A coring drill suitable for deep-sea loose and broken strata exploration

Abstract

The present invention discloses a coring drill tool suitable for deep-sea loose and broken formation exploration, comprising a core tube, an inner tube joint, an inner tube, a core cutting and sealing device, and a core protection forming mechanism. The lower end of the inner tube joint is fixedly connected to the upper end of the inner tube; the upper end of the core tube is interference-fitted with a suspension bushing, and the suspension bushing is interference-fitted with the inner tube; the suspension bushing is an annular structure made of rubber material, and the lower end of the inner hole of the suspension bushing is a conical shape with a larger bottom and a smaller top; a retaining spring seat is fixedly installed at the lower end of the inner tube; the core cutting and sealing device is installed at the lower end of the retaining spring seat, and is used to cut the core after the drill tool coring; the core protection forming mechanism comprises a film positioning buckle, a core protection film, a film transition sleeve, and a core top cover. During the drilling process, the core protection film of the present invention can simultaneously wrap the loose and broken core sample to form a columnar sample with better integrity, effectively solving the problem of core stuck and core blocked due to the difficulty of the sample entering the core tube due to the unformed sample.

Description

Technical Field

[0001] The invention relates to a deep-sea loose and broken stratum exploration and coring drill tool suitable for a seabed drilling rig. Background Art

[0002] With the increasing scarcity of global energy resources and the gradual depletion of terrestrial mineral resources, the mining and utilization of marine mineral resources has become a new trend in the future of energy demand. Seafloor polymetallic sulfides (SMS) have been explored and tested in numerous rounds around the world due to their high ore grade, good enrichment, and shallow mineralization depths.

[0003] Due to the fragmented, loose, and anisotropic nature of polymetallic sulfide-bearing formations, drilling in these formations is prone to low coring rates and core sticking / blocking. This is partly because the fragmented and loose nature of the formations directly leads to sample loss and spillage from the core barrel during the recovery process. Furthermore, due to the poor formability of the core samples, they cannot form a complete columnar sample upon entering the core barrel, resulting in a reduced coring rate. More importantly, the fragmented sample easily enters the gap between the drill bit and the retaining ring seat, causing repeated wear and accumulation on both the drill bit and retaining ring seat, and increasing the likelihood of core sticking and blockage. Furthermore, the anisotropic nature of the formations can easily cause the subsea drilling rig to slip and slide during drilling, leading to borehole deflection and preventing the core from entering the core barrel.

[0004] To improve the quality and recovery rate of coring in these formations, existing seabed coring technologies typically incorporate a core-breaking protection mechanism consisting of a retaining spring and a retaining spring at the bottom of the drill string, with the goal of increasing the recovery rate. However, this approach cannot completely seal the bottom, meaning it cannot fundamentally solve the problem of sample loss. Furthermore, when drilling soft samples, the retaining spring will also disturb the sample, affecting the quality of coring. While improving the surface roughness of the core barrel can reduce the resistance of the sample entering the barrel to a certain extent, it does not completely solve the problem of core sticking and blockage caused by the inability of the sample to form a complete column. Summary of the Invention

[0005] In order to solve the above technical problems, the present invention provides a deep-sea loose and broken formation exploration coring drill tool suitable for seabed drilling rigs, which has a simple and compact structure, good flow performance, high reliability, and can completely solve the problems of core sticking and blockage caused by the inability of samples to effectively form a complete columnar shape.

[0006] The technical solution adopted by the present invention is: a coring drill tool suitable for deep-sea loose and broken formation exploration, comprising a core tube, an inner tube joint, an inner tube, a core cutting and sealing device and a core protection forming mechanism.

[0007] The invention is characterized in that: the lower end of the inner tube joint is fixedly connected to the upper end of the inner tube; the upper end of the core tube is interference-fitted with the suspension bushing, and the suspension bushing is interference-fitted with the inner tube; the suspension bushing is an annular structure made of rubber, and the lower end of the inner hole of the suspension bushing is conical with a larger bottom and a smaller top; a retaining spring seat is fixedly installed at the lower end of the inner tube; the core cutting and sealing device is installed at the lower end of the retaining spring seat, and is used to cut the core after coring by the drilling tool;

[0008] The core protection forming mechanism includes a film positioning buckle, a core protection film, a film transition sleeve and a core top cover; the film positioning buckle cooperates with the outer wall of the core tube, and the core protection film is tubular; the film positioning buckle clamps the upper end of the core protection film; the lower end of the core protection film is connected to the core top cover; the core top cover is located below the core tube and is coaxial with the core tube; the core protection film is located in the annular gap between the core tube and the inner tube; the film transition sleeve is installed at the lower end of the core tube.

[0009] In the above-mentioned coring drill tool for deep-sea loose and broken formation exploration, the core cutting and sealing device includes a joint, a base, a blade, an anti-leakage film, a torsion spring, a spring, a slider, a trigger ring and a trigger seat; the joint is installed at the lower end of the retaining spring seat, coaxial with the retaining spring seat, and the bottom of the joint is coaxially connected to the base; a plurality of grooves are provided on the top surface of the base, a rotating shaft is fixedly installed at one end of the groove, a torsion spring and a blade are installed on the rotating shaft, one end of the torsion spring is connected to the blade, and the other end is connected to the rotating shaft; the back of the blade is connected to one end of the anti-leakage film; the other end of the anti-leakage film is installed on the top surface of the base; a spring is installed at the other end of the groove, one end of the spring is connected to the base, and the other end is connected to the slider, and a wedge block is provided at the lower end of the slider, and the cross-section of the wedge block is a right triangle; the back of the blade is squeezed with the side wall of the groove to form elastic deformation, and is restricted from popping out of the groove by the slider;

[0010] A guide hole is provided in the groove corresponding to the slider, and the wedge block is placed in the guide hole, with the wedge-shaped surface of the wedge block facing away from the spring; the trigger seat is a tubular structure, the trigger seat is installed at the lower end of the base, and the lower end of the trigger seat is a cone with a larger upper part and a smaller lower part; the trigger ring is placed in the trigger seat, and the conical surface on the side wall of the trigger ring cooperates with the conical hole at the lower end of the trigger seat; a push rod is provided on the top surface of the trigger ring corresponding to each guide hole, the push rod has a square cross-section, the push rod is inserted in the guide hole, and the upper end of the push rod contacts the wedge-shaped surface of the wedge block.

[0011] In the above-mentioned coring drill tool for deep-sea loose and broken formation exploration, a return spring is provided between the top surface of the trigger ring and the base, and the return spring is sleeved on the outside of the three push rods on the top surface of the trigger ring.

[0012] In the above-mentioned coring drill tool for deep-sea loose and fractured strata exploration, three grooves are provided on the top surface of the base.

[0013] Compared with the prior art, the present invention has the following beneficial effects:

[0014] 1) During the drilling process, the core protection film of the present invention can simultaneously wrap the loose and broken core samples to form columnar samples with better integrity, effectively solving the problems of core sticking and core blockage caused by the difficulty of the sample entering the core tube due to the lack of shape.

[0015] 2) The blade of the core cutting and sealing device of the present invention has an energy storage function when in the release state; the elastic deformation of the blade itself and the torsion spring jointly store energy, further improving the cutting and sealing performance of the blade, while reducing the requirements for the torsion spring, thereby improving the reliability, practicality and applicability of the present invention to different formations.

[0016] 3) The present invention can completely seal the lower end of the core barrel after drilling is completed. The sealing solution of the blade + anti-loss film combination adopted by the present invention is similar to the blade cutting principle. Compared with the semi-sealed method of conventional multiple sets of spring plates, the present invention greatly reduces the disturbance and damage to the sample and can achieve full sealing, which can avoid sample loss and damage during the recovery process and effectively improve the coring rate and coring quality.

[0017] 4) The core protection film in the core protection forming mechanism of the present invention is naturally drooped before the core enters the core barrel. As the core contacts the core cap, the core protection film is tightened, wrapping the core and entering the core barrel. This ensures the normal and reliable operation of the core protection film during drilling, avoiding the risks of abnormal breakage and entanglement, and improving the reliability of the present invention. Furthermore, the core protection film storage method of the present invention can be flexibly adjusted according to the length of the core barrel, without being restricted by radial space, and can achieve full coverage of the core sample.

[0018] 5) During drilling, the core cap in the core protection forming mechanism of the present invention moves upward under the axial force of the core sample, while the core protection film simultaneously pulls the film positioning buckle toward the lower end, thereby improving the centering ability and stability of the core tube. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 It is a cross-sectional schematic diagram of the drilling tool assembly of the present invention.

[0020] Figure 2 It is a cross-sectional schematic diagram of the core cutting and sealing device of the present invention.

[0021] Figure 3 This is a structural schematic diagram of the core cutting and sealing device of the present invention in the unforced state.

[0022] Figure 4 This is a structural schematic diagram of the core cutting and sealing device of the present invention in the power storage and activation state.

[0023] Figure 5It is a structural schematic diagram of the groove on the base of the present invention.

[0024] Figure 6 It is a schematic structural diagram of the blade of the present invention.

[0025] Figure 7 It is a schematic structural diagram of the trigger ring of the present invention.

[0026] Figure 8 It is a structural schematic diagram of the slider of the present invention.

[0027] Figure 9 It is a structural schematic diagram of the core cutting and sealing device of the present invention in an excited state.

[0028] In the figure: 1-connector; 2-base; 3-blade; 4-leakage prevention film; 5-torsion spring; 6-spring; 7-slider; 8-groove; 9-trigger ring; 10-reset spring; 11-trigger seat; 12-suspension bushing; 13-core barrel; 14-film positioning buckle; 15-core protection film; 16-film transition sleeve; 17-core top cover; 18-circlip; 19-circlip seat; 20-outer tube; 21-buffer spring; 22-inner tube; 23-one-way valve; 24-inner tube joint; 25-single-action assembly; 26-outer tube; 27-outer tube joint; 101-conical surface; 102-screw hole; 103-countersunk screw; 201-countersunk hole; 202-rotating axis; 203-guide hole; 204-circumferential end face; 301-pin hole; 302-narrow slot; wedge block-701; 901-push rod. DETAILED DESCRIPTION

[0029] The present invention will be further described below with reference to the accompanying drawings.

[0030] like Figure 1-8 As shown, the present invention includes an outer tube assembly, an inner tube assembly, a single-action component, a suspension bushing 12, a core tube 13, a core cutting and sealing device, and a core protection molding mechanism. The outer tube assembly includes an outer tube joint 27, an outer tube 26, and a drill bit, which are connected in sequence from top to bottom. The inner tube assembly includes a single-action component 25, an inner tube joint 24, and an inner tube 22, which are connected in sequence from top to bottom. The upper end of the single-action component 25 is connected to the outer tube joint 27, and the outer tube assembly is located outside the inner tube assembly. The upper end of the single-action component 25 is connected to the outer tube joint 27. The inner tube joint 24 is provided with a through hole along the diameter direction and a valve core hole connected to the through hole. A one-way valve 23 is installed in the valve core hole; the one-way valve 23 only allows water in the inner tube 22 to flow toward the gap between the inner tube 22 and the outer tube 26.

[0031] The upper end of the core barrel 13 has an interference fit with the suspension bushing 12, which in turn has an interference fit with the inner tube 22. The suspension bushing 12 is a rubber ring with a conical lower end and a narrower upper end. A retaining spring seat 18 is fixedly mounted at the lower end of the inner tube 22. The core shearing and sealing device is mounted at the lower end of the retaining spring seat and is used to shear the core after coring with the drill.

[0032] The core protection forming mechanism includes a film positioning buckle 14, a core protection film 15, a film transition sleeve 16, and a core cap 17. The film positioning buckle 14 engages with the outer wall of the core barrel 13. The core protection film 15 is tubular. The film positioning buckle 14 clamps the upper end of the core protection film 15. The lower end of the core protection film 15 is connected to the core cap 17, which is located below and coaxial with the core barrel 13. The core protection film 15 is located in the annular gap between the core barrel 13 and the inner tube 22. The film transition sleeve 16 is installed at the lower end of the core barrel 13.

[0033] The core cutting and sealing device includes a joint 1, a base 2, a blade 3, a leak-proof film 4, a torsion spring 5, a spring 6, a slider 7, a trigger ring 9, a return spring 10, and a trigger base 11. The joint 1 is mounted at the lower end of the retaining spring base and is coaxial with the retaining spring base 18. The bottom of the joint 1 is coaxially connected to the base 2 via a countersunk screw 103. The bottom of the center hole of the joint 1 is provided with a conical surface 101, which is provided with multiple screw holes 102. The countersunk screws 103 connect the joint 1 to the base 2.

[0034] Three grooves 8 are provided on the top surface of the base 2 (the number of grooves 8 is not limited to three, and can be two or more than three). A countersunk hole 201 is provided at one end of the groove 8. A rotating shaft 202 is fixedly installed in the countersunk hole 201. A torsion spring 5 and a blade 3 are installed on the rotating shaft 202. One end of the torsion spring 5 is connected to the blade 3, and the other end is connected to the rotating shaft 202. A narrow groove 302 is provided on the back of the blade 3, and the narrow groove 302 clamps one end of the anti-leakage film 4. The other end of the anti-leakage film 4 is installed on the top surface of the base 2. A spring 6 is installed at the other end of the groove 8. One end of the spring 6 is connected to the base 2, and the other end is connected to the slider 7. A wedge block 701 is provided at the lower end of the slider 7. The cross-section of the wedge block 701 is a right triangle; the back of the blade 3 is squeezed against the side wall of the groove 8 to form an elastic deformation, and is restricted from popping out of the groove 8 by the slider 7.

[0035] A guide hole 203 is provided in the groove 8, corresponding to the slider 7. A wedge block 701 is positioned within the guide hole 203, with the wedge surface of the wedge block 701 facing away from the spring 6. The trigger seat 11 is a tubular structure mounted on the base 2. The lower end of the trigger seat 11 is conical, with a larger top and smaller bottom. The trigger ring 9 is positioned within the trigger seat, with the conical surface on its sidewall mating with the conical hole at the lower end of the trigger seat 11. A push rod 901 is provided on the top surface of the trigger ring 9, corresponding to each guide hole. The push rods 901 have a square cross-section and are inserted into the guide holes, with their upper ends contacting the wedge surface of the wedge block 701. A return spring 10 is positioned between the top surface of the trigger ring 9 and the base 2. The return spring 10 is sheathed around the three push rods 901 on the top surface of the trigger ring 9. The return spring 10 prevents the axial vibration during drilling from causing the trigger ring 9 to move and trigger the device by mistake, thereby ensuring the stability and reliability of the core cutting and sealing device. At the same time, when the blade 3 is pushed into the groove 8 to complete the power storage, the trigger ring 9 will automatically pop down and sit on the trigger seat 11, releasing the constraint on the slider 7.

[0036] The method of use of the present invention is as follows:

[0037] Before drilling, the core protection forming mechanism and the core cutting and sealing device must be assembled. The core protection forming mechanism is installed as follows: The film retaining buckle 14 clamps one end of the core protection film 15 and places it over the top of the core tube 13, allowing the end of the core protection film 15, which is connected to the core cap 17, to naturally hang down at the lower opening of the core tube 13. Next, the suspension bushing 12 is placed over the top of the core tube 13, with the upper end of the suspension bushing 12 aligned with the upper end of the core tube 13. The outer diameter of the suspension bushing 12 expands due to the radial restraining force of the conical surface at the lower end of the suspension bushing 12. The assembly process of the core cutting and sealing device is as follows: first, push the trigger ring 9 upwards. The flange 901 at the upper end of the trigger ring 9 moves upwards under the constraint of the guide hole 203 of the base 2 and contacts the wedge surface of the wedge block 701 of the slider 7. The slider 7 slides backward along the groove 8. At this time, the blade 3 and the anti-leakage film 4 are pushed into the special-shaped annular groove 8. The blade 3 produces elastic deformation, and the back of the blade completely fits the side wall of the groove 8. Release the trigger ring 9. Under the action of the elastic force of the reset spring 10, the trigger ring 9 moves downward and sits on the trigger seat 11. The push rod 901 at the upper end of the trigger ring 9 releases the constraint on the slider 7. Under the action of the elastic force of the spring 6, it slides forward. The front end of the slider 7 presses against the front end of the blade 3, so that the blade 3 cannot be ejected around the rotating axis 202. At this point, the closed cutting mechanism has completed energy storage and is in a state of energy storage waiting to be triggered. Then insert the circlip ring 18 into the circlip seat 19 from the lower end opening of the circlip seat 19; install the core cutting and sealing device at the lower end of the circlip seat 19, and the axial distance from the lower end of the trigger ring 9 to the inner slope of the drill bit is 4-6mm.

[0038] During the drilling process, the core sample moves upward along the core cutting and sealing mechanism, and continues to move upward after hitting the core top cover 17. The core top cover 17 pulls the core protection film 15 into the core tube 13, while the core protection film 15 continues to wrap the core, thereby protecting and shaping the core; while the core protection film 15 on the inner annular surface of the core tube 13 moves upward, it passes through the film transition sleeve 16 at its lower end, and the core protection film 15 on the outer annular surface pulls the film positioning buckle 14 downward to achieve centering and stabilization of the core tube 13.

[0039] After drilling is completed, as the outer tube 27 is lifted, the retaining spring 18 moves downward, shrinking its diameter and gripping the core. The inner tube 22 is constrained axially. Under the action of the buffer spring 21, the inner tube 22 moves downward relative to the outer tube 20. The inner conical surface of the drill bit contacts the lower end of the trigger ring 9. The upward movement of the trigger ring 9 drives the push rod 901 upward, bringing it into contact with the wedge surface of the wedge block 701, forcing the slider 7 to retract. The blade 3 in the special-shaped annular groove 8 pops out and deploys the anti-loss film 4. At this point, the core shearing and sealing device is activated, the loose and broken core is sheared, and the lower end of the drilling tool is completely sealed.

Claims

1. A coring drill tool suitable for deep-sea loose and broken formation exploration, comprising a core tube, an inner tube joint, an inner tube, a core cutting and sealing device, and a core protection forming mechanism. Its characteristics are: The lower end of the inner tube joint is fixedly connected to the upper end of the inner tube; the upper end of the core tube is interference-fitted with the suspension bushing, and the suspension bushing is interference-fitted with the inner tube; the suspension bushing is an annular structure made of rubber, and the lower end of the inner hole of the suspension bushing is conical with a larger bottom and a smaller top; a retaining spring seat is fixedly installed at the lower end of the inner tube; the core cutting and sealing device is installed at the lower end of the retaining spring seat, and is used to cut the core after coring by the drilling tool; The core protection forming mechanism includes a film positioning buckle, a core protection film, a film transition sleeve and a core top cover; the film positioning buckle cooperates with the outer wall of the core tube, and the core protection film is tubular; the film positioning buckle clamps the upper end of the core protection film; the lower end of the core protection film is connected to the core top cover; the core top cover is located below the core tube, and the core top cover and the core tube are coaxial; the core protection film is located in the annular gap between the core tube and the inner tube; the film transition sleeve is installed at the lower end of the core tube.

2. The coring drill tool suitable for deep-sea loose and fractured strata exploration according to claim 1 is characterized by: The core cutting and sealing device includes a joint, a base, a blade, an anti-leakage film, a torsion spring, a spring, a slider, a trigger ring and a trigger seat; the joint is installed at the lower end of the retaining spring seat and is coaxial with the retaining spring seat, and the bottom of the joint is coaxially connected to the base; a plurality of grooves are provided on the top surface of the base, a rotating shaft is fixedly installed at one end of the groove, a torsion spring and a blade are installed on the rotating shaft, one end of the torsion spring is connected to the blade, and the other end is connected to the rotating shaft; the back of the blade is connected to one end of the anti-leakage film; the other end of the anti-leakage film is installed on the top surface of the base; a spring is installed at the other end of the groove, one end of the spring is connected to the base, and the other end is connected to the slider, and a wedge block is provided at the lower end of the slider, and the cross-section of the wedge block is a right triangle; the back of the blade is squeezed against the side wall of the groove to form elastic deformation, and is restricted from popping out of the groove by the slider; A guide hole is provided in the groove corresponding to the slider, and the wedge block is placed in the guide hole, with the wedge-shaped surface of the wedge block facing away from the spring; the trigger seat is a tubular structure, the trigger seat is installed at the lower end of the base, and the lower end of the trigger seat is a cone with a larger upper part and a smaller lower part; the trigger ring is placed in the trigger seat, and the conical surface on the side wall of the trigger ring cooperates with the conical hole at the lower end of the trigger seat; a push rod is provided on the top surface of the trigger ring corresponding to each guide hole, the push rod has a square cross-section, the push rod is inserted in the guide hole, and the upper end of the push rod contacts the wedge-shaped surface of the wedge block.

3. The coring drill tool suitable for deep-sea loose and fractured strata exploration according to claim 2 is characterized by: A return spring is provided between the top surface of the trigger ring and the base, and the return spring is sleeved on the outer sides of the three push rods on the top surface of the trigger ring.

4. The coring drill tool suitable for deep-sea loose and fractured strata exploration according to claim 2 is characterized by: Three grooves are provided on the top surface of the base.

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