A borehole stress measurement device

Abstract

The utility model relates to the field of measurement technology especially, relates to a kind of borehole stress measuring device, to solve the problem that the existing borehole stress gauge and borehole linear contact lead to monitoring accuracy and reliability are insufficient. The utility model provides borehole stress measuring device including oil bladder pipe, first blanking plate, second blanking plate and oil pipe;Oil bladder pipe both ends are blocked by first blanking plate and second blanking plate and form hollow cavity;Oil pipe one end passes through second blanking plate and is communicated with hollow cavity, for injecting hydraulic oil into hollow cavity. The utility model provides borehole stress measuring device by injecting hydraulic oil into oil bladder pipe makes oil bladder pipe expand, so that the outer wall of oil bladder pipe and borehole inner wall are fully attached, form surface contact, avoid the problem that linear contact leads to monitoring accuracy and reliability are insufficient.

Description

Technical Field

[0001] This utility model relates to the field of measurement technology, and in particular to a borehole stress measuring device. Background Technology

[0002] In mining engineering, borehole stress monitoring is crucial for preventing disasters such as rockbursts. Compared with other methods, borehole stress monitoring can more directly and accurately reflect the stress state of the surrounding rock in the mine, providing an important basis for safe mining and stability assessment.

[0003] Traditional oil-pillar borehole stress gauges have poor coupling due to their linear contact with the borehole, making it difficult to obtain comprehensive and accurate stress information around the borehole in practical applications, thus limiting the accuracy and reliability of borehole stress monitoring. Utility Model Content

[0004] The purpose of this invention is to provide a borehole stress measuring device to solve the problem of insufficient monitoring accuracy and reliability caused by the linear contact between the existing borehole stress gauge and the borehole.

[0005] To solve the above-mentioned technical problems, the technical solution provided by this utility model is as follows:

[0006] This utility model provides a drilling stress measuring device, characterized in that it includes an oil bladder tube, a first plug plate, a second plug plate, and an oil pipe;

[0007] The two ends of the oil bladder tube are sealed by the first blocking plate and the second blocking plate, forming a hollow cavity;

[0008] One end of the oil pipe passes through the second plug plate and communicates with the hollow cavity, and is used to inject hydraulic oil into the hollow cavity.

[0009] In some alternative embodiments, the cross-section of the oil bladder tube is a regular polygon or a circle.

[0010] In some optional embodiments, the regular polygon has a number of sides, a∈[4, 12].

[0011] In some alternative embodiments, process grooves are provided on the sides of the regular polygon.

[0012] In some optional embodiments, the ratio of the circumcircle diameter of the regular polygon to the wall thickness of the oil bladder tube is b, where b ∈ [25, 45].

[0013] The ratio of the diameter of the circumcircle of the regular polygon to the diameter of the borehole is c, where c ∈ [0.91, 0.98].

[0014] The ratio of the diameter of the circumcircle of the regular polygon to the diameter of the fully expanded oil bladder tube is d, where d ∈ [0.82, 0.93].

[0015] In some alternative embodiments, the oil bladder tube is in a spiral shape extending along its length.

[0016] In some alternative embodiments, the oil bladder tube is made of 12Cr1MoV.

[0017] In some alternative embodiments, ...

[0018] In some optional embodiments, the oil bladder tube is twisted about its axis by an angle α along its length, where α ∈ [0°, 10°].

[0019] The technical effects achieved by this utility model, combining the above-mentioned technical solutions, are as follows:

[0020] The drilling stress measuring device provided by this utility model includes an oil bladder tube, a first blocking plate, a second blocking plate, and an oil pipe; both ends of the oil bladder tube are sealed by the first blocking plate and the second blocking plate to form a hollow cavity; one end of the oil pipe passes through the second blocking plate and communicates with the hollow cavity, and is used to inject hydraulic oil into the hollow cavity.

[0021] The borehole stress measuring device provided by this utility model expands the oil bladder tube by injecting hydraulic oil into it, thereby making the outer wall of the oil bladder tube fully fit with the inner wall of the borehole to form surface contact, thus avoiding the problem of insufficient monitoring accuracy and reliability caused by linear contact. Attached Figure Description

[0022] To more clearly illustrate the specific embodiments of this utility model or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this utility model. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0023] Figure 1 A schematic diagram of the borehole stress measuring device provided in this embodiment of the utility model;

[0024] Figure 2 This is a schematic diagram of the cross-section of the oil bladder tube;

[0025] Figure 3 This is a schematic diagram of the oil bladder tube.

[0026] Figure 4 This is a top view of the oil bladder tube.

[0027] Icons: 100, oil bladder tube; 200, first blocking plate; 300, second blocking plate; 400, oil pipe; 110, process groove. Detailed Implementation

[0028] To make the objectives, technical solutions, and advantages of the embodiments of this utility model clearer, the technical solutions of the embodiments of this utility model will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this utility model, and not all embodiments. The components of the embodiments of this utility model described and shown in the accompanying drawings can generally be arranged and designed in various different configurations.

[0029] The following detailed description, in conjunction with the accompanying drawings, outlines some embodiments of the present invention. Unless otherwise specified, the following embodiments and features can be combined with each other.

[0030] Traditional oil-filled borehole stress gauges have a single monitoring direction and poor coupling due to their linear contact with the borehole. In practical applications, it is difficult to obtain comprehensive and accurate stress information around the borehole, which limits the accuracy and reliability of borehole stress monitoring.

[0031] In view of this, the present invention provides a drilling stress measuring device, including an oil bladder tube 100, a first blocking plate 200, a second blocking plate 300, and an oil pipe 400; the two ends of the oil bladder tube 100 are blocked by the first blocking plate 200 and the second blocking plate 300 to form a hollow cavity; one end of the oil pipe 400 passes through the second blocking plate 300 and communicates with the hollow cavity, for injecting hydraulic oil into the hollow cavity.

[0032] The borehole stress measuring device provided by this utility model expands the oil bladder tube 100 by injecting hydraulic oil into it, thereby making the outer wall of the oil bladder tube 100 fully fit with the inner wall of the borehole to form surface contact, thus avoiding the problem of insufficient monitoring accuracy and reliability caused by linear contact.

[0033] The following combination Figures 1-4 The structure and shape of the borehole stress measuring device provided in this embodiment will be described in detail.

[0034] In this embodiment, the second blocking plate 300 is provided with a through hole. The oil pipe 400 passes through the through hole and communicates with the hollow cavity, and is connected to the second blocking plate 300 by welding.

[0035] In this embodiment, the oil bladder tube 100 is made of thin-walled alloy tube, that is, alloy steel. Specifically, its material can be 12Cr1MoV.

[0036] In this embodiment, the cross-section of the oil bladder tube 100 is either a regular polygon or a circle. The number of sides of the regular polygon is 'a'. Considering the actual processing and application, the preferred value range for 'a' is a∈[4, 12]. Obviously, 'a' is a positive integer. When 'a' approaches infinity, it becomes a circle.

[0037] When the cross-section of the oil bladder tube 100 is a regular polygon, a process groove 110 is provided on the side of the regular polygon, such as... Figure 2 As shown. The process groove 110 is used to improve the ability of the oil bladder tube 100 to resist external deformation when there is no oil pressure inside. More importantly, it realizes the expansion deformation when the inside is pressurized, so that the oil bladder tube 100 after expansion deformation can achieve good coupling contact with the inner wall of the borehole in the radial direction.

[0038] Similarly, when the cross-section of the oil bladder tube 100 is circular, process grooves 110 can be evenly distributed along the circumference.

[0039] It should be noted that using a circular cross-section for the 100mm oil bladder tube is less practical. This is because a circle is less prone to expansion, and when the diameter of the circular tube is small, poor coupling can occur, while when the diameter of the circular tube is large, installation becomes difficult.

[0040] To reduce stress concentration during processing and expansion deformation, smooth rounded corners are provided at the corners of the regular polygon, the process groove 110, and the connection between each side and the process groove 110.

[0041] When hydraulic oil is injected and expands, the oil bladder tube 100 expands into a round tube and makes full contact with the borehole.

[0042] In some optional embodiments, to ensure that the oil bladder tube 100 has optimal deformability and resistance to deformation, it is necessary to control the ratio b of the circumscribed circle diameter of the regular polygon to the wall thickness of the oil bladder tube 100, the ratio c of the circumscribed circle diameter of the regular polygon to the diameter of the borehole, and the ratio d of the circumscribed circle diameter of the regular polygon to the diameter of the fully expanded oil bladder tube 100.

[0043] Specifically, b∈[25, 45], c∈[0.91, 0.98], d∈[0.82, 0.93].

[0044] When the oil bladder tube is filled with oil and pressurized, the radial oil pressure causes the oil bladder tube 100 to expand outward. Since the radial force area is greater than the axial force area, the radial deformation precedes the axial deformation and the amount of deformation is greater than that of the axial deformation. When the wall thickness remains unchanged, the axial length shortens as the radial expansion deformation increases, which in turn causes the oil bladder tube 100 to move away from the bottom of the borehole and make it impossible to detect changes in axial stress.

[0045] In this embodiment, in order to monitor axial pressure and simultaneously monitor the radial and axial stresses of the borehole, thereby more accurately reflecting the stress state of the surrounding rock and providing important basis for safe mining and stability assessment, the oil bladder tube 100 is spirally extended along its length to compensate for the reduction in axial length during radial expansion. That is, the oil bladder tube 100 twists around its own axis, with a twist angle α along its length, α∈[0°, 10°]. Figure 3 , Figure 4 As shown.

[0046] Obviously, the torsion angle of the oil bladder tube 100 needs to be set according to actual needs, ensuring an appropriate amount of compensation.

[0047] When hydraulic oil is injected into the oil bladder tube 100 and it expands, its axial dimension shortens, and the spiral shape creates a certain dimensional redundancy. During expansion, the torsion of the oil bladder tube 100 is eliminated, and it elongates along its length, thus compensating for the length shortening caused by radial expansion. This ensures contact between the end of the oil bladder tube 100 and the bottom of the borehole, thereby enabling simultaneous monitoring of radial and axial stresses. In other words, during use, it ensures contact between the first blocking plate 200 and the bottom of the borehole.

[0048] The spiral shape is achieved by twisting a straight line at a certain angle. Through the spiral design, axial oil pressure straightens and elongates the spiral oil bladder tube 100°, compensating for the axial shortening caused by radial deformation. This ensures axial contact between the oil bladder and the coal and rock wall at the bottom of the borehole, thereby enabling the sensing of axial pressure.

[0049] In this embodiment, the oil pipe 400 is made of stainless steel, and the outer contours of the first blocking plate 200 and the second blocking plate 300 are consistent with the cross-sectional contours of the oil bladder pipe 100, and are regular polygons of equal size.

[0050] Compared to traditional oil conservators and polygonal oil bladders, the polygonal oil bladder tube 100, after deformation, has a larger coupling area with the borehole inner wall, allowing for more sensitive and precise sensing of pressure changes. The spiral oil bladder tube 100 can simultaneously sense radial pressure and monitor borehole axial stress.

[0051] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this utility model, and are not intended to limit it. Although the utility model has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of this utility model.

Claims

1. A borehole stress measuring device, characterized in that, It includes an oil bladder tube (100), a first plug plate (200), a second plug plate (300), and an oil pipe (400); The oil bladder tube (100) is sealed at both ends by the first blocking plate (200) and the second blocking plate (300) to form a hollow cavity; One end of the oil pipe (400) passes through the second plug plate (300) and communicates with the hollow cavity, for injecting hydraulic oil into the hollow cavity; The cross-section of the oil bladder tube (100) is a regular polygon or a circle; The ratio of the diameter of the circumcircle of the regular polygon to the wall thickness of the oil bladder tube (100) is b, where b ∈ [25, 45]. The ratio of the diameter of the circumcircle of the regular polygon to the diameter of the borehole is c, where c ∈ [0.91, 0.98]. The ratio of the diameter of the circumcircle of the regular polygon to the diameter of the fully expanded oil bladder tube (100) is d, where d ∈ [0.82, 0.93].

2. The borehole stress measuring device according to claim 1, characterized in that, The regular polygon has a number of sides, where a ∈ [4, 12].

3. The borehole stress measuring device according to claim 1, characterized in that, The regular polygon has process grooves (110) on its sides.

4. The borehole stress measuring device according to claim 3, characterized in that, The corners of the regular polygon, the process groove (110), and the connection between each side and the process groove (110) are all provided with smooth rounded corner transitions.

5. The borehole stress measuring device according to any one of claims 1-4, characterized in that, The oil bladder tube (100) is spiral-shaped, extending along its length.

6. The borehole stress measuring device according to any one of claims 1-4, characterized in that, The oil bladder tube (100) is made of 12Cr1MoV.

7. The borehole stress measuring device according to any one of claims 1-4, characterized in that, The oil bladder tube (100) is twisted about its axis, and the twist angle along its length is α, where α ∈ [0°, 10°].

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