A directional coring drill

Abstract

The present invention discloses a directional coring drill tool, comprising: a drill bit, a central shaft connected to the drill bit, and an outer tube sleeved on the outer periphery of the central shaft, the outer tube being in clearance fit with the central shaft; a biasing assembly connected to the outer tube and used for adjusting the deflection degree of the central shaft; a packer connected to the outer tube and used for pressing against the hole wall under the action of drilling fluid at a preset pressure; and sealing devices respectively arranged at both ends of the packer, the sealing devices being radially floating so as to always seal both ends of the packer with the central shaft when adjusting the central shaft. When directional drilling is required, the biasing assembly is used to adjust the deflection degree of the central shaft. At this time, the sealing devices radially float along with the change of the radial position of the central shaft, so that the central shaft drives the drill bit to adjust the inclination angle to achieve the purpose of directional drilling; when the drill bit rotates, both ends of the packer are sealed by the sealing devices to ensure the pressure of the drilling fluid in the packer, so that the packer presses against the hole wall to prevent the outer tube and the biasing assembly from rotating and lock the inclination direction of the drill bit.

Description

Technical Field

[0001] The present invention relates to the technical field of geological exploration directional coring equipment, and more specifically, to a directional coring drill tool. Background Art

[0002] During geological exploration, in order to study the geological rock layers to be explored, it is usually desired to use directional drilling equipment to obtain geological core samples at specific positions.

[0003] However, the existing directional drilling equipment in the prior art, such as a positive displacement motor, is only applicable to drilling and cannot complete coring. And the existing coring equipment in the prior art, such as wireline coring drill tool, is only applicable to coring in vertical holes, and for directional hole coring, it cannot be applied due to its lack of deviation correction function.

[0004] Therefore, how to provide a directional coring drill tool with a borehole trajectory deviation correction function is an urgent problem to be solved by those skilled in the art at present. Summary of the Invention

[0005] In view of this, the purpose of the present invention is to provide a directional coring drill tool with a borehole trajectory deviation correction function.

[0006] To achieve the above purpose, the present invention provides the following technical solutions:

[0007] A directional coring drill tool includes:

[0008] A drill bit, a central shaft connected to the drill bit, and an outer tube sleeved on the outer periphery of the central shaft, the outer tube being in clearance fit with the central shaft;

[0009] An offset assembly connected to the outer tube and used to adjust the deflection degree of the central shaft;

[0010] A packer connected to the outer tube and used to press against the hole wall under the action of drilling fluid at a preset pressure;

[0011] Sealing devices respectively arranged at both ends of the packer, the sealing devices being radially floating so that when adjusting the central shaft, both ends of the packer are always sealed with the central shaft.

[0012] Preferably, mounting grooves are respectively arranged at both ends of the packer, and the sealing device includes:

[0013] A sealing sleeve that is radially floating and arranged in the mounting groove;

[0014] A first sealing member arranged between the sealing sleeve and the central shaft.

[0015] Preferably, the sealing sleeve is in clearance fit with the central shaft.

[0016] Preferably, the first seal includes at least two sealing rings forming a combined seal.

[0017] Preferably, couplings are respectively provided at both ends of the packer, and a stepped end face is provided inside the couplings;

[0018] The outer pipe includes an extension pipe and a cantilever bearing respectively connected to the two couplings, and the end faces of the extension pipe and the cantilever bearing are respectively arranged opposite to the stepped end faces of the two couplings in a one-to-one correspondence to form the mounting groove.

[0019] Preferably, a second seal is provided between the sealing sleeve and the stepped end face; and / or, a third seal is provided between the sealing sleeve and the end faces of the extension pipe and the cantilever bearing respectively.

[0020] Preferably, the packer includes a housing, a pressure pad and a guiding support plate symmetrically arranged with respect to the housing, and the housing is provided with a relief hole for allowing the pressure pad to protrude from the housing under the action of the drilling fluid to press against the hole wall.

[0021] Preferably, an expansion rubber is provided inside the pressure pad, and the expansion rubber expands under the action of the drilling fluid to make the pressure pad protrude from the relief hole.

[0022] Preferably, the guiding support plate is provided with ribs for clamping the hole wall.

[0023] Preferably, the housing is a cylinder with an eccentric inner wall and outer wall.

[0024] During the working process of the directional coring drill tool provided by the present invention, when the drilling trajectory needs to be corrected, the offset assembly is used to adjust the deflection degree of the central axis, and then the central axis drives the drill bit to adjust the inclination angle, so as to achieve the purpose of adjusting the drilling direction of the drill bit; meanwhile, during the rotation and cutting of the drill bit, the two ends of the packer are sealed by the sealing device to ensure the pressure of the drilling fluid inside the packer, so that the packer presses against the hole wall during work, thereby ensuring that the positions of the outer pipe and the offset assembly remain unchanged, and achieving the purpose of locking the inclination direction of the drill bit.

[0025] Since the sealing device is radially floating, during the process of adjusting the deflection degree of the central axis, the sealing device can radially float with the change of the radial position of the central axis to ensure the sealing performance between the packer and the central axis.

[0026] That is to say, the directional coring drill tool has a deviation correction function, and at the same time, a radially floating sealing device is used to ensure the sealing performance at both ends of the packer, ensure the liquid pressure required for the work of the packer, and achieve the purpose of locking the inclination direction of the drill bit. Brief Description of the Drawings

[0027] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required for use in the description of the embodiments or the prior art. Obviously, the drawings in the following description are only the embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on the provided drawings.

[0028] Figure 1 It is a schematic structural diagram of the directional coring drill provided by a specific embodiment of the present invention;

[0029] Figure 2 For Figure 1 a partial schematic view of A in

[0030] Figure 3 For Figure 2 a partial schematic view of B in

[0031] Figures 1 to 3 The reference numerals in

[0032] 1 is the drill bit, 2 is the central shaft, 3 is the offset assembly, 4 is the packer, 41 is the installation groove, 42 is the coupling, 43 is the housing, 44 is the pressure pad, 45 is the guiding support plate, 46 is the expanding rubber, 5 is the sealing device, 51 is the sealing sleeve, 52 is the first seal, 53 is the second seal, 54 is the third seal, 61 is the extension pipe, 62 is the cantilever bearing, 63 is the distance pipe, 7 is the fulcrum bearing, 8 is the locking mechanism, 9 is the drill pipe, 91 is the drill pipe connecting pipe. Specific embodiments

[0033] The following will clearly and completely describe the technical solutions in the embodiments of the present invention with reference to the drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts fall within the protection scope of the present invention.

[0034] The core of the present invention is to provide a directional coring drill, which specifically has a deviation correction function.

[0035] Please refer to Figures 1 - 3 , Figure 1 It is a schematic structural diagram of the directional coring drill provided by a specific embodiment of the present invention; Figure 2 For Figure 1 a partial schematic view of A in Figure 3 For Figure 2 a partial schematic view of B in

[0036] The present invention provides a directional coring drill tool, which mainly includes a drill bit 1, a central shaft 2, an outer pipe, a biasing assembly 3, a packer 4, a sealing device 5, etc.

[0037] Specifically, the drill bit 1 is fixedly connected to the central shaft 2, so that when the driving torque is transmitted to the central shaft 2, the drill bit 1 is driven to rotate and cut by the central shaft 2; at the same time, the drilling direction of the drill bit 1 is adjusted by adjusting the flexure degree of the central shaft 2.

[0038] The outer pipe is sleeved on the outer peripheral part of the central shaft 2, and there is a certain gap between the outer pipe and the central shaft 2, that is, they are in clearance fit.

[0039] The biasing assembly 3 is used to adjust the flexure degree of the central shaft 2, so that the central shaft 2 drives the drill bit 1 to change the inclination angle, so that the directional coring drill tool can perform directional drilling during the drilling process.

[0040] Among them, the biasing assembly 3 is connected to the outer pipe, and the outer pipe plays a role in fixing and supporting the biasing assembly 3 to ensure the position of the biasing assembly 3.

[0041] The packer 4 is connected to the outer pipe and is used to press against the hole wall under the action of drilling fluid at a preset pressure, that is, during the rotation of the drill bit 1, the packer 4 presses against the hole wall to prevent the outer pipe from rotating, so as to ensure that the position of the biasing assembly 3 remains unchanged, so as to lock the inclination direction of the drill bit 1 connected to the central shaft 2 and avoid affecting the drilling direction of the drill bit 1.

[0042] The number of the sealing devices 5 is two, and the two sealing devices 5 are respectively arranged at both ends of the packer 4 to seal both ends of the packer 4 and prevent the pressure of the drilling fluid in the packer 4 from leaking.

[0043] It should be noted that the sealing device 5 can float radially, so that when the biasing assembly 3 adjusts the flexure degree of the central shaft 2, the sealing device 5 can float radially with the change of the radial position of the central shaft 2, so that both ends of the packer 4 are always sealed with the central shaft 2.

[0044] It can be seen from this that in the working process of the directional coring drill tool provided by the present invention, when the drilling trajectory needs to be corrected, the biasing assembly 3 is used to adjust the flexure degree of the central shaft 2, and then the central shaft 2 drives the drill bit 1 to adjust the inclination angle, so as to achieve the purpose of adjusting the drilling direction of the drill bit 1, so that the directional coring drill tool can perform directional drilling according to the design requirements during the drilling process; at the same time, during the rotation and cutting of the drill bit 1, both ends of the packer 4 are sealed by the sealing device 5 to ensure the pressure of the drilling fluid in the packer 4, so that the packer 4 presses against the hole wall during work, so as to ensure that the positions of the outer pipe and the biasing assembly 3 remain unchanged, and achieve the purpose of locking the inclination direction of the drill bit 1 connected to the central shaft 2.

[0045] Since the sealing device 5 is radially floating, during the process of adjusting the deflection degree of the central shaft 2, the sealing device 5 can radially float as the radial position of the central shaft 2 changes, so as to ensure the sealing performance between the packer 4 and the central shaft 2 all the time.

[0046] That is to say, the directional coring drill tool has a deviation rectification function. At the same time, the radially floating sealing device 5 is used to ensure the sealing performance at both ends of the packer 4, ensure the liquid pressure required for the operation of the packer 4, and achieve the purpose of locking the inclination direction of the drill bit 1 connected to the central shaft 2.

[0047] It should be noted that the present invention does not limit the specific structure of the offset assembly 3 and the specific connection method between the offset assembly 3 and the outer pipe. For example, the offset assembly 3 has an eccentric part. By rotating the offset assembly 3, the position of the eccentric part changes, and then the eccentric part abuts against different positions on the same circumference of the central shaft 2, causing the central shaft 2 to generate a displacement in the radial direction, so as to achieve the purpose of adjusting the deflection degree of the central shaft 2.

[0048] The offset assembly 3 can be detachably connected to the outer pipe. For example, the offset assembly 3 is locked on the outer pipe by screws or pin shafts. When it is necessary to adjust the deflection degree of the central shaft 2, the screws or pin shafts are removed to rotate the offset assembly 3; after rotation in place, the offset assembly 3 can be locked by screws or pin shafts again.

[0049] In addition, those skilled in the art can understand that the central shaft 2 is a hollow structure, and the drilling fluid with a preset pressure can pass through the inner hole of the central shaft 2; at the same time, a through hole penetrating the side wall of the central shaft 2 is provided at the position of the central shaft 2 aligned with the packer 4, so that the drilling fluid flows from the inner hole of the central shaft 2 into the packer 4, and the packer 4 abuts against the hole wall under the action of the drilling fluid with a preset pressure.

[0050] Furthermore, the present invention does not limit the specific structure of the sealing device 5. On the basis of the above embodiments, mounting grooves 41 are respectively provided at both ends of the packer 4. The sealing device 5 includes a sealing sleeve 51 and a first sealing member 52. The sealing sleeve 51 is installed in the mounting groove 41, and the inner diameter of the mounting groove 41 is larger than the outer diameter of the sealing sleeve 51, so that the sealing sleeve 51 can radially float in the mounting groove 41. It can be understood that the radial clearance between the sealing sleeve 51 and the mounting groove 41 needs to meet the requirements of the maximum eccentricity of the offset assembly 3, that is, it can adapt to the adjustment requirements of the maximum deflection degree of the central shaft 2.

[0051] At the same time, the sealing sleeve 51 is sleeved on the central shaft 2, and the first sealing member 52 is arranged between the sealing sleeve 51 and the central shaft 2 to ensure the sealing performance between the sealing sleeve 51 and the central shaft 2.

[0052] In order to reduce the wear of the sealing sleeve 51 and the central shaft 2, on the basis of the above embodiments, the sealing sleeve 51 and the central shaft 2 are in clearance fit.

[0053] That is, the inner diameter of the sealing sleeve 51 is greater than the outer diameter of the central shaft 2, so that there is a certain gap between the sealing sleeve 51 and the central shaft 2, avoiding friction between the central shaft 2 and the sealing sleeve 51 when the central shaft 2 rotates. Therefore, the wear of the sealing sleeve 51 and the central shaft 2 can be reduced.

[0054] In order to improve the sealing effect of the first seal 52, on the basis of the above embodiment, the first seal 52 includes at least two sealing rings forming a combined seal.

[0055] It can be understood that the combined seal has a better sealing effect, making the sealing device 5 more suitable for the mud environment.

[0056] Such as Figure 3 As shown, the first seal 52 includes an O-ring and an L-ring. One right-angled side of the L-ring is in fitting contact with the central shaft 2, and a plurality of grooves are provided on the side of this right-angled side facing the central shaft 2 to form a labyrinth seal.

[0057] Considering the limiting problem of the first seal 52, preferably, on the basis of the above embodiment, the sealing sleeve 51 is provided with a first groove for setting the first seal 52 to play a limiting role on the first seal 52.

[0058] Considering the specific formation method of the installation groove 41, on the basis of the above embodiment, coupling devices 42 are respectively provided at both ends of the packer 4, and a stepped end face is provided inside the coupling device 42; the outer pipe includes an extension pipe 61 and a cantilever bearing 62 respectively connected to the two coupling devices 42. The end faces of the extension pipe 61 and the cantilever bearing 62 are respectively arranged opposite to the stepped end faces of the two coupling devices 42 in a one-to-one correspondence to form the installation groove 41.

[0059] That is to say, both ends of the packer 4 are fixedly connected to the extension pipe 61 and the cantilever bearing 62 through the coupling devices 42 respectively, and the installation groove 41 for installing the sealing sleeve 51 is jointly formed by the end face of the extension pipe 61 and the stepped end face inside the coupling device 42 (or the end face of the cantilever bearing 62 and the stepped end face inside the coupling device 42).

[0060] Considering the convenience of connecting the coupling device 42 to the extension pipe 61 and the cantilever bearing 62 respectively, preferably, the coupling devices 42 at both ends of the packer 4 are respectively threadedly connected to the extension pipe 61 and the cantilever bearing 62.

[0061] Such as Figure 3 As shown, the extension pipe 61 is provided with an external thread, the coupling device 42 is provided with an internal thread, and after the extension pipe 61 is threadedly connected to the coupling device 42, an installation groove 41 is formed.

[0062] Furthermore, considering the radial sealing performance, on the basis of the above embodiments, a second seal 53 is provided between the sealing sleeve 51 and the stepped end face; and / or, a third seal 54 is provided between the sealing sleeve 51 and the end faces of the extension pipe 61 and the cantilever bearing 62 respectively.

[0063] That is to say, the radial seal between the sealing sleeve 51 and the stepped end face is achieved by the second seal 53; the radial seal between the sealing sleeve 51 and the extension pipe 61 or the cantilever bearing 62 is achieved by the third seal 54.

[0064] The present invention does not limit the specific structures of the second seal 53 and the third seal 54. For example, the second seal 53 and the third seal 54 are preferably O-ring seals respectively.

[0065] In addition, the present invention does not limit the specific setting methods of the second seal 53 and the third seal 54. For example, preferably, on the basis of the above embodiments, second grooves and third grooves are respectively provided at both ends of the sealing sleeve 51, and the second grooves and the third grooves are respectively used to set the second seal 53 and the third seal 54, playing a role in limiting the second seal 53 and the third seal 54.

[0066] It can be understood that the radial widths of the second groove and the third groove are greater than the maximum dimensions of the corresponding second seal 53 and third seal 54 to meet the radial floating of the sealing sleeve 51.

[0067] Of course, grooves for installing the third seal 54 can also be provided on the end faces of the extension pipe 61 and the cantilever bearing 62; meanwhile, a groove for installing the second seal 53 is provided on the stepped end face.

[0068] It should be noted that the present invention does not specifically limit the specific structure and working principle of the packer 4, as long as the packer 4 can press against the hole wall to prevent the outer pipe from rotating when it works.

[0069] As a preferred embodiment, on the basis of the above embodiments, the packer 4 includes a housing 43, and a pressure pad 44 and a guiding support plate 45 symmetrically arranged with respect to the housing 43. The housing 43 is provided with a relief hole for allowing the pressure pad 44 to protrude from the housing 43 under the action of drilling fluid to press against the hole wall.

[0070] That is to say, during operation, when the packer 4 is filled with drilling fluid at a preset pressure, the drilling fluid exerts pressure on the pressure pad 44, causing the part of the pressure pad 44 aligned with the relief hole to protrude from the relief hole and contact the hole wall, so that the pressure pad 44 is pressed against the hole wall.

[0071] At this time, it can be understood that under the reaction force of the hole wall on the pressure pad 44, the guiding support plate 45 is stuck to the hole wall. Furthermore, under the combined action of the pressure pad 44 and the guiding support plate 45, the position of the packer 4 is fixed to prevent it from rotating.

[0072] In order to make the pressure pad 44 protrude from the relief hole better, on the basis of the above embodiment, an expansion rubber 46 is provided inside the pressure pad 44. The expansion rubber 46 expands under the action of the drilling fluid, causing the pressure pad 44 to protrude from the relief hole.

[0073] That is to say, when the drilling fluid with a preset pressure flows into the space between the expansion rubber 46 and the central shaft 2 from the through hole of the central shaft 2, under the action of the drilling fluid, the expansion rubber 46 expands. Furthermore, under the extrusion action of the expansion rubber 46, the pressure pad 44 protrudes from the relief hole.

[0074] In order to improve the firmness of the guiding support plate 45 in sticking to the hole wall, on the basis of the above embodiment, the guiding support plate 45 is provided with ribs for sticking to the hole wall.

[0075] That is to say, under the reaction force of the hole wall on the pressure pad 44, the ribs are clamped into the hole wall, making the guiding support plate 45 firmly stick to the hole wall.

[0076] Preferably, the ribs are made of hard alloy.

[0077] Furthermore, in order to ensure that the axis of the housing 43 coincides with the axis of the central shaft 2 during the rotation of the central shaft 2, on the basis of the above embodiment, the housing 43 is a cylinder with an eccentric inner wall and outer wall.

[0078] That is to say, the axis of the inner wall of the housing 43 is eccentric with the axis of its outer wall.

[0079] It can be understood that when the pressure pad 44 protrudes from the relief hole, under the reaction force of the hole wall on the pressure pad 44, the axis of the housing 43 will shift a certain distance in the direction away from the pressure pad 44. Therefore, the housing 43 is set as an eccentric cylinder to utilize the eccentricity of the housing 43 to compensate for the offset distance of the axis of the housing 43, ensuring that the axis of the housing 43 coincides with the axis of the central shaft 2 during the rotation of the central shaft 2.

[0080] It should be noted that in the above various embodiments, the specific structure of the outer tube of the present invention is not limited. For example, Figure 1 As shown, the outer tube includes a distance tube 63, an extension tube 61, and a cantilever bearing 62. The biasing assembly 3 is provided between the distance tube 63 and the extension tube 61. The extension tube 61 and the cantilever bearing 62 are respectively fixedly connected to both ends of the packer 4.

[0081] In addition, as Figure 1As shown, preferably, the drill bit 1 is fixedly connected to the central shaft 2 through a fulcrum bearing 7.

[0082] It can be understood that the outer ring of the fulcrum bearing 7 is connected to the distance pipe 63.

[0083] Further preferably, one end of the central shaft 2 away from the drill bit 1 is connected to the fixed part of the locking mechanism 8. The locking mechanism 8 includes a moving part, and the moving part is selectively connected to the outer ring of the cantilever bearing 62.

[0084] When the moving part is connected to the outer ring of the cantilever bearing 62, the outer pipe rotates with the rotation of the central shaft 2; when the moving part is not connected to the outer ring of the cantilever bearing 62, the power of the outer pipe can be cut off, the outer pipe does not rotate, and only the central shaft 2 rotates.

[0085] Preferably, a drill pipe connecting pipe 91 is provided between the locking mechanism 8 and the drill pipe 9, that is, the locking mechanism 8 is connected to the drill pipe 9 through the drill pipe connecting pipe 91.

[0086] It should also be noted that in this specification, relational terms such as first and second are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any actual relationship or order between these entities or operations.

[0087] The various embodiments in this specification are described in a progressive manner. Each embodiment focuses on the differences from other embodiments. The same or similar parts between the various embodiments can be referred to each other.

[0088] The above has introduced the directional coring drill provided by the present invention in detail. Specific examples are used in this article to elaborate on the principle and implementation manner of the present invention. The description of the above embodiments is only used to help understand the method and its core idea of the present invention. It should be pointed out that for those of ordinary skill in the art, without departing from the principle of the present invention, several improvements and modifications can be made to the present invention, and these improvements and modifications also fall within the protection scope of the claims of the present invention.

Claims

1. A directional coring tool, characterized in that, Comprising: a drill bit (1), a central shaft (2) connected to the drill bit (1), and an outer tube sleeved on the outer periphery of the central shaft (2), the outer tube being in clearance fit with the central shaft (2); a biasing assembly (3) connected to the outer tube for adjusting the deflection degree of the central shaft (2); a packer (4) connected to the outer tube for pressing against the hole wall under the action of drilling fluid at a preset pressure; sealing devices (5) respectively arranged at both ends of the packer (4), the sealing devices (5) being radially floating so that when the central shaft (2) is adjusted, both ends of the packer (4) are always sealed with the central shaft (2); Mounting grooves (41) are respectively arranged at both ends of the packer (4), and the sealing device (5) includes: a sealing sleeve (51) radially floatingly arranged in the mounting groove (41); a first seal (52) arranged between the sealing sleeve (51) and the central shaft (2); the sealing sleeve (51) is in clearance fit with the central shaft (2); Couplings (42) are respectively arranged at both ends of the packer (4), and a stepped end face is arranged in the couplings (42); The outer tube includes an extension tube (61) and a cantilever bearing (62) respectively connected to the two couplings (42), and the end faces of the extension tube (61) and the cantilever bearing (62) are respectively arranged opposite to the stepped end faces of the two couplings (42) in one-to-one correspondence to form the mounting groove (41).

2. The directional coring drill tool according to claim 1, characterized in that, The first seal (52) includes at least two seals forming a combined seal.

3. The directional coring drill tool according to claim 1, characterized in that, A second seal (53) is arranged between the sealing sleeve (51) and the stepped end face; and / or, a third seal (54) is arranged between the sealing sleeve (51) and the end faces of the extension tube (61) and the cantilever bearing (62) respectively.

4. The directional coring drill tool according to any one of claims 1-3, characterized in that, The packer (4) includes a housing (43), a pressure pad (44) and a guiding support plate (45) symmetrically arranged with respect to the housing (43), and the housing (43) is provided with a relief hole for allowing the pressure pad (44) to protrude from the housing (43) under the action of the drilling fluid to press against the hole wall.

5. The directional coring drill tool according to claim 4, wherein, An expansion rubber (46) is arranged inside the pressure pad (44), and the expansion rubber (46) expands under the action of the drilling fluid to make the pressure pad (44) protrude from the relief hole.

6. The directional coring drill tool according to claim 4, characterized in that The guiding support plate (45) is provided with ribs for clamping the hole wall.

7. The directional coring drill tool according to claim 4, wherein The housing (43) is a cylinder with an eccentric inner wall and outer wall.

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