Active and passive source metal mine seismic exploration method

Abstract

The invention provides an active and passive source metal mine seismic exploration method, which comprises the following steps of: acquiring geological exploration data of a target area, and analyzing and judging to obtain a metallogenic favorable part of the target area; obtaining seismic geologic features of the target area and distribution features of natural field sources; according to the acquired geological exploration data, the passive source seismometers are arranged in a grid mode in a target area to form a passive source detection grid; the active source seismographs are arranged in a cross shape at the favorable metallogenic part to form two active source detection lines; artificial source seismic waves are excited, active source seismic data of the active source seismograph and passive source seismic data of the passive source seismograph are collected, and after the artificial source seismic waves are excited, the passive source seismic data of the passive source seismograph are continuously collected. The problem of active and passive source seismic data fusion acquisition is solved, the exploration cost is reduced, and the working efficiency and the detection precision are improved.

Description

Technical Field

[0001] The present invention relates to the technical field of geological exploration, and particularly to an active and passive source seismic exploration method for metal mines. Background Art

[0002] As an important means for exploring deep mineral resources, metal mine seismic exploration technology is currently mainly divided into two categories of methods: active source and passive source. Among them, since the 1990s, the active source reflection seismic exploration technology has been successfully applied to the detection and research of sedimentary deposits, sulfide deposits, and ore-controlling structures, forming a mature 2D / 3D exploration method system. This method uses artificial seismic sources to generate seismic waves and analyzes the underground structure by using the characteristics of reflected waves, refracted waves, etc. However, it has significant defects: 1. It is difficult to eliminate the interference of side reflection waves and diffraction waves in 2D exploration, resulting in imaging distortion of complex-shaped ore bodies and structures; 2. Although 3D exploration can improve imaging accuracy, the construction cost is high, and it is difficult to be applied on a large scale during the exploration stage.

[0003] As an emerging direction, passive source seismic exploration technology uses natural seismic activities or environmental noise as seismic sources, with the advantages of low cost and environmental friendliness. The metal mine passive source detection project launched by the European Union in 2018 verified the feasibility of this technology, but its inherent defects limit the application scope: 1. The spatio-temporal distribution of natural seismic sources is uncontrollable, resulting in significant differences in data quality; 2. The signal frequency band is relatively narrow, and the exploration resolution is about 30%-50% lower than that of the active source. Especially in the ore body positioning detection, passive source seismic data is difficult to meet the requirements of fine detection.

[0004] The high-resolution characteristics of active source exploration and the low-cost advantages of passive source exploration are complementary. However, there are currently technical obstacles in the combined application of the two, that is, how to achieve data fusion, complementary advantages, and further improve the imaging accuracy in complex environments through systematic methods based on the hardware facilities provided by sensor technology for hybrid acquisition. The specific problems are mainly manifested as follows: 1. Lack of a hybrid layout scheme for special geological conditions of metal mines; 2. Unable to solve the problem of uneven azimuth distribution of natural field sources in passive source seismic exploration; 3. Difficulty in fusion caused by inconsistent spatio-temporal benchmarks of active and passive source data. To solve the above problems and achieve hybrid acquisition of active and passive source seismic data for metal mines, the present invention will provide a systematic active and passive source seismic data fusion acquisition scheme. By constructing a cross + grid observation system and using a hybrid excitation method of artificial seismic sources and natural field sources, it conducts exploration of metal mines and ore-controlling geological bodies, and promotes the practical application process of metal mine seismic exploration. Summary of the Invention

[0005] The purpose of the present invention is to provide an active and passive source seismic exploration method for metal mines, which solves the technical problem that it is difficult to integrate active source exploration and passive source exploration technologies.

[0006] To solve the above problems, the present invention provides a passive and active source seismic exploration method for metal mines, comprising the following steps: Step S10000: Obtain geological exploration data of the target area, analyze and judge to obtain the favorable ore-forming parts of the target area; Step S20000: Obtain the seismic geological characteristics and the distribution characteristics of natural field sources in the target area; Step S30000: According to the obtained geological exploration data, arrange passive source seismographs in a grid pattern in the target area to form a passive source detection grid; Step S40000: Arrange active source seismographs in a cross shape in the favorable ore-forming parts to form two active source detection lines; Step S50000: Excite artificial source seismic waves and collect the active source seismic data of the active source seismographs and the passive source seismic data of the passive source seismographs, and continue to collect the passive source seismic data of the passive source seismographs after the excitation of the artificial source seismic waves is completed.

[0007] Further, in the above passive and active source seismic exploration method for metal mines, the geological exploration data includes: geological information, drilling information, and rock physical parameter data of the target area.

[0008] Further, in the above passive and active source seismic exploration method for metal mines, step S10000 further includes: Step S10100: Construct a deposit model according to the geological information and the drilling information, and obtain formation, ore body, and fault structure data; Further, in the above passive and active source seismic exploration method for metal mines, the distance between the passive source seismographs is less than or equal to 50 meters.

[0009] Further, in the above passive and active source seismic exploration method for metal mines, the distance between the active source seismographs is less than or equal to 10 meters.

[0010] Further, in the above passive and active source seismic exploration method for metal mines, step S5000 further includes: Step S20100: Arrange three of the passive source seismographs in a triangle in the target area, record the passive source seismic data for no less than 48 hours, and analyze the distribution characteristics of the passive source seismic natural field sources in the target area.

[0011] Further, after step S5000 in the above passive and active source seismic exploration method for metal mines, it further includes: Step S50100: According to the seismic geological characteristics and the distribution characteristics of the natural field sources obtained in step 20100 and step S20200, excite seismic waves in the weak distribution area of the natural field sources to supplement the active source seismic signals.

[0012] Furthermore, in the above active-passive source metal ore seismic exploration method, passive source seismic data is continuously collected for at least 20 days.

[0013] Furthermore, in step S5000 of the above active-passive source metal ore seismic exploration method, active source seismographs are arranged perpendicular and parallel to the strike direction of the ore body or ore-controlling structure of the metal ore.

[0014] The above technical solution of the present invention has the following beneficial technical effects: By arranging active source seismographs in the target area to form two mutually perpendicular active source detection lines, and at the same time arranging passive source seismographs in a grid pattern in the target area, actively exciting artificial source seismic waves to collect active source seismic data through the active source seismographs, and collecting passive source seismic data through the passive source seismographs, thus it can take into account both the active source and passive source methods, solve the problem of integrated acquisition of active-passive source seismic data, reduce the exploration cost while improving the utilization rate of passive source seismic data. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 is a flowchart of the steps of the embodiment shown in the present invention; Figure 2 is a schematic diagram of the on-site layout of the embodiment shown in the present invention. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0016] In order to make the purpose, technical solution and advantages of the present invention clearer, the present invention will be further described in detail below in conjunction with the specific embodiments and with reference to the accompanying drawings. It should be understood that these descriptions are exemplary and not intended to limit the scope of the present invention. In addition, in the following description, the descriptions of well-known structures and technologies are omitted to avoid unnecessarily confusing the concepts of the present invention.

[0017] The embodiments shown in the present invention will be described below with reference to the accompanying drawings. Referring to Figure 1 , a flowchart of the steps of this embodiment is shown, including: Step S10000: Obtain geological exploration data of the target area, analyze and judge to obtain the favorable ore-forming parts of the target area; Among them, the exploration data includes: geological information, drilling information, and rock physical parameter data of the target area.

[0018] Step S10000 further includes: Step S10100: Construct a deposit model according to the geological information and drilling information, and obtain formation, ore body and fault structure data; Step S10200: Obtain the velocity and density data of rock and ore according to the sample analysis and testing or geophysical logging data of the target area.

[0019] Step S20000: Obtain the seismic geological characteristics of the target area and the distribution characteristics of natural field sources. Step S20000 further includes: Step S20100: Use forward modeling methods based on wave equations or acoustic wave equations in combination with seismic illumination techniques to analyze seismic wavefield characteristics. Optimize data acquisition parameters and observation systems to obtain the best imaging effects.

[0020] Step S20200: Arrange three passive source seismographs in a triangular pattern in the target area and record passive source seismic data for no less than 48 hours.

[0021] Step S20300: Use the beamforming technique to analyze and estimate the azimuth and horizontal slowness of the noise source signal in the target area based on the characteristic that the wavefronts of plane waves take different times to propagate to different stations, and analyze the distribution characteristics of passive source natural field sources in the target area.

[0022] Step S30000: According to the obtained geological exploration data, seismic geological characteristics and distribution characteristics of natural field sources, arrange passive source seismographs in a grid pattern in the target area to form a passive source detection grid; According to the geological background and ore deposit characteristics of the target area, make the distance between the passive source seismographs less than or equal to 50 meters, so as to be more accurate in receiving data related to strata, rock masses and structures related to mineralization in the target area.

[0023] Step S40000: Arrange active source seismographs in a cross shape in the favorable ore-forming parts to form two active source detection lines; To obtain better measurement accuracy, when arranging the active source seismographs, arrange the active source seismographs vertically and parallel to the strike direction of the metal ore body or ore-controlling structure. At the same time, the distance between the active source seismographs is less than or equal to 10 meters.

[0024] The two cross-shaped active source detection lines simultaneously receive active source seismic data, thus obtaining a cross section passing through the metal ore. Different from the traditional 2D seismic data processing method, the improved two cross-shaped active source detection lines will adopt 3D seismic data processing techniques. According to the actual data quality collected and detection requirements, processing such as pre-stack / post-stack migration and time-depth conversion can be added. The above data acquisition and processing methods can effectively eliminate the artifacts caused by side reflection waves and diffracted waves during conventional 2D exploration, and can accurately image complex-shaped ore bodies and geological structures. At the same time, compared with 3D exploration, it has a lower construction cost, and compared with 2D exploration, it has higher exploration accuracy.

[0025] Step S50000: Excite artificial source seismic waves and collect the active source seismic data and passive source seismic data of the active source seismograph. After exciting the artificial source seismic waves, continue to collect the passive source seismic data of the passive source seismograph.

[0026] In order to overcome the influence that the traditional passive source seismic data cannot meet the random distribution of the noise field sources, resulting in a reduction in detection accuracy, it is also necessary to supplement the active source seismic signals to make the distribution of the environmental noise field sources uniform, thereby improving the exploration accuracy of the passive source seismic data. Therefore, step S50000 also includes: Step S50100: According to the seismic geological characteristics and the distribution characteristics of the natural field sources obtained in step 20100 and step 20200, excite seismic waves in the weak distribution area of the natural field sources to supplement the active source seismic signals.

[0027] Step S50200: Decode the active source seismic data, load the shot point and geophone point information of two cross sections, and create a three-dimensional seismic observation system; Step S50300: Edit the seismic traces of the active source seismic data, and remove the signals of bad traces and strong noise interference traces; Step S50400: Static correction processing, pick up the first arrival of seismic waves, and calculate the static correction amounts of the shot points and geophone points of the active source seismic data by using the method of tomographic static correction.

[0028] Step S50500: Data denoising and amplitude compensation, eliminate the energy differences between shot points and geophone points caused by factors such as excitation, reception, and formation anisotropy.

[0029] Specifically, techniques such as band-pass filtering and dip filtering can be used to denoise the data, and the surface consistency technique can be applied to compensate the amplitude.

[0030] Step S50600: Surface consistency deconvolution processing, compress the seismic wavelet. By eliminating multiple reflections, ghost reflections, etc., the resolution of seismic signals is improved.

[0031] Step S50700: Velocity analysis and residual static correction processing, establish a high-precision stacking velocity model by carefully picking up the energy spectrum of the velocity field, and calculate the residual static correction amount.

[0032] Step S50800: Normal moveout correction (NMO) and stacking, carry out dynamic correction and stacking processing by applying the stacking velocity model, and establish a three-dimensional data volume.

[0033] Step S50900: Apply dip moveout correction (DMO) to make the reflections of steep dips migrate to their correct positions.

[0034] Step S51000: Post-stack noise suppression. Perform filtering processing on the stacked data volume for random noise, linear interference, surface waves, etc., to enhance the reflection signal.

[0035] Post-stack noise suppression. Perform filtering processing on the stacked data volume for random noise, linear interference, surface waves, etc., to enhance the reflection signal.

[0036] Step S51100: Decode the passive-source seismic data, and perform passive-source data processing according to the seismic noise interference technology method to obtain the passive-source seismic exploration result; To make the measurement results more accurate, it is necessary to continuously collect passive-source seismic data for at least 20 days. There are various ways to generate artificial seismic waves. One can reasonably select explosives according to the depth of the metal ore to generate seismic waves, or use a controllable seismic vehicle or a drop hammer as the seismic source to generate seismic waves. When generating seismic waves, it is necessary to ensure that the active-source seismographs on the two active-source detection lines can receive seismic data.

[0037] It should be understood that the above specific embodiments of the present invention are only used for exemplary illustration or explanation of the principle of the present invention, and do not constitute a limitation to the present invention. Therefore, any modifications, equivalent replacements, improvements, etc. made without departing from the spirit and scope of the present invention shall be included within the protection scope of the present invention. In addition, the appended claims of the present invention are intended to cover all changes and modifications that fall within the scope and boundaries of the appended claims, or equivalent forms of such scope and boundaries.

Claims

1. An active and passive source metal mine seismic exploration method, characterized in that: The steps include: Step S10000: Acquire geological exploration data of the target area, analyze and determine favorable mineralization locations in the target area; Step S20000: Acquire the seismic geological characteristics and distribution characteristics of natural field sources in the target area; Step S30000: According to the acquired geological exploration data, the seismic geological characteristics and the natural field source distribution characteristics, passive source seismographs are arranged in a grid manner in the target area to form a passive source detection grid; Step S40000: arranging active source seismographs in a cross shape at the favorable mineralization location to form two active source detection lines; Step S50000: exciting artificial source seismic waves and collecting active source seismic data of the active source seismograph and passive source seismic data of the passive source seismograph, and continuing to collect passive source seismic data of the passive source seismograph after exciting artificial source seismic waves.

2. The active and passive source metal mine seismic exploration method according to claim 1, characterized in that: The geological exploration data include: geological information of the target area, drilling information, and rock physical parameter data.

3. The active and passive source metal mine seismic exploration method according to claim 2, characterized in that: The step S10000 also includes: Step S10100: constructing a mineral deposit model according to the geological information and the drilling information, and obtaining stratum, ore body and fault structure data; Step S10200: Obtain rock velocity and density data based on sample analysis tests or geophysical logging data in the target area.

4. The active and passive source metal mine seismic exploration method according to claim 1, characterized in that: The distance between the passive source seismometers is less than or equal to 50 meters.

5. The active and passive source metal mine seismic exploration method according to claim 1, characterized in that: The distance between the active source seismometers is less than or equal to 10 meters.

6. The active and passive source metal mine seismic exploration method according to claim 1, characterized in that: The step S20000 also includes: Step S20100: Analyze seismic wave field characteristics using wave equation or acoustic wave equation forward modeling method combined with seismic illumination technology; Step S20200: Arrange three passive source seismographs in a triangle shape in the target area, record the passive source seismic data for no less than 48 hours, and analyze the distribution characteristics of the natural field sources of passive source seismic in the target area; Step S20300: Using the beamforming technology, based on the characteristic that the time required for the wavefront of a plane wave to propagate to different stations is different, the azimuth and horizontal slowness of the noise source signal in the target area are analyzed and estimated, and the distribution characteristics of the passive source natural field source in the target area are analyzed.

7. The active and passive source metal mine seismic exploration method according to claim 6, characterized in that: The step S50000 also includes: Step S50100: Based on the seismic geological characteristics and the distribution characteristics of the natural field source obtained in step S20100 and step S20200, seismic waves are excited in the weak distribution area of ​​the natural field source to supplement the active source seismic signal.

8. The active and passive source metal mine seismic exploration method according to claim 1, characterized in that: Passive source seismic data were collected continuously for at least 20 days.

9. The active and passive source metal mine seismic exploration method according to claim 1, characterized in that: In step S50000, active source seismometers are arranged perpendicularly and parallel to the strike direction of the ore body or ore-controlling structure of the metal mine.

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