Directional drilling entrance and exit seismic exploration method and equipment based on mathematical phased array

Abstract

The embodiment of the invention provides a directional drilling entrance and exit seismic exploration method and device based on a mathematical phased array. The method comprises the steps that seismic survey lines including detectors and shot points are arranged; performing shock processing on each shot point in sequence by using the same seismic source; performing mathematical phased array synthesis on the collected seismic signals according to the principle of superposition of the same receiving position to obtain a target seismic wave field; based on the target seismic wave field, geological parameter information of the preset depth of the mountain is obtained; and according to the geological parameter information, determining a target entrance and exit position of the directional drill. According to the embodiment of the invention, the single seismic source is arranged to sequentially hit the shot points, then the signal-to-noise ratio of the seismic signal is improved through a mathematical phased array synthesis mode, the detection depth and the transverse resolution are increased, a plurality of seismic sources do not need to be arranged for simultaneous excitation, and the cost expenditure of seismic exploration is greatly reduced.

Description

Technical Field

[0001] Embodiments of the present disclosure belong to the technical field of geophysical exploration, and particularly relate to a seismic exploration method and device for the entrance and exit of directional drilling based on a mathematical phased array. Background Art

[0002] The rock mass at the entrance and exit positions of mountain directional drilling is usually severely weathered and loose, and geological disasters such as landslides and collapses are likely to occur. In case of rainy seasons, debris flows are also likely to be triggered during construction. Therefore, before directional drilling construction, it is necessary to understand the geological conditions inside the mountain as deeply as possible in order to select appropriate positions and routes, which is beneficial to reducing project costs and ensuring construction safety. Conventional surface exploration techniques for mountains include the ground penetrating radar method and the shallow seismic method. The detection depth of ground penetrating radar is small, usually less than 30m. Due to mountain vegetation and terrain undulations, coupling is not easy, and it is very difficult to obtain good signals, resulting in very limited understanding of geological structures by ground penetrating radar. Seismic exploration is sensitive to the mechanical properties of rocks and is suitable for understanding the geological structures inside the mountain where the entrance and exit points of directional drilling are located, and is a commonly used means for mountain exploration.

[0003] In related technologies regarding seismic exploration methods, the phased array technology of the seismic source is mostly used for exploration. By arranging multiple sub-seismic sources in an array combination, the purpose of high energy is achieved for deep detection; this method requires configuring multiple seismic sources and making them excited simultaneously, resulting in too high costs for seismic exploration and implementation costs. In related technologies, there is also a method of linearly arranging multiple controllable seismic sources at uniform intervals and making them excited simultaneously, so that the seismic exploration depth can be increased and directional detection can also be carried out; however, this method still requires a large number of physical seismic source devices to work simultaneously, which also increases the cost of seismic exploration.

[0004] In the seismic exploration process of related technologies, it is usually also necessary to set the length of the survey line to be greater than the detection depth for exploring the mountain depth range, but there is still a lack of in-depth research on the aspect of setting the length of the survey line to be less than the detection depth. Summary of the Invention

[0005] Embodiments of the present disclosure aim to at least solve one of the technical problems existing in the prior art, and provide a seismic exploration method and device for the entrance and exit of directional drilling based on a mathematical phased array.

[0006] On the one hand, embodiments of the present disclosure provide a seismic exploration method for the entrance and exit of directional drilling based on a mathematical phased array, and the method includes:

[0007] Extend and arrange seismic survey lines on the surfaces of the mountains on both sides of the initial entrance and exit positions of the directional drilling; wherein, a plurality of geophones arranged at intervals and linearly are provided on the seismic survey lines, and each geophone is correspondingly provided with a shot point;

[0008] Using the same seismic source, perform shock treatment on each of the said shot points in sequence;

[0009] Perform mathematical phased array synthesis on the collected seismic signals according to the principle of stacking at the same receiving position to obtain the target seismic wave field;

[0010] Based on the said target seismic wave field, obtain the geological parameter information at the preset depth of the mountain body;

[0011] According to the said geological parameter information, determine the target entrance and exit positions of the directional drill.

[0012] Optionally, the performing mathematical phased array synthesis on the collected seismic signals according to the principle of stacking at the same receiving position to obtain the target seismic wave field includes:

[0013] Collect the seismic signals by using a rolling acquisition method, and perform stacking in the way of synthesizing adjacent records according to the same stake number to obtain the said target seismic wave field.

[0014] Optionally, the following relational expression is used to obtain the said target seismic wave field:

[0015]

[0016] When θ = 0,

[0017] where, p r is the target seismic wave field, A is the amplitude, r is the distance between the receiver and the target point, e is represented by the wave number equation of the point, ω is the angular frequency, k is the wave number, d is the receiver spacing, θ is the angle between the target point and the center, j is the imaginary unit, t is the time, and n is the number of seismic sources.

[0018] Optionally, the obtaining the geological parameter information at the preset depth of the mountain body based on the said target seismic wave field includes:

[0019] Based on the said target seismic wave field, perform velocity scanning calculation and geological interface migration imaging to respectively obtain the wave velocity of the surrounding rock and the migration image of the geological difference interface;

[0020] Based on the wave velocity of the surrounding rock and the migration image of the geological difference interface, inversely obtain the geological parameter information at the preset depth of the mountain body; wherein, the geological parameter information includes geological structure information, rock mechanical property information and surrounding rock classification information.

[0021] Optionally, the method further includes:

[0022] After the geological parameter information of the preset depth of the mountain body is inverted, the strength level of the surrounding rock and the distribution of the geological structure are reflected according to the geological parameter information, and the target entrance and exit positions are determined based on the strength level of the surrounding rock and the distribution of the geological structure.

[0023] Optionally, the plurality of geophones are arranged at intervals and have the same height.

[0024] Optionally, the shot point is arranged at a position facing the ground below the geophone.

[0025] Optionally, the length of the seismic line is less than the preset depth of the mountain body.

[0026] On the other hand, an embodiment of the present disclosure provides a seismic exploration device for the entrance and exit of a directional drill based on a mathematical phased array, including:

[0027] An arrangement module, configured to extend and arrange seismic lines on the surfaces of the mountains on both sides of the initial entrance and exit positions of the directional drill; wherein, a plurality of geophones arranged at intervals and linearly arranged are provided on the seismic lines, and each geophone is provided with a corresponding shot point;

[0028] A shock module, configured to perform shock processing on each of the shot points in sequence using the same seismic source;

[0029] A synthesis module, configured to perform mathematical phased array synthesis on the collected seismic signals according to the principle of superposition at the same receiving position to obtain a target seismic wave field;

[0030] A calculation module, configured to obtain the geological parameter information of the preset depth of the mountain body based on the target seismic wave field;

[0031] A positioning module, configured to determine the target entrance and exit positions of the directional drill according to the geological parameter information.

[0032] Optionally, the synthesis module is specifically further configured to:

[0033] Collect the seismic signals in a rolling acquisition mode, and perform superposition in the manner of synthesizing adjacent records according to the same stake number to obtain the target seismic wave field.

[0034] The seismic exploration method and device for the entrance and exit of a directional drill based on a mathematical phased array according to the embodiment of the present disclosure effectively improve the signal-to-noise ratio of seismic signals by setting a single seismic source to shock the shot points in sequence, and then obtaining a target seismic wave field through mathematical phased array synthesis. It can increase the detection depth from the mountain rock wall to the interior, improve the lateral resolution, and there is no need to set multiple seismic sources to be excited simultaneously, greatly reducing the cost expenditure of seismic exploration; and it can set the length of the seismic line to be less than the detection depth, which is beneficial to adapting to different working conditions for seismic exploration. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] Figure 1 A schematic flow chart of a directional drilling entrance and exit seismic exploration method based on a mathematical phased array according to an embodiment of the present disclosure;

[0036] Figure 2 A schematic diagram of a mathematical phased array algorithm according to another embodiment of the present disclosure;

[0037] Figure 3 is a schematic diagram of a source phased array according to another embodiment of the present disclosure;

[0038] Figure 4 A schematic diagram of the principle of a mathematical phased array according to another embodiment of the present disclosure;

[0039] Figure 5 A recording diagram synthesized from a single source recording and a mathematical phased array according to another embodiment of the present disclosure;

[0040] Figure 6 A wavefield diagram synthesized from a single source wavefield and a mathematical phased array according to another embodiment of the present disclosure;

[0041] Figure 7 A geological migration and wave velocity profile diagram of another embodiment of the present disclosure;

[0042] Figure 8 It is a module schematic diagram of a directional drilling entrance and exit seismic exploration equipment based on a mathematical phased array according to another embodiment of the present disclosure. DETAILED DESCRIPTION

[0043] In order to enable those skilled in the art to better understand the technical solution of the present disclosure, the present disclosure is further described in detail below in conjunction with the accompanying drawings and specific implementation methods.

[0044] As an application example, for a mountain with a relatively shallow tunnel design depth, a fully to strongly weathered gneiss vault, poor self-stabilization ability, prone to collapse and block falling during construction, and complex geological structures, the directional drilling entrance and exit seismic exploration method based on a mathematical phased array provided by the embodiment of the present disclosure can further identify the geological conditions of the surrounding rock within a preset depth range in front of the face, thereby predicting the unfavorable geology and hidden major geological problems ahead, including: faults and impact zones, joint and fissure development zones, karst, etc., and determining the location, form, and scale of unfavorable geology. Avoid and reduce the risk of geological disasters, and provide a reliable basis for directional drilling construction.

[0045] like Figure 1As shown in the figure, the method includes: S110. Extend and arrange seismic survey lines on the mountain surface on both sides of the initial entrance and exit positions of the directional drill. Among them, a plurality of geophones are arranged at intervals and linearly on the seismic survey line, and each geophone is correspondingly provided with a shot point.

[0046] Specifically, in this step, take the initial entrance and exit of the directional drill as the midpoint, that is, take the tunnel entrance as the midpoint, and then extend and arrange the seismic survey line from this midpoint to the mountain surface on both sides. For example, when the preset depth of the mountain is 100 m and the length of the seismic survey line can only be set below 50 m, transverse seismic survey lines with a length of 24 m can be extended and arranged from the midpoint position to the mountain surface on both sides. The transverse seismic survey line is parallel to the ground surface, and the transverse seismic survey line includes a plurality of geophones arranged at intervals and linearly. The plurality of geophones are arranged at equal intervals and have the same height from the ground surface. The specific number of the plurality of geophones is 24, and they are evenly distributed on the mountain surface on both sides along the center point. The geophone trace interval on each side of the mountain surface is set to 2 m. Of course, the number of geophones and the trace interval can be designed according to the actual situation. For example, 48 geophones are set and the trace interval is 1 m. This embodiment does not make specific limitations on this. Each geophone is also correspondingly provided with a shot point, and each shot point is located below the corresponding geophone, that is, on the mountain between the corresponding geophone and the ground surface.

[0047] S120. Use the same seismic source to perform shock treatment on each of the shot points in turn.

[0048] Specifically, in this step, set a single seismic source as the seismic wave injection source, and use a sledgehammer or other seismic source to perform shock treatment on each shot point in turn to obtain the seismic signals generated at each shot point.

[0049] S130. Synthesize the collected seismic signals by mathematical phased array according to the principle of superposition at the same receiving position to obtain the target seismic wave field.

[0050] Specifically, in this step, with reference to Figure 2 , adopt a rolling acquisition method to collect the seismic signals mentioned above, and perform superposition in the way of synthesizing adjacent records according to the same stake number to obtain the target seismic wave field. For example, synthesize the multiple seismic signals at the position of the Kth stake according to the principle of superposition at the same receiving position. The synthesized signal can greatly improve the signal-to-noise ratio of the scattering signals of geological anomalies below the seismic source at this position, thereby improving the resolution and detection depth. Finally, use the mathematical phased array synthesis method to obtain the target seismic wave field of the preset depth of the entire mountain.

[0051] Furthermore, the following relational expression is used to obtain the target seismic wave field:

[0052]

[0053] When θ = 0,

[0054] where p r is the target seismic wave field, A is the amplitude, r is the distance between the receiver and the target point, e is the wave number equation representation of the point, ω is the angular frequency, k is the wave number, d is the receiver spacing, θ is the angle between the target point and the center, j is the imaginary unit, t is the time, and n is the number of seismic sources.

[0055] It should be noted that the seismic source phased array technology is an effective means to improve the detection resolution of complex geological bodies. A seismic source phased array uses multiple linearly arranged or arrayed seismic sources that are simultaneously excited. Through the coherent superposition of seismic waves, the wave field in the detection area is strengthened, and the wave field outside the detection area is greatly weakened. It is similar to adding a spotlight hood to a flashlight, making the energy more focused and able to illuminate farther. Refer to Figure 3 simultaneously. As a specific example of a seismic source phased array, it uses multiple linearly arranged seismic sources with a spacing of d and an arrangement length of L. The arrangement length L needs to be greater than the wavelength λ, and the wavelength λ is also the preset depth of the mountain body. When simultaneously excited, the longitudinal waves are superposed. In the detection direction θ = 0 below the seismic source, the seismic wave field is strengthened and has a maximum value. The wave field weakens on both sides and decreases rapidly. The wave field near the center line of the seismic source is approximately a plane wave field.

[0056] Refer to Figure 2 and Figure 4 and Figure 6 simultaneously. In the method for seismic exploration at the entrance and exit of a directional drill based on a mathematical phased array disclosed in this embodiment, only one seismic source needs to be set, and then it is excited sequentially at the linear arrangement positions, and the seismic signals are synthesized according to the principle of superposition at the same receiving position. Since the seismic wave field is a linear field and conforms to the superposition principle, according to the superposition principle, the seismic wave field synthesized by the mathematical phased array is the same as the result of the seismic source phased array, which can greatly improve the intensity of the reflection / scattering signals in the mountain body detection area, significantly weaken the signals outside the detection area, and improve the detection depth and the resolution of the detection area. Using the mathematical phased array algorithm can further perform signal enhancement processing on the seismic signals, continue to improve the detection resolution, and achieve the detection effects of further increasing the detection depth and orientation.

[0057] Refer to Figure 5 and Figure 6 simultaneously, where Figure 5 and Figure 6 on the left side are all single seismic source records. Figure 5 and Figure 6 on the right side are all seismic records synthesized by the mathematical phased array. From Figure 5 and Figure 6It can be seen that the single-shot record of the single seismic source on the left has small energy and wide illumination, and can clearly reflect the shallow anomalies, but the scattered energy of the deep anomalies is weak, and there are many anomalies, so it is not clearly reflected. The data of the synthetic record of the mathematical phased array on the right clearly reflects the deep anomalies.

[0058] Exemplarily, through the method for seismic exploration at the entrance and exit of a directional drill based on a mathematical phased array according to this embodiment, the length of the seismic survey line can be set to be less than the preset depth of the mountain body, and the signal-to-noise ratio of the seismic signal can be improved by means of mathematical phased array synthesis, so as to improve the resolution and detection depth, so that when the length of the seismic survey line is set to be less than the preset depth of the mountain body, the required preset depth of the mountain body can still be detected.

[0059] S140. Obtain geological parameter information of the preset depth of the mountain body based on the target seismic wave field.

[0060] Specifically, in this step, based on the target seismic wave field, velocity scanning calculation and geological interface migration imaging are performed to obtain the wave velocity of the surrounding rock and the migration image of the geological difference interface respectively. Then, based on the wave velocity of the surrounding rock and the migration image of the geological difference interface, the geological parameter information of the preset depth of the mountain body can be inversely obtained. Among them, the geological parameter information includes geological structure information, rock mechanical property information, and surrounding rock classification information.

[0061] As a specific application example, as Figure 7 shown, for the exploration of a tunnel mountain body, through velocity scanning calculation and geological interface migration imaging of the obtained target seismic wave field, the wave velocity profile of the surrounding rock ( Figure 7 right side) and the migration image of the geological difference interface ( Figure 7 left side) are obtained respectively. Then, based on the migration image and the wave velocity image, the geological parameter information of the tunnel mountain body is inversely analyzed to provide detailed data for construction decision-making. Specifically, refer to Table 1 below: Geological Parameters and Related Prediction Conclusions.

[0062] Table 1: Geological Parameters and Related Prediction Conclusions

[0063]

[0064]

[0065] S150. Determine the target entrance and exit positions of the directional drill according to the geological parameter information.

[0066] Specifically, after inversely obtaining the geological parameter information of the preset depth of the mountain body, according to the strength level of the surrounding rock and the geological structure distribution reflected by the geological parameter information, the target entrance and exit positions are determined through the strength level of the surrounding rock and the geological structure distribution.

[0067] As a specific application example, such as Figure 7 shown, referring to the wave velocity profile of the surrounding rock ( Figure 7 on the right side) and the migration image of the geological difference interface ( Figure 7 on the left side), according to the geological parameter information reflected in the migration image and the wave velocity image, the wave velocity of the surrounding rock is relatively high within the range of 20 - 90 m, indicating that the surrounding rock has relatively high strength and good integrity. The surrounding rock is relatively stable, with a high construction safety factor and stable hole formation. It is suitable as the target entrance and exit for directional drilling.

[0068] Geological parameter information such as geological structure information, rock mechanical property information, and surrounding rock classification information is obtained from the wave velocity of the surrounding rock and the migration image of the geological difference interface. The geological parameter information reflects the strength of the surrounding rock and the distribution of the geological structure, which has a great impact on construction safety and difficulty, so it is used to determine the location of the target entrance and exit.

[0069] In the seismic exploration method for the directional drilling entrance and exit based on mathematical phased array according to the embodiments of the present disclosure, by setting a single seismic source to sequentially shock the shot points, and then obtaining the target seismic wave field through the method of mathematical phased array synthesis, the signal-to-noise ratio of the seismic signal is effectively improved, the detection depth from the mountain rock wall to the interior can be increased, the lateral resolution is improved, there is no need to set multiple seismic sources to be excited simultaneously, greatly reducing the cost expenditure of seismic exploration; and the length of the seismic survey line can be set to be less than the detection depth, which is beneficial to adapting to different working conditions for seismic exploration.

[0070] On the other hand, as Figure 8 shown, the embodiments of the present disclosure provide a seismic exploration device for the directional drilling entrance and exit based on mathematical phased array, including:

[0071] A layout module 111, configured to extend and layout seismic survey lines on the mountain surface on both sides of the initial entrance and exit positions of the directional drilling. Among them, a plurality of geophones are arranged at intervals and linearly on the seismic survey line, and each geophone is correspondingly provided with a shot point.

[0072] A shock module 121, configured to use the same seismic source to sequentially perform shock processing on each of the shot points.

[0073] A synthesis module 131, configured to perform mathematical phased array synthesis on the collected seismic signals according to the principle of superposition at the same receiving position to obtain the target seismic wave field.

[0074] A calculation module 141, configured to obtain the geological parameter information of the preset depth of the mountain based on the target seismic wave field.

[0075] A positioning module 151, configured to determine the target entrance and exit positions of the directional drilling according to the geological parameter information.

[0076] Furthermore, the synthesis module 131 is specifically further configured to collect the seismic signals by using a rolling acquisition method, and perform superposition in a manner of synthesizing adjacent records according to the same stake number to obtain the target seismic wave field.

[0077] The directional drilling inlet and outlet seismic exploration device based on mathematical phased array according to the embodiments of the present disclosure can, through the arranged arrangement module, shock module, synthesis module, calculation module and positioning module, realize setting a single seismic source to shock the shot points in sequence, and then obtain the target seismic wave field through the method of mathematical phased array synthesis, effectively improving the signal-to-noise ratio of the seismic signals, being able to increase the detection depth from the mountain rock wall to the interior, improving the lateral resolution, without the need to set multiple seismic sources to be excited simultaneously, greatly reducing the cost expenditure of seismic exploration; and being able to set the length of the seismic survey line to be less than the detection depth, which is beneficial to adapting to different working conditions for seismic exploration.

[0078] It can be understood that the above embodiments are merely exemplary embodiments adopted to illustrate the principle of the present disclosure, but the present disclosure is not limited thereto. For those of ordinary skill in the art, various modifications and improvements can be made without departing from the spirit and essence of the present disclosure, and these modifications and improvements are also regarded as the protection scope of the present disclosure.

Claims

1. A directional drilling inlet and outlet seismic exploration method based on a mathematical phased array, characterized in that, The method includes: Arranging seismic survey lines on the surface of the mountains on both sides of the initial entrance and exit positions of the directional drill; wherein, a plurality of geophones are arranged at intervals and linearly on the seismic survey line, and each geophone is correspondingly provided with a shot point; Using the same seismic source to perform shock treatment on each of the shot points in sequence; Mathematically phased array synthesizing the collected seismic signals according to the principle of stacking at the same receiving position to obtain a target seismic wave field; Based on the target seismic wave field, obtaining geological parameter information at a preset depth of the mountain; Determining the target entrance and exit positions of the directional drill according to the geological parameter information; 2. The method according to claim 1, wherein The step of mathematically phased array synthesizing the collected seismic signals according to the principle of stacking at the same receiving position to obtain a target seismic wave field includes: Collecting the seismic signals by using a rolling acquisition method, and stacking the adjacent records in the way of synthesizing at the same stake number to obtain the target seismic wave field; 3. The method according to claim 1, characterized in that Obtaining the target seismic wave field by using the following relational expression: When θ = 0, where p r is the target seismic wave field, A is the amplitude, r is the distance between the receiver and the target point, e is represented by the wavenumber equation of the point, ω is the angular frequency, k is the wavenumber, d is the receiver spacing, θ is the angle between the target point and the center, j is the imaginary unit, t is the time, and n is the number of seismic sources.

4. The method according to any one of claims 1 to 3, characterized in that, The step of obtaining the geological parameter information at a preset depth of the mountain based on the target seismic wave field includes: Based on the target seismic wave field, performing velocity scanning calculation and geological interface migration imaging to respectively obtain the wave velocity of the surrounding rock and the migration image of the geological difference interface; Inverting to obtain the geological parameter information at a preset depth of the mountain based on the wave velocity of the surrounding rock and the migration image of the geological difference interface; wherein, the geological parameter information includes geological structure information, rock mechanical property information and surrounding rock classification information; 5. The method according to claim 4, wherein The method further includes: After inverting to obtain the geological parameter information at a preset depth of the mountain, according to the strength level of the surrounding rock and the geological structure distribution reflected by the geological parameter information, determining the target entrance and exit positions through the strength level of the surrounding rock and the geological structure distribution; 6. The method according to any one of claims 1 to 3, characterized in that, The plurality of geophones are arranged at intervals and have the same height; 7. The method according to any one of claims 1 to 3, characterized in that The shot point is arranged at a position facing the ground below the geophone; 8. The method according to any one of claims 1 to 3, characterized in that The length of the seismic survey line is less than the preset depth of the mountain; 9. A directional drilling inlet and outlet seismic exploration device based on a mathematical phased array, characterized in that, It includes: An arrangement module for arranging seismic survey lines on the surface of the mountains on both sides of the initial entrance and exit positions of the directional drill; wherein, a plurality of geophones are arranged at intervals and linearly on the seismic survey line, and each geophone is correspondingly provided with a shot point; A shock module for using the same seismic source to perform shock treatment on each of the shot points in sequence; A synthesis module for mathematically phased array synthesizing the collected seismic signals according to the principle of stacking at the same receiving position to obtain a target seismic wave field; A calculation module for obtaining the geological parameter information at a preset depth of the mountain based on the target seismic wave field; A positioning module for determining the target entrance and exit positions of the directional drill according to the geological parameter information; 10. The directional drilling inlet and outlet seismic exploration device based on a mathematical phased array according to claim 9, wherein, The synthesis module is specifically further used for: Collecting the seismic signals by using a rolling acquisition method, and stacking the adjacent records in the way of synthesizing at the same stake number to obtain the target seismic wave field.

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