An in-hole transient electromagnetic advanced detection device and method

Abstract

The present invention discloses a borehole transient electromagnetic advanced detection device and method. The detection head is used to provide the space for the rotation of the transient electromagnetic detection device, and the pushing and connecting mechanism is used to adjust the penetration depth of the detection head; the control mechanism is used to control the rotation of the transient electromagnetic detection device. Through control, the z-component of the transient electromagnetic detection device can be rotated and detected in different planes, and finally, at each measuring point position in the borehole, the -90° to +90° rotation superposition detection of the z-component of the transient electromagnetic detection device in multiple planes is realized. Then, for the data obtained by rotation superposition, the depth conversion correction formula is used to correct the depth coordinates on a line in a direction different from the borehole axis in the three-dimensional space to the borehole axis, so as to realize the one-to-one correspondence between the apparent resistivity and the depth D in the borehole direction, and finally complete the advanced detection process for 30 to 50 m in front of the borehole. It can utilize the existing transient electromagnetic detection device, which is not only convenient to implement but also can effectively reduce the borehole construction volume.

Description

Technical Field

[0001] The present invention relates to an advanced detection technology method, specifically an in-hole transient electromagnetic advanced detection device and method. Background Art

[0002] In roadway tunneling, it is crucial to pre-evaluate the geological conditions ahead. The hydrogeological conditions are an important aspect. There may be water-conducting types such as fault fracture zones with water conduction, water-conducting collapse columns, water accumulation in goafs, and karst water-rich areas in front of the tunneling. Common means for exploring adverse geological factors are drilling and geophysical prospecting. Although drilling has high precision, it has high costs, long time consumption, limited exploration range, and because multiple detection holes need to be drilled, the formed detection holes are also prone to becoming channels for concealed water-bearing bodies to enter the roadway, triggering secondary accidents. It is difficult to meet the actual production needs only with drilling. Geophysical exploration is widely used in water exploration due to its advantages such as low cost, large exploration range, and rapidity. Although there are many types of geophysical methods, such as seismic reflection wave method, direct current method, electromagnetic methods (transient electromagnetic method and radio wave cross-measurement in pits), Rayleigh surface wave method, ground penetrating radar, radioactive measurement, and infrared temperature measurement, etc., due to the sensitive characteristics of various methods themselves, the spatial limitations of roadway tunneling, and external influences such as metal bolt support, most methods are difficult to be applied at the tunneling working face.

[0003] Based on the above situation, conventional transient electromagnetic detection devices on the market can detect the drilling holes being drilled in the tunneling tunnel, roadway heading, and working face by means of drilling holes, but are also limited to the detection around the holes, that is, the length of the drilling hole is how much, and the axial detection depth is how much. In addition, in actual projects, when the geological conditions are poor, the hole-forming quality is also correspondingly poor, and the phenomenon of hole collapse is prone to occur, resulting in low actual utilization rate of the drilling holes. Therefore, whether the drilling holes provided by the construction party can be fully utilized, the utilization rate of the drilling holes can be improved, and true advanced detection based on the length of the drilling hole is an urgent problem to be solved.

[0004] Therefore, how to provide a new device and method that can not only detect around the drilling holes being drilled in the tunneling tunnel, roadway heading, and working face, but also conduct advanced detection in front of the head of the drilling hole, and finally form an effective detection and prediction that is 30 - 50 m longer than the axial length of the drilling hole is the research direction required by the present invention. Summary of the Invention

[0005] Aiming at the problems existing in the above-mentioned prior art, the present invention provides an in-hole transient electromagnetic advanced detection device and method, which can effectively solve the above technical problems.

[0006] To achieve the above object, the technical solution adopted by the present invention is: an in-hole transient electromagnetic advanced detection device, including a detection head, a pushing and connecting mechanism, a control mechanism, and a transient electromagnetic detection device;

[0007] The detection head, the pushing connection mechanism, and the control mechanism are all cylindrical and coaxially connected. A plurality of guiding rings I are fixed to the inner wall of the detection head. Each guiding ring I is penetrated by a push rod I, and each push rod I can move along the axial direction of the detection head. The transient electromagnetic detection device is installed in the detection head and is movably connected to one end of each push rod I. The transient electromagnetic detection device is used to emit transient electromagnetic signals to the surroundings and receive the detected data in feedback.

[0008] A plurality of guiding rings II are fixed to the inner wall of the pushing connection mechanism. Each guiding ring II is penetrated by a push rod II, so that each push rod II can move along the axial direction of the pushing connection mechanism, and one end of each push rod II is coaxially connected to the other end of its corresponding push rod I respectively.

[0009] A plurality of guiding rings III are fixed to the inner wall of the control mechanism. Each guiding ring III is penetrated by a push rod III, and each push rod III can move along the axial direction of the control mechanism. One end of each push rod III is coaxially connected to the other end of its corresponding push rod II respectively. When a thrust or a pull force is applied to the other end of any push rod III, the push rod III can drive the coaxial push rod II and push rod I, and further turn the detection direction of the transient electromagnetic detection device. By applying a thrust or a pull force to the other end of different push rods III, the steering control of the detection direction of the transient electromagnetic detection device is realized.

[0010] Furthermore, there are four push rods I, push rods II, and push rods III respectively, and the push rods I are evenly distributed in the same cross-section of the detection head.

[0011] Furthermore, one end of the push rod I is connected to the transient electromagnetic detection device through a universal joint, which is convenient for the push rod to drive the transient electromagnetic detection device to rotate when pushing and pulling.

[0012] Furthermore, the receiver of the transient electromagnetic detection device is a three-component receiving coil.

[0013] Furthermore, the coaxial push rod I and push rod II, and the push rod II and push rod III are connected by mortise and tenon joints. This method is convenient for connection and has good stability after connection.

[0014] Furthermore, there are a plurality of pushing connection mechanisms, and the plurality of pushing connection mechanisms are coaxially connected. In this way, the corresponding number of pushing connection mechanisms can be selected according to the drilling depth to ensure the stable progress of detection.

[0015] The working method of the above transient electromagnetic advanced detection device in the hole is specifically as follows:

[0016] Step 1: Detection drilling construction: Drill a hole with a certain depth in the required detection direction. The diameter of the hole is larger than the transient electromagnetic advanced detection device, and the hole washing and hole cleaning work is done well to ensure that the transient electromagnetic advanced detection device can extend into the hole.

[0017] Step 2: Plan the measuring points and determine the number of push-connection mechanisms: According to the length of the borehole constructed in step 1, plan the number of measuring points in the borehole and the spacing between adjacent measuring points, and determine the number of push-connection mechanisms according to the length of the borehole;

[0018] Step 3, acquisition of detection data: With the borehole axial direction as the z-axis, the x-axis and y-axis are set perpendicular to each other in the cross section of the borehole to establish an xyz coordinate system, the transient electromagnetic advance detection device is placed in the borehole and extended along the borehole, and the detection head is stopped after it is advanced to the first measuring point. Initially, the three-component receiving coils of the transient electromagnetic detection device are parallel to the x, y and z axes respectively; by pushing and pulling the push-pull rods III of the control mechanism, the transient electromagnetic detection device is driven to turn, so that the transient electromagnetic detection device first rotates in the yz plane with the x-axis as the axis at the measuring point (that is, the z component of the transient electromagnetic detection device is in yz plane), and after completion, the initial position is restored, and then the transient electromagnetic detection device is rotated in the xz plane with the y axis as the axis at the position of the measuring point (that is, the z component of the transient electromagnetic detection device rotates in the xz plane), and during each rotation process, the transient electromagnetic detection device transmits and receives transient electromagnetic detection data to the surrounding in real time, and wirelessly transmits the received detection data to the ground data processing center, thereby completing the detection process of the first measuring point; then the transient electromagnetic advance detection device is advanced to the next measuring point, and the detection process of the first measuring point is repeated at each measuring point until the detection of all measuring points in the borehole is completed;

[0019] Step 4: Obtaining angle information: During the process of rotating detection at each measuring point, the transient electromagnetic detection device records the angle of two rotations of each measuring point;

[0020] Step 5, depth conversion correction: according to the detection data obtained in steps 3 and 4, the three-dimensional apparent resistivity software provided by the transient electromagnetic detection device is used to perform depth inversion. The depth inversion results in that the three-dimensional coordinates of the depth of any point on a line in the three-dimensional space model with the end of the detection head as the reference point in the xyz coordinate system are D(x, y, z). On this line, the apparent resistivity ρ and the depth D correspond one to one. The depth conversion correction formula is used to correct the depth coordinates on a line in a different direction from the borehole axis in the three-dimensional space to the axis of the borehole, that is, the z-axis of the xyz coordinate system, so as to achieve a one-to-one correspondence between the apparent resistivity and the ρ depth D in the borehole direction, and finally complete the advance detection process in front of the borehole.

[0021] Furthermore, the depth conversion correction formula in step 5 is specifically as follows: Assume that the angle of rotation about the x-axis is The angle of rotation about the y-axis is θ; the specific calculation process of the three transformed coordinates is:

[0022]

[0023] Further, the angle range of each rotation in step 3 is -90° to +90°.

[0024] The innovative principle of the present invention is as follows: Conventional borehole transient electromagnetic detection is restricted by the borehole. The detection length is the same as the borehole length, and it is impossible to conduct further advanced detection. Moreover, when receiving three components of the conventional borehole transient electromagnetic, since only the abnormal bodies around the borehole in the radial direction are detected, that is, only the transient electromagnetic signals of the radial components (X component, Y component) are detected, and the same is true for the later imaging. An image is formed with the abscissa being the borehole length (i.e., the pushing depth of the probe) and the ordinate being the detection depth. A large amount of information about the dip angle and trend of the underground space in the axial component Z for forward detection is ignored. This application fully utilizes the Z component through the multi-directional rotation method, achieving borehole transient electromagnetic advanced detection beyond the borehole length.

[0025] Compared with the prior art, the present invention combines a detection head, a pushing and connecting mechanism, a control mechanism, and a transient electromagnetic detection device. The detection head is used to hold the transient electromagnetic detection device and provide a space for the rotation of the transient electromagnetic detection device. The pushing and connecting mechanism is used to adjust the penetration depth of the detection head and coaxially connect the detection head and the control mechanism for subsequent rotational detection. The control mechanism is used to control the rotation of the transient electromagnetic detection device. Through control, the Z component of the transient electromagnetic detection device can be rotated and detected in different planes. Finally, a -90° to +90° rotational superposition detection process of the Z component of the transient electromagnetic detection device in multiple planes is realized at each measuring point position in the borehole. Then, the data obtained from the rotational superposition is processed using a depth conversion correction formula to correct the depth coordinates on a line in a direction different from the borehole axis in three-dimensional space to the borehole axis, thereby achieving a one-to-one correspondence between the apparent resistivity and the depth D in the borehole direction, and finally completing the advanced detection process for 30 - 50 m in front of the borehole. The present invention can achieve advanced detection beyond the borehole length by using the existing transient electromagnetic detection device, which is not only easy to implement but also can effectively reduce the borehole construction volume. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 is a schematic structural diagram of the present invention;

[0027] Figure 2 is a schematic diagram of depth conversion correction of the present invention.

[0028] In the figure: 1 - transient electromagnetic detection device, 2 - push rod, 3 - angle measurement tool, 4 - upper push rod, 5 - lower push rod, 6 - left push rod, 7 - right push rod. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0029] The present invention will be further described below.

[0030] AsFigure 1 As shown in the figure, a transient electromagnetic advanced detection device in a hole includes a detection head, a pushing and connecting mechanism, a control mechanism, and a transient electromagnetic detection device 1; the receiver of the transient electromagnetic detection device 1 is a three-component receiving coil.

[0031] The detection head, the pushing and connecting mechanism, and the control mechanism are all cylindrical and coaxially connected. A plurality of guiding rings I are fixed on the inner wall of the detection head. Each guiding ring I is penetrated by a push rod I, and each push rod I can move along the axial direction of the detection head. The transient electromagnetic detection device 1 is installed in the detection head, and the transient electromagnetic detection device 1 is movably connected to one end of each push rod I; the transient electromagnetic detection device 1 is used to emit transient electromagnetic signals to the surroundings and receive the detected data fed back.

[0032] A plurality of guiding rings II are fixed on the inner wall of the pushing and connecting mechanism. Each guiding ring II is penetrated by a push rod II, so that each push rod II can move along the axial direction of the pushing and connecting mechanism, and one end of each push rod II is coaxially connected to the other end of its corresponding push rod I respectively;

[0033] A plurality of guiding rings III are fixed on the inner wall of the control mechanism. Each guiding ring III is penetrated by a push rod III, and each push rod III can move along the axial direction of the control mechanism. One end of each push rod III is coaxially connected to the other end of its corresponding push rod II respectively; when a thrust or a pull force is applied to the other end of any push rod III, the push rod III can drive the push rod II and the push rod I coaxial with it, and further turn the detection direction of the transient electromagnetic detection device 1. By applying a thrust or a pull force to the other ends of different push rods III, the turning control of the detection direction of the transient electromagnetic detection device 1 is realized;

[0034] There are four push rods I, push rods II, and push rods III respectively, and the push rods I are evenly distributed in the same cross-section of the detection head. One end of the push rod I is connected to the transient electromagnetic detection device 1 through a universal joint. The coaxial push rod I and push rod II, and the push rod II and push rod III are connected by mortise and tenon joints. There are a plurality of pushing and connecting mechanisms, and the plurality of pushing and connecting mechanisms are coaxially connected.

[0035] The working method of the above transient electromagnetic advanced detection device in a hole specifically includes the following steps:

[0036] Step 1: Detection drilling construction: Drill a hole with a certain depth in the required detection direction, and the diameter of the hole is more than 5 mm larger than the diameter of the transient electromagnetic advanced detection device, and do a good job in hole washing and hole cleaning to ensure that the transient electromagnetic advanced detection device can extend into the hole.

[0037] Step 2. Planning measurement points and determining the number of pushing and connecting mechanisms: According to the drilling length constructed in Step 1, plan the number of each measurement point in the borehole and the spacing between adjacent measurement points, and determine the number of pushing and connecting mechanisms according to the drilling length.

[0038] Step 3. Acquisition of detection data: Establish an xyz coordinate system with the axial direction of the borehole as the z-axis and the x-axis and y-axis perpendicular to the cross-section of the borehole. Place the transient electromagnetic advanced detection device into the borehole and extend it along the borehole. When the detection head advances to the position of the first measurement point and stops advancing, initially, the three-component receiving coils of the transient electromagnetic detection device (i.e., the x-component, y-component, and z-component) are respectively parallel to the x, y, and z axes; by pushing and pulling different push rods III of the control mechanism, drive the transient electromagnetic detection device 1 to turn. Specifically, divide the four push rods III. Determine the two push rods III on the y-axis as the upper push rod 4 and the lower push rod 5 according to the positional relationship, and determine the two push rods III on the x-axis as the left push rod 6 and the right push rod 7 according to the positional relationship. Keep the left push rod 6 and the right push rod 7 stationary. By simultaneously pushing or pulling the upper push rod 4 and pulling or pushing the lower push rod 5, make the transient electromagnetic detection device 1 rotate around the x-axis in the yz plane at this measurement point position (i.e., the z-component of the transient electromagnetic detection device 1 rotates in the yz plane). After completion, restore to the initial position. Then, keep the upper push rod 4 and the lower push rod 5 stationary. By simultaneously pushing or pulling the left push rod 6 and pulling or pushing the right push rod 7, make the transient electromagnetic detection device 1 rotate around the y-axis in the xz plane at this measurement point position (i.e., the z-component of the transient electromagnetic detection device 1 rotates in the xz plane). The angle range of each rotation of the transient electromagnetic detection device 1 is -90° to +90°; and during each rotation process, the transient electromagnetic detection device 1 emits and receives transient electromagnetic detection data in real time to the surrounding area, and wirelessly transmits the received detection data to the ground data processing center. Thus, the transient electromagnetic detection device 1 completes the -90° to +90° rotation superposition detection process of the axial z-component of the first measurement point in multiple planes; then the transient electromagnetic advanced detection device advances to the next measurement point, and each measurement point repeats the detection process of the first measurement point until the detection of all measurement points in the borehole is completed.

[0039] Step 4. Acquisition of angle information: During the rotation detection process of the transient electromagnetic detection device 1 at each measurement point, use the angle measurement tool 3 to record the angles of the two rotations at each measurement point.

[0040] Step Five: Depth Conversion and Correction: Use the three-dimensional apparent resistivity software built into the transient electromagnetic detection device 1 to perform depth inversion based on the detection data obtained in Steps Three and Four. The depth inversion yields the three-dimensional depth coordinates D(x, y, z) of any point on a certain line in the three-dimensional space model with the end of the detection head as the reference point. On this line, the apparent resistivity ρ and the depth D correspond one-to-one. Use the depth conversion and correction formula to correct the depth coordinates on a line in a different direction from the borehole axis in the three-dimensional space to the borehole axis, that is, the z-axis of the xyz coordinate system, so as to achieve a one-to-one correspondence between the apparent resistivity and the depth D in the borehole direction. As Figure 2 shown, specifically: Let the angle of rotation around the x-axis be and the angle of rotation around the y-axis be θ; The specific calculation process of the three converted coordinates is as follows:

[0041]

[0042] Finally, the advanced detection process for 30 to 50 m in front of the borehole is completed.

[0043] The above is only the preferred implementation mode of the present invention. It should be noted that for those of ordinary skill in the art, without departing from the principle of the present invention, several improvements and refinements can be made, and these improvements and refinements should also be regarded as the protection scope of the present invention.

Claims

1. A transient electromagnetic advanced detection device in a borehole, characterized in that It includes a detection head, a pushing and connecting mechanism, a control mechanism and a transient electromagnetic detection device; The detection head, the pushing and connecting mechanism and the control mechanism are all cylindrical and coaxially connected. A plurality of guiding rings I are fixed on the inner wall of the detection head. Each guiding ring I is penetrated by a push rod I, and each push rod I can move along the axial direction of the detection head. The transient electromagnetic detection device is installed in the detection head and is movably connected to one end of each push rod I; the transient electromagnetic detection device is used to emit transient electromagnetic signals to the surroundings and receive the detected data in feedback; A plurality of guiding rings II are fixed on the inner wall of the pushing and connecting mechanism. Each guiding ring II is penetrated by a push rod II, so that each push rod II can move along the axial direction of the pushing and connecting mechanism, and one end of each push rod II is coaxially connected to the other end of the corresponding push rod I respectively; A plurality of guiding rings III are fixed on the inner wall of the control mechanism. Each guiding ring III is penetrated by a push rod III, and each push rod III can move along the axial direction of the control mechanism. One end of each push rod III is coaxially connected to the other end of the corresponding push rod II respectively; there are four push rods I, push rods II and push rods III respectively, and the push rods I are evenly distributed in the same cross section of the detection head; when a thrust or a pull force is applied to the other end of any push rod III, the push rod III can drive the push rod II and the push rod I coaxial with it, and further turn the detection direction of the transient electromagnetic detection device. By applying a thrust or a pull force to the other end of different push rods III, the steering control of the detection direction of the transient electromagnetic detection device is realized.

2. The borehole transient electromagnetic advanced detection device according to claim 1, characterized in that One end of the push rod I is connected to the transient electromagnetic detection device through a universal joint.

3. The borehole transient electromagnetic advanced detection device according to claim 1, characterized in that, The receiver of the transient electromagnetic detection device is a three-component receiving coil.

4. The borehole transient electromagnetic advanced detection device according to claim 1, characterized in that The coaxial push rod I and push rod II, and the push rod II and push rod III are connected by mortise and tenon joints.

5. The transient electromagnetic wave ahead detection device in borehole according to claim 1, characterized in that There are a plurality of pushing and connecting mechanisms, and the plurality of pushing and connecting mechanisms are coaxially connected.

6. A working method of the transient electromagnetic wave ahead detection device in borehole according to claim 1, characterized in that, The specific steps are as follows: Step 1: Detection drilling construction: Drill a hole with a certain depth in the required detection direction. The diameter of the hole is larger than the transient electromagnetic advance detection device, and the hole washing and hole cleaning work is done to ensure that the transient electromagnetic advance detection device can extend into the hole; Step 2: Plan the measuring points and determine the number of pushing and connecting mechanisms: According to the length of the hole drilled in Step 1, plan the number of each measuring point in the hole and the distance between adjacent measuring points, and determine the number of pushing and connecting mechanisms according to the length of the hole; Step 3, acquisition of detection data: with the borehole axial direction as the z axis, the x axis and the y axis are set perpendicular to each other in the cross section of the borehole to establish an xyz coordinate system, the transient electromagnetic advance detection device is placed in the borehole and extended along the borehole, and the detection head stops advancing when it is advanced to the first measuring point. Initially, the three-component receiving coils of the transient electromagnetic detection device are parallel to the x, y and z axes respectively; by pushing and pulling the push-pull rods III of the control mechanism, the transient electromagnetic detection device is driven to turn, so that the transient electromagnetic detection device rotates in the yz plane with the x axis as the axis at the measuring point, and then restores the initial position after completion, and then the transient electromagnetic detection device rotates in the xz plane with the y axis as the axis at the measuring point, and during each rotation, the transient electromagnetic detection device transmits and receives transient electromagnetic detection data to the surrounding in real time, and wirelessly transmits the received detection data to the ground data processing center, thereby completing the detection process of the first measuring point; then the transient electromagnetic advance detection device is advanced to the next measuring point, and each measuring point repeats the detection process of the first measuring point until the detection of all measuring points in the borehole is completed; Step 4: Obtaining angle information: During the process of rotating detection at each measuring point, the transient electromagnetic detection device records the angle of two rotations of each measuring point; Step 5, depth conversion correction: according to the detection data obtained in steps 3 and 4, the three-dimensional apparent resistivity software provided by the transient electromagnetic detection device is used to perform depth inversion. The depth inversion results in that the three-dimensional coordinates of the depth of any point on a line in the three-dimensional space model with the end of the detection head as the reference point in the xyz coordinate system are D(x, y, z). On this line, the apparent resistivity ρ and the depth D correspond one to one. The depth conversion correction formula is used to correct the depth coordinates on a line in a different direction from the borehole axis in the three-dimensional space to the axis of the borehole, that is, the z-axis of the xyz coordinate system, so as to achieve a one-to-one correspondence between the apparent resistivity and the ρ depth D in the borehole direction, and finally complete the advance detection process in front of the borehole.

7. The working method according to claim 6, characterized in that, The specific formula for deep conversion correction in the fifth step is as follows: Let the angle of rotation about the x-axis be φ , and the angle of rotation about the y-axis be θ ; The specific calculation process for the three coordinates after conversion is as follows: 。 8. The working method according to claim 6, characterized in that, The angle range of each rotation in step 3 is -90° to +90°.

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