A static axial push high pressure water jet hole coring device

Abstract

The application provides a static axial high-pressure water jet hole coring device, which comprises a hollow connecting drill rod, a jet cutting sleeve, a water flow control system and two water delivery pipes. The jet cutting sleeve is coaxially and fixedly sleeved by an outer cylinder and an inner cylinder, so that a ring-shaped fan-shaped jet outlet, a connecting channel and a pressure buffer cavity are sequentially formed from front to back between the outer cylinder and the inner cylinder. The jet cutting sleeve is detachably connected with the connecting drill rod and is provided with a comprehensive channel, which is connected with the inner cylinder and the connecting drill rod. Three triangular guide rails are fixedly installed on the inner wall of the inner cylinder. The two water delivery pipes are connected with the pressure buffer cavity at the front side and are fixedly connected with the water flow control system at the rear side. The application avoids the winding and breaking of the hollow inclusion stress meter cable, realizes the normal transmission of the cable signal, reduces the signal noise and improves the inversion accuracy of the stress release data.

Description

Technical Field

[0001] This invention relates to the technical field of stress measurement in mining rock mass, and in particular to a static axially advancing high-pressure water jet core sampling device. Background Technology

[0002] Traditional hollow inclusion stress relief experiments typically employ a mechanical drilling process, requiring the cable of the hollow inclusion stress gauge to be threaded through the drill rod. However, this mechanical drilling process has the following drawbacks:

[0003] (1) The high-speed rotation of the drill rod will cause the cable to rub violently against the inner wall of the drill rod and accumulate torsional stress, which can easily induce the cable to become entangled, broken and interrupted.

[0004] (2) The strong vibration and heat generated by mechanical drilling will produce huge “signal noise”, which seriously interferes with the micro-strain acquisition of the hollow inclusion stress gauge and reduces the accuracy of stress relief data inversion.

[0005] (3) In deep high ground stress environment, due to large rock mass rheology or the risk of rock burst, traditional equal diameter mechanical drilling tools are very prone to "drill sticking" or "jamming" due to large deformation of the borehole wall, resulting in interruption of core sampling operations or even equipment damage. Summary of the Invention

[0006] The present invention aims to provide a static axially advancing high-pressure water jet core sampling device to avoid the entanglement and breakage of the hollow inclusion stress gauge cable, realize the normal transmission of cable signal, reduce signal noise, improve the inversion accuracy of stress relief data, and avoid the jet cutting sleeve from jamming.

[0007] Therefore, the technical solution adopted by the present invention is: a static axially advancing high-pressure water jet core drilling device, including a hollow connecting drill rod, a jet cutting sleeve, a water flow control system, and at least two water supply pipes;

[0008] The jet cutting sleeve is composed of an outer cylinder and an inner cylinder that are coaxially spaced and fixedly fitted together. This forms a circumferential fan-shaped jet outlet, a connecting channel, and a pressure buffer chamber between the outer and inner cylinders from front to back. This allows the jet cutting sleeve to spray high-pressure water jets to form an annular cutting groove and cut the rock core without rotating. The connecting drill rod is detachably connected to the rear side of the jet cutting sleeve. A comprehensive channel is provided on the rear side of the jet cutting sleeve. The comprehensive channel connects the inner cylinder and the connecting drill rod so that the cable of the hollow inclusion stress gauge passes through the inner cylinder, the comprehensive channel, and the connecting drill rod in sequence before connecting to the strain monitoring equipment.

[0009] At least three triangular guide rails are fixedly installed on the inner wall of the inner cylinder, evenly spaced around the center line of the inner cylinder, so that the at least three triangular guide rails can correct the movement path of the jet cutting sleeve by contacting the rock core through line.

[0010] All the aforementioned water pipes are connected to a pressure buffer chamber at the front and are evenly spaced around the center line of the jet cutting sleeve. The rear side is fixedly connected to a water flow control system so as to control the pressure and flow rate of the water jet ejected from the circumferential fan-shaped jet outlet through the water flow control system.

[0011] As a preferred embodiment of the above scheme, the integrated channel is provided with a flow-guiding spiral pattern to generate a spiral flow field that induces the return water to generate a centrifugal vortex, so that the rock debris is discharged against the wall of the integrated channel while forming a hydraulic sheath at the axis of the integrated channel to protect the cable.

[0012] More preferably, a plurality of radial support ribs are provided between the outer cylinder and the inner cylinder, and the plurality of radial support ribs are fixedly connected to the inner wall of the outer cylinder and the outer wall of the inner cylinder, so as to realize the coaxial and spaced fixed assembly of the outer cylinder and the inner cylinder.

[0013] More preferably, the connecting drill rod is symmetrically provided with two negative pressure suction ports so as to actively suck out rock cuttings.

[0014] More preferably, a plurality of hollow drill rods are detachably connected to the rear side of the connecting drill rod in sequence.

[0015] More preferably, the jet cutting sleeve, the connecting drill rod, and the rear sides of the plurality of hollow drill rods are all fixedly installed with connectors. The connectors are provided with external threads, and the front sides of the connecting drill rod and the plurality of hollow drill rods are all provided with connecting grooves. The connecting grooves are provided with internal threads that are compatible with the external threads, so that the jet cutting sleeve and the connecting drill rod, the connecting drill rod and the hollow drill rod, and two adjacent hollow drill rods can be detachably connected through the threaded connection of the connectors and the connecting grooves.

[0016] More preferably, the length of the jet cutting sleeve is greater than the length of the rock core.

[0017] More preferably, the water supply pipe is a flexible hose.

[0018] The beneficial effects of this invention are:

[0019] 1. By adopting a water supply pipe, a water flow control system, a circumferential fan-shaped jet outlet, a connecting channel, and a pressure buffer chamber, the static advancement of the jet cutting sleeve and the hydraulic cutting of rock cores can be achieved. This eliminates the need for the connecting drill rod and the jet cutting sleeve to rotate during core extraction. The cable of the hollow inclusion stress gauge is less prone to tangling and breakage, and the cable signal can maintain normal transmission.

[0020] 2. The high-pressure water jet ejected from the circumferential fan-shaped jet outlet has the characteristics of non-contact, low vibration and no thermal effect, which minimizes the disturbance to the original rock stress, thereby reducing the signal noise of the hollow inclusion stress gauge and improving the inversion accuracy of stress relief data.

[0021] 3. By employing at least three triangular guide rails in contact with the rock core inside the inner cylinder, the jet cutting sleeve can be moved axially along the rock core, ensuring the accuracy of the jet cutting sleeve's movement path and avoiding the influence of deviations in the movement path on micro-strain data. The at least three triangular guide rails also provide support and restraint for the rock core, preventing damage to the hollow inclusion stress gauge caused by violent shaking of the rock core during core breakage.

[0022] 4. The pressure buffer chamber can convert the pulsating water flow from the water flow control system into a stable constant pressure jet before supplying it to the circumferential fan-shaped jet outlet, thereby improving the cutting quality and protecting the rock core from being broken by the pressure fluctuations of the high-pressure water jet.

[0023] 5. This invention can use high-pressure water jet to expand the hole and form an annular groove with a wall thickness slightly greater than that of the jet cutting sleeve on the moving path of the jet cutting sleeve. This makes the jet cutting sleeve less likely to get stuck, ensuring the normal progress of the coring operation, effectively relieving the compression of the surrounding rock, and greatly expanding the applicable depth of the stress relief method in extreme working conditions such as kilometer-deep wells. Attached Figure Description

[0024] Figure 1 This is a schematic diagram of the structure of the present invention.

[0025] Figure 2 This is a cross-sectional view of the jet cutting sleeve in this invention.

[0026] Figure 3 This is a rear view of the jet cutting sleeve in this invention. Detailed Implementation

[0027] The present invention will now be further described with reference to the accompanying drawings and embodiments.

[0028] like Figure 1-3 As shown, a static axially advancing high-pressure water jet core drilling device consists of a hollow connecting drill rod 4, a jet cutting sleeve 1, a water flow control system 2, and at least two water supply pipes 3.

[0029] The jet cutting sleeve 1 is coaxially and fixedly fitted with an outer cylinder 10 and an inner cylinder 13, thus forming a circumferential fan-shaped jet outlet 12, a connecting channel 14, and a pressure buffer chamber 17 sequentially from front to back between the outer cylinder 10 and the inner cylinder 13. This allows the jet cutting sleeve 1 to spray high-pressure water jets to form an annular cutting groove and cut the rock core while remaining stationary. The connecting drill rod 4 is detachably connected to the rear side of the jet cutting sleeve 1, and a comprehensive channel 9 is provided on the rear side of the jet cutting sleeve 1. The comprehensive channel 9 connects the inner cylinder 13 and the connecting drill rod 4, so that the cable of the hollow inclusion stress gauge passes sequentially through the inner cylinder 13, the comprehensive channel 9, and the connecting drill rod 4 before connecting to the strain monitoring equipment.

[0030] At least three triangular guide rails 16 are fixedly installed on the inner wall of the inner cylinder 13, evenly spaced around the center line of the inner cylinder 13, so that the at least three triangular guide rails 16 can correct the movement path of the jet cutting sleeve 1 by contacting the rock core through line.

[0031] All water supply pipes 3 are connected to the pressure buffer chamber 17 at their front ends and are evenly spaced around the center line of the jet cutting sleeve 1. The rear ends are fixedly connected to the water flow control system 2, which controls the pressure and flow rate of the water jet exiting the circumferential fan-shaped jet outlet 12. The water supply pipes 3 are flexible hoses, and the water flow control system 2 is existing technology and will not be described in detail here.

[0032] There are three triangular guide rails 16 and two water supply pipes 3. Two water inlet connectors 7 are fixedly installed on the rear side of the jet cutting sleeve 1, and the water inlet connectors 7 are connected to the pressure buffer chamber 17. The front side of the water supply pipe 3 is connected to the water inlet connectors 7, thereby realizing the connection between the front side of the water supply pipe 3 and the pressure buffer chamber 17. Two outlet connectors 8 are fixedly installed on the water flow control system 2, and the rear side of the water supply pipe 3 is connected to the outlet connectors 8, forming a connection between the rear side of the water supply pipe 3 and the water flow control system 2. The water supply design of the two water supply pipes 3 is designed to ensure the symmetry of the energy distribution of the fan-shaped jet field at the bottom of the borehole. After the two water supply pipes 3 are connected, the invention is tested under low pressure to check the circuit sealing and prevent water leakage from affecting the high-pressure water jet cutting effect or even causing a high-pressure water leakage accident.

[0033] The cable of the hollow inclusion stress gauge is inserted into the inner cylinder 13, led out through the integrated channel 9, and then enters the connecting drill rod 4. After the jet cutting sleeve 1 is pushed to the predetermined position in the borehole, the cable is led out from the tail of the connecting drill rod 4 and connected to the strain monitoring equipment. According to the lithological physical and mechanical parameters of the target stratum, the water flow control system 2 is operated to preset the initial water pressure and flow rate. Then, the water flow control system 2 is started, and high-pressure water flows out from the water flow control system 2 and passes through the water supply pipe 3, pressure buffer chamber 17, connecting channel 14, and circumferential fan-shaped jet outlet 12 in sequence before being ejected, forming a high-pressure water jet to perform circumferential erosion cutting on the rock mass at the bottom of the borehole. Then, by pushing the connecting drill rod 4, the jet cutting sleeve 1 is slowly advanced forward. At this time, the triangular guide rail 16 is in line contact with the surface of the rock core, ensuring that the high-pressure water jet always cuts along the preset path, avoiding damage and jamming of the jet cutting sleeve 1. Every certain depth interval (3~5mm), the strain monitoring equipment records a strain reading and plots a stress relief curve.

[0034] When the strain data stabilizes, it indicates that the stress state of the core has been completely relieved from the original rock stress field. At this point, cutting and advancement are stopped. Thanks to the non-contact cutting characteristics of the high-pressure water jet, the secondary disturbance to the internal stress field of the core during the cutting process is minimal, ensuring the smoothness and reliability of the stress relief curve. This allows for the acquisition of original rock stress data that better reflects the actual conditions of deep rock masses. By instantaneously increasing the pressure and flow rate of the water flow control system 2, the high-pressure water jet performs a large-scale impact on the bottom of the core, inducing brittle fracture at the root and allowing the core to slide into the inner cylinder 13. Finally, the jet cutting sleeve 1 is removed, yielding a complete core containing a hollow inclusion stress gauge.

[0035] In the initial stage of the cutting operation, the distance between the circumferential fan-shaped jet outlet 12 and the bottom rock wall of the borehole (i.e., the target distance) should be strictly controlled, typically maintained at 5 to 10 times the diameter of the circumferential fan-shaped jet outlet 12. This is to utilize the divergent characteristics of the high-pressure water jet to create a "hole-expanding effect," producing an annular groove with a wall thickness slightly larger than the wall thickness of the jet cutting sleeve 1. This annular groove not only provides the necessary radial clearance for the static advancement of the jet cutting sleeve 1, preventing jamming caused by surrounding rock compression, but also constructs a physical channel for slag return and discharge.

[0036] When the jet cutting sleeve 1 is pushed to the predetermined position in the borehole, the triangular guide rail 16 begins to contact the surface of the rock core, so that the axis of the jet cutting sleeve 1 coincides with the axis of the borehole, laying the geometric reference for static cutting.

[0037] The integrated channel 9 is equipped with a flow-guiding spiral pattern 11 to generate a spiral flow field that induces centrifugal swirling of the return water. This allows rock cuttings to be discharged along the wall of the integrated channel 9 while simultaneously forming a hydraulic sheath at the axis of the integrated channel 9 to protect the cable and prevent water carrying rock cuttings from eroding the cable. Two negative pressure suction ports 5 are symmetrically provided on the connecting drill rod 4 for actively sucking out rock cuttings.

[0038] The cable of the hollow inclusion stress gauge (not shown in the attached diagram) should be as straight as possible. At the same time, the water supply pipe 3 should not be stretched too straight and should be left with a certain degree of slack to cope with the vibration or displacement that may occur during the cutting process, and to prevent the connection between the water supply pipe 3 and the jet cutting sleeve 1 from being loosened by force. An external extraction pipeline is connected at the negative pressure suction interface 5 of the drill rod 4 for active drainage and slag removal.

[0039] The power for slag removal is provided by a combination of passive hydraulic pressure drive and active negative pressure suction. The high-pressure water jet, after being obstructed at the bottom of the sealed borehole, generates strong reverse turbulence, forcibly suspending the detached rock cuttings. Under continuous backflow pressure, the rock cuttings and water are discharged through a dual path: First, the inner channel vortex protection path, where most of the rock cuttings and water enter the integrated channel 9 from the inner cylinder 13. Under the physical guidance of the guide spiral 11, the turbulent water flow is transformed into a controlled high-speed vortex, using centrifugal force to constrain the high-hardness rock cuttings to slide along the inner wall of the integrated channel 9, thus creating a hydraulic sheath for the cable at the axis of the integrated channel 9. Subsequently, the rock cuttings and water enter the connecting drill rod 4 and are rapidly discharged from the borehole under the active suction force of the negative pressure suction interface 5. Second, the outer annular gap auxiliary discharge path, where some fine rock cuttings flow out with the backflow water through the annular gap between the outer wall of the jet cutting sleeve 1 and the inner wall of the borehole.

[0040] This multi-channel cuttings removal mechanism ensures that the bottom of the borehole remains consistently clean without relying on drill string rotation. By maintaining the dynamic balance of the flow field at the bottom of the borehole, it fundamentally eliminates stuck drill accidents caused by cuttings deposition, significantly improving operational continuity under deep, high-stress conditions.

[0041] When the drilling depth is large, multiple hollow drill rods (not shown in the attached diagram) need to be detachably connected to the rear side of the connecting drill rod 4. The cable passes through the inside of each section of the drill rod in sequence to ensure that it is not squeezed or twisted throughout the process.

[0042] The jet cutting sleeve 1, the connecting drill rod 4, and the rear sides of multiple hollow drill rods are all fixedly equipped with connectors 6, which are provided with external threads. The front sides of the connecting drill rod 4 and the multiple hollow drill rods are all provided with connecting grooves, which are provided with internal threads that are compatible with the external threads, so that the jet cutting sleeve 1 and the connecting drill rod 4, the connecting drill rod 4 and the hollow drill rods, and two adjacent hollow drill rods can be detachably connected through the threaded connection of the connectors 6 and the connecting grooves.

[0043] Multiple radial support ribs 15 are provided between the outer cylinder 10 and the inner cylinder 13. These ribs are fixedly connected to the inner wall of the outer cylinder 10 and the outer wall of the inner cylinder 13, achieving a coaxial, spaced, and fixed fit between the outer cylinder 10 and the inner cylinder 13. The multiple radial support ribs 15 also improve the stability of the relative position between the outer cylinder 10 and the inner cylinder 13. The length of the jet cutting sleeve 1 is greater than the length of the rock core, facilitating the complete containment of the rock core within the jet cutting sleeve 1.

[0044] Although embodiments of the invention have been shown and described, those skilled in the art will understand that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the claims and their equivalents.

Claims

1. A statically axially advanced high-pressure water jet core drilling device, comprising a hollow connecting drill rod (4), characterized in that: It also includes a jet cutting sleeve (1), a water flow control system (2), and at least two water supply pipes (3); The jet cutting sleeve (1) is coaxially spaced and fixedly fitted with an outer cylinder (10) and an inner cylinder (13), thereby forming a circumferential fan-shaped jet outlet (12), a connecting channel (14) and a pressure buffer chamber (17) between the outer cylinder (10) and the inner cylinder (13) from front to back, so that a high-pressure water jet can be sprayed out to form an annular cutting groove to cut the rock core when the jet cutting sleeve (1) is not rotating. The connecting drill rod (4) is detachably connected to the rear side of the jet cutting sleeve (1). A comprehensive channel (9) is opened on the rear side of the jet cutting sleeve (1). The comprehensive channel (9) connects the inner cylinder (13) and the connecting drill rod (4) so ​​that the cable of the hollow package stress gauge passes through the inner cylinder (13), the comprehensive channel (9) and the connecting drill rod (4) in sequence and then connects to the strain monitoring equipment. At least three triangular guide rails (16) are fixedly installed on the inner wall of the inner cylinder (13) and are evenly spaced around the center line of the inner cylinder (13) so that the at least three triangular guide rails (16) can correct the movement path of the jet cutting sleeve (1) by contacting the rock core through the line. All the water pipes (3) are connected to the pressure buffer chamber (17) on the front side and are evenly spaced around the center line of the jet cutting sleeve (1), and are fixedly connected to the water flow control system (2) on the rear side so as to control the pressure and flow rate of the water jet ejected from the circumferential fan-shaped jet outlet (12) through the water flow control system (2).

2. The static axially advancing high-pressure water jet core sampling device according to claim 1, characterized in that: The integrated channel (9) is equipped with a flow-guiding spiral pattern (11) to generate a spiral flow field to induce the return water to generate a centrifugal vortex, so that the rock debris is discharged against the wall in the integrated channel (9) while forming a hydraulic sheath at the axis of the integrated channel (9) to protect the cable.

3. The static axially advancing high-pressure water jet core sampling device according to claim 1, characterized in that: Multiple radial support ribs (15) are provided between the outer cylinder (10) and the inner cylinder (13). The multiple radial support ribs (15) are fixedly connected to the inner wall of the outer cylinder (10) and the outer wall of the inner cylinder (13) to realize the coaxial spaced fixed assembly of the outer cylinder (10) and the inner cylinder (13).

4. The static axially advancing high-pressure water jet core sampling device according to claim 1, characterized in that: Two negative pressure suction ports (5) are symmetrically provided on the connecting drill rod (4) so ​​as to actively suck out rock cuttings.

5. The static axially advancing high-pressure water jet core sampling device according to claim 1, characterized in that: Multiple hollow drill rods are detachably connected to the rear side of the connecting drill rod (4).

6. The static axially advancing high-pressure water jet core sampling device according to claim 5, characterized in that: The jet cutting sleeve (1), the connecting drill rod (4), and the rear sides of the multiple hollow drill rods are all fixedly equipped with connectors (6). The connectors (6) are provided with external threads. The front sides of the connecting drill rod (4) and the multiple hollow drill rods are all provided with connecting grooves. The connecting grooves are provided with internal threads that are compatible with the external threads, so that the jet cutting sleeve (1) and the connecting drill rod (4), the connecting drill rod (4) and the hollow drill rod, and two adjacent hollow drill rods can be detachably connected through the threaded connection of the connectors (6) and the connecting grooves.

7. The static axially advancing high-pressure water jet core sampling device according to claim 1, characterized in that: The length of the jet cutting sleeve (1) is greater than the length of the rock core.

8. The static axially advancing high-pressure water jet core sampling device according to claim 1, characterized in that: The water supply pipe (3) is a flexible hose.

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