Directional drilling hole wall stability maintaining device applied to fractured stratum

Abstract

The utility model discloses a directional drilling hole wall stability maintaining device applied to a fractured stratum, which belongs to the technical field of engineering geological investigation and comprises a main pipe body, a sealing unit and a separating unit, and the sealing unit and the separating unit are respectively sleeved on the main pipe body. The two sealing units are arranged in the axial direction of the main pipe body in a spaced mode so that a closed space can be formed between the two sealing units. The closed space is divided into a plurality of subspaces through a plurality of separation units, and grouting holes are formed in the main pipe body so that the subspaces can be filled with slurry. The separation units in the hole wall stability maintaining device can provide radial support for the main pipe body while separating the closed space, then in the grouting process, grouting permeation reinforcement and active supporting of the separation units are achieved at the same time, meanwhile, an anchoring piece can be arranged so that mechanical anchoring can be achieved, a collaborative supporting system can be constructed, and the hole wall stability maintaining device can be used for maintaining the hole wall stability. The stability of grouting operation is greatly improved, the safety redundancy is improved, and the engineering accident risk is reduced.

Description

A device for maintaining borehole wall stability in directional drilling in fractured formations Technical Field

[0001] This utility model belongs to the field of engineering geological exploration technology, specifically relating to a device for maintaining the stability of the borehole wall in directional drilling applied to fractured strata. Background Technology

[0002] In the field of geological exploration technology, especially for directional drilling operations in fractured strata, there is a problem of difficulty in maintaining borehole wall stability, which seriously affects project progress and operational efficiency.

[0003] Due to their loose structure and poor integrity, fractured strata are prone to collapse and rockfall during drilling due to loss of support. This results in unstable borehole walls, easy collapse, and insufficient sealing when the borehole passes through fractured strata. The risk of borehole instability is exacerbated, especially during steep angle drilling or deep hole drilling, which poses risks to subsequent drilling operations.

[0004] Traditional drilling techniques and equipment reinforce the borehole walls by grouting when drilling directional boreholes in fractured formations. However, this often fails to provide precise reinforcement of the borehole walls in fractured formations, resulting in significant waste and impacting drilling efficiency.

[0005] Therefore, there is an urgent need for a borehole stability maintenance device for directional drilling in fractured formations to enhance borehole stability and ensure smooth subsequent drilling operations. Summary of the Invention

[0006] In view of one or more of the above-mentioned defects or improvement needs of the prior art, the present invention provides a device for maintaining the stability of the borehole wall in directional drilling in fractured formations, wherein the strength of the borehole wall is enhanced and its stability is improved by injecting grout into the borehole wall located in fractured formations.

[0007] To achieve the above objectives, this utility model provides a device for maintaining the stability of the borehole wall in directional drilling applied to fractured formations, which includes a main body, a sealing unit, and a partitioning unit.

[0008] The sealing unit and the partition unit are respectively sleeved on the outer peripheral wall of the main body;

[0009] The sealing unit is two units spaced apart along the axial direction of the main body. The sealing unit can abut against the inner wall of the borehole to form a closed space between the two sealing units.

[0010] The partition unit is disposed between the two sealing units, and there are multiple partition units spaced apart along the axial direction to divide the enclosed space into multiple subspaces;

[0011] The end of the main body furthest from the borehole is the grouting end, used for adding grout.

[0012] The outer peripheral wall of the main body is provided with a plurality of grouting holes, and each of the subspaces is provided with at least one of the grouting holes, so that the grout fills the subspace.

[0013] As a further improvement of this utility model, the dividing unit is a conical cylinder, which is sleeved on the outer peripheral wall of the main tube.

[0014] The small-diameter end of the conical cylinder is fixedly connected to the main body, and its large-diameter end is located near the grouting end.

[0015] As a further improvement of this utility model, the grouting hole is located in the internal space of the conical cylinder. By injecting grout into the conical cylinder and pressurizing it in conjunction with the grouting system, the conical cylinder expands to provide radial support force to the main body. At the same time, after the pressurization is removed, the conical cylinder contracts to facilitate the removal of the entire device.

[0016] As a further improvement of this utility model, at least one of the sealing units includes an expansion bladder and two limiting plates spaced apart along the axial direction.

[0017] The two limiting plates are fixedly connected to the main body, and the expansion bladder is disposed between the two limiting plates. The limiting plates allow the expansion bladder to expand radially to seal the borehole.

[0018] As a further improvement of this utility model, it also includes a fixing component, which includes a connecting plate and an anchoring member.

[0019] The connecting plate is fixedly connected to the main body, and one end of the anchor is connected to the bottom of the connecting plate, while the other end can be inserted into the ground, so that the relative position between the main body and the borehole remains constant.

[0020] As a further improvement of this utility model, the connecting plate is provided with a through hole, the main body is inserted into the through hole, and the relative position of the main body and the connecting plate is adjustable;

[0021] And / or,

[0022] The anchoring elements are multiple units arranged in an array.

[0023] As a further improvement of this utility model, an internal thread structure is provided on the inner peripheral wall of the through hole, and an external thread structure is provided on the outer peripheral wall of the main body, and the main body is threadedly connected to the connecting plate.

[0024] As a further improvement of this utility model, the main body includes a plurality of pipe fittings that are sequentially connected along the axial direction.

[0025] As a further improvement of this utility model, the pipes are detachably connected.

[0026] As a further improvement of this utility model, an exhaust port is provided on the side wall of the main body, and the exhaust port is located away from the drill hole.

[0027] The aforementioned improved technical features can be combined with each other as long as they do not conflict with each other.

[0028] In summary, the technical solutions conceived by this utility model have the following beneficial effects compared with the prior art:

[0029] This utility model relates to a device for maintaining the stability of directional borehole walls in fractured strata. It seals the borehole space corresponding to the borehole wall to be reinforced through two sealing units. The partitioning unit divides the sealed space into multiple sub-spaces and provides radial support to the main body. Thus, while performing the grouting process, it establishes two systems: grouting penetration reinforcement and active support by the partitioning unit. It can also be equipped with anchoring components to achieve mechanical anchoring, forming a collaborative support system during grouting operations. This significantly improves the stability of grouting operations, greatly increases safety redundancy, and reduces the risk of engineering accidents. Attached Figure Description

[0030] Figure 1 is a schematic diagram of the overall structure of the directional drilling borehole wall stability maintenance device applied to fractured strata in an embodiment of this utility model.

[0031] Figure 2 is a structural schematic diagram of the grouting end portion of the main body and the partition unit in an embodiment of this utility model;

[0032] Figure 3 is a cross-sectional view of the main tube and the conical cylinder in an embodiment of this utility model;

[0033] Figure 4 is a schematic diagram of the overall structure of a directional drilling borehole wall stability maintenance device applied to fractured formations in another embodiment of the present invention.

[0034] In all the accompanying drawings, the same reference numerals denote the same technical features, specifically: 1. borehole; 2. main body; 3. conical cylinder; 4. grouting hole; 5. cover plate; 6. limiting plate; 7. expansion bladder; 8. guide tube; 9. grout; 10. grouting port; 11. external thread structure; 12. connecting plate; 13. anchoring element; 14. vent; 15. intact formation; 16. fractured formation. Detailed Implementation

[0035] To make the objectives, technical solutions, and advantages of this utility model clearer, the present utility model will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only for explaining the present utility model and are not intended to limit the present utility model. Furthermore, the technical features involved in the various embodiments of the present utility model described below can be combined with each other as long as they do not conflict with each other.

[0036] In the description of this utility model, it should be understood that the terms "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc., indicating the orientation or positional relationship are based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this utility model and simplifying the description, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this utility model.

[0037] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this utility model, "a plurality of" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0038] In this utility model, unless otherwise explicitly specified and limited, the terms "installation," "connection," "joining," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components, unless otherwise explicitly limited. Those skilled in the art can understand the specific meaning of the above terms in this utility model according to the specific circumstances.

[0039] In this utility model, unless otherwise explicitly specified and limited, "above" or "below" the second feature can mean that the first feature is in direct contact with the second feature, or that the first feature is in indirect contact with the second feature through an intermediate medium. Furthermore, "above," "on top of," and "over" the second feature can mean that the first feature is directly above or diagonally above the second feature, or simply that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature can mean that the first feature is directly below or diagonally below the second feature, or simply that the first feature is at a lower horizontal level than the second feature.

[0040] Example:

[0041] The borehole wall stability maintenance device for directional drilling in fractured strata according to a preferred embodiment of this utility model is shown in Figures 1-4. The borehole wall stability maintenance device includes a main body 2, sealing units, and partition units. The sealing units and partition units are respectively sleeved on the outer peripheral wall of the main body 2. Two sealing units are spaced apart along the axial direction of the main body 2, while multiple partition units are spaced apart between the two sealing units. Simultaneously, the end of the main body 2 furthest from the borehole 1 is the grouting end, and multiple grouting holes 4 are correspondingly formed on the side wall of the main body 2.

[0042] In practical application, the two sealing units abut against the inner wall of the borehole 11, forming a closed space between the two sealing units. The borehole space where the two sealing units are located is directly opposite the intact stratum 15, so that the closed space between the two sealing units is directly opposite the fractured stratum 16. Multiple partitioning units divide the closed space into multiple subspaces. The grouting holes 4 are correspondingly set to the subspaces. There is at least one grouting hole 4 in each subspace, so that grouting material 9 is added into the main body 2 through the grouting end, so that the grouting material 9 flows out from the grouting hole 4, and then fills each subspace, filling the entire closed space to complete the reinforcement of the borehole wall of the fractured stratum 16.

[0043] To further explain, after the slurry 9 is filled into the sealed space, it is allowed to penetrate or adhere to the surface, but before the slurry 9 is completely solidified, pressure on the slurry 9 is stopped, and the borehole wall stability maintenance device is removed. After the slurry 9 solidifies in the borehole wall and the fractured formation 16, the borehole wall is reinforced. The solidification time of the slurry 9 can be calculated from its proportions, which will not be elaborated here.

[0044] Preferably, each partition unit is arranged at equal intervals along the axial direction so that the space size of each subspace is the same.

[0045] Furthermore, the dividing unit is a conical cylinder 3, which has an annular structure and is fitted onto the outer peripheral wall of the main pipe 2. Its small-diameter end is fixedly connected to the main pipe 2, while its large-diameter end is located near the grouting end of the main pipe 2 (i.e., the opening of the conical cylinder 3 faces the grouting end). Preferably, the conical cylinder 3 is coaxially arranged with the main pipe 2.

[0046] In a preferred embodiment, the outer peripheral wall of the large-diameter end of the conical cylinder 3 is in contact with the inner wall of the borehole. When grout 9 is injected into the subspace through the grouting hole 4 and pressurized, the conical cylinder 3 undergoes slight deformation, causing it to fit tightly against the inner wall of the borehole 1. When the axially spaced conical cylinders 3 are tightly against the inner wall of the borehole 1, they provide radial support for the main pipe body 2, thereby ensuring a constant relative position between the main pipe body 2 and the borehole 1, and thus ensuring that the main pipe body 2 remains stable during the grouting process. Furthermore, the material of the conical cylinder 3 is steel.

[0047] In another preferred embodiment, a certain gap is left between the outer peripheral wall of the large diameter end of the conical cylinder 3 and the inner wall of the borehole. When grout 9 is injected into the subspace through the grouting hole 4 and pressurized, the conical cylinder 3 expands outward, so that the outer peripheral wall of the conical cylinder 3 is tightly attached to the inner wall of the borehole 1, which also provides radial support force for the main body 2. When the pressurization operation stops, the conical cylinder 3 contracts, and the holding device can be easily removed. The conical cylinder 3 can also carry away the grout 9 at the center of the borehole.

[0048] Furthermore, the conical cylinder 3 is made of an elastic alloy, allowing it to expand under pressure and contract when the external pressure is removed, thus enabling the partition unit to flexibly handle various drilling methods. Preferably, the elastic alloy is an iron-nickel-chromium alloy, which includes elements such as iron, nickel, chromium, titanium, and aluminum, giving the conical cylinder 3 excellent expansion and contraction properties.

[0049] Furthermore, the grouting hole 4 is set in the internal space of the conical cylinder 3 to directly inject grout 9 into the conical cylinder 3, so that the conical cylinder 3 expands outward under the pressure of grout 9, realizing the rapid expansion of the conical cylinder 3, maintaining the structural stability of the main body 2, and also improving the work efficiency.

[0050] Furthermore, each sealing unit is a first sealing unit and a second sealing unit, wherein the first sealing unit is disposed near the grouting end of the main body 2, while the second sealing unit is disposed away from the grouting end, and the second sealing unit may be disposed at the end of the main body 2.

[0051] Furthermore, the sealing unit includes an expansion bladder 7 and a limiting plate 6. The limiting plate 6 consists of two plates spaced apart along the axial direction of the main body 2 and is fixedly connected to the main body 2. The expansion bladder 7 is correspondingly disposed between the two limiting plates 6. The limiting plates 6 restrict the expansion range of the expansion bladder 7 in the axial direction, allowing the expansion bladder 7 to expand radially along the borehole 1 and then fit tightly against the inner wall of the borehole to seal the borehole 1 and form a closed space.

[0052] More preferably, each of the two sealing units is provided with a conduit 8 to fill the expansion bladder 7 with sealing material. One end of the conduit 8 is connected to the expansion bladder 7, and the other end passes through the interior of the main tube 2, extends axially, and exits from the side wall of the main tube 2. The end of the conduit 8 away from the expansion bladder 7 is located in the external environment. Preferably, the conduit 8 can extend to the top of the grouting end of the main tube 2.

[0053] Furthermore, a valve is provided on the conduit 8 to control the flow of the conduit 8. The expansion bladder 7 is preferably an expansion tubing, and the conduit 8 can be configured as a rigid structure to isolate the slurry 9 from the sealing material in the conduit 8.

[0054] Furthermore, a fixing component is also provided for the main pipe body 2 to fix the main pipe body 2 to the ground, thereby ensuring that the hole wall stability maintaining device can keep its relative position with the borehole 1 constant through the fixing component during the entire hole wall reinforcement process, so as to ensure work efficiency.

[0055] Furthermore, the fixing component includes a connecting plate 12 and an anchor 13 disposed at the bottom of the connecting plate 12. The anchor 13 is a rod structure, and its end away from the connecting plate 12 can be inserted into the ground, thereby fixing the fixing component to the ground. The connecting plate 12 is fixedly connected to the main pipe 2, thereby realizing the connection between the main pipe 2 and the ground.

[0056] More preferably, the connecting plate 12 has a through hole through which the main pipe 2 passes, and the main pipe 2 can reciprocate in its axial direction, thereby making the relative position of the main pipe 2 and the connecting plate 12 adjustable.

[0057] In one embodiment, a cover plate 5 is provided on the outer periphery of the main pipe body 2. The cover plate 5 has a through hole that matches the main pipe body 2, and a support member is provided at the bottom of the cover plate 5. The support member abuts against the ground to support the main pipe body 2. As shown in Figure 4, when the broken stratum 16 is on the surface, the cover plate 5 can serve as a first sealing unit to cooperate with the second sealing unit to seal the borehole 1. Preferably, the support member is a ring structure, and the main pipe body 2 and the cover plate 5 are also sealed by a sealing member, and the cover plate 5 can be fixedly connected to the connecting plate 12.

[0058] Furthermore, the connecting plates 12 may be two on both sides of the cover plate 5, or the connecting plates 12 may be annular structures, allowing the cover plate 5 to be embedded therein. Preferably, the anchoring members 13 may be multiple ones disposed at the bottom of the connecting plates 12, and the anchoring members 13 may be arranged in an array.

[0059] To further explain, the main body 2 can be divided into two parts along the axial direction, namely the hole wall support part and the position adjustment part. The two ends of the hole wall support part are respectively fitted with sealing units, while the position adjustment part is used to adjust the position of the hole wall support part in the borehole 1 so as to lower the hole wall support part to the designated position.

[0060] In a preferred embodiment, the inner wall surface of the through hole on the connecting plate 12 is in contact with the outer wall surface of the position adjustment part, so that the position adjustment part is slidably connected to the connecting plate 12. A clamping mechanism can also be configured on the connecting plate 12 so that when the hole wall holding part moves to the designated position, the main body 2 can be clamped and fixed, thereby realizing the fixed connection between the main body 2 and the connecting plate 12.

[0061] In another preferred embodiment, an internal thread structure is provided on the inner peripheral wall of the through hole, and an external thread structure 10 is correspondingly provided on the outer peripheral wall of the hole wall support portion of the main body 2, so that the main body 2 and the connecting plate 12 are threadedly connected. Then, by rotating the main body 2, it can move axially, and the internal and external threads are locked without the action of external force, so as to ensure that a locked connection is formed between the connecting plate 12 and the main body 2.

[0062] More preferably, an internally threaded sleeve can be nested in the through hole of the connecting plate 12, and the internally threaded sleeve is threadedly connected to the position adjustment part of the main body 2.

[0063] Furthermore, the main body 2 includes multiple pipe fittings connected sequentially along the axial direction. The pipe fitting corresponding to the position adjustment part is the first pipe fitting, and the pipe fitting corresponding to the hole wall maintenance part is the second pipe fitting. By adding, reducing, or replacing the first and second pipe fittings, the lengths of the position adjustment part and the hole wall maintenance part can be changed to adapt to different application scenarios.

[0064] Furthermore, in the position adjustment section, the outer diameters of each first pipe are the same, but their lengths may be the same or different, so as to achieve length adjustment of the position adjustment section.

[0065] Furthermore, in the bore wall support section, each of the second pipe fittings is provided with a sealing unit and / or a partition unit, and the two pipe fittings provided with the sealing unit are respectively located at both ends of the bore wall support section.

[0066] More preferably, the second pipe fitting is matched one-to-one with the sealing unit and the dividing unit. Preferably, the dividing unit is located in the middle of the second pipe fitting, and the length can be adjusted by adding or removing second pipe fittings with dividing units.

[0067] Alternatively, some second fittings may not be equipped with a partition unit, which is used to adjust the length of the entire bore wall support section by being placed between two second fittings with partition units.

[0068] Furthermore, the pipe fittings can be welded together, so that after determining the length of the borehole 1 and the location of the fractured stratum 16, suitable pipe fittings can be selected and welded to form a suitable main body 2, or the pipe fittings can be detachably connected.

[0069] In one embodiment, one end of the pipe fitting has an internal thread, and the other end has an external thread, so that two adjacent pipe fittings are threaded together.

[0070] Furthermore, through the arrangement of multiple pipe fittings and the movable connection between the main pipe 2 and the cover plate 5 or the connecting plate 12, combined with the adaptive change of the conical cylinder 3, the hole wall stability maintenance device can be applied to different geological conditions and various strata, with good flexibility and a wider range of applications.

[0071] Furthermore, the grouting end of the main body 2 is positioned away from the borehole 1, allowing the operator to control the borehole stability maintenance device through it. A grouting port 10 is provided on the side wall of the grouting end, through which grout 9 is injected into the interior of the main body 2 and flows into the borehole space from the grouting hole 4.

[0072] More preferably, an exhaust port 14 is also provided on the grouting end. The exhaust port 14 is connected to the inside of the main body 2. It can collect gas inside the borehole for sampling before operation, and can also discharge harmful gases inside the borehole and achieve auxiliary pressure stabilization.

[0073] Preferably, an exhaust pipe is provided in the main body 2 corresponding to the exhaust port 14. The exhaust pipe can be arranged with multiple sampling ports along the axial direction. The sampling holes pass through the main body 2 and communicate with the borehole 1 to accurately sample the internal gas of the borehole 1.

[0074] Those skilled in the art will readily understand that the above description is merely a preferred embodiment of the present utility model and is not intended to limit the present utility model. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present utility model should be included within the protection scope of the present utility model.

Claims

1. A device for maintaining borehole wall stability in directional drilling applied to fractured formations, characterized in that, The system includes a main body, a sealing unit, and a partition unit. The sealing unit and the partition unit are respectively sleeved on the outer peripheral wall of the main body. Two sealing units are spaced apart along the axial direction of the main body, and each sealing unit can abut against the inner wall of the borehole to form a closed space between the two sealing units. Multiple partition units are disposed between the two sealing units and are spaced apart along the axial direction to divide the closed space into multiple subspaces. The end of the main body away from the borehole is a grouting end for injecting grout. Multiple grouting holes are opened on the outer peripheral wall of the main body, and each subspace is provided with at least one grouting hole so that the grout fills the subspace.

2. The directional drilling borehole wall stability maintenance device applied to fractured formations according to claim 1, wherein, The dividing unit is a conical cylinder, which is sleeved on the outer peripheral wall of the main body. The small diameter end of the conical cylinder is fixedly connected to the main body, and its large diameter end is located near the grouting end.

3. The directional drilling borehole wall stability maintenance device applied to fractured formations according to claim 2, wherein, The grouting hole is located inside the conical cylinder.

4. The device for maintaining borehole wall stability in directional drilling according to any one of claims 1 to 3, wherein, At least one of the sealing units includes an expansion bladder and two limiting plates spaced apart along the axial direction, the two limiting plates being fixedly connected to the main body, and the expansion bladder being disposed between the two limiting plates.

5. The device for maintaining borehole wall stability in directional drilling according to any one of claims 1 to 3, wherein, It also includes a fixing component, which includes a connecting plate and an anchor. The connecting plate is fixedly connected to the main body, and one end of the anchor is connected to the bottom of the connecting plate, while the other end can be inserted into the ground, so that the relative position between the main body and the borehole is kept constant.

6. The device for maintaining borehole wall stability in directional drilling applied to fractured formations according to claim 5, wherein, The connecting plate has a through hole, the main tube is inserted through the through hole, and the relative position of the main tube and the connecting plate is adjustable; and / or, the anchoring members are multiple units arranged in an array.

7. The directional drilling borehole wall stability maintenance device applied to fractured formations according to claim 6, wherein, An internal thread structure is provided on the inner peripheral wall of the through hole, and an external thread structure is provided on the outer peripheral wall of the main body. The main body is threadedly connected to the connecting plate.

8. The device for maintaining borehole wall stability in directional drilling according to any one of claims 1 to 3, wherein, The main body includes multiple pipe fittings that are connected sequentially along the axial direction.

9. The device for maintaining borehole wall stability in directional drilling applied to fractured formations according to claim 8, wherein, The pipe fittings are detachably connected.

10. The device for maintaining borehole wall stability in directional drilling according to any one of claims 1 to 3, wherein, The main body has an exhaust port on its side wall, and the exhaust port is located away from the drill hole.

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