A method for comprehensively identifying a sand source horizon of a mine outburst disaster based on multiple source feature parameters of sand grains

Abstract

The application discloses a kind of mine sand burst disaster sand source horizon comprehensive identification method, it is related to underground mine safety production technical field.Different geological ages of loose sand layer sample of mine surface drilling and underground sand burst sample are collected;Screen out the drilling sample with different granularity characteristic parameter evaluation grade;Screen out the drilling sample with different sedimentary environment;The frequency difference of the appearance of various morphological characteristics of quartz grain surface of the retained drilling sample is less than 10%;Through the retained drilling sample, the horizon and burial depth of the underground sand burst sand source are targeted positioned.Compared with the traditional technical method, the mine sand burst disaster sand source horizon comprehensive identification method disclosed in the application integrates more data, and the identification result is more accurate and efficient, which has an important guiding role for targeted development of mine sand burst accident post-disaster rescue, management and mine recovery work.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of underground mine safety production, and particularly relates to a method for comprehensively identifying a sand source layer of a mine sand inrush disaster based on multiple source characteristic parameters of sand particles. BACKGROUND

[0002] The mine sand inrush disaster is a typical dynamic geological disaster that often occurs in the mining of thick unconsolidated layers in eastern China, and has the characteristics of concealment, suddenness, disaster, and secondary disaster, and is known as one of the five disasters affecting the safe and efficient mining of coal mines. After the mine sand inrush accident occurs, it will quickly destroy the underground production system, causing production interruption, damage to mine roadway engineering and production equipment, and even causing serious personnel casualties and property losses. In recent years, with the increasing depth and intensity of coal seam mining, the frequency of mine sand inrush accidents has shown a gradually increasing trend, which has brought a serious threat to the safety production of coal mines. For example, a sudden water inrush and sand inrush accident occurred during the heading process of a return air inclined shaft of a mine in Shandong, and only 10 minutes of water and sand inrush buried more than 2000m of roadway, causing huge economic losses.

[0003] After the mine water inrush and sand inrush accident occurs, accurate identification of the water inrush source and the sand inrush source is two key problems that need to be solved when formulating post-disaster rescue and treatment schemes. The rapid identification of the water inrush source has relatively mature equipment and methods, such as the Chinese invention patents "Mine Water Inrush Source Rapid Discrimination Device (Authorized Publication Number: CN104297308B)" and "Mine Water Inrush Source Comprehensive Rapid Identification Device and Method (Authorized Publication Number: CN103592420B)", which have solved the key problem of accurate and rapid identification of the water source in the mine water inrush and sand inrush disaster. However, there is no accurate and scientific method for identifying the sand inrush source layer in the mine water inrush and sand inrush disaster, especially for mines with thick unconsolidated layer roofs, which have multiple layers of unconsolidated sand layers deposited in different geological eras. Accurate identification of which layer of sand source material inrush into the underground mine plays an important guiding role in targeted post-disaster rescue, treatment, and mine recovery work. If the sand source layer cannot be accurately identified, the treatment engineering will be blind, and the purpose of effective treatment cannot be achieved, which will also cause serious waste of economy, time, and materials. SUMMARY

[0004] The present application proposes a method for comprehensively identifying the sand source layer of a mine sand inrush disaster based on multiple source characteristic parameters of sand particles, which is accurate and efficient, and can target the positioning of the sand source layer inrush into the roof of the mine at a low cost, and plays an important guiding role in targeted post-disaster rescue, treatment, and mine recovery work of the mine sand inrush accident.

[0005] A method for comprehensive identification of sand source horizon of mine inrush sand disaster based on multiple source feature parameters of sand particles is proposed, which comprehensively uses ESR dating method, engineering geological analogy method and statistical analysis method, mainly according to various geological characteristics reserved by sand particles in the geological formation process, the range of inrush sand source is gradually reduced through comparative analysis, and finally the accurate horizon of underground inrush sand source is determined.

[0006] The method firstly uses the method capable of measuring the age of sand sample such as ESR dating method or isotope dating method or X dating method to preliminarily determine the burial age of the underground inrush sand sample, and determines the possible sand source burial depth range by comparing the stratum lithology; since the stratum thickness of the same geological age changes greatly, the thickness can be up to 500 m or more. Therefore, in order to further reduce the range, according to the different sedimentary environment of sand particles, the parameters capable of distinguishing the sedimentary environment such as the particle size characteristics of sand particles will have obvious differences, the particle size characteristics parameters or other parameters capable of distinguishing the sedimentary environment of the sand sample in the drilling hole in the predetermined burial depth range and the inrush sand particle sample are statistically analyzed to determine the same sedimentary environment and reduce the sand source range. Since the surface morphology of quartz particles or other mineral particles in sand particles will change in the geological evolution and transformation process (such as transportation, deposition, collision, weathering, etc.), the surface morphology or other parameters of quartz particles or other mineral particles under different transformation have unique characteristics, the various morphological characteristics or other parameter characteristics of quartz particles or other mineral particles are statistically analyzed to finely characterize the geological process experienced by the quartz particles or other mineral particles, and the various morphological characteristic parameters or other characteristic parameters of the quartz particles or other mineral particles in the inrush sand sample and the drilling hole sand sample under the same sedimentary environment are compared, so that whether the two are subjected to the same geological transformation process can be determined, and the inrush sand source can be accurately determined.

[0007] The technical scheme of the present application is performed according to the following steps:

[0008] S1, collecting samples of loose sand layers deposited in different geological eras in a research area (such as a mine surface drilling hole) and inrush sand samples underground;

[0009] It should be noted that step S2 is an optional step, which is not necessary for the present case.

[0010] S2, performing ESR or isotope dating on the inrush sand sample collected underground to preliminarily determine the burial age, and preliminarily determining the burial depth range of the underground inrush sand source in combination with geological data and drilling logging data;

[0011] Reserving the drilling hole samples within the above burial depth range and screening out the drilling hole samples outside the burial depth range;

[0012] S3, according to the characteristics of the geological reformation, the evaluation grade of the characteristic parameters of the sample is judged by the fine analysis of the distinguishable sedimentary environment parameters (such as the granularity characteristic) of the downhole sand collapse sample and the borehole sample;

[0013] On the basis of step S3, the borehole sample with the same evaluation grade of the granularity characteristic parameter is retained, and the borehole sample with the different evaluation grade of the granularity characteristic parameter is screened out;

[0014] S4, the sedimentary environment of the borehole sample and the downhole sand collapse sample is calculated by using the sedimentary environment discrimination formula, and the discrimination is carried out;

[0015] On the basis of step S3, the borehole sample with the same evaluation grade of the granularity characteristic parameter is retained, and the borehole sample with the different evaluation grade of the granularity characteristic parameter is screened out;

[0016] S5, whether the frequency difference of the various morphological characteristics of the quartz particle surface in the downhole sand collapse sample and the borehole sample is less than 10% is judged;

[0017] On the basis of step S4, the borehole sample with the frequency difference of the various morphological characteristics of the quartz particle surface less than 10% is retained;

[0018] S6, the horizon and the burial depth of the downhole sand collapse sand source are targeted and positioned by the borehole sample retained in step S5.

[0019] Further, in step S1, when the borehole sample is obtained, the surface borehole should expose each loose sand deposited above the coal seam roof bedrock, and one sample is collected at the horizon where the lithology of each stratum in the borehole columnar diagram changes.

[0020] Further, after the preliminary judgment of the burial age in step S2, the geological data and the borehole logging data are combined, the borehole samples with the same burial period are first screened out from all the borehole samples, and then the basic properties of the downhole sand collapse sample and the borehole sample are compared, the borehole samples with the obviously different basic physical properties are excluded, for example, the different colors, the different roundness, the different sorting, the different mineral composition, etc., and the burial depth range of the downhole sand collapse sand source is preliminarily judged in combination with the borehole columnar diagram.

[0021] Further, the granularity characteristic parameters in step S3 include the average particle size, the sorting coefficient, the skewness coefficient, the kurtosis coefficient, and the median particle size, and the calculation formula and the geological meaning of each parameter are as follows:

[0022] (1) Average particle size (Mz): The average particle size (Mz) reflects the average value of the granularity of the sand layer, and represents the dominant range of the granularity distribution of the sand layer;

[0023] (2) Sorting coefficient (σ): The sorting coefficient (σ) reflects the sorting degree of the sand layer particle size, and the sorting degree is directly related to the hydrodynamic condition of the sedimentary environment, so the good or bad of the particle size sorting is also used as a mark of the sedimentary environment.

[0024] (3) Skewness coefficient (SK): The skewness (SK) represents the asymmetry degree of the particle size distribution of the sand layer;

[0025] (4) Kurtosis coefficient (KG): The kurtosis coefficient (KG) represents the peak type and sharpness, and represents the shape ratio of the middle and tail of the particle size distribution. If the KG is zero, it represents a normal curve.

[0026] (5) Median particle size (Md): d d 50 The median particle size (Md) represents the average value of the average particle size.

[0027] In the above formula, the φ value represents the particle size, and the calculation formula is φ = -log2d (d is the particle diameter, unit: mm). Among them, φ5, φ16, φ25, φ50, φ75, φ84, φ95 respectively represent the φ values corresponding to 5%, 16%, 25%, 50%, 75%, 84%, 95% on the probability cumulative curve.

[0028] Further, step S3 first calculates the particle size characteristic parameters of all the downhole sand collapse samples, takes the average value as a reference, and obtains the evaluation grade of the particle size characteristic parameters of the downhole sand collapse samples;

[0029] For each borehole sample left in step S2, the particle size characteristic parameters are calculated respectively, and the evaluation grade is obtained.

[0030] Finally, on the basis of step S2, the borehole samples with the same evaluation grade of the particle size characteristic parameters are retained, and the borehole samples with different evaluation grades of the particle size characteristic parameters are screened out.

[0031] Further, the sedimentary environment discrimination formula in step S4 is shown in Table 1:

[0032] Table 1 Sedimentary environment discrimination formula

[0033]

[0034] ​​Further, the various morphological features on the surface of the quartz particles in step S5 are classified into mechanical causes, chemical causes and mechanical-chemical causes according to the causes, the morphological features of the mechanical causes include angular, sub-angular, sub-round, round, shell-shaped fracture, straight or curved impact groove, parallel joint surface, parallel step, V-shaped impact crater, crescent-shaped impact crater, butterfly-shaped crater, underwater polished surface, scratch or notch, curved ridge, the morphological features of the chemical causes include dissolution pit, dissolution crack, siliceous ball, siliceous scale, siliceous film, and the morphological features of the mechanical-chemical causes include low relief, medium relief, high relief and adhered particles.

[0035] The average of the frequency of the morphological features on the surface of the quartz particles in the subsidence sand sample is calculated, and the frequency of the morphological features on the surface of the quartz particles in the retained drilling sample in step S4 is calculated, and the drilling sample in which the difference between the frequency of the various morphological features on the surface of the quartz particles is less than 10% is retained.

[0036] Compared with the prior art, the method has the beneficial effects that:

[0037] After the subsidence sand accident occurs in the mine, the traditional subsidence sand source identification method is obtained through the experience of experts or technical personnel and the analysis of geological conditions, and has a certain blindness. Compared with the traditional technical method, the method for comprehensively identifying the sand source horizon of the mine subsidence disaster disclosed in the application integrates more data and methods, and the identification result is more accurate and efficient. The method has an important guiding role for the targeted post-disaster rescue, treatment and mine recovery of the mine subsidence accident. In actual application, after the sand source position is accurately located, the sand source horizon can be targeted for grouting reinforcement, so that the reoccurrence of the mine subsidence disaster is avoided from the root, and the method has good practical value and popularization value. BRIEF DESCRIPTION OF DRAWINGS

[0038] Figure 1 It is a mine subsidence disaster mechanism diagram in the embodiment of the application;

[0039] Figure 2 It is a method flowchart of the application;

[0040] Figure 3 It is a mine subsidence underground sample position and number of a mine in Shandong collected in the embodiment;

[0041] Figure 4 Part of the drilling columnar chart

[0042] Figure 5 It is a quartz particle surface morphological feature frequency chart of the subsidence sand sample;

[0043] Figure 6 It is a quartz particle surface morphological feature frequency chart of the ZK34 sample. DETAILED DESCRIPTION

[0044] In order to clearly illustrate the technical features of the patent, the patent will be described in detail below with the specific embodiments and in conjunction with the accompanying drawings.

[0045] Embodiment 1

[0046] A coal mine in Shandong Province occurred a serious water inrush and sand inrush accident in the process of driving a return air inclined shaft. The accident was caused by the low strength and poor stability of the surrounding rock of the return air inclined shaft roadway, the extremely broken surrounding rock affected by the fault, and the failure to timely treat the top leakage. As a result, the structure broken zone was expanded, the water inrush and sand inrush channel was generated, the roof aquifer and sand layer were connected under the action of mine pressure and water pressure, and the water inrush and sand inrush accident was induced. The sand inrush mechanism is shown in Figure 1 After the sand inrush accident occurred, the water source of the water inrush was quickly determined, but the sand source horizon of the underground sand inrush appeared different judgments. In order to accurately determine the sand source horizon of the water inrush and sand inrush accident in the mine, the sand inrush samples at different positions in the mine and the samples at different depths of the No. 1 supplementary drill hole close to the underground sand inrush site were collected. The comprehensive identification method proposed by the present application accurately locates the sand source horizon of the underground sand inrush, and provides a favorable reference for the later treatment engineering. The specific process of the comprehensive identification method proposed by the present application is shown in Figure 2 .

[0047] In combination with the present embodiment, the present application proposes a method for comprehensively identifying the sand source horizon of a mine sand inrush disaster, which specifically includes the following steps:

[0048] S1, collecting samples of loose sand layers of different geological eras and samples of underground sand inrush. In the present embodiment, 30 samples of underground sand inrush in the mine are collected, and the positions and numbers are shown in Figure 3 . 35 samples in the range of 0-700m of the No. 1 supplementary drill hole close to the underground sand inrush site are collected, and one sample is collected at each horizon where the lithology of the drill hole columnar section changes, and the numbers are ZK1-ZK35 in turn.

[0049] Step S2 is an optional step, which is not necessary for the present case.

[0050] S2, quartz ESR dating is performed on the downhole sand collapse sample collected downhole to determine the approximate burial age, and in combination with geological data and drilling log data, the geological age and approximate burial depth of the downhole sand collapse sand source are preliminarily determined. In this embodiment, the quartz ESR dating result of the downhole sand collapse sample shows that the geological age of the downhole sand collapse sand source is Neogene. According to the comparison of the basic properties of the downhole sand collapse sample and the Neogene drilling sample, including color, roundness, sorting, mineral composition, etc., in combination with the drilling columnar graph, the approximate burial depth is determined to be 725.39-773.31 m. Therefore, after preliminary screening, 10 drilling samples in the range of 725.39-773.31 m are left, numbered ZK26-ZK35, and the detailed lithological characteristics and depth of each sample left are shown in Table 1. Figure 4

[0051] S3, whether the particle size characteristic parameters of the downhole sand collapse sample and the drilling sample are the same is determined through fine analysis of the particle size characteristics of the downhole sand collapse sample and the drilling sample. In this embodiment, the particle size frequency curve and the cumulative distribution curve of the downhole sand collapse sample and the ZK26-ZK35 drilling samples left in step S2 are drawn, and the average particle size, the sorting coefficient, the skewness coefficient, the kurtosis coefficient, and the median particle size of each sample are calculated according to the formula in the technical solution.

[0052] For the downhole sand collapse sample, the average values of the above coefficients are taken as references after being calculated for each sample. In this embodiment, the average value of the sorting coefficient of the downhole sand collapse sample is 1.5, the average value of the skewness coefficient is -0.52, and the average value of the kurtosis coefficient is 1.48. According to Table 2, it can be determined that the particle size characteristics of the downhole sand collapse sample are poor sorting, very negative skewness, and sharpness. For the ZK26-ZK35 drilling samples left in step S2, the sorting coefficient, the skewness coefficient, and the kurtosis coefficient are calculated respectively, and the detailed calculation results and evaluation levels are shown in Table 3.

[0053] Table 2 Evaluation level table of sand sample particle size characteristics

[0054]

[0055]

[0056] According to the comparison results of the particle size characteristic parameters of the downhole sand collapse sample and the ZK26-ZK35 drilling samples, it can be seen that the particle size characteristic parameters of the ZK31-ZK35 drilling samples are the same as those of the downhole sand collapse sample. After comparative analysis of the particle size characteristic parameters of the samples, the ZK31-ZK35 drilling samples are left after screening in this step, and the corresponding burial depth is 744.47-773.31 m.

[0057] Table 3 Particle size parameters of ZK26-ZK35 drilling samples ​

[0058] Sample No. Sort Coefficient σ Skewness Coefficient SK Kurtosis Coefficient KG ZK26 0.77 (moderate sorting) -0.42 (very negative skew) 2.12 (very sharp) ZK27 1.03 (poor sorting) -0.07 (near symmetric) 1.14 (sharp) ZK28 0.68 (good sorting) -0.90 (very negative skew) 1.10 (moderate) ZK29 1.04 (poor sorting) -0.77 (very negative skew) 2.28 (very sharp) ZK30 1.99 (poor sorting) -0.23 (negative skew) 0.36 (very flat) ZK31 1.10 (poor sorting) -0.48 (very negative skew) 1.40 (sharp) ZK32 2.56 (poor sorting) -0.44 (very negative skew) 1.16 (sharp) ZK33 1.87 (poor sorting) -0.62 (very negative skew) 1.25 (sharp) ZK34 2.05 (poor sorting) -0.52 (very negative skew) 1.20 (sharp) ZK35 1.45 (poor sorting) -0.60 (very negative skew) 1.38 (sharp)

[0059] S4, using the sedimentary environment discrimination formula to discriminate the sedimentary environment of the ZK31-ZK35 borehole samples and the downhole sand collapse samples left in step S3. In this embodiment, the average value of the Y values of some of the downhole sand collapse samples calculated according to the sedimentary environment discrimination formula and the corresponding sedimentary environment are shown in Table 4, and the sedimentary environment of the downhole sand collapse samples is determined to be fluvial facies. The Y values of the ZK31-ZK35 borehole samples and the corresponding sedimentary environment are shown in Table 5, and through comparative analysis, the sedimentary environment of the ZK34 and ZK35 samples is the same as that of the downhole sand collapse samples.

[0060] Table 4 Sedimentary environment discrimination values of sand collapse samples

[0061]

[0062]

[0063] Table 5 Sedimentary environment discrimination values of borehole samples

[0064]

[0065] S5, judging whether the frequencies of occurrence of various morphological features on the surface of quartz grains in the ZK34 and ZK35 samples screened out in S4 are similar to those in the downhole sand collapse samples. In the technical solution of the present application, the morphological features on the surface of quartz grains are counted, and the frequencies of occurrence of various morphological features are analyzed. If the frequencies of occurrence of various morphological features are similar, it is proved that the layer of the sand source is the same. In this technical solution, the frequency of each of the 10 types of morphological features on the surface of quartz grains with the highest frequency of occurrence is defined to be within 10%. In this embodiment, the average value of the frequencies of occurrence of the morphological features on the surface of quartz grains in the downhole sand collapse samples is shown in Table 6, and the frequencies of occurrence of the morphological features on the surface of quartz grains in the ZK34 sample are shown in Table 7. Through comparative analysis of Table 6 and Table 7, it can be found that the frequencies of occurrence of various morphological features on the surface of quartz grains in the downhole sand collapse samples and the ZK34 sample are similar, while the frequencies of occurrence of various morphological features on the surface of quartz grains in the downhole sand collapse samples and the ZK35 sample are more than 10%. Figure 4 Figure 5 Figure 4 Figure 5

[0066] S6, targeting the layer of the downhole sand collapse sand source. In this embodiment, through steps S1-S5 described above, it can be targeted that the sand source of the downhole sand collapse samples and the ZK34 sample is the same, and from Table 3, it can be obtained that the depth range of the layer of the sand source corresponding to the ZK34 sample is 751.02-752.69 m.

[0067] ​​​​The present application has many specific implementation approaches, and the above description is only the preferred embodiment of the present application. It should be pointed out that for ordinary skilled in the art, without departing from the principles of the present application, several improvements can be made, and these improvements should also be considered as the protection scope of the present application.

Claims

1. A method for comprehensively identifying a sand source horizon of a mine outburst sand disaster, characterized in that, The following steps are taken: S1, collecting samples of loose sand layers of different geological ages from the surface drilling of the mine and samples of underground sand collapse; S2, determining whether the evaluation grades of the particle size characteristics of the samples are the same through fine analysis of the particle size characteristics of the samples of underground sand collapse and the drilling samples; retaining the drilling samples with the same evaluation grades of the particle size characteristics and screening out the drilling samples with different evaluation grades of the particle size characteristics; S3, calculating the sedimentary environment of the drilling samples and the samples of underground sand collapse using a sedimentary environment discrimination formula and discriminating; on the basis of step S2, retaining the drilling samples with the same sedimentary environment and screening out the drilling samples with different sedimentary environments; S4, determining whether the frequency differences of various morphological characteristics of quartz particles on the surface of the samples of underground sand collapse and the drilling samples are all less than 10%; on the basis of step S3, retaining the drilling samples with the frequency differences of various morphological characteristics of quartz particles on the surface of the samples all less than 10%; S5, targeting the horizon and burial depth of the underground sand collapse sand source through the drilling samples retained in step S4.

2. The method according to claim 1, characterized in that, When the drilling samples are obtained, the surface drilling should pass through each loose sand deposited above the coal seam roof bedrock, and a sample is collected at each horizon where the lithology of the drilling columnar diagram changes.

3. The method according to claim 1, characterized in that, The particle size characteristic parameters include the average particle size, the sorting coefficient, the skewness coefficient, the kurtosis coefficient, and the median particle size.

4. The method according to claim 3, characterized in that, After the particle size characteristic parameters of all the samples of underground sand collapse are calculated, the average value is taken as a reference, and the evaluation grades of the particle size characteristic parameters of the samples of underground sand collapse are obtained; For each drilling sample, the particle size characteristic parameters are calculated, and the evaluation grades are obtained; Finally, the drilling samples with the same evaluation grades of the particle size characteristic parameters are retained, and the drilling samples with different evaluation grades of the particle size characteristic parameters are screened out.

5. The method according to claim 1, characterized in that, The various morphological characteristics of quartz particles on the surface are divided into mechanical origin, chemical origin, and mechanical-chemical origin according to the origin. The morphological characteristics of mechanical origin include angular, sub-angular, sub-round, round, shell-shaped fracture, straight and curved impact grooves, parallel joint surfaces, parallel steps, V-shaped impact craters, crescent-shaped impact craters, butterfly-shaped craters, underwater polished surfaces, scratches or notches, and curved ridges. The morphological characteristics of chemical origin include dissolution pits, dissolution cracks, siliceous spheres, siliceous scales, and siliceous films. The morphological characteristics of mechanical-chemical origin include low relief, medium relief, high relief, and adhering particles. The average value of the frequency of the morphological characteristics of quartz particles on the surface of the samples of underground sand collapse is calculated, and the frequency of the morphological characteristics of quartz particles on the surface of the retained drilling samples is retained. The drilling samples with the frequency differences of various morphological characteristics of quartz particles on the surface all less than 10% are retained.

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