A measuring device and a measuring method for determining the direction of terrestrial stresses

Abstract

The application discloses a kind of measuring device and measurement method for determining ground stress direction, belong to petroleum exploitation technical field.A kind of measuring device for determining ground stress direction, including positioning rod, element cylinder and connecting sleeve are installed in sequence on it, coarse grinding plate is symmetrically installed on connecting sleeve, driving element is installed in element cylinder, further include: inner cylinder and L-shaped connecting arm, inner cylinder is provided with fine grinding plate on both sides, two ends of L-shaped connecting arm are rotatably connected with coarse grinding plate and inner cylinder, by driving element forward rotation, coarse grinding plate is rotated, under the action of centrifugal force, it is adapted to be combined with hole wall, the rough surface of the preliminary polishing of borehole wall is removed, driving element reversely rotates, connecting piece makes L-shaped connecting arm pull inner cylinder and move upwards, so that the coarse grinding plate of two sides is withdrawn, fine grinding plate is contacted with borehole wall under the action of centrifugal force, the surface of polished borehole wall is smooth, suitable for the operation of subsequent strain sensor's combination and measurement.

Description

Technical Field

[0001] This invention relates to the field of oil extraction technology, and in particular to a measuring device and method for determining the direction of geostress. Background Technology

[0002] In fields such as geological engineering, oil exploration, and mining, the measurement of geostress is an important basis for assessing the stability of underground rock masses, optimizing drilling design, and predicting formation fracturing behavior. Geostress refers to the natural stress field existing in the Earth's crustal rock layers, which is usually formed by the combined effects of factors such as gravity, tectonic movement, and formation deformation. Among these factors, the directional information of geostress is of great significance for analyzing formation mechanical properties, determining the direction of hydraulic fracturing, and controlling the risk of wellbore instability.

[0003] Currently, among the existing geostress measurement technologies, commonly used methods include hydraulic fracturing, acoustic emission Kessel effect method, strain release method (such as core stress relief method), etc. These methods usually rely on in-situ stress measurement inside the borehole or laboratory testing of rock core samples to invert the geostress state.

[0004] Especially when using strain sensors to determine the direction of ground stress, the flatness of the borehole wall directly affects the degree of contact between the sensor and the rock wall, and thus affects the accuracy of the measurement results. If the borehole wall is rough, has loose debris or irregular undulations, the sensor will not be able to accurately sense the true strain response of the formation, thus introducing a large measurement error. Summary of the Invention

[0005] The purpose of this invention is to address the problem in the prior art that the flatness of the borehole wall directly affects the degree of contact between the sensor and the rock wall, thereby affecting the accuracy of the measurement results. If the borehole wall is rough, contains loose debris or irregular undulations, the sensor will be unable to accurately sense the true strain response of the stratum, thus introducing a large measurement error. Therefore, this invention proposes a measuring device and method for determining the direction of geostress.

[0006] To achieve the above objectives, the present invention adopts the following technical solution:

[0007] A measuring device for determining the direction of ground stress includes a positioning rod, on which an element cylinder is fixedly mounted. A connecting sleeve is rotatably mounted at the end of the element cylinder away from the positioning rod. Coarse grinding plates are symmetrically mounted on the connecting sleeve. A driving component for driving the connecting sleeve to rotate forward is installed inside the element cylinder. The device also includes an inner cylinder with symmetrically arranged through holes on its outer surface. A limiting pin is slidably mounted in the through holes, and a fine grinding plate is fixedly mounted at the end of the limiting pin outside the inner cylinder. A partition is fixedly mounted inside the element cylinder, and a connecting rod is rotatably mounted on the partition. The connecting rod is connected to the inner cylinder via a connecting component. An L-shaped connecting arm is rotatably mounted on the connecting sleeve, with its two ends rotatably connected to the coarse grinding plate and the inner cylinder, respectively.

[0008] In order to provide a sliding guide path for the coarse grinding plate while realizing the elastic expansion and contraction function of the coarse grinding plate in the radial direction to adapt to the irregular surface of the drill hole wall, preferably, the connecting sleeve is fixedly installed with symmetrically arranged guide blocks, the guide blocks are provided with guide grooves on both sides, the coarse grinding plate is slidably installed on the guide blocks, and a first spring is fixedly connected between the coarse grinding plate and the inner side wall of the guide groove.

[0009] For grinding the borehole wall using a coarse grinding plate, preferably, the driving component includes: a connecting sleeve coaxially disposed inside the component cylinder, one end of which is fixedly mounted with a first wedge rod, and the side of the connecting sleeve away from the first wedge rod has a first oblique groove; a connecting rod, one end of which is fixed to the inner wall of the connecting sleeve, and the other end of which is slidably mounted with a second wedge rod via an elastic element; a support frame, fixedly mounted inside the component cylinder for supporting the connecting sleeve; a conical disc, rotatably mounted on the support frame, having a through groove at its center and toothed grooves evenly spaced along its circumferential direction on its edge, and a first elastic plate mounted on the side of the conical disc near the connecting sleeve; a motor fixedly mounted on the inner wall of the component cylinder, and a bevel gear mounted on the output end of the motor, the bevel gear meshing with the conical disc.

[0010] To provide stable support for the conical disc, a support rod is fixedly installed on the support frame, a slider is fixedly installed on the support rod, and a groove adapted to the slider is provided on the conical disc.

[0011] In order to drive the inner cylinder and the fine grinding plate to rotate and grind, a second inclined groove is further provided on the connecting rod, and a second elastic plate is installed on the inner wall of the through groove.

[0012] In order to control the movement of the inner cylinder and retract the coarse grinding plates on both sides, preferably, the connecting member includes spring seats respectively installed on the connecting rod and the bottom surface of the inner cylinder, a second spring is fixedly connected between the symmetrical spring seats, and an electromagnet is fixedly installed on the inner wall of each symmetrical spring seat.

[0013] To ensure that the fine grinding plate is located inside the coarse grinding plate during coarse grinding, and that the coarse grinding plates on both sides are restrained and retracted by the L-shaped connecting arms during fine grinding, the length of the limiting pin is L1, and the length of the guide groove is L2, where L1 < L2.

[0014] To cool the grinding device, a sealing plate is fixedly installed between the partition and the top wall of the component cylinder. A piston plate is slidably installed inside the sealing plate, and a trigger rod is fixedly installed on the piston plate. The end of the trigger rod away from the piston plate passes through the partition and is fixedly installed with a first wedge block. A vertical rod is fixedly installed on the connecting rod, and a second wedge block is fixedly installed on the vertical rod, abutting against the inclined surface of the first wedge block. The sealing plate has a water inlet and a water outlet. A water pipe is fixedly connected between the water outlet and the coarse grinding plate and the fine grinding plate. A one-way valve is installed in both the water pipe and the water inlet.

[0015] In order to effectively collect the dust and debris generated during the polishing process, preferably, one end of the connecting rod located inside the inner cylinder is provided with an air inlet, a filter screen is installed on the air inlet, the other end of the connecting rod is connected to a negative pressure air source, and an air inlet groove is provided on the inner cylinder.

[0016] A measurement method for determining the direction of ground stress includes the following steps:

[0017] Step 1: Use a drilling locator to precisely place the device in the predetermined position;

[0018] Step 2: Grind the hole wall after drilling;

[0019] Step 3: Add a water mist system to reduce the impact of dust and temperature;

[0020] Step 4: Place the strain measurement probe on the polished borehole wall.

[0021] Compared with the prior art, the present invention provides a measuring device and method for determining the direction of ground stress, which has the following advantages:

[0022] 1. This measuring device for determining the direction of ground stress rotates forward when the drive unit is activated, which in turn drives the connecting sleeve to rotate, causing the coarse grinding plate to rotate. Under the action of centrifugal force, the coarse grinding plate adaptively fits into the borehole wall, performing preliminary grinding on the borehole wall to remove loose rock debris and rough surfaces. The connecting component causes the L-shaped connecting arm to pull the inner cylinder upward and retract the coarse grinding plates on both sides. When the drive unit rotates in the opposite direction, the fine grinding plate is subjected to centrifugal force to contact the borehole wall, performing fine grinding on the basis of coarse grinding. The surface of the borehole wall after grinding is flat, which is suitable for subsequent bonding and measurement operations of strain sensors.

[0023] 2. The measuring device for determining the direction of ground stress generates a vertical thrust by the inclined contact between the first and second wedge blocks, which squeezes the piston plate. Coolant flows out through the water outlet and is transported to the surfaces of the coarse and fine grinding plates through the water pipe for cooling and lubrication.

[0024] 3. This measuring device for determining the direction of ground stress draws in air through the air inlet of the connecting rod, creating a negative pressure environment. The filter at the air inlet prevents large particles from entering the air path system. The negative pressure airflow enters the interior of the connecting rod through the air inlet, is transmitted to the inner cylinder through the connecting rod, and flows out from the air inlet groove. Dust and debris generated during the grinding process are adsorbed by the negative pressure airflow and discharged from the borehole along with the airflow. After grinding is completed, the negative pressure air source is turned off. Because the inner cylinder is detachable, the air inlet and air inlet groove can be cleaned to ensure unobstructed airflow for the next use. Attached Figure Description

[0025] Figure 1 This is a schematic diagram of the overall structure of a measuring device for determining the direction of ground stress proposed in this invention.

[0026] Figure 2 This is a schematic diagram of the internal structure of the component box of a measuring device for determining the direction of ground stress proposed in this invention;

[0027] Figure 3 This is a schematic diagram of the internal structure of the connecting sleeve of a measuring device for determining the direction of ground stress proposed in this invention;

[0028] Figure 4 This is a schematic diagram of the connecting rod structure of a measuring device for determining the direction of ground stress proposed in this invention;

[0029] Figure 5 This is a schematic diagram of the guide block structure of a measuring device for determining the direction of ground stress proposed in this invention;

[0030] Figure 6 This is a schematic diagram of a conical disk structure for a measuring device used to determine the direction of ground stress according to the present invention;

[0031] Figure 7 This is a schematic diagram of the inner cylinder structure of a measuring device for determining the direction of ground stress proposed in this invention;

[0032] Figure 8 This is a schematic diagram of the L-shaped connecting arm mounting position of a measuring device for determining the direction of ground stress proposed in this invention.

[0033] In the diagram: 1. Positioning rod;

[0034] 2. Component cylinder; 201. Partition plate; 202. Sealing plate; 2021. Water inlet; 2022. Water outlet;

[0035] 3. Connecting sleeve; 4. Coarse grinding plate;

[0036] 5. Driving component; 501. Connecting sleeve; 5011. First inclined groove; 502. First wedge rod; 503. Connecting rod; 5031. Second wedge rod; 5032. Fourth spring; 504. Support frame; 505. Conical disc; 5051. Through groove; 5052. Tooth groove; 5053. First elastic plate; 5054. Slide groove; 5055. Second elastic plate; 506. Motor; 507. Bevel gear; 508. Support rod; 509. Slider;

[0037] 6. Inner cylinder; 601. Through hole; 602. Air inlet slot;

[0038] 7. Limit pin; 701. Third spring;

[0039] 8. Fine grinding plate;

[0040] 9. Connecting rod; 901. Second inclined groove; 902. Air inlet; 903. Filter screen; 904. Platform section;

[0041] 10. L-shaped connecting arm;

[0042] 11. Guide block; 1101. Guide groove; 1102. First spring;

[0043] 12. Connecting component; 1201. Spring seat; 1202. Second spring; 1203. Electromagnet;

[0044] 13. Piston plate; 14. Trigger rod; 15. First wedge block; 16. Vertical rod; 17. Second wedge block; 18. Water pipe. Detailed Implementation

[0045] The technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments.

[0046] In the description of this invention, it should be understood that the terms "upper", "lower", "front", "rear", "left", "right", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0047] Example 1:

[0048] Reference Figures 1-8 A measuring device for determining the direction of ground stress includes a positioning rod 1 that can be inserted into the borehole and maintain a stable posture. An element cylinder 2 is fixedly installed on the positioning rod 1. A connecting sleeve 3 is rotatably installed at the end of the element cylinder 2 away from the positioning rod 1. A coarse grinding plate 4 is symmetrically installed on the connecting sleeve 3, allowing the coarse grinding plate 4 to rotate with it for preliminary grinding of the borehole wall. A driving component 5 for driving the connecting sleeve 3 to rotate in the forward direction is installed inside the element cylinder 2. The device also includes an inner cylinder 6 and an L-shaped connecting arm 10.

[0049] Specifically, the outer circular surface of the inner cylinder 6 is provided with symmetrically arranged through holes 601. A limit pin 7 is slidably installed in the through hole 601. A fine grinding plate 8 is fixedly installed at one end of the limit pin 7 outside the inner cylinder 6 to control the position change of the fine grinding plate 8. A third spring 701 is sleeved on the limit pin 7. The two ends of the third spring 701 are fixed to the end of the limit pin 7 and the inner wall of the inner cylinder 6, respectively, to drive the fine grinding plate 8 to reset. By performing fine grinding on the basis of coarse grinding, the flatness of the drilled hole wall is improved, providing good surface conditions for the adhesion of the strain sensor.

[0050] Specifically, a partition plate 201 is fixedly installed inside the component cylinder 2, and a connecting rod 9 is rotatably installed on the partition plate 201. The connecting rod 9 is connected to the inner cylinder 6 through a connector 12. A platform part 904 is slidably installed on the connecting rod 9, and the inner cylinder 6 is fixedly installed on the platform part 904 by bolts.

[0051] Specifically, the two ends of the L-shaped connecting arm 10 are rotatably connected to the coarse grinding plate 4 and the inner cylinder 6, respectively, to coordinate the sequence of coarse grinding and fine grinding actions and ensure the continuity and consistency of the grinding process.

[0052] This embodiment provides a measuring device for determining the direction of ground stress. In the initial state, the device is in a retracted state, which facilitates insertion into the borehole. The drive component 5 is activated to rotate forward, driving the connecting sleeve 3 to rotate, which in turn drives the coarse grinding plate 4 to rotate. Under the action of centrifugal force, the coarse grinding plate 4 adaptively fits into the borehole wall, performing preliminary grinding on the borehole wall to remove loose rock debris and rough surfaces. The connecting component 12 causes the L-shaped connecting arm 10 to pull the inner cylinder 6 upward and retract the coarse grinding plates 4 on both sides. The drive component 5 rotates in the opposite direction, and the fine grinding plate 8 is subjected to centrifugal force to contact the borehole wall, performing fine grinding on the basis of coarse grinding. The surface of the borehole wall after grinding is flat, which is suitable for subsequent bonding and measurement operations of strain sensors.

[0053] Example 2:

[0054] The measuring device provided in Embodiment 1 is further optimized, referring to... Figure 3 and Figure 5A symmetrically arranged guide block 11 is fixedly installed on the connecting sleeve 3. Guide grooves 1101 are opened on both sides of the guide block 11. The rough grinding plate 4 is slidably installed on the guide block 11 and a first spring 1102 is fixedly connected between it and the inner side wall of the guide groove 1101 to provide a restoring force. While providing a sliding guide path for the rough grinding plate 4, it also realizes the elastic extension and contraction function of the rough grinding plate 4 in the radial direction to adapt to the irregular surface of the drill hole wall.

[0055] Furthermore, the length of the limiting pin 7 is L1, and the length of the guide groove 1101 is L2, where L1 < L2.

[0056] With the above structure, the device is inserted into the target depth by positioning rod 1. Component cylinder 2 starts drive component 5, which drives connecting sleeve 3 to rotate. The rotation of connecting sleeve 3 drives coarse grinding plate 4 to rotate synchronously. Coarse grinding plate 4 expands outward under the combined action of centrifugal force and spring force, and contacts the borehole wall. If there are local protrusions or depressions in the borehole wall, coarse grinding plate 4 can slide in guide groove 1101 and achieve automatic adjustment by spring. The length of limit pin 7 is less than the length of guide groove 1101, so that when the device is coarsely grinding, fine grinding plate 8 is located inside coarse grinding plate 4. When finely grinding, the coarse grinding plates 4 on both sides are constrained and pulled back by the L-shaped connecting arm 10 and located inside fine grinding plate 8.

[0057] Example 3:

[0058] The measuring device provided in Embodiment 2 was further optimized, referring to... Figures 2-6 The driving component 5 includes a connecting sleeve 501, a connecting rod 503, a support frame 504, a conical disc 505, and a motor 506. Specifically, the connecting sleeve 501 is coaxially arranged inside the component cylinder 2. One end of the connecting sleeve 501 is fixedly installed with a first wedge rod 502, which forms a wedge linkage structure with the second wedge rod 5031. During the sliding process, a lateral force is generated to push the connecting sleeve 501 to rotate. The side of the connecting sleeve 501 away from the first wedge rod 502 is provided with a first inclined groove 5011, which is used to cooperate with other structures and guide the direction of movement.

[0059] One end of the connecting rod 503 is fixed to the inner wall of the connecting sleeve 3, and the other end is slidably mounted with a second wedge rod 5031 via an elastic element. The elastic element is preferably a fourth spring 5032, which allows for adaptive adjustment within a certain range. The second wedge rod 5031 and the first wedge rod 502 form a wedge-shaped contact surface, receive the thrust from the wedge linkage structure, and convert it into rotational motion.

[0060] The support frame 504 is fixedly installed inside the component cylinder 2 to support the connecting sleeve 501 and provide structural stability and rigid support.

[0061] The conical disc 505 is rotatably mounted on the support frame 504. It has a through groove 5051 at the center to facilitate the installation of other components. The edge is provided with toothed grooves 5052 at equal intervals along the circumferential direction. A first elastic piece 5053 is installed on the side of the conical disc 505 near the connecting sleeve 501. Furthermore, a support rod 508 is fixedly installed on the support frame 504, and a slider 509 is fixedly installed on the support rod 508. The conical disc 505 is provided with a sliding groove 5054 that matches the slider 509 to ensure that the conical disc 505 rotates smoothly and participates in linkage.

[0062] A motor 506 is fixedly installed on the inner wall of the component cylinder 2. A bevel gear 507 is installed on the output end of the motor 506. The bevel gear 507 meshes with the conical disk 505 to achieve vertical transmission.

[0063] With the above structure, the output end of the motor 506 rotates in the forward direction, and the bevel gear 507 drives the bevel disk 505 meshing with it to rotate synchronously. The first elastic plate 5053 is embedded in the first inclined groove 5011, which drives the connecting sleeve 501 to rotate accordingly. The first wedge rod 502 and the second wedge rod 5031 form contact on the horizontal surface, pushing the connecting rod 503 to move. The movement of the connecting rod 503 drives the connecting sleeve 3 to rotate, and the rough grinding plate 4 grinds the borehole wall.

[0064] Example 4:

[0065] The measuring device provided in Embodiment 2 or 3 is further optimized, referring to Figure 6 and Figure 7 The connecting rod 9 is the core transmission component connecting the conical disc 505 and the inner cylinder 6. The connecting rod 9 has a second inclined groove 901, and a second elastic plate 5055 is installed on the inner wall of the through groove 5051 to achieve the limiting function.

[0066] Specifically, the connector 12 includes spring seats 1201 respectively installed on the bottom surface of the connecting rod 9 and the inner cylinder 6. A second spring 1202 is fixedly connected between the symmetrical spring seats 1201 on the connecting rod 9. An electromagnet 1203 is fixedly installed on the inner wall of each symmetrical spring seat 1201. When energized, the electromagnet generates a magnetic attraction force, causing the spring seats 1201 to close and lock the position of the inner cylinder 6. When de-energized, the locking state is released, allowing the inner cylinder to move.

[0067] With the above structure, the output end of the motor 506 rotates in the opposite direction, and at the same time the electromagnet 1203 is energized, generating magnetic attraction between the spring seats 1201, compressing the second spring 1202, causing the inner cylinder 6 to move upward, and the L-shaped connecting arm 10 to rotate under force, causing the coarse grinding plates 4 on both sides to retract, while the fine grinding plate 8, under the action of centrifugal force, adheres to the inner wall of the drill hole and begins fine grinding.

[0068] Example 5:

[0069] The measuring device provided in the above embodiments can be further optimized, referring to... Figure 1 and Figure 2 A sealing plate 202 is fixedly installed between the partition 201 and the inner top wall of the component cylinder 2. A piston plate 13 is slidably installed inside the sealing plate 202. A trigger rod 14 is fixedly installed on the piston plate 13. One end of the trigger rod 14 away from the piston plate 13 passes through the partition 201 and is fixedly installed with a first wedge block 15. A vertical rod 16 is fixedly installed on the connecting rod 503. A second wedge block 17 that abuts against the inclined surface of the first wedge block 15 is fixedly installed on the vertical rod 16.

[0070] Specifically, the sealing plate 202 has an inlet hole 2021 and an outlet hole 2022. A water pipe 18 is fixedly connected between the outlet hole 2022 and the coarse grinding plate 4 and the fine grinding plate 8. A one-way valve is installed in both the water pipe 18 and the inlet hole 2021. The one-way valve in the inlet hole 2021 allows liquid to enter the sealing cavity from the outside. The one-way valve in the outlet hole 2022 prevents liquid backflow and ensures that the liquid flows to the water pipe 18.

[0071] With the above structure, whether the motor 506 rotates forward or backward, the first wedge block 15 and the second wedge block 17 make inclined contact, generating vertical thrust, squeezing the piston plate 13, and the coolant flows out through the water outlet 2022 and is transported to the surface of the coarse grinding plate 4 and the fine grinding plate 8 through the water pipe 18 for cooling and lubrication.

[0072] Example 6:

[0073] The measuring device provided in the above embodiments can be further optimized, referring to... Figure 7 The connecting rod 9 has an air inlet 902 at one end inside the inner cylinder 6. A filter screen 903 is installed on the air inlet 902 to prevent large particles of impurities from entering the air system. The other end of the connecting rod 9 is connected to a negative pressure air source. An air inlet groove 602 is provided on the inner cylinder 6 to form a uniformly distributed dust collection area that covers the entire grinding surface and effectively collects the dust and debris generated during the grinding process.

[0074] With the above structure, the motor 506 is started, driving the conical disk 505 to rotate, which in turn drives the coarse grinding plate 4 to perform preliminary grinding. During this process, the negative pressure air source is turned on. The negative pressure air source draws in air through the air inlet 902 of the connecting rod 9 to form a negative pressure environment. The filter screen 903 at the air inlet 902 blocks large particles from entering the air path system. The negative pressure airflow enters the interior of the connecting rod 9 through the air inlet 902. The airflow is transmitted to the inner cylinder 6 through the connecting rod 9 and flows out from the air inlet groove 602. The dust and debris generated during the grinding process are adsorbed by the negative pressure airflow and discharged from the drill hole along with the airflow. After grinding is completed, the negative pressure air source is turned off. Since the inner cylinder 6 is detachable, the air inlet 902 and the air inlet groove 602 can be cleaned to ensure that the air path is unobstructed for the next use.

[0075] A measurement method for determining the direction of ground stress includes the following steps:

[0076] Step 1: When the device is not started, it is in a retracted state, which makes it easy to insert into the borehole. The entire device is sent into the target borehole depth by positioning rod 1 and maintains a stable posture.

[0077] Step 2: Start the motor 506. The bevel gear 507 drives the conical disk 505 to rotate synchronously. The first elastic plate 5053 is embedded in the first inclined groove 5011 of the connecting sleeve 501, which drives the connecting sleeve 501 to rotate. The second wedge rod 5031 on the connecting rod 503 contacts the first wedge rod 502, which drives the connecting sleeve 3 to rotate. The rotation of the connecting sleeve 3 drives the symmetrically installed coarse grinding plate 4 to rotate synchronously. Under the combined action of centrifugal force and the first spring 1102 in the guide groove 1101, the coarse grinding plate 4 expands outward and fits against the borehole wall. The guide block 11 provides a sliding path, so that the coarse grinding plate 4 can adapt to irregular surfaces for adaptive grinding, initially removing rock chips, burrs and rough surfaces, laying the foundation for subsequent fine grinding.

[0078] Step 3: During the rough grinding process, the first wedge block 15 and the second wedge block 17 make inclined contact, pushing the trigger rod 14 to compress the piston plate 13. The coolant flows out from the sealed cavity through the water outlet 2022 and is transported to the surface of the rough grinding plate 4 through the water pipe 18 for cooling and lubrication.

[0079] Step 4: The negative pressure air source is turned on, and air is drawn in through the air inlet 902 of the connecting rod 9 to form a negative pressure environment. The dust and debris generated during grinding are adsorbed, enter the air circuit system through the air inlet groove 602 of the inner cylinder 6 and are discharged. The filter screen 903 prevents large particles of impurities from entering the air circuit.

[0080] Step 5: The output end of motor 506 rotates in the opposite direction, and the conical disk 505 rotates in the reverse direction, which drives the linkage mechanism of connecting rod 9 to move. The output end of motor 506 rotates in the opposite direction, and the conical disk 505 rotates in the reverse direction, which drives the linkage mechanism of connecting sleeve 501 and connecting rod 9 to move. The L-shaped connecting arm 10 rotates under force, which drives the coarse grinding plates 4 on both sides to return. Under the action of limit pin 7 and third spring 701, fine grinding plate 8 expands outward due to centrifugal force and fits against the borehole wall. Fine grinding plate 8 performs fine grinding on the borehole wall to improve flatness and provide good surface conditions for the fit of strain sensor.

[0081] Step 6: Coolant is continuously supplied to the surface of the fine grinding plate 8;

[0082] Step 7: The negative pressure air source continues to operate to ensure effective dust collection during the fine grinding process.

[0083] The above description is only a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art within the scope of the technology disclosed in the present invention, based on the technical solution and inventive concept of the present invention, should be covered within the scope of protection of the present invention.

Claims

1. A measuring device for determining the direction of ground stress, comprising a positioning rod (1), characterized in that, A component cylinder (2) is fixedly installed on the positioning rod (1). A connecting sleeve (3) is rotatably installed at one end of the component cylinder (2) away from the positioning rod (1). A coarse grinding plate (4) is symmetrically installed on the connecting sleeve (3). A driving component (5) for driving the connecting sleeve (3) to rotate in the forward direction is installed inside the component cylinder (2). The system also includes: The inner cylinder (6) has symmetrically arranged through holes (601) on its outer circular surface. A limiting pin (7) is slidably installed in the through hole (601). A fine grinding plate (8) is fixedly installed at one end of the limiting pin (7) located outside the inner cylinder (6). The component cylinder (2) is fixedly installed with a partition plate (201), and a connecting rod (9) is rotatably installed on the partition plate (201). The connecting rod (9) is connected to the inner cylinder (6) through a connector (12). An L-shaped connecting arm (10) is rotatably installed on the connecting sleeve (3). The two ends of the L-shaped connecting arm (10) are rotatably connected to the rough grinding plate (4) and the inner cylinder (6) respectively. The driving component (5) includes: a connecting sleeve (501) coaxially disposed within the component cylinder (2), one end of which is fixedly mounted with a first wedge rod (502), and the side of the connecting sleeve (501) away from the first wedge rod (502) having a first inclined groove (5011); a connecting rod (503), one end of which is fixed to the inner wall of the connecting sleeve (3), and the other end of which is slidably mounted with a second wedge rod (5031) via an elastic element; and a support frame (504), fixedly installed within the component cylinder (2) for supporting the drive component. Connecting sleeve (501); conical disc (505), rotatably mounted on the support frame (504), with a through groove (5051) at the center and toothed grooves (5052) evenly spaced along the circumferential direction at the edge, and a first elastic plate (5053) installed on the side of the conical disc (505) near the connecting sleeve (501); a motor (506) is fixedly mounted on the inner wall of the component cylinder (2), and a bevel gear (507) is mounted on the output end of the motor (506), and the bevel gear (507) meshes with the conical disc (505).

2. The measuring device for determining the direction of ground stress according to claim 1, characterized in that, The connecting sleeve (3) is fixedly installed with symmetrically arranged guide blocks (11). Guide grooves (1101) are opened on both sides of the guide blocks (11). The rough grinding plate (4) is slidably installed on the guide blocks (11) and a first spring (1102) is fixedly connected between it and the inner side wall of the guide groove (1101).

3. A measuring device for determining the direction of ground stress according to claim 1, characterized in that, A support rod (508) is fixedly installed on the support frame (504), and a slider (509) is fixedly installed on the support rod (508). A groove (5054) adapted to the slider (509) is opened on the conical disk (505).

4. A measuring device for determining the direction of ground stress according to claim 1, characterized in that, The connecting rod (9) has a second inclined groove (901), and a second elastic sheet (5055) is installed on the inner wall of the through groove (5051).

5. A measuring device for determining the direction of ground stress according to claim 1, characterized in that, The connector (12) includes a spring seat (1201) installed on the bottom surface of the connecting rod (9) and the inner cylinder (6) respectively. A second spring (1202) is fixedly connected between the symmetrical spring seats (1201). An electromagnet (1203) is fixedly installed on the inner wall of each symmetrical spring seat (1201).

6. A measuring device for determining the direction of ground stress according to claim 2, characterized in that, The length of the limiting pin (7) is L1, and the length of the guide groove (1101) is L2, where L1 < L2.

7. A measuring device for determining the direction of ground stress according to claim 1, characterized in that, A sealing plate (202) is fixedly installed between the partition (201) and the inner top wall of the component cylinder (2). A piston plate (13) is slidably installed inside the sealing plate (202). A trigger rod (14) is fixedly installed on the piston plate (13). One end of the trigger rod (14) away from the piston plate (13) passes through the partition (201) and is fixedly installed with a first wedge block (15). A vertical rod (16) is fixedly installed on the connecting rod (503). A second wedge block (17) is fixedly installed on the vertical rod (16) and abuts against the inclined surface of the first wedge block (15). The sealing plate (202) is provided with a water inlet (2021) and a water outlet (2022). A water pipe (18) is fixedly connected between the water outlet (2022) and the coarse grinding plate (4) and the fine grinding plate (8). A one-way valve is installed in both the water pipe (18) and the water inlet (2021).

8. A measuring device for determining the direction of ground stress according to claim 1, characterized in that, The connecting rod (9) has an air inlet (902) at one end inside the inner cylinder (6), a filter screen (903) is installed on the air inlet (902), and a negative pressure air source is connected to the other end of the connecting rod (9). An air inlet groove (602) is provided on the inner cylinder (6).

9. A measurement method for determining the direction of ground stress, comprising a measurement device for determining the direction of ground stress according to any one of claims 1-8, characterized in that, Includes the following steps: Step 1: Use a drilling locator to precisely place the device in the predetermined position; Step 2: Grind the hole wall after drilling; Step 3: Add a water mist system to reduce the impact of dust and temperature; Step 4: Place the strain measurement probe on the polished borehole wall.

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