig.10 A partial enlarged view of the G in the middle;

[0041] Fig.13 is a schematic diagram of the structure of the present invention after the lower core claw is retracted;

[0042] Fig.14 is a schematic diagram of the structure of the present invention after coring;

[0043] Fig.15 yes Fig.14 A partial enlarged view of point H in the middle.

[0044] In the figure: 1-coring rope; 2-drill string; 3-center rod of section A; 4-bayonet; 5-transmission rod; 6-shear pin; 7-block; 8-locker; 9-bearing; 10-A liquid storage cylinder; 11-A liquid isolation chamber; 12-bayonet locking groove; 13-B liquid storage cylinder; 14-center rod of section B; 15-B liquid isolation chamber; 16-A liquid migration channel; 17-B liquid migration channel; 18-check valve; 19 - confluence channel; 20 - upper core claw; 21 - static mixer; 22 - lower core claw; 23 - rock formation; 24 - drill string slot; 25 - coring drill bit; 26 - core; 27 - film-forming space at the top of the core; 28 - film-forming space at the side of the core; 29 - film-forming space at the bottom of the core; 30 - bottom sealing core block; 31 - short core claw slot; 32 - long core claw slot; 33 - latch gate; 34 - connecting hole. DETAILED DESCRIPTION

[0045] In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Generally, the components of the embodiments of the present invention described and shown in the drawings here can be arranged and designed in various different configurations.

[0046] Therefore, the following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the claimed invention, but merely represents selected embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in the field without creative work are within the scope of protection of the present invention. It should be noted that the embodiments of the present invention and the features in the embodiments can be combined with each other without conflict.

[0047] like Figure 1 to Figure 15 As shown, the rope-type continuous film-forming coring device of this embodiment comprises a drill string 2, the uppermost end of which is connected to a top drive or a rotary table at a wellhead on the ground, a coring drill bit 25 is connected to the bottom of the drill string 2, and a drill string clamping groove 24 is provided in the drill string 2; it also comprises a coring rope 1, the uppermost end of which is connected to a wellhead winch on the ground, the lower end of which is connected to a center rod 3 of section A, a locker 8 is connected to the center rod 3 of section A through a shear pin 6, and blocks 7 are provided on both sides of the locker 8, respectively. The bottom of the block 7 is connected to the locker 8 through a pin shaft, and a pre-compressed spring is connected between the block 7 and the locker 8, so that the block 7 has the potential energy to rotate away from the locker 8. A bayonet gate 33 is sleeved on the center rod 3 of section A, and a transmission rod 5 is rotatably connected between the block 7 and the bayonet gate 33. Both ends of the transmission rod 5 are connected by pin shafts. The bayonet gate 33 is connected to a bayonet 4 on the side facing the center rod 3 of section A through a pre-compressed spring, and a bayonet locking groove 12 is provided in the middle of the center rod 3 of section A. From top to bottom, the drill string slot 24 gradually tilts toward the center of the drill string 2, and a limiting step is provided on the upper side of the drill string slot 24 to limit the block 7.

[0048] The lower end of the locker 8 is connected to an A liquid storage cylinder 10 through a bearing 9, and the A section center rod 3 extends into the A liquid storage cylinder 10, and an A liquid isolation chamber 11 for storing A liquid is formed between the A section center rod 3 and the A liquid storage cylinder 10; the lower end of the A liquid storage cylinder 10 is connected to a B liquid storage cylinder 13 through a pin, and the lower end of the A section center rod 3 is connected to a B section center rod 14 through a thread, and the B section center rod 14 extends into the B liquid storage cylinder 13, and a B liquid isolation chamber 15 for storing B liquid is formed between the B section center rod 14 and the B liquid storage cylinder 13; The center rod 14 of section B is provided with an A liquid migration channel 16 connected to the A liquid isolation chamber 11 and a B liquid migration channel 17 connected to the B liquid isolation chamber 15. Both the A liquid migration channel 16 and the B liquid migration channel 17 are provided with a one-way valve 18. The lower end of the center rod 14 of section B is also penetrated by a merging channel 19. The A liquid migration channel 16 and the B liquid migration channel 17 are respectively connected to the merging channel 19. A static mixer 21 is provided in the merging channel 19. The lower part of the B liquid storage cylinder 13 is provided with a core claw assembly for clamping the core 26.

[0049] Among them, liquid A is epoxy resin, silicone rubber, etc., and liquid B is curing agent, cross-linking agent, etc.

[0050] The coring device is lowered into the drill string 2 as a whole through the wellhead surface winch and the coring rope 1. The shear pin 6 can withstand the shear force generated by the net weight of the entire coring device. When the coring device is lowered to the bottom of the drill string 2, the locking device 8 is located in the drill string slot 24.

[0051] Lock the ground winch and drive the top drive or drill disc to rotate the drill string 2 and the coring drill bit 25 downward to drill the core. The center rod 3 of section A is axially stationary, and the block 7 is pushed downward by the drill string slot 24, causing the shear force on the shear pin 6 to exceed its strength limit and be sheared. The A liquid storage cylinder 10 and the B liquid storage cylinder 13 only move downward without rotating. The center rod 3 of section A and the center rod 14 of section B respectively move relative to the A liquid storage cylinder 10 and the B liquid storage cylinder 13, so that the pressure of A liquid and B liquid increases, exceeding the initial sealing force of the one-way valve 18, and is discharged from the A liquid transport channel 16 and the B liquid transport channel 17 respectively, and merges at the confluence channel 19 to form a film-forming liquid with a certain delayed solidification ability.

[0052] The core 26 is generated during the drilling process. After entering the B liquid storage cylinder 13, the core claw assembly clamps the core 26, and the film-forming liquid enters the core top film-forming space 27, the core side film-forming space 28, and the core bottom film-forming space 29 around the core 26. The film-forming liquid wraps the core 26 in real time, does not invade and pollute the pores of the core 26, and prevents foreign fluids from invading the pores of the core 26, thereby achieving preliminary isolation and protection of the core 26.

[0053] After the predetermined coring depth is completed, the bayonet locking groove 12 in the middle of the center rod 3 of section A just moves to the position of the bayonet 4 box. The bayonet 4 is inserted into the bayonet locking groove 12 under the thrust of the spring. The center rod 3 of section A drives the bayonet 4 box to move upward. Under the action of the transmission rod 5, the trigger block 7 shrinks inward, so that the rope-type lowering mechanism is unlocked.

[0054] The film-forming liquid undergoes a chemical reaction in a short time, changing from liquid to solid. The solid sealing film has good barrier properties, wrapping the surfaces of the core 26, isolating the core 26 from the exchange of external substances, and protecting the original material information in the pores of the core 26 in situ. Then the coring device is lifted to the wellhead by a winch, and coring is completed. When the bottom of the well returns to the initial state, another set of coring devices can be lowered again to carry out continuous film-forming coring while drilling.

[0055] In summary, during the drilling process of the drill string 2 of the present invention, the processes of lowering the coring device, coring, film forming and pulling out the coring device can be realized. The film forming device while drilling is not lowered with the drill string 2, and multiple film forming and coring while drilling can be realized in the target formation downhole, which greatly improves the efficiency of obtaining deep in-situ fidelity cores 26 and reduces labor costs.

[0056] It should be noted that the lower part of the A-section center rod 3 is the A-section piston block, which seals the lower part of the A-liquid isolation chamber 11, and a channel connecting the A-liquid isolation chamber 11 and the A-liquid transport channel 16 is provided in the A-section piston block. The A-section piston block can seal the lower part of the A-liquid isolation chamber 11 to prevent leakage of A-liquid.

[0057] The lower part of the A liquid storage cylinder 10 is provided with a through communication hole 34. When the A section piston block moves to the bottom to contact the B liquid storage cylinder 13, the upper surface of the A section piston block is higher than the communication hole 34. After the A section piston block moves upward relative to the A liquid isolation chamber 11, the space between the drill string 2 and the A liquid storage cylinder 10 is connected to the lower space of the A section piston block, thereby preventing the lower space of the A section piston block from forming a vacuum.

[0058] The lower part of the B-section center rod 14 is a B-section piston block, which seals the lower part of the B-liquid isolation chamber 15, and the A-liquid transport channel 16 extends into the B-section piston block. The B-liquid transport channel 17 and the confluence channel 19 are arranged in the B-section piston block. The B-section piston block can seal the lower part of the B-liquid isolation chamber 15 to prevent leakage of the B-liquid.

[0059] When the bayonet 4 is engaged in the bayonet locking groove 12, the A-section piston block contacts the upper side of the A-liquid isolation chamber 11 and the B-section piston block contacts the upper side of the B-liquid isolation chamber 15. When the bayonet 4 is engaged in the bayonet locking groove 12, the A-liquid storage cylinder 10 and the A-section center rod 3, the B-liquid storage cylinder 13 and the B-section center rod 14 no longer move relative to each other. At this time, the A-liquid and the B-liquid have been completely discharged to avoid the A-liquid and the B-liquid residue.

[0060] Specifically, the core claw assembly includes an upper core claw 20 and a lower core claw 22, a short core claw groove 31 and a long core claw groove 32 located below the short core claw groove 31 are provided at the lower part of the center rod 14 of the B section, the upper core claw 20 is sleeved in the short core claw groove 31, and the lower core claw 22 is sleeved in the long core claw groove 32; a film-forming liquid flow channel connecting the short core claw groove 31 and the long core claw groove 32 is provided on the short core 26 claw. The axial length of the long core claw groove 32 is greater than the axial length of the short core claw groove 31.

[0061] When the drill string 2 is drilled and the coring rope 1 is fixed and the bayonet 4 has not yet engaged in the bayonet locking groove 12, the core 26 is generated during the drilling process. In the process of entering the B liquid storage cylinder 13, the upper core claw 20 and the lower core claw 22 are opened, and the upper core claw 20 and the lower core claw 22 are moved to the highest point of the short core claw groove 31 and the long core claw groove 32 respectively through friction. The annular gap between the side of the core 26 and the inner wall of the B liquid storage cylinder 13 is the film-forming space 28 on the side of the core. During the coring process, the core 26 enters the cylinder while drilling, and the film-forming liquid is dynamically generated while drilling.

[0062] After the bayonet 4 is engaged in the bayonet locking groove 12, the ground winch is driven to lift the corer. During the lifting process of the corer, the core 26 claw will be tightened and the core 26 will be broken under the friction force with the core 26. As the corer is lifted, a fracture will appear in the core 26 between the upper core claw 20 and the lower core claw 22. Further lifting the corer will make the lower core claw 22 reach the stroke of complete contraction, and the core 26 will be pulled out again. Since the axial length of the short core claw groove 31 is shorter, the stroke used for the upper core claw 20 to be fully tightened is shorter, and the core 26 will be broken first within the shorter lifting distance. Since the axial length of the long core claw groove 32 is longer, the lower core claw 22 has not reached the complete tightening stroke at this time. Therefore, as the corer is lifted, a fracture will first appear in the core 26 between the core 26 claw and the lower core claw 22. Further pulling the corer upward will make the lower core claw 22 reach the stroke of full contraction, and the core 26 will be pulled out again. As the upper core claw 20 and the lower core claw 22 pull out the core 26 successively, the core 26 and the bottom sealed core block 30 are formed respectively. The gap between the core 26 and the bottom sealed core block 30 is the film forming space 29 at the bottom of the core.

[0063] From top to bottom, the short core claw groove 31 and the long core claw groove 32 are gradually inclined toward the center of the drill string 2; the upper side of the short core claw groove 31 is provided with a limiting step for limiting the upper core claw 20, and the upper side of the long core claw groove 32 is provided with a limiting step for limiting the lower core claw 22.

[0064] The operation process of the present invention:

[0065] 1) The process of lowering the coring device to the bottom of the well:

[0066] Fill the A liquid isolation chamber 11 with A liquid in advance on the ground, and fill the B liquid isolation chamber 15 with B liquid. The one-way valve 18 provides a certain initial sealing force to prevent leakage of A liquid and B liquid before coring. Figure 1 and Figure 2 As shown, the coring device is lowered into the drill string 2 as a whole through the wellhead surface winch and the coring rope 1. The shear pin 6 can withstand the shear force generated by the net weight of the entire coring device, and will not be sheared during the lowering of the coring device to prevent the A liquid and the B liquid from being discharged in advance. During the lowering of the coring device, the clamping block 7 is in a retracted state. Figure 3 to Figure 5 As shown, when the corer is lowered to the bottom of the drill string 2, the locker 8 is located in the drill string slot 24. The block 7 opens a certain angle under the action of the spring.

[0067] 2) Film-forming and coring while drilling process:

[0068] like Figure 6As shown, the ground winch is locked so that the coring rope 1 cannot be lowered any further. The top drive or drill disc is driven to rotate the drill string 2 and the coring drill bit 25 downward to drill the core. The center rod 3 of section A is axially stationary, and the block 7 is pushed downward by the drill string slot 24, causing the shear force on the shear pin 6 to exceed its strength limit and be sheared off. Due to the presence of the bearing 9, the A liquid storage cylinder 10 and the B liquid storage cylinder 13 only move downward without rotation. The center rod 3 of section A and the center rod 14 of section B respectively move relative to the A liquid storage cylinder 10 and the B liquid storage cylinder 13, causing the pressure of the A liquid and the B liquid to increase, exceeding the initial sealing force of the one-way valve 18, and being discharged from the A liquid transport channel 16 and the B liquid transport channel 17 respectively, and merged at the confluence channel 19, and uniformly premixed under the action of the static mixer 21 to form a film-forming liquid with a certain delayed curing ability.

[0069] The core 26 is generated during the drilling process. When entering the B liquid storage cylinder 13, the upper core claw 20 and the lower core claw 22 are opened, and the upper core claw 20 and the lower core claw 22 are moved to the highest point of the short core claw groove 31 and the long core claw groove 32 respectively through friction. The gap between the top surface of the core 26 and the bottom surface of the B section center rod 14 is the core top film forming space 27. The annular gap between the side of the core 26 and the inner wall of the B liquid storage cylinder 13 is the core side film forming space 28. During the coring process, the core 26 enters the cylinder while drilling, and the film forming liquid is dynamically generated while drilling. The film forming liquid displaces the drilling fluid and other foreign fluids in the well in real time, covering the core top film forming space 27 and the core side film forming space 28. The film forming liquid wraps the core 26 in real time, does not invade and pollute the pores of the core 26, and prevents foreign fluids from invading the pores of the core 26, thereby achieving preliminary isolation and protection of the core 26.

[0070] 3) Unlocking process:

[0071] like Figure 7 to Figure 9 As shown in the figure, after the predetermined coring depth is completed, the bayonet locking groove 12 in the middle of the center rod 3 of section A just moves to the position of the bayonet 4 box. The bayonet 4 is inserted into the bayonet locking groove 12 under the thrust of the spring. The center rod 3 of section A drives the bayonet 4 box to move upward. Under the action of the transmission rod 5, the trigger block 7 shrinks inward, so that the rope-type lowering mechanism is unlocked.

[0072] 4) Core bottom sealing process:

[0073] like Figure 10 to Figure 12As shown, after the predetermined coring footage is completed, the film-forming liquid has completely wrapped the top and side surfaces of the core 26. The ground winch is driven to lift the corer. During the lifting process of the corer, the core 26 claw will be tightened and the core 26 will be broken under the friction between the core 26 and the core 26. Since the axial length of the short core claw groove 31 is shorter, the stroke used for the upper core claw 20 to be fully tightened is shorter, and the core 26 will be first broken within the shorter lifting distance. Since the axial length of the long core claw groove 32 is longer, the lower core claw 22 has not yet reached the full tightening stroke. Therefore, as the corer is lifted, a fracture will first appear in the core 26 between the core 26 claw and the lower core claw 22.

[0074] like Fig.13 As shown, further pulling up the corer will make the lower core claw 22 reach the fully retracted stroke, and the core 26 will be pulled out again. As the upper core claw 20 and the lower core claw 22 pull out the core 26 successively, the core 26 and the bottom sealed core block 30 are formed respectively. The gap between the core 26 and the bottom sealed core block 30 is the film-forming space 29 at the bottom of the core. The film-forming liquid can further fill this space, and the bottom sealed core block 30 can prevent the film-forming liquid from leaking. In this way, the film-forming liquid can completely cover all surfaces of the core 26.

[0075] 5) Extraction process:

[0076] like Fig.14 and Fig.15 As shown, the coring device is suspended at the bottom of the well for a period of time, and the temperature and pressure are maintained in situ. The film-forming liquid undergoes a chemical reaction in a short time, changing from liquid to solid. The solid sealing film has good barrier properties, wraps the surfaces of the core 26, isolates the core 26 from the exchange of external substances, and protects the original material information in the pores of the core 26 in situ. Then the coring device is lifted to the wellhead by a winch, and a coring is completed. When the bottom of the well returns to the initial state, another set of coring devices can be lowered again to carry out continuous film-forming coring while drilling.

[0077] The present invention is not limited to the above-mentioned optional implementation modes. Anyone can derive other various forms of products under the inspiration of the present invention. However, no matter what changes are made in the shape or structure, all technical solutions that fall within the scope defined by the claims of the present invention fall within the protection scope of the present invention.

Claims

1. A rope-type continuous film-forming and coring device while drilling, characterized in that: The drill string (2) comprises a drill string slot (24) arranged in the drill string (2); the drill string (2) also comprises a coring rope (1), the coring rope (1) is connected to a center rod (3) of section A, a locking device (8) is connected to the center rod (3) of section A via a shear pin (6), a clamping block (7) is rotatably connected to the locking device (8), a pre-compressed spring is connected between the clamping block (7) and the locking device (8), a bayonet gate (33) is sleeved on the center rod (3) of section A, a transmission rod (5) is rotatably connected between the clamping block (7) and the bayonet gate (33), a side of the bayonet gate (33) facing the center rod (3) of section A is connected to a bayonet (4) via a pre-compressed spring, and a bayonet locking slot (12) is provided in the middle of the center rod (3) of section A; The lower end of the lock (8) is connected to an A liquid storage cylinder (10), the A section center rod (3) extends into the A liquid storage cylinder (10), and an A liquid isolation chamber (11) for storing A liquid is formed between the A section center rod (3) and the A liquid storage cylinder (10); the lower end of the A liquid storage cylinder (10) is connected to a B liquid storage cylinder (13), the lower end of the A section center rod (3) is connected to a B section center rod (14), the B section center rod (14) extends into the B liquid storage cylinder (13), and a B liquid isolation chamber (11) for storing B liquid is formed between the B section center rod (14) and the B liquid storage cylinder (13). 5); the B-section center rod (14) is provided with an A-liquid transport channel (16) communicating with the A-liquid isolation chamber (11) and a B-liquid transport channel (17) communicating with the B-liquid isolation chamber (15); both the A-liquid transport channel (16) and the B-liquid transport channel (17) are provided with a one-way valve (18); the lower end of the B-section center rod (14) is also penetrated by a merging channel (19); the A-liquid transport channel (16) and the B-liquid transport channel (17) are respectively communicated with the merging channel (19); the lower part of the B-liquid storage cylinder (13) is provided with a core claw assembly for clamping a core (26); The core claw assembly comprises an upper core claw (20) and a lower core claw (22); a short core claw groove (31) and a long core claw groove (32) located below the short core claw groove (31) are provided at the lower part of the center rod (14) of the B section; the upper core claw (20) is sleeved in the short core claw groove (31), and the lower core claw (22) is sleeved in the long core claw groove (32); a film-forming liquid flow channel connecting the short core claw groove (31) and the long core claw groove (32) is provided on the short core (26) claw; the axial length of the long core claw groove (32) is greater than the axial length of the short core claw groove (31); From top to bottom, the drill string clamping groove (24) gradually tilts toward the center of the drill string (2), and a limiting step for limiting the clamping block (7) is provided on the upper side of the drill string clamping groove (24); After the latch (4) is engaged in the latch locking groove (12), the ground winch is driven to lift the corer. During the lifting process of the corer, the core claw will be tightened and the core (26) will be broken under the action of the friction between the core claw and the core (26). As the corer is lifted, a fracture appears in the core (26) between the upper core claw (20) and the lower core claw (22). Further lifting of the corer will cause the lower core claw (22) to reach a fully contracted stroke, and the core (26) will be pulled out again. Since the axial length of the short core claw groove (31) is short, the stroke used for the upper core claw (20) to be fully tightened is short, and the core (26) will be broken first within a shorter lifting distance. Since the axial length of the long core claw groove (32) is relatively long, the lower core claw (22) has not yet reached the fully tightened stroke; therefore, as the corer is lifted, a fracture first appears in the core (26) between the upper core claw (20) and the lower core claw (22); further lifting the corer will cause the lower core claw (22) to reach the fully contracted stroke, and the core (26) will be pulled out again; since the upper core claw (20) and the lower core claw (22) successively pull out the core (26), the core (26) and the bottom sealed core block (30) are formed respectively; the gap between the core (26) and the bottom sealed core block (30) is the core bottom film forming space (29).

2. A rope-type continuous film-forming and coring device while drilling according to claim 1, characterized in that: The lower part of the section A center rod (3) is a section A piston block, which seals the lower part of the liquid A isolation chamber (11), and a channel connecting the liquid A isolation chamber (11) and the liquid A transport channel (16) is provided in the section A piston block.

3. A rope-type continuous film-forming and coring device while drilling according to claim 2, characterized in that: The lower portion of the A liquid storage cylinder (10) is provided with a through communication hole (34); when the A section piston block moves to the bottom to contact the B liquid storage cylinder (13), the upper surface of the A section piston block is higher than the communication hole (34).

4. A rope-type continuous film-forming and coring device while drilling according to claim 2, characterized in that: The lower part of the section B center rod (14) is a section B piston block, the section B piston block seals the lower part of the B liquid isolation chamber (15), the A liquid transport channel (16) extends into the section B piston block, and the B liquid transport channel (17) and the confluence channel (19) are arranged in the section B piston block.

5. A rope-type continuous film-forming and coring device while drilling according to claim 4, characterized in that: When the bayonet (4) is engaged in the bayonet locking groove (12), the A-section piston block contacts the upper side of the A-liquid isolation chamber (11) and the B-section piston block contacts the upper side of the B-liquid isolation chamber (15).

6. A rope-type continuous film-forming and coring device while drilling according to claim 1, characterized in that: A static mixer (21) is arranged in the merging channel (19).

7. The rope-type continuous film-forming and coring device for drilling according to claim 1, characterized in that: From top to bottom, the short core claw groove (31) and the long core claw groove (32) are gradually inclined toward the center of the drill string (2); a limiting step for limiting the position of the upper core claw (20) is provided on the upper side of the short core claw groove (31), and a limiting step for limiting the position of the lower core claw (22) is provided on the upper side of the long core claw groove (32).

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