阅读说明：本技术 电性源矿井瞬变电磁法探测方法 (Electric source mine transient electromagnetic method detection method ) 是由 苏本玉 于景邨 于 2021-01-08 设计创作，主要内容包括：本发明公开了一种电性源矿井瞬变电磁方法,适用于矿井巷道内使用。首先在矿井巷道内布设长导线电性源,通过电极激发电磁场,在工作面另一侧巷道内布置电场传感器接收电磁场信号,进而对工作面富水区域进行探测；导线电性源为接触式电流源探测,有效减少巷道内金属干扰,提高探测的定向性,改善探测的准确率。其有效弥补小线圈发射的能量不足问题,改善全空间‘镜面效应’的多解性问题,通过接触式电流源探测的导线电性源,有效减少巷道内金属干扰,提高探测的定向性,改善探测的准确率。(The invention discloses a mine transient electromagnetic method for an electrical source, which is suitable for being used in a mine roadway. Firstly, arranging a long lead electric source in a mine roadway, exciting an electromagnetic field through an electrode, arranging an electric field sensor in the roadway on the other side of a working face to receive an electromagnetic field signal, and further detecting a water-rich area of the working face; the wire electrical source is detected for the contact current source, effectively reduces the interior metal interference of tunnel, improves the directionality of surveying, improves the rate of accuracy of surveying. The problem of insufficient energy emitted by a small coil is effectively solved, the problem of multi-solution of the 'mirror effect' of the whole space is improved, metal interference in a roadway is effectively reduced through a wire electrical source detected by a contact current source, the detection directionality is improved, and the detection accuracy is improved.)

1. A mine electric source transient electromagnetic detection method is characterized by comprising the following steps: laying a lead current source in a roadway arranged on one side of a working face coal rock layer along the trend of the roadway, arranging electric field sensors on the coal rock layer wall of the roadway arranged on the other side of the coal rock layer at intervals according to the trend of the roadway, and determining the number and the interval of the electric field sensors according to the length of the working face coal rock layer; the wire current source transmits an electromagnetic field signal to a working face coal rock layer under the control of the industrial and mining host, the transmitted electromagnetic field signal is a primary electromagnetic field signal, a secondary electromagnetic field signal carrying stratum information is formed after the primary electromagnetic field signal meets a low-resistance abnormal body, the secondary electromagnetic field signal penetrates through the whole working face coal rock layer and is received by an electromagnetic field sensor arranged on the wall of the coal rock layer, the electromagnetic field sensor only receives the secondary electromagnetic field signal, and the electromagnetic field sensor transmits the received secondary electromagnetic field signal to the industrial and mining host, so that the specific position and the profile shape of the low-resistance abnormal body in the coal rock layer are confirmed.

2. The mine electrical source transient electromagnetic detection method of claim 1, wherein: the low-resistance abnormal body is water contained in the coal rock layer, the water serving as the good-conductivity geological body can generate induction secondary signals when encountering a primary electromagnetic field signal, and after the detection data carrying the good-conductivity geological body are processed and interpreted, whether the conductive body exists in the driving working face or not and the relative size and relative position information of the abnormal body are judged, so that early warning of underground construction is realized, and water damage of a mine is avoided.

3. The electrical source mine transient electromagnetic detection method of claim 1, wherein: the two ends of the wire current source are A and B, the two ends A and B of the wire current source are embedded on the side wall of a working face by using electrodes during arrangement, meanwhile, a plurality of electromagnetic field sensors which are arranged in another roadway at intervals along the direction of the roadway send received secondary electromagnetic field signals to the industrial and mining host, each electromagnetic field sensor sends signals to the industrial and mining host, the signals sent to the industrial and mining host all comprise the time received by the secondary electromagnetic field signals and the received electric field information, and the industrial and mining host utilizes a formula:converting the secondary electromagnetic field signal and the receiving time sequence into depth, wherein t is observation time, rho is background field resistivity, pi is constant circumferential rate, and omega is angleFrequency: ω ═ 100 π ρ t/(μ₀L²)]^1/4L is the length of the electrical source of the conducting wire, d (t) is the depth of view obtained by calculating the corresponding time, namely the depth corresponding to the time; the industrial and mining host machine utilizes a formula:converting the electric field information into apparent resistivity of the coal and rock formations, wherein rho_aApparent resistance for switching, p₁The resistivity of the uniform background field is uniform,is a theoretical calculation of the background field, E_xMeasuring an electric field value for the electric field sensor;

through the conversion, the time for receiving the signals is converted into the detection depth, the electric field signals are converted into the coal rock resistivity information, and the purpose of detecting the resistivity distribution in the coal rock stratum is finally achieved.

4. The electrical source mine transient electromagnetic method of claim 1, wherein: because the electric source is adopted for detection and the electric field sensor is adopted, the detection directivity is stronger, and the interference of metal in the roadway is weakened.

5. The electrical source mine transient electromagnetic method of claim 1, 3 or 4, wherein the method for determining the position of the low-resistance abnormal body in the coal rock comprises the following steps:

according to mine geological data, researching the stratum attitude of a coal rock layer, designing an electric source mine transient electromagnetic observation system according to the characteristics of the stratum attitude, paving a cable in a roadway on one side of a working face coal rock layer in the whole process, connecting the cable with an electric source to form a lead electric source for transmitting an electromagnetic signal, and paving a plurality of electric field sensors on the roadway coal wall on the other side of the working face coal rock layer at intervals; the industrial and mining host is used as a host of transient electromagnetism of an electrical source, is connected with the electric field sensor through a cable and is used for recording and storing electric field information received by the electric field sensor; the electric field sensors are linearly arranged at intervals in the roadway, after the electric field sensors receive information, each electric field sensor records the received information into two parts, namely time and an electric field, converts the time into visual depth vertical to the linear arrangement, converts the corresponding electric field into visual resistance, further obtains a position chart with the total coordinate as depth and the abscissa as linear arrangement, namely receives the position chart of the sensors, and the chart displays the visual resistivity distribution; and obtaining the accurate position of the low-resistance abnormal body in the coal rock according to the picture.

6. The electromagnetic method of electrical source mine transients as claimed in claim 5, characterised in that specifically:

i, storing electric field information received by an electric field sensor in a form of [ time, electric field ], wherein the electric field is provided with a plurality of channel maps;

and II, performing apparent conductivity conversion on the measured electric field component data to obtain geoelectric information in different directions, and performing comprehensive geological interpretation on the geologic body by integrating the existing geoelectric information.

Technical Field

The invention relates to a detection method, in particular to a detection method of an electric source mine transient electromagnetic method used in a mine roadway, and belongs to the field of coal mining water inrush prevention and control.

Background

In the aspect of coal mine water inrush prevention and control, the transient electromagnetic method is widely applied, coal mine water inrush accidents are reduced, economic loss is reduced, and safety of people is guaranteed. The mine transient electromagnetic method is widely applied to the water prevention and control work of coal mines, is one of the main means of mine geophysical prospecting at present, but is limited by the construction space of underground roadways, and a multi-turn small loop overlapping or separating magnetic source device with the side length of 2-3m and the number of turns of 30-60 is a main device form of the mine transient electromagnetic method, but has the following technical bottlenecks. (1) The emitted magnetic moment is small, and the detection effective distance is short; (2) the shielding effect of the metal anchor net of the roadway is serious and the interference signal is strong; (3) the directional detection of geological anomalies is difficult. Wherein. The fundamental reason for the problems is that the transient electromagnetic method of the magnetic source of the multi-turn small loop is influenced by the construction environment of the underground roadway. At present, the environment of the underground mine roadway cannot be changed, the change of the construction mode and the source property is expected to relieve and eliminate the problems, and an electric source mine transient electromagnetic detection method is provided, is transmitted in one roadway and received in the other roadway and is used for detecting the water-rich disaster water source of a working face.

Disclosure of Invention

The invention has the following problems: aiming at the defects of the technology, the electrical source mine transient electromagnetic detection method can make up the problem of insufficient energy emitted by a small coil, can improve the multi-solution problem of the 'mirror effect' of the whole space, and can provide more reliable geological data for mine water prevention and control.

The technical scheme is as follows: in order to achieve the technical purpose, the transient electromagnetic detection method for the mine electric source comprises the following steps: laying a lead current source in a roadway arranged on one side of a working face coal rock layer along the trend of the roadway, arranging electric field sensors on the coal rock layer wall of the roadway arranged on the other side of the coal rock layer at intervals according to the trend of the roadway, and determining the number and the interval of the electric field sensors according to the length of the working face coal rock layer; the wire current source transmits an electromagnetic field signal to a working face coal rock layer under the control of the industrial and mining host, the transmitted electromagnetic field signal is a primary electromagnetic field signal, a secondary electromagnetic field signal carrying stratum information is formed after the primary electromagnetic field signal meets a low-resistance abnormal body, the secondary electromagnetic field signal penetrates through the whole working face coal rock layer and is received by an electromagnetic field sensor arranged on the wall of the coal rock layer, the electromagnetic field sensor only receives the secondary electromagnetic field signal, and the electromagnetic field sensor transmits the received secondary electromagnetic field signal to the industrial and mining host, so that the specific position and the profile shape of the low-resistance abnormal body in the coal rock layer are confirmed.

The low-resistance abnormal body is water contained in the coal rock layer, the water serving as the good-conductivity geological body can generate induction secondary signals when encountering a primary electromagnetic field signal, and after the detection data carrying the good-conductivity geological body are processed and interpreted, whether the conductive body exists in the driving working face or not and the relative size and relative position information of the abnormal body are judged, so that early warning of underground construction is realized, and water damage of a mine is avoided.

The two ends of the wire current source are A and B, the two ends A and B of the wire current source are embedded on the side wall of a working face by using electrodes during arrangement, meanwhile, a plurality of electromagnetic field sensors which are arranged in another roadway at intervals along the direction of the roadway send received secondary electromagnetic field signals to the industrial and mining host, each electromagnetic field sensor sends signals to the industrial and mining host, the signals sent to the industrial and mining host all comprise the time received by the secondary electromagnetic field signals and the received electric field information, and the industrial and mining host utilizes a formula:converting the secondary electromagnetic field signal and the receiving time sequence into depth, wherein t is observation time, rho is background field resistivity, pi is constant circumferential rate, and omega is angular frequency: ω ═ 100 π ρ t/(μ₀L²)]^1/4L is the length of the electrical source of the conducting wire, d (t) is the depth of view obtained by calculating the corresponding time, namely the depth corresponding to the time; the industrial and mining host machine utilizes a formula:converting the electric field information into apparent resistivity of the coal and rock formations, wherein rho_aApparent resistance for switching, p₁The resistivity of the uniform background field is uniform,is a theoretical calculation of the background field, E_xMeasuring an electric field value for the electric field sensor;

through the conversion, the time for receiving the signals is converted into the detection depth, the electric field signals are converted into the coal rock resistivity information, and the purpose of detecting the resistivity distribution in the coal rock stratum is finally achieved.

Because the electric source is adopted for detection and the electric field sensor is adopted, the detection directivity is stronger, and the interference of metal in the roadway is weakened.

The method for determining the position of the low-resistance abnormal body in the coal rock comprises the following steps:

according to mine geological data, researching the stratum attitude of a coal rock layer, designing an electric source mine transient electromagnetic observation system according to the characteristics of the stratum attitude, paving a cable in a roadway on one side of a working face coal rock layer in the whole process, connecting the cable with an electric source to form a lead electric source for transmitting an electromagnetic signal, and paving a plurality of electric field sensors on the roadway coal wall on the other side of the working face coal rock layer at intervals; the industrial and mining host is used as a host of transient electromagnetism of an electrical source, is connected with the electric field sensor through a cable and is used for recording and storing electric field information received by the electric field sensor; the electric field sensors are linearly arranged at intervals in the roadway, after the electric field sensors receive information, each electric field sensor records the received information into two parts, namely time and an electric field, converts the time into visual depth vertical to the linear arrangement, converts the corresponding electric field into visual resistance, further obtains a position chart with the total coordinate as depth and the abscissa as linear arrangement, namely receives the position chart of the sensors, and the chart displays the visual resistivity distribution; and obtaining the accurate position of the low-resistance abnormal body in the coal rock according to the picture.

In particular, the method comprises the following steps of,

i, storing electric field information received by an electric field sensor in a form of [ time, electric field ], wherein the electric field is provided with a plurality of channel maps;

and II, performing apparent conductivity conversion on the measured electric field component data to obtain geoelectric information in different directions, and performing comprehensive geological interpretation on the geologic body by integrating the existing geoelectric information.

Has the advantages that: compared with the traditional transient electromagnetic method with the multiple turns of small loops, the method has the advantages that the electric source of the conducting wire is laid in the roadway, the electric source of the conducting wire is detected by a contact type current source, and the directionality is good; a plurality of electromagnetic field sensors are arranged in the roadway on the other side of the coal rock layer relative to the electric source of the lead in a facing manner, the electric field sensors are in contact with the rock wall of the roadway, electric field signals are received, whether low-resistance abnormal bodies exist in the coal rock layer or not can be quickly determined through the received information, the position of the low-resistance abnormal bodies is required to be accurately obtained, and meanwhile interference signals are effectively reduced.

Drawings

FIG. 1 is a schematic layout diagram of the detection method of the electric source mine transient electromagnetic method of the invention;

FIG. 2 is a multi-channel data diagram of electric field values detected by the electrical source mine transient electromagnetic method of the present invention;

FIG. 3 is a diagram of electrical source mine transient electromagnetic resistivity profile of the present invention;

FIG. 4 is a schematic flow chart of the electric source mine transient electromagnetic method of the present invention.

Detailed description of the invention

The invention will be further described with reference to the following examples in which the accompanying drawings are set forth in detail:

as shown in fig. 1 and 4, the transient electromagnetic detection method for the mine electrical source of the invention comprises the following steps: firstly, collecting hydrogeological data and mine roadway data of a detection area, and according to mine geological characteristics such as topographic relief in a roadway, designing how to arrange a transmitting source and arrange a receiving sensor to complete the design of a detection scheme; and then, constructing the detection scheme on a working face: firstly, laying a lead current source in a roadway arranged on one side of a coal rock layer of a working face along the trend of the roadway, laying an electric field sensor on the wall of the coal rock layer of the roadway arranged on the other side of the coal rock layer at intervals of 5 meters according to the trend of the roadway, detecting by adopting an electric source and adopting the electric field sensor, and further strengthening the detection directivity and weakening the interference of metal in the roadway; the number of the electric field sensors is determined by the length of the coal rock layer of the working face; wherein the wire current source is under the control of industrial and mining host computer to the working face coal rock stratum transmission electromagnetic field signal, and the electromagnetic field signal at this moment is primary electromagnetic field signal, forms the secondary electromagnetic field signal that carries the stratum information after the primary electromagnetic field signal meets the low resistance abnormal body, and the secondary electromagnetic field signal is received by electromagnetic field sensor after penetrating whole working face coal rock stratum, utilizes transient electromagnetic method characteristics: the electromagnetic field sensor only receives a secondary field, during detection, the primary field is closed, namely measurement is carried out at the moment of primary closing, the electromagnetic field sensor sends received secondary electromagnetic field signals to the industrial and mining host, so that the specific position and the outline shape of a low-resistance abnormal body in a coal rock layer are confirmed, the low-resistance abnormal body contains water in the coal rock layer, the water serving as a good-conductivity geological body can generate induction secondary signals when encountering the primary electromagnetic field signals, and after detection data carrying the good-conductivity geological body are processed and interpreted, whether a normal body exists in a tunneling working face or not and the relative size and relative position information of the abnormal body are judged, so that early warning of underground construction is achieved, and mine water damage is avoided.

The two ends of the wire current source are A and B, the two ends A and B of the wire current source are embedded on the side wall of a working face by using electrodes during arrangement, meanwhile, a plurality of electromagnetic field sensors which are arranged in another roadway at intervals along the direction of the roadway send received secondary electromagnetic field signals to the industrial and mining host, each electromagnetic field sensor sends signals to the industrial and mining host, the signals sent to the industrial and mining host all comprise the time received by the secondary electromagnetic field signals and the received electric field information, and the industrial and mining host utilizes a formula:converting the secondary electromagnetic field signal and the receiving time sequence into depth, wherein t is observation time, rho is background field resistivity, pi is constant circumferential rate, and omega is angular frequency: ω ═ 100 π ρ t/(μ₀L²)]^1/4L is the length of the electrical source of the conducting wire, d (t) is the depth of view obtained by calculating the corresponding time, namely the depth corresponding to the time; the industrial and mining host machine utilizes a formula:converting the electric field information into apparent resistivity of the coal and rock formations, wherein rho_aApparent resistance for switching, p₁The resistivity of the uniform background field is uniform,is a theoretical calculation of the background field, E_xMeasuring an electric field value for the electric field sensor; through the conversion, the time for receiving the signals is converted into the detection depth, the electric field signals are converted into the coal rock resistivity information, and the purpose of detecting the resistivity distribution in the coal rock stratum is finally achieved.

The method for determining the position of the low-resistance abnormal body in the coal rock comprises the following steps:

according to mine geological data, researching the stratum attitude of a coal rock layer, designing an electric source mine transient electromagnetic observation system according to the characteristics of the stratum attitude, paving a cable in a roadway on one side of a working face coal rock layer in the whole process, connecting the cable with an electric source to form a lead electric source for transmitting an electromagnetic signal, and paving a plurality of electric field sensors on the roadway coal wall on the other side of the working face coal rock layer at intervals; the industrial and mining host is used as a host of transient electromagnetism of an electrical source, is connected with the electric field sensor through a cable and is used for recording and storing electric field information received by the electric field sensor; the electric field sensors are linearly arranged at intervals in the roadway, after the electric field sensors receive information, each electric field sensor records the received information into two parts, namely time and an electric field, converts the time into visual depth vertical to the linear arrangement, converts the corresponding electric field into visual resistance, further obtains a position chart with the total coordinate as depth and the abscissa as linear arrangement, namely receives the position chart of the sensors, and the chart displays the visual resistivity distribution; and obtaining the accurate position of the low-resistance abnormal body in the coal rock according to the picture.

I, storing electric field information received by an electric field sensor in a form of [ time, electric field ], wherein the electric field is provided with a plurality of channel maps; referring to fig. 2, a schematic diagram of multiple tracks receiving an electric field by using a contact type electric field sensor is shown.

II, performing apparent conductivity conversion on the measured electric field component data to obtain geoelectric information in different directions, and performing comprehensive geological interpretation on the geologic body by integrating the existing geoelectric information; specifically, as shown in fig. 3, for the measured electric field data, time information is converted into depth information, electric field information is converted into resistivity information, and the converted data is plotted into a view resistivity profile, so that the distribution of the rich water region can be analyzed.