Core rod jacking type mechanical reaming device and method

Abstract

The invention belongs to the technical field of coal seam pressure relief and permeability improvement, and relates to a core rod jacking type mechanical reaming device and method, and the device comprises a core rod jacking type reamer, a core rod drill rod, a combined type rotary water tail and a hydraulic propeller which are sequentially connected from head to tail. The core rod jacking type reamer adopts a core rod pushing linkage structure, and the opening or closing state of a tool arm is accurately controlled; the core rod drill rod provides core rod guiding conduction, and deep hole reaming is achieved. The composite rotary water tail is used for rotary dynamic sealing connection of the drill rod core rod and the hydraulic propeller; the hydraulic propeller is used for being connected with hydraulic power and providing hydraulic propelling power for the guide rod. According to the device, hydraulic pressure serves as power to achieve rapid unfolding and retracting of the reaming cutter, the reaming speed is increased, the gas extraction drilling and reaming requirements are met, stable operation can be achieved under the complex geological condition, and the high field popularization value is achieved.

Description

Technical Field

[0001] The invention belongs to the technical field of coal seam pressure relief and permeability enhancement, and relates to a core rod jacking type mechanical hole enlarging device and method. Background Art

[0002] my country boasts abundant coal reserves, which play a vital role in its energy mix and are a key pillar in ensuring national energy security. However, as coal mining continues to increase in depth, coal seam gas content and pressure continue to rise, significantly increasing the risk of gas accidents and posing a serious challenge to coal mine safety. Gas extraction is a crucial component of ensuring safe production in coal mines. However, coal seams in most mining areas in my country have poor permeability and are classified as low-permeability. This results in low gas extraction efficiency, making it difficult to meet the dual requirements of safe production and efficient extraction. Therefore, improving gas extraction efficiency has become a key issue that needs to be urgently addressed in coal mining.

[0003] Coal seam permeability enhancement technology, a key tool for improving gas extraction efficiency, has garnered widespread attention. However, the cramped working environment of underground coal mines places extremely stringent demands on permeability enhancement equipment, requiring it to be high-strength, compact, and easy to operate. Currently, traditional coal seam permeability enhancement technologies have numerous drawbacks. Conventional hydraulic or explosive hole enlargement techniques, while the former presents significant safety risks during implementation, face significant implementation difficulties. High-pressure water jet cutting, while effective to a certain extent, is complex, consumes significant amounts of water, and is prone to hole wall collapse during the cutting process, compromising subsequent gas extraction operations. Explosive hole enlargement not only presents significant safety risks, but also poses challenges in precisely controlling the shape and size of the enlarged hole, making it ineffective for efficient gas extraction. Conventional drilling tools, when used with standard drill bits, only produce cylindrical holes, failing to achieve "hole-shaped" enlargement, resulting in limited coal seam permeability enhancement. Traditional mechanical hole expansion methods mostly rely on the thrust of the drilling rig to achieve drill bit diameter change. The hole expansion speed is slow and the working cycle is long, which makes it difficult to adapt to the actual needs of efficient gas extraction.

[0004] In summary, existing coal seam permeability enhancement technologies have shortcomings in terms of safety, borehole expansion effectiveness, and efficiency, failing to meet the demands of safe coal mine production and efficient gas extraction. Therefore, there is an urgent need to develop a new type of coal seam borehole expansion device to effectively enhance the pressure relief and permeability enhancement effects of coal seams, providing a strong guarantee for safe coal mine production and efficient mining. Summary of the Invention

[0005] In view of this, the purpose of the present invention is to provide a core rod jacking type mechanical reaming device and method, which controls the opening speed of the reaming knife arm through the core rod inside the device to achieve coal seam reaming, so as to solve the problems of difficulty in opening and recovering the reaming knife arm and slow reaming speed.

[0006] In order to achieve the above object, the present invention provides the following technical solutions:

[0007] A core rod jacking type mechanical reaming device comprises a core rod jacking type reamer, a core rod drill pipe, a composite rotary water tail and a hydraulic propeller which are connected in sequence from head to tail;

[0008] The tool is connected to the drill bit by the push-pull action of the push-pull mechanism, and the push-pull mechanism is connected with the push-pull mechanism by the push-pull action of the push-pull mechanism.

[0009] The core drill rod comprises a drill rod body and a drill rod core rod, the two ends of the drill rod body are respectively connected to the reamer body and the composite rotary water tail, the drill rod core rod is axially movably arranged in the inner cavity of the drill rod body and connected to the reamer core rod to axially push the reamer core rod;

[0010] The hydraulic propeller is installed at the tail end of the composite rotating water tail and has a guide rod for driving the drill pipe core rod to move axially.

[0011] The core rod jacking reamer adopts a core rod propulsion linkage structure to accurately control the opening or closing state of the cutter arm; the core rod drill rod provides core rod guidance and conduction to achieve deep hole reaming; the composite rotary water tail is used for rotating and sealing the connection between the drill rod core rod and the hydraulic thruster; the hydraulic thruster is used to connect hydraulic power to provide hydraulic propulsion power for the guide rod.

[0012] Furthermore, the female joint gland is connected to the reamer core rod as a stopper to limit the axial displacement of the reamer core rod toward the core rod drill rod;

[0013] A compression spring is sleeved on one end of the reamer core rod close to the male connector, and the two ends of the compression spring are respectively connected to the protrusion on the outside of the reamer core rod and the male connector to provide an elastic force to the reamer core rod toward the female connector cover to accelerate the closing of the knife arm.

[0014] Furthermore, the outer wall of the drill rod body adopts a shallow thread design, and the inner cavity is provided with a groove for installing the drill rod core rod and an axial advancement space is reserved.

[0015] Furthermore, a limiting protrusion is provided on the outside of the drill rod core rod, and a corresponding stop is provided in the groove of the drill rod body to limit the axial position of the drill rod core rod.

[0016] Furthermore, the composite rotary water tail includes an access port, a rotary sealing body and a water tail joint, the access port and the water tail joint are respectively arranged at both ends of the rotary sealing body, the access port is used to connect a water pipe or an air supply pipe for drilling and slag removal, the rotary sealing body is used for the rotary dynamic sealing connection between the drill rod core rod and the hydraulic thruster and the access port, and the water tail joint is used to match and connect with the core rod drill rod.

[0017] Furthermore, the tailgate joint and the core drill pipe are connected by a threaded or plug-in connection.

[0018] Furthermore, the hydraulic propulsion device further includes a hydraulic valve body and a hydraulic guide mechanism. The hydraulic valve body is installed at the tail end of the compound rotating water tail and is used to connect the hydraulic pipeline. The hydraulic guide mechanism is arranged in the hydraulic valve body to provide hydraulic propulsion power for the guide rod.

[0019] The guide rod axially passes through the composite rotary water tail and is connected to the drill rod core rod to drive the drill rod core rod to move axially.

[0020] A method for using the core rod jacking type mechanical reaming device comprises the following steps:

[0021] S1: Install the core drill rod on the drilling rig, install the core rod jacking reamer and drill bit in sequence, adjust the hole height, inclination and azimuth according to the drilling design, and start drilling;

[0022] S2: After the hole reaches the designed depth, the tailgate joint and hydraulic thruster are installed in sequence, and the hydraulic thruster is connected with a hydraulic pipeline to control the opening and closing of the cutter arm;

[0023] S3: According to the drilling and reaming design, reaming operation is carried out from the bottom of the hole to the hole mouth.

[0024] Furthermore, during the hole expansion operation, the oil pressure of the hydraulic pipeline is controlled at 2-4 MPa.

[0025] Furthermore, in step S2, the specific method for controlling the opening and closing of the knife arm is:

[0026] Cutter arm opening: The guide rod of the hydraulic thruster moves toward the bottom of the hole under the oil pressure of the hydraulic pipeline, thereby driving the drill pipe core rod and the reamer core rod to move toward the bottom of the hole, so that the cutter arm opens by meshing with the reamer core rod and is kept open by the oil pressure of the hydraulic pipeline;

[0027] Cutter arm closing: the oil pressure drive of the hydraulic pipeline is stopped, and the cutter arm is automatically closed under the pressure of the inner wall of the borehole. The reamer core rod moves toward the hole mouth under the action of meshing with the cutter arm, thereby driving the drill rod core rod and guide rod to reset.

[0028] The beneficial effects of the present invention are:

[0029] 1. This invention proposes a core rod jacking mechanical reaming device, the core of which lies in the innovative design of a core rod jacking reamer, a core rod drill pipe, a composite rotary water tail, and a hydraulic thruster. These components are hydraulically powered and can quickly deploy and retract the reaming cutter arms, significantly improving reaming speed and efficiency. Compared to traditional reaming equipment, this device can not only flexibly adapt to the needs of reaming holes of different diameters, but also maintain stable operation under complex geological conditions. This design reduces equipment failure rates, ensures construction safety, and provides reliable technical support for operations in industries such as coal mining.

[0030] 2. Through its blade-arm reaming technology, the device efficiently cuts and removes large volumes of coal, creating larger-diameter cavities and fracture networks. This not only increases the exposed area of ​​the coal seam but also significantly improves its permeability, creating more favorable conditions for gas migration and extraction. In practical applications, this reaming method has significantly increased gas extraction efficiency and yield, effectively reducing the safety hazards associated with gas accumulation. Compared to traditional methods, it creates a wider fracture network, resulting in better extraction results, providing a crucial guarantee for safe coal mine production.

[0031] 3. The device boasts a simple structural design, easy operation, and precise control, achieving integrated drilling and reaming operations. Operators can easily master the system without extensive training, reducing operational and maintenance costs. Its modular design and high level of integration further enhance its adaptability to field applications, making it an attractive option for practical deployment. Whether improving construction efficiency or reducing financial investment, this technical solution demonstrates significant practical value and market potential, is applicable to a wide range of complex working conditions, and holds broad application prospects.

[0032] Other advantages, objects, and features of the present invention will be described in part in the following description and, in part, will be apparent to those skilled in the art upon examination of the following description or may be learned from practice of the present invention. The objects and other advantages of the present invention may be realized and obtained through the following description. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] In order to make the purpose, technical solutions and advantages of the present invention more clear, the present invention will be described in detail below with reference to the accompanying drawings, in which:

[0034] Figure 1 Schematic diagram of the overall structure of a core rod jacking type mechanical reaming device in an embodiment;

[0035] Figure 2 Schematic diagram of the structure of the core rod jacking reamer in the embodiment;

[0036] Figure 3 Schematic diagram of the structure of the core drill rod in the embodiment;

[0037] Figure 4 Schematic diagram of the structure of the composite rotating water tail in the embodiment;

[0038] Figure 5 Schematic diagram of the structure of the hydraulic propulsion device in the embodiment.

[0039] Reference numerals: 1-core rod jacking reamer, 2-core rod drill pipe, 3-compound rotary water tail, 4-hydraulic propeller;

[0040] Core rod jacking type reamer: 1-1-female joint cover, 1-2-reamer core rod, 1-3-knife arm, 1-4-reamer body, 1-5-male joint, 1-6-compression spring;

[0041] Core drill rod: 2-1-drill rod body, 2-2-drill rod core rod;

[0042] Composite rotary water tail: 3-1- access port, 3-2-rotating seal body, 3-3-water tail joint;

[0043] Hydraulic thruster: 4-1-hydraulic valve body, 4-2-hydraulic guide mechanism, 4-3-guide rod. DETAILED DESCRIPTION

[0044] The following describes the embodiments of the present invention by means of specific examples, and those skilled in the art can easily understand other advantages and effects of the present invention from the contents disclosed in this specification. The present invention can also be implemented or applied through other different specific embodiments, and the details in this specification can also be modified or changed in various ways based on different viewpoints and applications without departing from the spirit of the present invention. It should be noted that the illustrations provided in the following embodiments are only schematic illustrations of the basic concept of the present invention, and the following embodiments and features in the embodiments can be combined with each other without conflict.

[0045] Among them, the accompanying drawings are only for illustrative purposes and represent only schematic diagrams rather than actual pictures, and should not be understood as limiting the present invention. In order to better illustrate the embodiments of the present invention, some parts of the accompanying drawings may be omitted, enlarged or reduced, and do not represent the dimensions of actual products. For those skilled in the art, it is understandable that some well-known structures and their descriptions may be omitted in the accompanying drawings.

[0046] The same or similar numbers in the drawings of the embodiments of the present invention correspond to the same or similar parts; in the description of the present invention, it should be understood that if there are terms such as "upper", "lower", "left", "right", "front", "back", etc. indicating directions or positional relationships, they are based on the directions or positional relationships shown in the drawings. They are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific direction, be constructed and operate in a specific direction. Therefore, the terms describing the positional relationship in the drawings are only used for illustrative purposes and cannot be understood as limiting the present invention. For ordinary technicians in this field, the specific meanings of the above terms can be understood according to specific circumstances.

[0047] Example 1

[0048] This embodiment provides a core rod jacking type mechanical hole expansion device and its use method, which is used to solve the problem of drilling and expanding holes in coal seam gas extraction. Figure 1 As shown, it includes a core rod jacking reamer 1, a core rod drill pipe 2, a composite rotary water tail 3 and a hydraulic propeller 4 which are connected in sequence from the beginning to the end.

[0049] The core rod jacking reamer 1 comprises a female joint cover 1-1, a male joint 1-5, a reamer core rod 1-2, a knife arm 1-3 and a reamer body 1-4.

[0050] A groove for installing the reamer core rod 1-2 is processed inside the reamer body 1-4, and an axial advancement space is reserved; grooves for installing the knife arms 1-3 are provided on both sides of the middle part.

[0051] The reamer core rod 1-2 is movable in the axial direction and is installed in a groove in the inner cavity of the reamer body 1-4.

[0052] Two blade arms 1-3 are provided, located outside the reamer core rod 1-2 and arranged symmetrically. One end of each blade arm is connected to the reamer body 1-4 via a hinge. A blade arm gear is provided at the hinge, meshing with the core rod gear on the reamer core rod 1-2. The blade arms 1-3 can be opened and closed by pushing and pulling the reamer core rod 1-2.

[0053] The female joint gland 1-1 and the male joint 1-5 are respectively installed at both ends of the reamer body 1-4 and are used to connect the drill pipe body 2-1** and the drill bit. The connection adopts a threaded connection design.

[0054] The core drill rod 2 includes a drill rod body 2-1 and a drill rod core rod 2-2.

[0055] Both ends of the drill pipe body 2-1 are connected to the reamer body 1-4 and the composite rotary water tail 3 respectively.

[0056] The drill rod core rod 2-2 is axially movably arranged in the inner cavity of the drill rod body 2-1, connected to the reamer core rod 1-2, and is used to push the reamer core rod 1-2 to move.

[0057] The composite rotary water tail 3 comprises an inlet 3-1, a rotary sealing body 3-2 and a water tail joint 3-3.

[0058] Inlet 3-1 is connected to a water pipe for drilling and slag removal.

[0059] The rotary seal body 3-2 ensures a rotary dynamic seal between the drill pipe core rod 2-2, the hydraulic propeller 4 and the access port 3-1.

[0060] The tail pipe joint 3-3 is connected to the core drill pipe 2 by a threaded connection.

[0061] The hydraulic thruster 4 includes a hydraulic valve body 4-1, a hydraulic guide mechanism 4-2 and a guide rod 4-3.

[0062] The hydraulic valve body 4-1 is installed at the tail end of the composite rotating water tail 3 and connected to the hydraulic pipeline.

[0063] The hydraulic guide mechanism 4-2 provides hydraulic propulsion power for the guide rod 4-3.

[0064] The guide rod 4-3 axially penetrates the composite rotary water tail 3 and is connected to the drill pipe core rod 2-2 to drive the same to move axially.

[0065] It should be noted that the key to this embodiment lies in the structural combination of the core rod jacking reamer 1, the core rod drill rod 2, the compound rotary water tail 3 and the hydraulic propeller 4 and the specific structure of the core rod jacking reamer 1, wherein the core rod drill rod 2, the compound rotary water tail 3 and the hydraulic propeller 4 can also be replaced by other conventional structures in the prior art. Therefore, the above only briefly describes its functional structure without further elaboration.

[0066] The method of using the core rod jacking type mechanical reaming device is as follows:

[0067] Install the core drill rod 2 to the drilling rig, connect the core rod jacking reamer 1 and the drill bit in sequence, adjust the hole height, inclination and azimuth, and perform drilling operations.

[0068] After the borehole reaches the designed depth, the tail joint 3-3 and the hydraulic thruster 4 are installed, and the hydraulic pipeline is connected to control the opening and closing of the cutter arm 1-3.

[0069] Ream the hole from the bottom toward the hole mouth, controlling the hydraulic pressure at 2-4 MPa. Ream the entire coal section of the through-seam drilling. For in-seam drilling, the length of the reaming section is 1 meter, with intervals of 4 meters between sections. Stop reaming 15 meters from the hole mouth. Count the coal output during the reaming section. After reaming is complete, remove the reaming drill tool and store it securely.

[0070] Furthermore, the composite rotary water tail 3 can also be connected to the core drill pipe 2 during the drilling operation to assist in slag removal during the drilling operation.

[0071] Example 2

[0072] Based on Specific Example 1, this embodiment further optimizes the device structure to improve operating efficiency and stability.

[0073] Improvement of core rod jacking reamer 1

[0074] The female joint gland 1-1 is connected to the reamer core rod 1-2 by a stopper to limit excessive displacement of the reamer core rod 1-2 toward the core rod drill rod 2.

[0075] A compression spring 1-6 is sleeved on one end of the reamer core rod 1-2 close to the male connector 1-5, and its two ends are respectively connected with the outer protrusion of the reamer core rod 1-2 and the male connector 1-5, providing elastic force toward the female connector cover 1-1 to accelerate the closing of the knife arm 1-3.

[0076] Improvement of core drill rod 2

[0077] The outer wall of the drill rod body 2-1 adopts a shallow thread design to enhance the friction with the inner wall of the borehole; the inner cavity is provided with a groove for the installation of the drill rod core rod 2-2, and axial advancement space is reserved.

[0078] A limiting protrusion is provided on the outside of the drill rod core rod 2-2, and a corresponding stop is provided in the groove of the drill rod body 2-1 to achieve axial limiting.

[0079] Specifically, the drill rod core rod 2-2 is installed into the drill rod body 2-1 through one end of the drill rod body 2-1. After the installation is completed, the male joint of the drill rod body is welded to the drill rod body 2-1, and then the drill rod core rod 2-2 that forms a stop connection with the drill rod body 2-1 is installed into the drill rod body 2-1.

[0080] Specifically, in this embodiment, the outer diameter of the core rod jacking reamer 1 is Φ96 mm, the length is 650 mm, the length of the blade arm is 200 mm, and the length of the groove for installing the blade arm is 210 mm;

[0081] The outer diameter of the drill rod body 2-1 is Φ76mm and the length is 1000mm. The outer diameter of the drill rod core rod 2-2 is Φ30mm and the length is 1000mm.

[0082] The size of the inlet 3-1 in the composite rotating water tail is Φ25mm, the hydraulic pipeline in the hydraulic propeller is Φ10mm, the oil pressure is 2-4MPa, and the guide rod stroke is 100mm.

[0083] The method of using the core rod jacking type mechanical reaming device is as follows:

[0084] Same as in Example 1, complete the drilling operation and install the relevant components.

[0085] Opening and closing control of blade arms 1-3:

[0086] Opening: The guide rod 4-3 of the hydraulic thruster 4 moves toward the bottom of the hole under hydraulic drive, pushing the drill pipe core rod 2-2 and the reamer core rod 1-2 to move, and the cutter arm 1-3 opens through gear engagement and is maintained in the open state by hydraulic pressure.

[0087] Closing: Stop the hydraulic drive, the cutter arm 1-3 is squeezed by the inner wall of the borehole and automatically closes, the compression spring 1-6 assists the reamer core rod 1-2 to reset, and drives the drill rod core rod 2-2 and the guide rod 4-3 to return to their original positions.

[0088] Specifically, Example 2 involves a through-seam drilling and reaming operation. The coal seam is 6m thick, the drilling depth is 40m, and the inclination angle is 80°. The through-seam drilling involves reaming the entire coal section to a depth of 6m. Coal output during the reaming section is calculated. After reaming is complete, the reaming drill tool is removed and properly stored, and the hole is sealed and pumped continuously.

[0089] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not limiting. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solutions of the present invention can be modified or replaced by equivalents without departing from the purpose and scope of the technical solutions, which should all be included in the scope of the claims of the present invention.

Claims

1. A core rod jacking type mechanical reaming device, characterized in that: It includes a core rod jacking type reamer, a core rod drill pipe, a composite rotary water tail and a hydraulic propeller connected in sequence from the beginning to the end; The tool is connected to the drill bit by the push-pull action of the push-pull mechanism, and the push-pull mechanism is connected with the push-pull mechanism by the push-pull action of the push-pull mechanism. The core drill rod comprises a drill rod body and a drill rod core rod, the two ends of the drill rod body are respectively connected to the reamer body and the composite rotary water tail, the drill rod core rod is axially movably arranged in the inner cavity of the drill rod body and connected to the reamer core rod to axially push the reamer core rod; The hydraulic propeller is installed at the tail end of the composite rotating water tail and has a guide rod for driving the drill pipe core rod to move axially.

2. The device according to claim 1, characterized in that: The female joint gland is connected to the reamer core rod as a stopper to limit the axial displacement of the reamer core rod toward the core rod drill rod; A compression spring is sleeved on one end of the reamer core rod close to the male connector, and the two ends of the compression spring are respectively connected to the protrusion on the outside of the reamer core rod and the male connector to provide an elastic force to the reamer core rod toward the female connector cover to accelerate the closing of the knife arm.

3. The device according to claim 1, characterized in that: The outer wall of the drill rod body adopts a shallow thread design, and the inner cavity is provided with a groove for installing the drill rod core rod and an axial advancement space is reserved.

4. The device according to claim 3, characterized in that: A limiting protrusion is provided on the outer side of the drill rod core rod, and a corresponding stop is provided in the groove of the drill rod body to limit the axial position of the drill rod core rod.

5. The device according to claim 1, characterized in that: The composite rotary water tail includes an access port, a rotary sealing body and a water tail joint, wherein the access port and the water tail joint are respectively arranged at both ends of the rotary sealing body. The access port is used to connect a water pipe or an air supply pipe for drilling and slag removal. The rotary sealing body is used for the rotary dynamic sealing connection between the drill rod core rod and the hydraulic thruster and the access port. The water tail joint is used to match and connect with the core rod drill rod.

6. The device according to claim 5, characterized in that: The tailgate joint and the core drill rod are connected in a threaded or plug-in manner.

7. The device according to claim 1, characterized in that: The hydraulic propulsion device further includes a hydraulic valve body and a hydraulic guide mechanism. The hydraulic valve body is installed at the tail end of the compound rotating water tail and is used to connect to the hydraulic pipeline. The hydraulic guide mechanism is arranged in the hydraulic valve body to provide hydraulic propulsion power for the guide rod. The guide rod axially passes through the composite rotary water tail and is connected to the drill rod core rod to drive the drill rod core rod to move axially.

8. A method for using the core rod jacking type mechanical reaming device according to any one of claims 1 to 7, characterized in that: The following steps are involved: S1: Install the core drill rod on the drilling rig, install the core rod jacking reamer and drill bit in sequence, adjust the hole height, inclination and azimuth according to the drilling design, and start drilling; S2: After the hole reaches the designed depth, the tailgate joint and hydraulic thruster are installed in sequence, and the hydraulic thruster is connected with a hydraulic pipeline to control the opening and closing of the cutter arm; S3: According to the drilling and reaming design, reaming operation is carried out from the bottom of the hole to the hole mouth.

9. The method according to claim 8, characterized in that: During the hole expansion operation, the oil pressure of the hydraulic pipeline is controlled at 2-4 MPa.

10. The method according to claim 8, characterized in that: In step S2, the specific method for controlling the opening and closing of the knife arm is: Cutter arm opening: The guide rod of the hydraulic thruster moves toward the bottom of the hole under the oil pressure of the hydraulic pipeline, thereby driving the drill pipe core rod and the reamer core rod to move toward the bottom of the hole, so that the cutter arm opens by meshing with the reamer core rod and is kept open by the oil pressure of the hydraulic pipeline; Cutter arm closing: the oil pressure drive of the hydraulic pipeline is stopped, and the cutter arm is automatically closed under the pressure of the inner wall of the borehole. The reamer core rod moves toward the hole mouth under the action of meshing with the cutter arm, thereby driving the drill rod core rod and guide rod to reset.

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