A comprehensive intelligent identification method of transient electromagnetic in-situ magnetic monopole drilling

Abstract

The present invention discloses a magnetic monopole drilling transient electromagnetic omnidirectional intelligent identification method, wherein the axial positioning is performed by the shape of the radial component multi-track graph curve in M ​​shape or anti-M shape, and the shape of the axial component multi-track graph curve in S shape or anti-S shape, thereby obtaining the axial positioning of the abnormal body during the drilling process; then the magnetic monopole drilling transient electromagnetic device and the abnormal body are placed on the same drilling cross section and rotated, and the radial component has different sine and cosine shapes, and the center position of the abnormal body is determined to be the center position of the sine and cosine in the shape, and then the shape is used to calculate the angle information of the abnormal body relative to the drilling hole, and finally the azimuth information of the abnormal body in the whole space is obtained, thereby realizing the omnidirectional and accurate identification and judgment of the position of the abnormal body, and providing data support for the subsequent safe excavation of the tunnel.

Description

Technical Field

[0001] The invention relates to a magnetic monopole borehole transient electromagnetic omnidirectional intelligent identification method, which is applicable to the technical field of underground space geophysical detection. Background Art

[0002] The main methods for detecting underground geological structures are drilling and geophysical detection. Among them, the drilling method is the most direct and effective, but it has a high construction cost and is only a "one-hole view". After the structure conducts water, its resistivity becomes significantly lower than that of the surrounding rock, showing low-resistance anomaly characteristics, which provides a detection basis for the application of geophysical methods based on resistivity differences. The transient electromagnetic method has the advantages of high sensitivity to low-resistance anomalies and high resolution, and is widely used in exploring coal mine geological structures and their water-rich properties. Conventional mine transient electromagnetic methods are seriously affected by metal interference such as mining machines, anchor bolts, anchor nets and hydraulic supports because they complete transmission and reception in the tunnel. The collected secondary field data is easily distorted, which brings great difficulties to data interpretation, and the existing interference suppression methods have general processing effects.

[0003] The use of advance water exploration drilling holes in the tunneling tunnel to perform the borehole transient electromagnetic method to detect distant water-bearing bodies outside the borehole wall avoids the "one-hole view" of conventional logging methods that can only detect the rock formations on the borehole wall. However, the current borehole transient electromagnetic method is affected by the full-space effect, and the received single-component response cannot determine the orientation of the anomaly. Although the multi-component response can approximately determine the approximate orientation of the anomaly, it is difficult to accurately locate it through intuitive and effective methods such as mapping. Therefore, how to provide a method that can not only detect distant low-resistance anomalies outside the borehole wall through borehole transient electromagnetics, but also conduct all-round and accurate identification and judgment of the location of the anomaly in three components is a research direction of this industry. Summary of the invention

[0004] In view of the problems existing in the above-mentioned prior art, the present invention provides a magnetic monopole drilling transient electromagnetic all-round intelligent identification method, which utilizes a pair of mutually parallel and oppositely polarized magnetic dipoles to form a local magnetic monopole drilling transient electromagnetic device for drilling transient electromagnetic detection. It can not only detect low-resistance anomalies at a long distance outside the borehole wall, but also accurately identify and judge the position of the anomalies in all radial directions, thereby providing data support for subsequent safe tunneling.

[0005] In order to achieve the above purpose, the technical solution adopted by the present invention is: a magnetic monopole drilling transient electromagnetic omnidirectional intelligent identification method, the specific steps are:

[0006] Step 1: Detection drilling construction: Fix the magnetic monopole drilling transient electromagnetic device on the drill rod near the drill bit, determine the drilling position and path, and start construction through the drill bit to detect the drilling in advance;

[0007] Step 2: Acquisition of detection data: During the drilling process, the magnetic monopole drilling transient electromagnetic device transmits and receives transient electromagnetic data to the surrounding area in real time as the drill rod is drilled. Every time a certain distance is drilled, the magnetic monopole drilling transient electromagnetic device wirelessly transmits the received transient electromagnetic data to the ground data processing center;

[0008] Step 3, determine whether there is an abnormal body: the data processing center analyzes and processes the transient electromagnetic data obtained each time, and forms multi-channel graph curves in real time from the data obtained from the radial component and the axial component. If the shape of the multi-channel graph curve of the radial component is M-shaped and the shape of the multi-channel graph curve of the axial component is S-shaped during the drilling process, it is determined that there is an abnormal body around the borehole, and the drilling is stopped and the process goes to step 4; otherwise, the drilling work continues;

[0009] Step 4: Axial positioning of the abnormal body: determine the center position of the abnormal body to be the position corresponding to the center of the M shape and the S shape, and realize the axial positioning of the abnormal body along the detection drilling direction, and then drive the magnetic monopole drilling transient electromagnetic device to move in the borehole by retracting the drill bit until the magnetic monopole drilling transient electromagnetic device and the center position of the abnormal body are on the same cross section of the detection borehole and stop;

[0010] Step 5. Angle positioning of the anomaly in space: Start the drill bit to drive the magnetic monopole drilling transient electromagnetic device to rotate in the current section. The magnetic monopole drilling transient electromagnetic 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. According to the shape of the multi-track curve formed by the radial component of the detection data during the rotation process, the center position of the anomaly is determined to be the center position of the sine and cosine in the shape, and then the angle information of the anomaly relative to the borehole is calculated. Finally, according to the angle information and the axial positioning information determined in step 4, the orientation information of the anomaly in the entire space is finally obtained.

[0011] Furthermore, the magnetic monopole drilling transient electromagnetic device includes a host, a first transmitting coil, a second transmitting coil and a receiving coil. The first transmitting coil and the second transmitting coil are parallel and coaxial to each other. The host respectively passes equal and opposite currents into the two transmitting coils so that the surrounding magnetic fields partially cancel each other out to form a magnetic monopole emission source. The receiving coil is located at the midpoint of the first transmitting coil and the second transmitting coil, and is coaxial with the two transmitting coils. It is used to receive electromagnetic data and feed it back to the host. The host transmits data through a wireless communication module.

[0012] Furthermore, the receiving coil is a three-component receiving coil for receiving three-component electromagnetic data, namely x, y, and z components, wherein the x and y components are radial components, and the z component is an axial component.

[0013] Furthermore, the specific calculation process of the angle information of the abnormal body relative to the borehole in step 5 is as follows:

[0014] Assume the rotation angle is α, the specific formula is:

[0015]

[0016] Among them, V x0 ,V y0 are the normalized induced electromotive force of the x component and the y component respectively, are the induced electromotive force of x component and y component respectively;

[0017] According to the above formula, the rotation angle α of the abnormal body relative to the magnetic monopole drilling transient electromagnetic device during the rotation process is calculated; then the roll angle of the magnetic monopole drilling transient electromagnetic device is obtained. Finally, the true angle information η of the abnormal body relative to the borehole is calculated according to the following formula:

[0018]

[0019] Furthermore, the drill hole is a horizontal drill hole or a drill hole whose angle with the horizontal direction does not exceed 45°.

[0020] The working principle of the present invention is as follows: a magnetic monopole academically refers to a single magnetic pole with only a south pole or only a north pole. Currently, there are only magnetic dipoles in nature, that is, one side has a south pole and the other side has a north pole, and there are no magnetic monopoles. The inventor has found that when two transmitting coils of the same size are arranged coaxially and parallel to each other, and equal and opposite currents are respectively passed through the two transmitting coils, this method can make the surrounding magnetic fields partially cancel each other to form a magnetic monopole emission source. By arranging a receiving coil at the midpoint of the two transmitting coils, the electromagnetic data emitted by the magnetic monopole emission source can be obtained. Using this characteristic, a magnetic monopole drilling transient electromagnetic device is made. Figure 3 The side view of the magnetic field generated by the magnetic monopole drilling transient electromagnetic device is given. Two magnetic monopoles with opposite polarities (N pole or S pole) are formed by two magnetic dipoles. Figure 4 yes Figure 3 The top view of the magnetic field shows a diffuse shape, indicating that the magnetic monopoles generated by the magnetic monopole drilling transient electromagnetic device only have single magnetic pole properties. The inventor used this characteristic to further study and found that when the magnetic monopole drilling transient electromagnetic device continues to emit transient electromagnetic signals and moves along the drilling process, if there is an abnormal body around it, and this movement causes the magnetic monopole drilling transient electromagnetic device to move from close to the abnormal body to away from the abnormal body, at this time, the shape of the radial component multi-track graph curve is M shape or anti-M shape, the shape of the axial component multi-track graph curve is S shape or anti-S shape, and the center position of the abnormal body is the position corresponding to the center of the M shape and the center of the S shape. Using this discovery, the axial positioning of the abnormal body during the drilling process can be achieved;

[0021] In addition, the radial component is divided into x and y components, among which the cosine shape of the x component is just a kind of the sine shape of the y component, and the two components have the same interpretation effect; therefore, when the anomaly is located at different angles around the borehole, according to the reverse sign phenomenon of the magnetic monopole emission source excited by the magnetic monopole drilling transient electromagnetic device, it is concluded that the x and y components will have different sine and cosine shapes, and the center position of the anomaly is determined to be the center position of the sine and cosine in the shape, and then this feature is used to calculate the angle information of the anomaly relative to the borehole.

[0022] Compared with the prior art, the present invention utilizes the principle of discovery, wherein the axial positioning is performed by the shape of the radial component multi-track graph curve in M ​​shape or anti-M shape, and the shape of the axial component multi-track graph curve in S shape or anti-S shape, thereby obtaining the axial positioning of the abnormal body during the drilling process; then the magnetic monopole drilling transient electromagnetic device and the abnormal body are placed on the same drilling section, and then the magnetic monopole drilling transient electromagnetic device is rotated, and the radial component has different sine and cosine shapes, and the center position of the abnormal body is determined to be the center position of the sine and cosine in the shape, and then the shape is used to calculate the angle information of the abnormal body relative to the drilling hole, and finally the azimuth information of the abnormal body in the whole space is obtained. It has been proved by experiments that the positioning accuracy of the present invention is high, so that the present invention can not only detect the long-distance low-resistance abnormal body outside the borehole wall through the drilling transient electromagnetic, but also perform all-round and accurate identification and judgment of the position of the abnormal body in three parts, providing data support for the subsequent safe excavation of the tunnel. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 It is a schematic diagram of the hole rotation angle in the present invention;

[0024] Figure 2 It is a schematic diagram of the principle of forming a magnetic monopole by a magnetic monopole drilling transient electromagnetic device in the present invention;

[0025] Figure 3 It is a side view of the distribution of magnetic force lines of the primary field of the magnetic monopole formed by the present invention;

[0026] Figure 4 It is a top view of the magnetic field lines of the primary field of the magnetic monopole formed by the present invention;

[0027] Figure 5 It is a schematic diagram of detection for axial positioning using the present invention;

[0028] Figure 6 It is a detection schematic diagram of angle information positioning using the present invention;

[0029] Figure 7 It is a multi-track graph curve obtained during the axial positioning process of the present invention;

[0030] Figure 8It is a multi-track graph curve obtained in the angle information positioning process of the present invention;

[0031] Fig. 9 It is the multi-channel graph curve of the x-component of the radial component during the axial positioning of the abnormal body in the effect verification;

[0032] Fig.10 It is the multi-channel graph curve of the y component of the radial component during the axial positioning of the abnormal body in the effect verification;

[0033] Fig.11 It is the multi-channel graph curve of the z component as the axial component in the axial positioning process of the abnormal body in the effect verification;

[0034] Fig.12 It is a comparison diagram of the actual angle information and the calculated angle information of the underground anomaly in the experimental verification of the present invention.

[0035] In the figure: 1-first transmitting coil, 2-second transmitting coil, 3-receiving coil, 4-drilling hole, 5-abnormal body. DETAILED DESCRIPTION

[0036] The present invention will be further described below.

[0037] like Figure 1 , 5 As shown in 6, the specific steps of the present invention are:

[0038] Step 1, detection drilling construction: fix the magnetic monopole drilling transient electromagnetic device on the drill rod near the drill bit, determine the drilling position and path, and start the advance detection drilling through the drill bit; the drilling hole 4 is generally a horizontal drilling hole or a drilling hole with an angle of no more than 45° with the horizontal direction.

[0039] Step 2: Acquisition of detection data: During the drilling process, the magnetic monopole drilling transient electromagnetic device transmits and receives transient electromagnetic data to the surrounding area in real time as the drill rod is drilled. Every time a certain distance is drilled, the magnetic monopole drilling transient electromagnetic device transmits the received transient electromagnetic data wirelessly to the ground data processing center; Figure 2 As shown, the magnetic monopole drilling transient electromagnetic device includes a host, a first transmitting coil 1, a second transmitting coil 2 and a receiving coil 3. The first transmitting coil 1 and the second transmitting coil 2 are parallel and coaxial to each other. The host respectively passes equal and opposite currents into the two transmitting coils so that the surrounding magnetic fields partially cancel each other out to form a magnetic monopole emission source. The receiving coil 3 is located at the midpoint of the first transmitting coil 1 and the second transmitting coil 2 and is coaxial with the two transmitting coils. It is used to receive electromagnetic data and feed it back to the host. The host transmits data through a wireless communication module. The receiving coil 3 is a three-component receiving coil, which is used to receive three-component electromagnetic data, namely x, y, and z components. The x and y components are radial components, and the z component is an axial component.

[0040] Step 3: Determine whether there is an abnormal body: The data processing center analyzes and processes the transient electromagnetic data obtained each time, and forms multi-channel graph curves in real time based on the data obtained from the radial component and the axial component. If the shape of the multi-channel graph curve of the radial component is M-shaped and the shape of the multi-channel graph curve of the axial component is S-shaped during the drilling process, it is determined that there is an abnormal body around the borehole. Figure 7 As shown, stop drilling and proceed to step 4; otherwise, continue drilling;

[0041] Step 4: Axial positioning of the abnormal body: determine the center position of the abnormal body to be the position corresponding to the center of the M shape and the S shape, and realize the axial positioning of the abnormal body along the detection drilling direction, and then drive the magnetic monopole drilling transient electromagnetic device to move in the borehole by retracting the drill bit until the magnetic monopole drilling transient electromagnetic device and the center position of the abnormal body are on the same cross section of the detection borehole and stop;

[0042] Step 5: Anomaly spatial angle positioning: Start the drill bit to drive the magnetic monopole drilling transient electromagnetic device to rotate in the current section. The magnetic monopole drilling transient electromagnetic 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. According to the shape of the multi-track curve formed by the radial component in the detection data during the rotation process, the center position of the anomaly is determined to be the center position of the sine and cosine in the shape, and then the angle information of the anomaly relative to the borehole is calculated, such as Figure 8 As shown, the specific calculation process is:

[0043] Assume the rotation angle is α, the specific formula is:

[0044]

[0045] Among them, V x0 ,V y0 are the normalized induced electromotive force of the x component and the y component respectively, are the induced electromotive force of x component and y component respectively;

[0046] According to the above formula, the rotation angle α of the abnormal body relative to the magnetic monopole drilling transient electromagnetic device during the rotation process is calculated; then the roll angle of the magnetic monopole drilling transient electromagnetic device is obtained. Finally, the true angle information η of the abnormal body relative to the borehole is calculated according to the following formula:

[0047]

[0048] Finally, according to the angle information and the axial positioning information determined in step 4, the orientation information of the abnormal body in the entire space is finally obtained.

[0049] Effect verification:

[0050] In the laboratory, the anomaly 5 is buried in the experimental rock formation at a depth of 1m in advance. At this time, the position information of the anomaly in the experimental rock formation is known. Then, a hole 4 is drilled into the experimental rock formation. The magnetic monopole drilling transient electromagnetic device moves to the deep part of the experimental rock formation along with the drilling. In this process, the corresponding detection data are obtained. The data obtained from the radial component and the axial component are respectively formed into a multi-channel graph curve in real time as shown in FIG. Figures 9 to 11 As shown, according to the present invention, the axial positioning depth of the abnormal body calculated based on the center position of the S and M shapes is H=1m, and the axial positioning is accurate.

[0051] Because the drill rod connected to the drill bit has the scale spacing marked with yellow tape in advance, then the depth H=1m of the abnormal body is compared, and the drill rod with the spacing scale is slowly moved to make the magnetic monopole drilling transient electromagnetic device retreat in the borehole 4 to the same borehole section as the abnormal body 5, and then the magnetic monopole drilling transient electromagnetic device is rotated, and the shape of the multi-track curve formed by the radial component during the rotation process is obtained, and the center position of the abnormal body 5 is determined to be the center position of the sine and cosine in the shape, and then the angle information of the abnormal body 5 relative to the borehole is calculated. Among them, since the buried abnormal body is known Kong Zhou The azimuth angle θ, the formula calculates the angle information as η, such as Fig.12 The anomaly is set at a variety of different positions (i.e., the actual azimuth angle θ of the anomaly relative to the borehole is changed each time), and multiple tests are performed respectively. It is found that the linear regression coefficient R of the two sets of data of the angle information calculated by the present invention and the actual azimuth angle is 2 =0.99369≈1, indicating that the two sets of data are highly positively correlated, and the error after comparison is extremely small. Combined with the previously determined axial positioning information of the abnormal body, it is shown that the positioning accuracy of the orientation information of the abnormal body in the entire space of the present invention is relatively high.

[0052] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principle of the present invention. These improvements and modifications should also be regarded as the scope of protection of the present invention.

Claims

1. A magnetic monopole drilling transient electromagnetic omnidirectional intelligent identification method, characterized in that: The specific steps are: Step 1: Detection drilling construction: Fix the magnetic monopole drilling transient electromagnetic device on the drill rod near the drill bit, determine the drilling position and path, and start construction through the drill bit to detect the drilling in advance; Step 2: Acquisition of detection data: During the drilling process, the magnetic monopole drilling transient electromagnetic device transmits and receives transient electromagnetic data to the surrounding area in real time as the drill rod is drilled. Every time a certain distance is drilled, the magnetic monopole drilling transient electromagnetic device wirelessly transmits the received transient electromagnetic data to the ground data processing center; Step 3, determine whether there is an abnormal body: the data processing center analyzes and processes the transient electromagnetic data obtained each time, and forms multi-channel graph curves in real time from the data obtained from the radial component and the axial component. If the shape of the multi-channel graph curve of the radial component is M-shaped and the shape of the multi-channel graph curve of the axial component is S-shaped during the drilling process, it is determined that there is an abnormal body around the borehole, and the drilling is stopped and the process goes to step 4; otherwise, the drilling work continues; Step 4: Axial positioning of the abnormal body: determine the center position of the abnormal body to be the position corresponding to the center of the M shape and the S shape, and realize the axial positioning of the abnormal body along the detection drilling direction, and then drive the magnetic monopole drilling transient electromagnetic device to move in the borehole by retracting the drill bit until the magnetic monopole drilling transient electromagnetic device and the center position of the abnormal body are on the same cross section of the detection borehole and stop; Step 5. Angle positioning of the anomaly in space: Start the drill bit to drive the magnetic monopole drilling transient electromagnetic device to rotate in the current section. The magnetic monopole drilling transient electromagnetic 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. According to the shape of the multi-track curve formed by the radial component of the detection data during the rotation process, the center position of the anomaly is determined to be the center position of the sine and cosine in the shape, and then the angle information of the anomaly relative to the borehole is calculated. Finally, according to the angle information and the axial positioning information determined in step 4, the orientation information of the anomaly in the entire space is finally obtained.

2. The magnetic monopole drilling transient electromagnetic omnidirectional intelligent identification method according to claim 1 is characterized in that: The magnetic monopole drilling transient electromagnetic device includes a host, a first transmitting coil, a second transmitting coil and a receiving coil. The first transmitting coil and the second transmitting coil are parallel and coaxial to each other. The host respectively passes equal and opposite currents into the two transmitting coils so that the surrounding magnetic fields partially cancel each other out to form a magnetic monopole emission source. The receiving coil is located at the midpoint of the first transmitting coil and the second transmitting coil and is coaxial with the two transmitting coils. It is used to receive electromagnetic data and feed it back to the host. The host transmits data through a wireless communication module.

3. The magnetic monopole drilling transient electromagnetic omnidirectional intelligent identification method according to claim 2 is characterized in that: The receiving coil is a three-component receiving coil, which is used to receive three-component electromagnetic data, namely x, y, and z components, wherein the x and y components are radial components, and the z component is an axial component.

4. The magnetic monopole drilling transient electromagnetic omnidirectional intelligent identification method according to claim 1 is characterized in that: The specific calculation process of the angle information of the abnormal body relative to the borehole in step 5 is as follows: Assume the rotation angle is α, the specific formula is: ； in, are the normalized induced electromotive force of the x component and the y component respectively, , are the induced electromotive force of x component and y component respectively; According to the above formula, the rotation angle of the anomaly relative to the magnetic monopole drilling transient electromagnetic device during the rotation process is calculated. ; Then obtain the roll angle of the magnetic monopole drilling transient electromagnetic device Finally, the true angle information of the anomaly relative to the borehole is calculated according to the following formula: ; 。 5. The magnetic monopole drilling transient electromagnetic omnidirectional intelligent identification method according to claim 1 is characterized in that: The drill hole is a horizontal drill hole or a drill hole whose angle with the horizontal direction does not exceed 45°.

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