阅读说明：本技术 一种金属矿地震勘探数据采集方法 (Metal ore seismic exploration data acquisition method ) 是由 王德利 张峻铭 胡斌 于 2021-08-19 设计创作，主要内容包括：本发明公开了一种金属矿地震勘探数据采集方法,包括：采集观测系统参数,构建初始观测系统；对所述初始观测系统的第一观测参数进行迭代优化,获得第二观测参数；基于所述第二观测参数构建目标观测系统,获得金属矿地震数据。本发明通过采取检波器不动的震源激发方式,选取不同于常规的观测参数,并减小环境噪声。通过对数据采集过程的修改,有效解决了金属矿地震勘探中由于矿体尺度小、不规则且倾角较大导致的信息采集不完全以及由于搬动检波器导致的环境噪声在单炮数据中位置不一致问题。(The invention discloses a metal ore seismic exploration data acquisition method, which comprises the following steps: collecting parameters of an observation system, and constructing an initial observation system; performing iterative optimization on the first observation parameter of the initial observation system to obtain a second observation parameter; and constructing a target observation system based on the second observation parameters to obtain the metal mine seismic data. The invention selects observation parameters different from the conventional observation parameters by adopting the seismic source excitation mode of the detector without movement and reduces the environmental noise. Through modification of the data acquisition process, the problems of incomplete information acquisition caused by small and irregular ore body size and large inclination angle in metal ore seismic exploration and position inconsistency of environmental noise caused by moving a detector in single shot data are effectively solved.)

1. A metal ore seismic exploration data acquisition method is characterized by comprising the following steps:

collecting parameters of an observation system, and constructing an initial observation system;

performing iterative optimization on the first observation parameter of the initial observation system to obtain a second observation parameter;

and constructing a target observation system based on the second observation parameters to obtain the metal mine seismic data.

2. The metal ore seismic survey data acquisition method of claim 1,

the parameters of the observation system comprise the exploration survey area range, the properties of a cover layer and an ore body, the depth of a target layer and the two-way travel time range of seismic waves.

3. The metal ore seismic survey data acquisition method of claim 1,

obtaining the second observed parameter further comprises:

determining a first observation parameter of the observation system according to a target measurement area;

constructing a forward model of the observation system based on the observation system and the first observation parameter, and analyzing the first observation parameter through the forward model to obtain a forward simulation result;

and carrying out iterative optimization on the first observation parameter based on the forward modeling result to obtain a second observation parameter.

4. The metal ore seismic survey data acquisition method of claim 3,

the first observation parameters comprise track spacing, maximum shot-geophone distance and shot spacing;

the channel spacing is the distance between the detectors, the maximum shot-geophone distance is the distance between a shot point and the farthest detector, and the shot spacing is the distance between seismic source points.

5. The metal ore seismic survey data acquisition method according to claim 4,

the track pitch formula is:

wherein r is track spacing, s is target volume dimension, v is overburden velocity, F_hAt the highest aliasing-free frequency, θ is the target body tilt angle, F_mIs the primary frequency of the target stratum.

6. The metal ore seismic survey data acquisition method according to claim 4,

the maximum offset formula is as follows:

wherein t is the time of double-pass travel of the reflected wave, F_pIs the main frequency of the reflected wave, V_rmsThe root mean square velocity of the stratum, A is a precision parameter, L is the length of a measuring area, and N is the number of receiving tracks.

7. The metal ore seismic survey data acquisition method according to claim 4,

the gun spacing formula is as follows:

S_pn × r/(2C), where C is the number of coverages.

8. The metal ore seismic survey data acquisition method of claim 3,

the iterative optimization includes optimizing a resolution, a signal-to-noise ratio, of the first observed parameter.

9. The metal ore seismic survey data acquisition method of claim 1,

the target observation system is an integral body formed by detectors and a seismic source, the detectors are distributed at intervals, adjacent seismic source points of the seismic source excite the seismic source at intervals of the seismic source, and the target observation system obtains the metal mine seismic data by fixing the detection points of the detectors and moving the acquisition mode of the seismic source.

Technical Field

The invention belongs to the field of metal ore seismic exploration, and particularly relates to a metal ore seismic exploration data acquisition method.

Background

At present, exploration and exploitation of metal mineral resources are gradually developed from a shallow layer to a deep layer, an earthquake method has the advantages of high resolution, large detection depth and the like in metal mineral exploration, and under the condition that mineral exploration gradually goes to the deep layer, the earthquake method becomes an ore exploration method with great potential, but the current metal mineral exploration technology is basically converted from oil exploration technology. The application effect of the seismic method is closely related to the structure, rock property and complexity of a medium, and when the seismic method is used for detecting a metal ore body, the related seismic geological conditions are more complicated than petroleum exploration.

The existing metal ore exploration still continues to use the observation system of the traditional oil exploration, however, compared with the oil and gas exploration, the metal ore exploration has the defects that the dip angle of an ore body is steep and irregular, the reflected signals of the ore body are scattered, and the traditional data acquisition mode is difficult to receive complete seismic signals, so that the information of seismic data is insufficient. Meanwhile, because the surface environment of the metal ore is complex, the environmental noise develops and depends on subsequent noise suppression, in the traditional data acquisition method, the detector can be moved in acquisition, so that the environmental noise changes due to changes of conditions such as buried depth and the like, in the whole acquisition process, time consumption is long due to multiple times of moving of the detector, the surrounding environmental noise is more likely to change, and the changed environmental noise causes troubles for the subsequent noise suppression process.

Disclosure of Invention

Aiming at the problems, the invention provides a metal ore seismic exploration data acquisition method, which solves the problems of incomplete seismic signal reception and overlarge environmental noise change and difficulty in suppression in metal ore exploration by improving the acquisition process of seismic data.

In order to achieve the purpose, the invention provides the following scheme: a method of metal ore seismic survey data acquisition, comprising:

collecting parameters of an observation system, and constructing an initial observation system;

performing iterative optimization on the first observation parameter of the initial observation system to obtain a second observation parameter;

and constructing a target observation system based on the second observation parameters to obtain the metal mine seismic data.

Preferably, the system parameters include survey area range of exploration, cap and ore body properties, depth of the target zone, two-way travel time range of seismic waves.

Preferably, obtaining the second observed parameter further comprises:

determining a first observation parameter of the observation system according to a target measurement area;

constructing a forward model of the observation system based on the observation system and the first observation parameter, and analyzing the first observation parameter through the forward model to obtain a forward simulation result;

and carrying out iterative optimization on the first observation parameter based on the forward modeling result to obtain a second observation parameter.

Preferably, the first observation parameters comprise track spacing, maximum offset and offset; the channel spacing is the distance between the detectors, the maximum shot-geophone distance is the distance between a shot point and the farthest detector, and the shot spacing is the distance between seismic source points.

Preferably, the track pitch formula is:

wherein r is track spacing, s is target volume dimension, v is overburden velocity, F_hAt the highest aliasing-free frequency, θ is the target body tilt angle, F_mIs the primary frequency of the target stratum.

Preferably, the maximum offset formula is:

wherein t is the time of double-pass travel of the reflected wave, F_pIs the main frequency of the reflected wave, V_rmsThe root mean square velocity of the stratum, A is a precision parameter, L is the length of a measuring area, and N is the number of receiving tracks.

Preferably, the gun spacing formula is:

S_pn × r/(2C), where C is the number of coverages.

Preferably, the iterative optimization comprises optimizing a resolution, a signal-to-noise ratio of the first observed parameter.

Preferably, the target observation system is an integral body formed by the detectors and the seismic source, the detectors are distributed at intervals, and the seismic source is excited by adjacent seismic source points of the seismic source at intervals of the shot, so that the seismic data of the metal ore are obtained.

The invention discloses the following technical effects:

the method does not adopt the traditional data acquisition method to acquire the metal mine seismic data any more, and the method is different from the conventional method in the mode of seismic source excitation, all detectors move along with the conventional method when one seismic source is excited by the conventional method, and the method adopts the mode of seismic source excitation with the detectors being not moved, so that the method can select different observation parameters from the conventional method and reduce the difference of environmental noise in each shot of data. Through modification of the data acquisition process, the problems of incomplete information acquisition caused by small and irregular ore body size and large inclination angle in metal ore seismic exploration and position inconsistency of environmental noise caused by moving a detector in single shot data are effectively solved.

Drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings needed in the embodiments will be briefly described below, and it is obvious that the drawings in the following description are only some embodiments of the present invention, and it is obvious for those skilled in the art to obtain other drawings without creative efforts.

FIG. 1 is a flow chart of a method of an embodiment of the present invention;

FIG. 2 is a schematic diagram of a metal mine exploration using a conventional observation system according to an embodiment of the present invention;

FIG. 3 is a schematic diagram of a metal mine seismic survey data acquisition of an embodiment of the invention.

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

In order to make the aforementioned objects, features and advantages of the present invention comprehensible, embodiments accompanied with figures are described in further detail below.

As shown in fig. 1, the present invention provides a method for collecting seismic exploration data of metal ores, comprising:

based on the existing data and the parameters of the exploration target acquisition observation system, an initial observation system is formulated;

determining a first observation parameter of the initial observation system according to a target measurement area;

establishing a forward model of the observation system based on the initial observation system and the second observation parameter, and analyzing the first observation parameter through the forward model to obtain a forward simulation result;

performing iterative optimization on the first observation parameter based on the forward modeling result to obtain a second observation parameter;

and setting a target observation system according to the second observation parameters, and acquiring and obtaining the seismic data of the metal ores.

The parameters of the observation system comprise the exploration survey area range, the properties of a cover layer and an ore body, the depth of a target layer and the two-way travel time range of seismic waves.

The first observation parameters comprise track spacing, maximum shot-geophone distance and shot spacing;

the channel spacing is the distance between the detectors, the maximum shot-geophone distance is the distance between a shot point and the farthest detector, and the shot spacing is the distance between seismic source points.

The track pitch formula is:

wherein r is track spacing, s is target volume dimension, v is overburden velocity, F_hAt the highest aliasing-free frequency, θ is the target body tilt angle, F_mIs the primary frequency of the target stratum.

The maximum offset formula is as follows:

wherein t is the time of double-pass travel of the reflected wave, F_pIs the main frequency of the reflected wave, V_rmsThe root mean square velocity of the stratum, A is a precision parameter, L is the length of a measuring area, and N is the number of receiving tracks.

The gun spacing formula is as follows:

S_pn × r/(2C), where C is the number of coverages.

The iterative optimization includes optimizing a resolution, a signal-to-noise ratio, of the first observed parameter.

The target observation system is an integral body formed by the detectors and the seismic source, the detectors are distributed at intervals, adjacent seismic source points of the seismic source excite the seismic source at intervals of the shot, and seismic data of the metal ore are obtained.

Specifically, the metal mine seismic exploration data acquisition method is mainly realized through the following processes:

the first step, performing the data collection of the previous stage: the method comprises the steps of referring to past seismic data and exploration targets, collecting relevant parameters for making an observation system, wherein the relevant parameters include a survey area range needing exploration, the properties of a cover layer and an ore body, the depth of a target layer, a two-way travel time range of seismic waves and the like, making parameters of the observation system by using data and a formula, selecting a range as the parameters, analyzing by using a group of parameters, selecting optimized parameters in the range if the parameters do not meet requirements, and finally determining a group of parameters for arranging the observation system to collect data.

Step two, formulating various parameters of the observation system according to the measuring area condition: several parameters that are important for the deployment of a data collection facility are: track spacing, maximum shot-geophone distance, and shot spacing.

The track spacing is the distance between the detectors, and is calculated by the formula

Determining the value range, wherein r is the track spacing, s is the target volume scale, v is the overburden formation velocity, F_hAt the highest aliasing-free frequency, θ is the target body tilt angle, F_mIs the primary frequency of the target stratum. In the metal mine seismic exploration example, the size s of an ore body is far smaller than that of a conventional oil and gas reservoir, the dip angle theta of the ore body is far larger than that of the oil and gas reservoir, and therefore the finally obtained track spacing r is smaller than that of a conventional observation system. The conventional observation system adopted at present has a track spacing of 10m or 15m or more, the track spacing which is obtained by the method and is suitable for the metal mine observation system is only a fraction of that of the conventional observation system, as shown in fig. 2 and 3, the smaller the track spacing is, the more dense detectors are arranged, the metal ore body is irregular, the distribution of reflected signals is irregular, and the dense detectors can acquire more reflected information, so that the ore body can be favorably carved, and the observation precision is improved.

Maximum offset: the distance between the shot point and the farthest detector is calculated by formula

Where t is the reflected wave, F, for a two-way travel_pIs the main frequency of the reflected wave, V_rmsThe root mean square velocity of the formation, a, is an accuracy parameter, in this embodiment, the accuracy parameter is 6%, L is the length of the measurement area, and N is the number of receiving channels, i.e., the number of detectors used.

Gun spacing: the distance between the seismic source points can be determined by the formula S_pObtained as N × r/(2C), where C is the number of coverages.

As the metal mine seismic data noise is relatively developed, in order to improve the signal to noise ratio, the covering times are far more than the covering times of conventional data acquisition, in the example, the covering times C are more than 200 and far more than the covering times of dozens of times of conventional data acquisition, and the condition that the effective signal is annihilated by the noise due to the conventional few covering times is avoided.

Thirdly, forward modeling: and (4) working out an observation system meeting the conditions according to the mode, and establishing a forward model of the observation system to analyze the target body.

Step four, iterative optimization: and optimizing parameter selection through forward modeling results, for example, under the conditions of insufficient resolution, low signal-to-noise ratio and the like, and continuously iterating and optimizing until the most suitable observation system parameters are selected.

And fifthly, data acquisition: and (3) laying a target observation system according to the parameters obtained in the step, specifically, laying a detector on a survey line at intervals of every two channels, wherein two adjacent seismic source points are separated by a shot interval, then exciting the seismic source to finish data acquisition, wherein the whole formed by the detector and the seismic source is the target observation system in the process, and the target observation system records seismic data of all the seismic sources through the detector to obtain metal mine seismic data with sufficient information and small environmental noise change.

As shown in fig. 2 and 3, the five-pointed star is the seismic source, and the triangle is the detector, it can be seen that the conventional data acquisition method can only collect part of effective signals for the irregular metal ore body with steep dip angle, because all the detectors move along with the conventional method every time one seismic source is excited,

the seismic source excitation mode of the metal ore seismic exploration data acquisition method is different from the seismic source excitation mode of the conventional method, and the seismic source excitation mode with the unmoved detector is adopted, so that observation parameters different from the conventional observation parameters can be selected, and the difference of environmental noise in each shot of data is reduced, so that the effective signals acquired during metal ore exploration are obviously more than those of the conventional method, and more ore body information can be provided. By modifying the data acquisition process, the invention effectively solves the problems of incomplete information acquisition caused by small and irregular ore body size and large inclination angle in metal ore seismic exploration and inconsistent positions of environmental noise in single shot data caused by moving a detector.

The above-described embodiments are merely illustrative of the preferred embodiments of the present invention, and do not limit the scope of the present invention, and various modifications and improvements of the technical solutions of the present invention can be made by those skilled in the art without departing from the spirit of the present invention, and the technical solutions of the present invention are within the scope of the present invention defined by the claims.