Coring device

Abstract

The invention belongs to the technical field of oil and gas drilling, and particularly relates to a coring device. The coring device comprises an outer barrel assembly and a coring drill bit fixedly arranged at the lower end of the outer barrel assembly. The coring device further comprises an inner barrel assembly arranged in the outer barrel assembly in a sleeved mode. The first core catcher is arranged at the lower end of the inner cylinder assembly, and the first core catcher can be matched with a coring drill bit after moving downwards, radially contracts and cuts a core in the coring device; wherein a second core catcher is further arranged between the inner barrel assembly and the first core catcher, the two radial sides of the second core catcher are shielded by the inner barrel assembly and the retractable core catcher respectively, and after the inner barrel assembly moves upwards relative to the first core catcher, the second core catcher makes contact with a core in the coring device and cuts the core. The method can be suitable for unconsolidated stratums and hard stratums at the same time.

Description

Technical Field

[0001] The invention belongs to the technical field of oil and gas drilling, and in particular relates to a coring device. Background Art

[0002] Currently, commonly used drilling coring tools include pull-up coring tools suitable for hard formations and mechanical or hydraulic pressurized coring tools suitable for loose formations. These two tools can only be used for hard formations or loose formations, and cannot be universally applied to soft to hard formations.

[0003] Since existing coring tools can only be used for formations with corresponding lithology, the type of coring tool needs to be determined in advance before coring. There is a lack of existing drilling data in deepwater exploration areas, and the lithology of the formation is unknown, which makes it difficult to select coring tools. If an unsuitable coring tool is used, the chance of coring will be greatly increased. In addition, in soft and hard interlaced formations, a coring tool that can adapt to both loose formations and hard formations is urgently needed.

[0004] In addition, in order to be able to continuously coring multiple barrels, the length of the inner barrel assembly and the outer barrel assembly is usually lengthened. However, the axial distance from the core claw of the coring tool to the drill bit needs to be within an accurate range. The lengthening of the inner barrel assembly and the outer barrel assembly will increase the effect of thermal expansion and contraction of the inner and outer barrels, making it difficult to accurately control the distance between the core claw and the drill bit. Summary of the invention

[0005] In view of the technical problems mentioned above, the present invention aims to provide a coring device which can be applicable to both loose formations and hard formations.

[0006] According to the present invention, a coring device is provided, comprising an outer barrel assembly and a coring drill bit fixedly arranged at the lower end of the outer barrel assembly, and the coring device further comprises:

[0007] An inner cylinder assembly sleeved in the outer cylinder assembly;

[0008] a first core claw disposed at the lower end of the inner barrel assembly, the first core claw being configured to cooperate with the coring drill bit after moving downward, contracting radially, and cutting the core in the coring device;

[0009] Among them, a second core claw is also arranged between the inner cylinder assembly and the first core claw, and the radial sides of the second core claw are respectively blocked by the inner cylinder assembly and the first core claw. When the inner cylinder assembly moves upward relative to the first core claw, the second core claw contacts the core in the coring device and cuts the core.

[0010] In a specific embodiment, the first core claw comprises a coaxially fixedly connected neck sleeve and a flap-type retractable core claw, wherein the neck sleeve is configured to be able to move downward only relative to the outer barrel assembly.

[0011] The inner cylinder assembly includes a shielding sleeve,

[0012] The top of the neck sleeve is sleeved on the lower part of the shielding sleeve, and the upper inner diameter of the neck sleeve is larger than the lower outer diameter of the shielding sleeve, so as to form an annular space between the neck sleeve and the shielding sleeve, and the second core claw is arranged in the annular space.

[0013] In a specific embodiment, the inner cylinder assembly also includes an outer sliding sleeve arranged outside the shielding sleeve, and a one-way locking block is arranged between the outer sliding sleeve and the outer cylinder assembly, so that the outer sliding sleeve can only move downward relative to the outer cylinder assembly, and the top of the neck sleeve is axially abutted against the outer sliding sleeve.

[0014] In a specific embodiment, the second core claw includes a necking short section and a clamp-type core claw fixedly connected to each other, the upper end of the necking short section is fixedly connected to the outer sliding sleeve, the lower end of the necking short section is axially abutted against the neck sleeve, and the clamp-type core claw is located in the annular space formed between the neck sleeve and the shielding sleeve.

[0015] In a specific embodiment, a first response mechanism is arranged in the outer cylinder assembly, the first response mechanism comprises a second ball seat arranged in an axially sliding seal along the outer cylinder assembly, and the lower end of the first response mechanism is connected to the inner cylinder assembly.

[0016] The first response mechanism is configured such that after a ball is dropped into the second ball seat to seal and pressurize, the first response mechanism can move downward relative to the outer cylinder assembly and drive the inner cylinder assembly to move downward.

[0017] In a specific embodiment, a second response mechanism is also provided in the outer cylinder assembly, the second response mechanism includes a third ball seat, and the second response mechanism is configured so that after a ball is thrown into the third ball seat for pressure application, the second response mechanism can be separated from the outer cylinder assembly. At this time, lifting the second response mechanism can drive the first response mechanism and the inner cylinder assembly to move upward, thereby making the second core claw contact the core in the coring device and cut the core.

[0018] In a specific embodiment, the first response mechanism includes a pressure rod fixedly connected to the second ball seat, a first positioning joint is arranged in the annulus between the pressure rod and the second response mechanism, a first locking block is radially penetrated and slidably arranged in the first positioning joint, the outer side of the first locking block is embedded in the second response mechanism, and the inner side of the first locking block abuts against the pressure rod, and the first locking block is constructed so that when the pressure rod moves downward, the first locking block releases the abutment with the pressure rod, thereby being able to move radially inward, releasing the embedded connection relationship with the second response mechanism, and allowing the first response mechanism to move downward relative to the second response mechanism.

[0019] In a specific embodiment, the pressure rod is fixedly connected to the first positioning joint via a shear pin, and a protrusion for abutting against the first locking block is provided on the outer wall of the pressure rod.

[0020] In a specific embodiment, a pressure bearing seat is fixedly arranged at the lower part of the first positioning joint, and two upper shear rings and a lower shear ring for cooperating with the pressure rod are axially spaced inside the pressure bearing seat.

[0021] When the pressure rod does not move downward, its lower end abuts against the upper shear ring, and the second ball seat and the second response mechanism are sealed with each other.

[0022] The pressure rod is subjected to the pressure of the second ball seat after the ball sealing to shear off the upper shear ring, and when it moves downward to abut against the lower shear ring, the first locking block is separated from the abutting relationship with the protrusion.

[0023] When the pressure rod continues to move downward to cut off the lower shear ring and move downward, the second ball seat and the second response mechanism release the sealing relationship, so that the upper and lower sides of the second ball seat lose the differential pressure and no longer move downward.

[0024] In a specific embodiment, a recessed telescopic slide groove is provided on the inner wall of the second response mechanism.

[0025] A telescopic head is fixedly arranged on the upper part of the first positioning joint, and the telescopic head is slidably matched with the telescopic slide groove.

[0026] After the second ball seat moves downward to drive the pressure rod to cut the lower shear ring, the second ball seat moves to the position of the telescopic slide groove, and a gap exists between the two.

[0027] In a specific embodiment, the second response mechanism includes a first upper joint inserted into the top of the outer cylinder assembly, the third ball seat sliding seal is arranged in the first upper joint, and a second positioning joint is provided in the first upper joint through a joint shear pin sleeve, the upper end of the second positioning joint abuts against the third ball seat, and a radially penetrated second locking block is provided between the first upper joint and the outer cylinder assembly, and the radial inner end of the second locking block abuts against the second positioning joint. After the second positioning joint moves downward, the second locking block can release the radial abutment with the second positioning joint, so that it can move radially inward, thereby releasing the radial penetration relationship with the first upper joint and the outer cylinder assembly, thereby enabling the first upper joint and the outer cylinder assembly to move axially relative to each other.

[0028] In a specific embodiment, a gap adjustment assembly is provided between the outer barrel assembly and the inner barrel assembly, and the gap adjustment assembly is configured to adjust the axial distance of the outer barrel assembly relative to the inner barrel assembly, thereby adjusting the axial distance of the first core claw relative to the coring drill bit.

[0029] In a specific embodiment, a joint shear pin is provided between the first upper joint and the second positioning joint.

[0030] In a specific embodiment, a gap adjustment component is provided between the first upper joint and the inner barrel assembly, and the gap adjustment component includes:

[0031] an adjustable outer joint fixedly connected to the first upper joint,

[0032] An adjusting inner joint is threadedly arranged in the adjusting outer joint, and the lower end of the adjusting inner joint is connected to the inner cylinder assembly. The adjusting inner joint rotates relative to the adjusting outer joint, driving the inner cylinder assembly to move axially relative to the outer cylinder assembly, thereby adjusting the axial distance of the first core claw relative to the coring drill bit.

[0033] In a specific embodiment, a plurality of axially opened pin grooves are evenly distributed along the circumferential direction on the outer wall of the adjusting inner joint, and the end of the joint shear pin extends into the pin groove.

[0034] Compared with the prior art, the advantages of the present application are as follows.

[0035] The present invention is provided with a first core claw and a second core claw at the same time. In the process of coring and cutting, both core claws can work, so that the present invention can be applied to both loose formations and hard formations. When the formation lithology is unknown, a universal coring tool applicable to soft to hard formations is provided, thereby solving the problem of difficult selection of coring tools.

[0036] In addition, the gap adjustment mechanism of the present invention can adjust the axial distance between the inner cylinder assembly and the outer cylinder assembly, and further adjust the distance from the first core claw to the coring drill bit. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] The present invention will be described below with reference to the accompanying drawings.

[0038] Figure 1 A schematic diagram showing an embodiment of a coring device according to the present invention;

[0039] Figure 2 A schematic diagram showing an upper section of a coring device according to the present invention is shown;

[0040] Figure 3 A schematic diagram showing a mid-section of a coring device according to the present invention is shown;

[0041] Figure 4 A schematic diagram showing the lower section of a coring device according to the present invention is shown;

[0042] Figure 5 It shows that according to the present invention Figure 2 Schematic diagram of the cross section in the AA direction;

[0043] Figure 6 It shows that according to the present invention Figure 2 A schematic cross-sectional view of the BB direction;

[0044] Figure 7 It shows that according to the present invention Figure 3 Schematic cross-sectional view of the CC direction;

[0045] Figure 8 It shows that according to the present invention Figure 4 Schematic diagram of the cross section in the DD direction.

[0046] In the figure: 01, outer cylinder assembly; 02, coring drill bit; 03, inner cylinder assembly; 04, first core claw; 05, first response mechanism; 06, second response mechanism; 07, gap adjustment assembly; 1, first upper joint; 2, third pressure holding ball; 3, third ball seat; 4, second positioning joint; 5, joint shear pin; 6, tooth joint; 61, strip teeth; 62, strip groove; 7, adjustment inner joint; 71, pin groove; 8, adjustment outer joint; 9, outer cylinder upper joint; 10, adjustable thread; 11, second pressure holding ball; 12, second ball seat; 13, telescopic head; 131, telescopic slide; 14, pressure rod; 141, bump; 15, third positioning joint; 16, first locking block; 17, first positioning joint; 18 , pressure seat; 19, upper shear pin; 20, upper shear ring; 21, lower shear pin; 22, lower shear ring; 23, bearing box; 24, suspension shaft; 25, bearing; 27, bearing support; 28, water diversion joint; 29, upper centralizer; 30, first pressure holding ball; 31, first ball seat; 32, connecting outer tube; 33, connecting inner tube; 34, lower centralizer; 35, inner sleeve; 351, push block; 36, outer sleeve; 361, sleeve shear pin; 37, lower joint of outer tube; 38, one-way locking block; 39, necking short section; 40, shielding sleeve; 41, second core claw; 411, clamp-type core claw; 42, necking sleeve; 43, flap-type retractable core claw; 44, second locking block; 100, coring device.

[0047] In the present application, all drawings are schematic drawings, which are only used to illustrate the principles of the present invention and are not drawn according to the actual scale. DETAILED DESCRIPTION

[0048] The present invention will be described below with reference to the accompanying drawings.

[0049] It should be noted that, in this application, the direction away from the core drill bit 02 of the present invention is described as "up", "top" or similar terms, that is, Figure 1 The left side of the present invention describes the direction close to the core drill bit 02 as "lower", "bottom" or similar terms, that is, Figure 1 On the right side of the figure, the direction of the present invention close to the central axis of the outer cylinder assembly 01 is described as "inside", and the direction of the present invention away from the central axis of the outer cylinder assembly 01 is described as "outside". They are not used to limit the absolute positions of the components involved, but can be changed according to specific circumstances.

[0050] Figure 1 The structure of the coring device 100 according to the present invention is shown. Due to the limitation of the image width, Figure 1 The coring device 100 is divided into three parts: an upper section, a middle section and a lower section, which are arranged in sequence from top to bottom. Figure 1 The connection relationship between the upper section, the middle section and the lower section of the coring device 100 is indicated by dashed lines with arrows.

[0051] like Figure 1 As shown, the coring device 100 includes an outer cylinder assembly 01 with a cavity and a hollow coring drill bit 02 fixedly arranged at the lower end of the outer cylinder assembly 01. When coring, the outer cylinder assembly 01 rotates, driving the coring drill bit 02 to rotate, enter the formation and drill continuously. During the drilling process, the cylindrical rock formed by the hollow part of the coring drill bit 02 is the core.

[0052] In this embodiment, the outer tube assembly 01 includes a tooth joint 6, an outer tube upper joint 9, an upper stabilizer 29, a connecting outer tube 32, a lower stabilizer 34 and an outer tube lower joint 37, which are arranged in sequence from top to bottom, and any two adjacent ones are fixedly connected to each other by threaded connection.

[0053] In one embodiment of the present invention, the coring device 100 further includes an inner cylinder assembly 03 sleeved in the outer cylinder assembly 01 , and the inner cylinder assembly 03 can slide axially relative to the outer cylinder assembly 01 .

[0054] A first core claw 04 is provided at the lower end of the inner cylinder assembly 03. The first core claw 04 is configured to cooperate with the core drill bit 02 after moving downward, contract radially, and cut the core in the core device 100. Specifically, a radial protrusion is provided on the inner side of the core drill bit 02, and the first core claw 04 can be pushed downward by the inner cylinder assembly 03. When the first core claw 04 moves downward to contact the radial protrusion provided on the inner side of the core drill bit 02, the radial protrusion of the core drill bit 02 will generate a radial thrust on the first core claw 04, thereby causing the first core claw 04 to contract radially and cut the core.

[0055] A second core claw 41 is also provided between the inner cylinder assembly 03 and the first core claw 04. The radial sides of the second core claw 41 are respectively blocked by the inner cylinder assembly 03 and the first core claw 04, and the second core claw 41 cannot cut the core. When the inner cylinder assembly 03 moves upward relative to the first core claw 04, the second core claw 41 can be exposed, so that the second core claw 41 contacts the core in the coring device 100 and cuts the core.

[0056] The first core claw 04 and the second core claw 41 are respectively suitable for structural members of loose formations and hard formations. The present invention firstly adopts the method of moving the inner cylinder assembly 03 downward relative to the outer cylinder assembly 01 to push the first core claw 04 and the second core claw 41 downward, and the first core claw 04 cooperates with the coring drill bit 02 to complete the action of radial contraction and cutting the core. While the first core claw 04 completes the action of cutting the core, it itself will be clamped between the coring drill bit 02 and the core. At this time, the inner cylinder assembly 03 is lifted up, and the inner cylinder assembly moves upward relative to the outer cylinder assembly 01. Since the first core claw 04 is stuck between the coring drill bit 02 and the core, the inner cylinder assembly 03 will move upward relative to the first core claw 04, so that the second core claw 41 is exposed to contact with the core, completing the action of cutting the core.

[0057] The two core cutting actions make the present invention applicable to both loose formations and hard formations.

[0058] In a specific embodiment, Figure 1 and Figure 4 As shown, the inner cylinder assembly 03 includes a shielding sleeve 40, and the shielding sleeve 40 is cylindrical in shape as a whole.

[0059] The first core claw 04 includes a coaxially fixedly connected neck sleeve 42 and a flap-type retractable core claw 43. The neck sleeve 42 is cylindrical in shape, and the upper part is sleeved with the shielding sleeve 40 of the inner cylinder assembly 03, and the lower end is fixedly connected with the flap-type retractable core claw 43 by an integral molding method.

[0060] The top of the neck sleeve 42 is sleeved on the lower part of the shielding sleeve 40, and the upper inner diameter of the neck sleeve 42 is larger than the lower outer diameter of the shielding sleeve 40, so that the neck sleeve 42 is sleeved on the outside of the shielding sleeve 40, and an annular space is formed between the neck sleeve 42 and the shielding sleeve 40, and the second core claw 41 is arranged in the annular space.

[0061] The second core claw 41 includes an integrally formed necking short section 39 and a clamp-type core claw 411. In this embodiment, the inner diameter of the necking short section 39 is equal to the outer diameter of the top of the clamp-type core claw 411, and the outer diameter of the necking short section 39 is equal to the outer diameter of the neck sleeve 42. In this setting, the lower end of the necking short section 39 abuts against the top of the neck sleeve 42, and the clamp-type core claw 411 is located in the annular space between the neck sleeve 42 and the shielding sleeve 40.

[0062] The inner cylinder assembly 03 also includes an inner sliding sleeve 35 , an outer sliding sleeve 36 , an outer cylinder lower joint 37 and a one-way locking block 38 .

[0063] The inner sleeve 35 is cylindrical in shape and is fixedly arranged on the upper end of the shielding sleeve 40 by threaded connection. The inner diameter and outer diameter of the inner sleeve 35 are equal to the inner diameter and outer diameter of the upper end of the shielding sleeve 40.

[0064] The outer sleeve 36 is cylindrical in shape and is slidably mounted on the outside of the inner sleeve 35 and the shielding sleeve 40. The outer diameter of the outer sleeve 36 is equal to the outer diameter of the necking short section 39, and the two are fixed to each other by threaded connection. A one-way locking block 38 is radially penetrated on the sleeve wall of the outer sleeve 36, and is combined with the inner sleeve 35 to prevent the inner sleeve 35 from sliding. Figure 8 As shown, in this embodiment, two one-way locking blocks 38 are evenly distributed along the circumferential direction. The radial inner side of the one-way locking block 38 abuts against the upper end of the shielding sleeve 40, and the radial outer side of the one-way locking block 38 cooperates with the outer tube lower joint 37 of the outer tube assembly 01. By providing a one-way ratchet on the contact surface of the one-way locking block 38 and the outer tube lower joint 37, the one-way locking block 38 can only move downward relative to the outer tube lower joint 37.

[0065] At the same time, in order to enable the inner sleeve 35 to push the outer sleeve 36 to move downward, a push block 351 protruding radially outward is provided on the outer wall of the inner sleeve 35. The push block 351 is located above the outer sleeve 36 and is used to abut against the upper end of the outer sleeve 36, so as to push the outer sleeve 36 to move downward.

[0066] Under the action of the one-way locking block 38, once the outer sleeve 36 moves downward under the pushing action of the pushing block 351 on the inner sleeve 35, it cannot move upward and reset, so that the neck sleeve 42 can only move downward relative to the outer cylinder assembly 01.

[0067] The outer sliding sleeve 36 will drive the necking short section 39, the necking sleeve 42 and the flap-type retractable core claws 43 to move downward, and the flap-type retractable core claws 43 cooperate with the coring drill bit 02 to complete the core cutting work.

[0068] The outer diameters of the upper and lower parts of the shielding sleeve 40 are different, and the outer diameter of the upper part of the shielding sleeve 40 is larger than the outer diameter of the lower part. After the core cutting work is completed, the flap-type retractable core claw 43 lifts the inner sleeve 35. Since the radial inner and outer sides of the one-way locking block 38 respectively abut the shielding sleeve 40 and the lower joint 37 of the outer cylinder, the outer sleeve 36 will be stationary relative to the outer cylinder assembly 01, and the inner sleeve 35 can drive the shielding sleeve 40 to move upward relative to the outer sleeve 36, the necking short section 39 and the necking sleeve 42, so as to expose the clamp-type core claw 411, contact with the core, and complete the cutting.

[0069] After the clamp-type core claw 411 completes the core cutting, the one-way locking block 38 moves to the lower part of the shielding sleeve 40. Since the outer diameter of the lower part of the shielding sleeve 40 is smaller than the outer diameter of the upper part, the one-way locking block 38 can move radially inward at this time, thereby releasing the one-way locking relationship with the lower joint 37 of the outer cylinder.

[0070] In a preferred embodiment, the outer sleeve 36 is fixedly connected to the inner sleeve 35 by a sleeve shear pin 361. In this arrangement, the inner sleeve 35 can be prevented from moving upward and exposing the clamp-type core claw 411 in advance during transportation or other unexpected situations.

[0071] In a specific embodiment, a first response mechanism 05 and a second response mechanism 06 are coaxially arranged inside the outer cylinder assembly 01. The first response mechanism 05 is used to control the inner cylinder assembly 03 to move downward, and the second response mechanism 06 is used to control the inner cylinder assembly 03 to move upward.

[0072] According to the present invention, the second response mechanism 06 is located above the first response mechanism 05. Figure 1 and Figure 3 As shown, the second response mechanism 06 includes a gap adjustment component 07 sleeved in the outer tube upper joint 9 of the outer tube assembly 01, and a third positioning joint 15 is fixedly provided at the lower end of the gap adjustment component 07 by means of a threaded connection.

[0073] The first response mechanism 05 includes a second ball seat 12 which is coaxially slidably sealed and arranged in the clearance adjustment assembly 07. The second ball seat 12 is used for ball pitching and pressure holding. A pressure rod 14 is fixedly arranged at the lower end of the second ball seat 12. The pressure rod 14 extends downward to the position of the third positioning joint 15, so that an annulus is formed between the pressure rod 14 and the third positioning joint 15. A first positioning joint 17 is sleeved in the annulus between the pressure rod 14 and the third positioning joint 15, and a first locking block 16 is radially penetrated on the first positioning joint 17. A radially protruding bump 141 is arranged on the outer side of the pressure rod 14, and a radially recessed groove is arranged on the inner side of the third positioning joint 15. Figure 7 As shown, the radial inner end surface of the first locking block 16 abuts against the protrusion 141 , and the radial outer portion of the first locking block 16 is inserted into the groove of the third positioning joint 15 .

[0074] A pressure seat 18 is coaxially fixedly arranged at the lower end of the first positioning joint 17 by means of threaded connection. An upper shear ring 20 and a lower shear ring 22 are arranged on the inner wall of the pressure seat 18 in order from top to bottom in the axial direction. The upper shear ring 20 and the lower shear ring 22 are fixed to the pressure seat 18 by an upper shear pin 19 and a lower shear pin 21, respectively. The pressure rod 14 is axially abutted against the upper shear ring 20.

[0075] Under this setting, when the inner cylinder assembly 03 needs to move downward to push the first core claw 04 to work, the ball seal is first dropped into the second ball seat 12, and then the second ball seat 12 is moved downward relative to the gap adjustment assembly 07 of the second response mechanism 06 by applying pressure. Driven by the second ball seat 12, the pressure rod 14 presses the upper shear ring 20 downward, so that the upper shear ring 20 cuts off the upper shear pin 19 and moves downward. When the pressure rod 14 moves to abut the lower shear ring 22, the protrusion 141 on the pressure rod 14 is disengaged from the abutment relationship with the first locking block 16, and the first locking block 16 can move radially inward and disengage from the groove of the third positioning joint 15. After the first locking block 16 disengages from the third positioning joint 15, the first positioning joint 17 can move downward relative to the third positioning joint 15. The pressure is continued, and the second ball seat 12 pushes the inner cylinder assembly 03 downward through the pressure rod 14, the upper shear ring 20, the lower shear ring 22, the lower shear pin 21 and the pressure seat 18 in sequence, so that the first core claw 04 completes the work of cutting the core.

[0076] In a preferred embodiment, an inwardly recessed telescopic slot 131 is provided on the inner wall of the connection between the gap adjustment component 07 and the third positioning joint 15. A telescopic head 13 is fixedly provided on the upper end of the first positioning joint 17 by threaded connection, and the upper end of the telescopic head 13 and the telescopic slot 131 are slidably matched with each other, and the upper end of the telescopic head 13 can slide within the axial range of the telescopic slot 131.

[0077] When the second ball seat 12 pushes the pressure rod 14 to squeeze the lower shear ring 22 under the action of pressure, so that the lower shear ring 22 cuts off the lower shear pin 21, the second ball seat 12 continues to move downward to the position of the telescopic slide groove 131. Since the outer diameter of the second ball seat 12 is smaller than the inner diameter of the telescopic slide groove 131, there is a gap between the two, so the second ball seat 12 loses its sealing effect, and continued pressure will not push the second ball seat 12.

[0078] According to the present invention, Figure 1 and Figure 2 As shown, the second response mechanism 06 includes a first upper joint 1 axially plugged into the top of the outer tube assembly 01 by means of a toothed connection. Specifically, the outer tube assembly 01 includes a toothed joint 6 fixedly arranged at the upper end of the outer tube upper joint 9 by means of a threaded connection, and a plurality of strip teeth 61 are evenly distributed along the circumferential direction at the top of the toothed joint 6, and the thickness of the strip teeth 61 is equal to the wall thickness of the toothed joint 6. Accordingly, a plurality of strip grooves 62 for plugging with the strip teeth 61 of the toothed joint 6 are evenly opened along the circumferential direction on the bottom outer wall of the first upper joint 1.

[0079] Combination Figure 5As shown, the outer diameter of the first upper joint 1 is equal to the outer diameter of the tooth joint 6, but the inner diameter of the first upper joint 1 is smaller than the inner diameter of the tooth joint 6, that is, the thickness of the first upper joint 1 is greater than the thickness of the tooth joint 6. A second locking block 44 is radially arranged on the joint wall of the first upper joint 1. In this embodiment, four strip teeth 61 are evenly arranged on the top of the tooth joint 6 along the circumferential direction, and correspondingly, four strip grooves 62 are evenly arranged on the outer wall of the first upper joint 1 along the circumferential direction. The two second locking blocks 44 are evenly distributed along the circumference of the first upper joint 1, wherein the radial outer side of the second locking block 44 is inserted into the strip teeth 61 of the tooth joint 6, so that the tooth joint 6 cannot move axially relative to the first upper joint 1. A second positioning joint 4 is provided in the sealed sliding sleeve in the first upper joint 1, and the outer wall of the second positioning joint 4 contacts the inner wall of the first upper joint 1, so the outer wall of the second positioning joint 4 abuts against the radial inner side of the second locking block 44 to prevent the second locking block 44 from being separated from the plug-in relationship with the strip teeth 61.

[0080] According to the present invention, a third ball seat 3 is provided in the sliding seal in the first upper joint 1, and the lower end surface of the third ball seat 3 abuts against the upper end surface of the second positioning joint 4. Under this arrangement, the second positioning joint 4 can be pushed downward by throwing a ball seal into the third ball seat 3 and then applying pressure, so that the second positioning joint 4 no longer abuts against the second locking block 44. After the second locking block 44 is no longer radially abutted against the second positioning joint 4, lifting the first upper joint 1 can cause the second locking block 44 to move radially, thereby releasing the plug-in relationship with the bar teeth 61, and then allowing the first upper joint 1 to move upward relative to the tooth joint 6. The lower end of the first upper joint 1 is connected to the inner cylinder assembly 03, so that the first upper joint 1 can drive the inner cylinder assembly 03 to move upward during the lifting process, thereby exposing the clamp-type core claw 411 to cut the core.

[0081] In a preferred embodiment, Figure 8 As shown, a joint shear pin 5 is provided between the second positioning joint 4 and the first upper joint 1. The joint shear pin 5 can prevent the second positioning joint 4 from moving in advance during transportation or other unexpected situations, causing the second locking block 44 to fall out, thereby causing the first upper joint 1 to move upward relative to the tooth joint 6, and the clamp-type core claw 411 to be exposed in advance.

[0082] In this embodiment, the lower end of the first upper joint 1 is connected to the first response mechanism 05 through the gap adjustment component 07, and further connected to the inner cylinder assembly 03.

[0083] Specifically, the gap adjustment assembly 07 includes an adjustment inner joint 7 and an adjustment outer joint 8. The upper end of the adjustment outer joint 8 is fixedly connected to the first upper joint 1 by threaded connection. The outer diameter of the adjustment inner joint 7 is smaller than the inner diameter of the adjustment outer joint 8, and is sleeved inside the adjustment outer joint 8.

[0084] An adjusting thread 10 is provided on the lower inner wall surface of the adjusting outer joint 8, and correspondingly, a thread that can cooperate with the adjusting thread 10 is provided on the outer wall surface of the adjusting inner joint 7. When the adjusting inner joint 7 rotates relative to the adjusting outer joint 8, the adjusting inner joint 7 can move axially relative to the adjusting outer joint 8 under the action of the adjusting thread 10.

[0085] The lower part of the adjusting inner joint 7 extends beyond the adjusting outer joint 8 and reaches the length range of the outer tube upper joint 9. Since the lower end of the adjusting inner joint 7 is fixedly connected to the inner tube assembly 03 through the third positioning joint 15 and other parts, and the adjusting outer joint 8 is fixedly connected to the outer tube assembly 01 through the first upper joint 1, after the adjusting inner joint 7 rotates relative to the adjusting outer joint 8, the adjusting inner joint 7 will drive the inner tube assembly 03 to move axially relative to the outer tube assembly 01.

[0086] According to the present invention, a slot for interlocking with a special tool (not shown) and capable of transmitting torque is provided on the top of the adjusting inner joint 7. The specific structure of the slot and the special tool can be based on the existing technology, which will not be described in detail here.

[0087] After the present invention is put into the well, when it is necessary to adjust the axial clearance between the inner cylinder assembly 03 and the outer cylinder assembly 01, a special tool is inserted from the upper joint 1 and stuck in the slot on the upper part of the adjusting inner joint 7. The special tool is rotated clockwise to drive the adjusting inner joint 7 to move downward along the adjusting thread 10, and the clearance between the inner cylinder assembly 03 and the outer cylinder assembly 01 is reduced until the first core claw 04 abuts against the coring drill bit 02 and cannot move further downward. At this time, the axial clearance between the first core claw 04 and the coring drill bit 02 is zero. Then the special tool is rotated counterclockwise to adjust the inner joint 7 to move upward along the adjusting thread 10, and the clearance between the inner cylinder assembly 03 and the outer cylinder assembly 01 is increased. The pitch of the adjusting thread 10 is a known quantity, and the temperature at the position where the adjusting thread 10 is located does not change much, and is almost not affected by thermal expansion and contraction. According to the number of rotations, the axial spacing between the first core claw 04 and the coring drill bit 02 can be controlled.

[0088] Furthermore, the inner end of the joint shear pin 5 extends to the position of the adjusting inner joint 7, and a plurality of axially opened pin grooves 71 are evenly distributed along the circumferential direction on the outer wall of the adjusting inner joint 7. After the adjusting inner joint 7 is adjusted, the joint shear pin 5 is inserted into the pin groove 71 of the adjusting inner joint 7 to limit the rotation of the adjusting inner joint 7.

[0089] Combination Figure 3As shown, the outer diameter of the lower end of the adjusting inner joint 7 of the gap adjustment assembly 07 is equal to the inner diameter of the outer tube upper joint 9, and the lower end of the adjusting inner joint 7 is fixedly connected to the third positioning joint 15 by threaded connection. The second ball seat 12 of the second response mechanism 06 is slidingly sealed in the lower end of the adjusting inner joint 7.

[0090] Under this arrangement, when the first upper joint 1 moves upward, the first upper joint drives the third positioning joint 15 to move upward through the gap adjustment component 07. When the telescopic groove 131 on the third positioning joint 15 is axially abutted against the telescopic head 13, the third positioning joint 15 can drive the telescopic head 13 to move upward, and then the telescopic head 13 drives the inner cylinder assembly 03 to move upward through the first positioning joint 17 and the pressure-bearing seat 18, so that the clamp-type core claw 411 is exposed to cut the core.

[0091] According to the present invention, Figure 1 and 3 As shown, a first ball seat 31 is also provided between the pressure-bearing seat 18 and the inner cylinder assembly 03 .

[0092] Specifically, a bearing box 23 is coaxially fixedly arranged at the lower end of the pressure seat 18 by means of a threaded connection, and a suspension shaft 24 is rotatably arranged in the bearing box 23 through a bearing 25. A bearing support 27 for fixing the bearing 25 is fixedly arranged at the lower end of the bearing box 23. A water diversion joint 28 is coaxially fixedly arranged at the lower end of the suspension shaft 24 by means of a threaded connection, and the lower end of the water diversion joint 28 is fixedly connected to the connecting inner cylinder 33 of the inner cylinder assembly 03 by means of a threaded connection. An annulus is arranged between the water diversion joint 28 and the inner cylinder assembly 03 and the outer cylinder assembly 01, and at least one through hole is arranged on the side wall of the water diversion joint 28 to connect the inner cavity of the water diversion joint 28 with the annulus between the outer cylinder assembly 01 and the inner cylinder assembly 03. The first ball seat 31 is sealed and fixedly arranged on the inner side of the lower end of the water diversion joint 28.

[0093] The operation steps of this embodiment are as follows.

[0094] After the present invention is lowered into the well bottom, the circulation pump is turned on to circulate the drilling fluid, and the drilling fluid flows through the first upper joint 1, the third ball seat 3, the gap adjustment component 07, the second ball seat 12, the pressure rod 14, the water diversion joint 28, the first ball seat 31, the inner cylinder assembly 03 and the coring drill bit 02, and then returns from the annular space between the outer cylinder assembly 01 and the well wall. In this way, the well bottom can be cleaned and the inner cylinder assembly 03 can be flushed to prevent the residual dirt in the inner cylinder assembly 03 from affecting the collection of cores.

[0095] After cleaning, the first pressure-holding ball 30 is placed into the first ball seat 31 to seal it. At this time, the circulating drilling fluid can only flow through the through hole on the side wall of the water diversion joint 28 to the annulus between the inner cylinder assembly 03 and the outer cylinder assembly 01, and then pass through the core drill bit 02 and then return through the annulus between the outer cylinder assembly 01 and the well wall. After that, the outer cylinder assembly 01 drives the core drill bit 02 to rotate and start core drilling.

[0096] After coring is completed, the second pressure-holding ball 11 is placed into the second ball seat 12. At this time, the drilling fluid pressure pushes the second ball seat 12 to move downward, and then the pressure rod 14 pushes the upper shear ring 20 to shear the upper shear pin 19. Then the second ball seat 12, the pressure rod 14 and the upper shear ring 20 move downward together until the upper shear ring 20 abuts against the lower shear ring 22. At this time, the first locking block 16 is no longer radially abutted against the protrusion 141 of the pressure rod 14, and the first locking block 16 slides radially inward and escapes from the groove of the third positioning joint 15. The second ball seat 12 continues to move downward, driving the pressure seat 18 to move downward through the lower shear ring 22 and the lower shear pin 21, and then driving the flap-type retractable core claw 43 to move downward through the inner cylinder assembly 03. After the flap-type retractable core claw 43 moves downward, it can radially contract under the radial extrusion of the inner wall cone surface of the coring drill bit 02, cut the core and wrap the core, so as to achieve the purpose of coring in soft formations.

[0097] It should be noted that, during the downward movement of the inner cylinder assembly 03, since there is a gap between the push block 351 of the inner sleeve 35 and the upper end surface of the outer sleeve 36, the inner sleeve 35 will shear the sleeve shear pin 361 when it is pushed downward by the second ball seat 12. After the push block 351 abuts against the upper end surface of the outer sleeve 36, the inner sleeve 35 pushes the outer sleeve 36 to move downward.

[0098] After the flap-type retractable core claw 43 completes the cutting of the core, the neck sleeve 42 abuts against the core bit 02, and the telescopic head 13 axially abuts against the lower end surface of the telescopic slot 131, the inner cylinder assembly 03 and the pressure-bearing seat 18 cannot move downward, but the second ball seat 12 is still subject to the drilling fluid pressure. At this time, the lower shear pin 21 is sheared off under the pressure, and the second ball seat 12 moves downward relative to the third positioning joint 15. When the second ball seat 12 moves to the length range of the telescopic slot 131, the second ball seat 12 fails to seal and is no longer subject to the downward drilling fluid pressure, and stops moving downward.

[0099] The third pressure-holding ball 2 is inserted into the third ball seat 3. The third ball seat 3 moves downward under the pressure of the drilling fluid and pushes the second positioning joint 4, so that the second positioning joint 4 cuts off the joint shear pin 5 and moves downward, thereby releasing the radial abutment against the second locking block 44. At this time, the first upper joint 1 is lifted up, and the second locking block 44 slides radially out of the bar teeth 61 of the tooth joint 6. Then the first upper joint 1 moves upward relative to the tooth joint 6, and drives the third positioning joint 15 to move upward through the gap adjustment component 07. The third positioning joint 15 drives the telescopic head 13 to move upward through the telescopic slide groove 131, and then drives the inner sleeve 35 of the inner cylinder assembly 03 to move upward through the first positioning joint 17 and the pressure seat 18 in turn, so that the inner side of the clamp-type core claw 411 is exposed, contacts with the core, cuts the core, and completes the purpose of coring the hard formation.

[0100] It is easy to understand that the inner diameter of the third ball seat 3 is larger than the inner diameter of the second ball seat 12 , and the inner diameter of the second ball seat 12 is larger than the inner diameter of the first ball seat 31 .

[0101] It is easy to understand that the axial end faces of the first locking block 16, the one-way locking block 38 and the second locking block 44 are all arranged as inclined surfaces. When the first locking block 16, the one-way locking block 38 and the second locking block 44 are subjected to an axial force, the arranged inclined surfaces will convert the axial force into a part of the radial force component, so that the first locking block 16, the one-way locking block 38 and the second locking block 44 can generate a tendency to move radially, and can move radially as long as there is no abutment in the radial direction.

[0102] The specific structures of the clamp-type core claw 411 and the flap-type retractable core claw 43 are both prior arts and will not be described in detail herein.

[0103] In the description of the present invention, it should be understood that the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of the features. In the description of the present invention, the meaning of "plurality" is two or more, unless otherwise clearly and specifically defined.

[0104] In the present invention, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be an indirect connection through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0105] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "examples", "specific examples", or "some examples" means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner.

[0106] Finally, it should be noted that the above is only a preferred embodiment of the present invention and does not constitute any limitation to the present invention. Although the present invention has been described in detail with reference to the aforementioned embodiments, it is still possible for a person skilled in the art to modify the technical solutions described in the aforementioned embodiments or to replace some of the technical features therein by equivalents. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A coring device, comprising an outer cylinder assembly (01) and a coring drill bit (02) fixedly arranged at the lower end of the outer cylinder assembly (01), characterized in that: The coring device also includes: An inner cylinder assembly (03) sleeved inside the outer cylinder assembly (01); A first core claw (04) disposed at the lower end of the inner barrel assembly (03), wherein the first core claw (04) is configured to cooperate with the coring drill bit (02) after moving downward, contract radially, and cut the core in the coring device; A second core claw (41) is further arranged between the inner cylinder assembly (03) and the first core claw (04), and radial sides of the second core claw (41) are respectively blocked by the inner cylinder assembly (03) and the first core claw (04); when the inner cylinder assembly (03) moves upward relative to the first core claw (04), the second core claw (41) contacts the core in the coring device and cuts the core.

2. The coring device according to claim 1, characterized in that: The first core claw (04) comprises a coaxially fixedly connected neck sleeve (42) and a flap-type retractable core claw (43), wherein the neck sleeve (42) is configured to be able to move downward only relative to the outer cylinder assembly (01). The inner cylinder assembly (03) comprises a shielding sleeve (40), The top of the neck sleeve (42) is sleeved on the lower part of the shielding sleeve (40), and the upper inner diameter of the neck sleeve (42) is greater than the lower outer diameter of the shielding sleeve (40), so that an annular space is formed between the neck sleeve (42) and the shielding sleeve (40), and the second core claw (41) is arranged in the annular space.

3. The coring device according to claim 2, characterized in that: The inner cylinder assembly (03) further comprises an outer sliding sleeve (36) arranged outside the shielding sleeve (40), and a one-way locking block (38) is arranged between the outer sliding sleeve (36) and the outer cylinder assembly (01), so that the outer sliding sleeve (36) can only move downward relative to the outer cylinder assembly (01), and the top of the neck sleeve (42) is axially abutted against the outer sliding sleeve (36).

4. The coring device according to claim 3, characterized in that: The second core claw (41) comprises a necking short section (39) and a clamp-type core claw (411) which are fixedly connected to each other, the upper end of the necking short section (39) is fixedly connected to the outer sliding sleeve (36), the lower end of the necking short section (39) is axially abutted against the necking sleeve (42), and the clamp-type core claw (411) is located in an annular space formed between the necking sleeve (42) and the shielding sleeve (40).

5. The coring device according to claim 1, characterized in that: A first response mechanism (05) is arranged in the outer cylinder assembly (01), the first response mechanism (05) comprising a second ball seat (12) arranged in an axially sliding sealing manner along the outer cylinder assembly (01), the lower end of the first response mechanism (05) being connected to the inner cylinder assembly (03), The first response mechanism (05) is configured such that after a ball is dropped into the second ball seat (12) to seal and pressurize, the first response mechanism (05) can move downward relative to the outer cylinder assembly (01) and drive the inner cylinder assembly (03) to move downward.

6. The coring device according to claim 5, characterized in that: A second response mechanism (06) is also provided in the outer cylinder assembly (01), and the second response mechanism (06) includes a third ball seat (3). The second response mechanism (06) is configured such that after a ball is thrown into the third ball seat (3) to pressurize it, the second response mechanism (06) can be separated from the outer cylinder assembly (01). At this time, lifting the second response mechanism (06) can drive the first response mechanism (05) and the inner cylinder assembly (03) to move upward, thereby making the second core claw (41) contact the core in the coring device and cut the core.

7. The coring device according to claim 5, characterized in that: The first response mechanism (05) includes a pressure rod (14) fixedly connected to the second ball seat (12), a first positioning joint (17) is arranged in the annular space between the pressure rod (14) and the second response mechanism (06), a first locking block (16) is radially penetrated and slidably arranged in the first positioning joint (17), the outer side of the first locking block (16) is embedded in the second response mechanism (06), the inner side of the first locking block (16) is abutted against the pressure rod (14), and the first locking block (16) is constructed so that when the pressure rod (14) moves downward, the first locking block (16) releases the abutment with the pressure rod (14), thereby being able to move radially inward, releasing the embedded connection relationship with the second response mechanism (06), so that the first response mechanism (05) can move downward relative to the second response mechanism (06).

8. The coring device according to claim 7, characterized in that: The pressure rod (14) is fixedly connected to the first positioning joint (17) via a shear pin, and a protrusion (141) for abutting against the first locking block (16) is provided on the outer wall of the pressure rod (14).

9. The coring device according to claim 8, characterized in that: A pressure bearing seat (18) is fixedly arranged at the lower part of the first positioning joint (17), and two upper shear rings (20) and a lower shear ring (22) for cooperating with the pressure rod (14) are axially spacedly arranged inside the pressure bearing seat (18). When the pressure rod (14) does not move downward, its lower end abuts against the upper shear ring (20), and the second ball seat (12) and the second response mechanism (06) are sealed with each other. When the pressure rod (14) is subjected to the pressure of the second ball seat (12) after the ball sealing, the upper shear ring (20) is sheared off and moves downward to abut against the lower shear ring (22), the first locking block (16) is separated from the abutment relationship with the protrusion (141). When the pressure rod (14) continues to move downward to cut off the lower shear ring (22) and move downward, the sealing relationship between the second ball seat (12) and the second response mechanism (06) is released, so that the upper and lower sides of the second ball seat (12) lose the differential pressure and no longer move downward.

10. The coring device according to claim 8, characterized in that: A recessed telescopic slide groove (131) is provided on the inner wall of the second response mechanism (06). A telescopic head (13) is fixedly arranged on the upper part of the first positioning joint (17), and the telescopic head (13) is slidably matched with the telescopic sliding groove (131). After the second ball seat (12) moves downward to drive the pressure rod (14) to shear the lower shear ring (22), the second ball seat (12) moves to the position of the telescopic sliding groove (131), and a gap exists between the two.

11. The coring device according to claim 6, characterized in that: The second response mechanism (06) comprises a first upper joint (1) inserted into the top of the outer cylinder assembly (01); the third ball seat (3) is slidingly sealed in the first upper joint (1); a second positioning joint (4) is sleeved in the first upper joint (1) through a joint shear pin (5); the upper end of the second positioning joint (4) abuts against the third ball seat (3); a second locking block (44) radially penetrated is provided between the first upper joint (1) and the outer cylinder assembly (01); the radial inner end of the second locking block (44) abuts against the second positioning joint (4); after the second positioning joint (4) moves downward, the second locking block (44) can release the radial abutment with the second positioning joint (4), thereby being able to move radially inward, releasing the radial penetration relationship with the first upper joint (1) and the outer cylinder assembly (01), thereby enabling the first upper joint (1) and the outer cylinder assembly (01) to move axially relative to each other.

12. The coring device according to claim 1, characterized in that: A gap adjustment assembly (07) is provided between the outer cylinder assembly (01) and the inner cylinder assembly (03), and the gap adjustment assembly (07) is configured to be able to adjust the axial distance of the outer cylinder assembly (01) relative to the inner cylinder assembly (03), thereby adjusting the axial distance of the first core claw (04) relative to the coring drill bit (02).

13. The coring device according to claim 11, characterized in that: A joint shear pin (5) is provided between the first upper joint (1) and the second positioning joint (4).

14. The coring device according to claim 13, characterized in that: A gap adjustment component (07) is provided between the first upper joint (1) and the inner cylinder assembly (03), and the gap adjustment component (07) comprises: an adjustable outer joint (8) fixedly connected to the first upper joint (1), An adjusting inner joint (7) is threadedly arranged in the adjusting outer joint (8), and the lower end of the adjusting inner joint (7) is connected to the inner cylinder assembly (03). The adjusting inner joint (7) rotates relative to the adjusting outer joint (8), thereby driving the inner cylinder assembly (03) to move axially relative to the outer cylinder assembly (01), thereby adjusting the axial distance of the first core claw (04) relative to the coring drill bit (02).

15. The coring device according to claim 14, characterized in that: A plurality of axially opened pin grooves (71) are evenly distributed along the circumferential direction on the outer wall of the adjusting inner joint (7), and the end of the joint shear pin (5) extends into the pin groove (71).

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