CN104568646A - Underground rapid coal seam gas content measurement method - Google Patents

Abstract

The invention relates to a method for quickly measuring the gas content of a coal seam underground, comprising the following steps: constructing a borehole with a diameter of 42 mm and a depth of 14 m on a coal roadway excavation face; measuring the total cuttings S of the section every 1 m of the borehole, Measure _the K1 or Δh2 value every 2m, and select the maximum value of the measured data as the final measured value of each index of the borehole; when _the borehole is drilled to 14m, use the direct method to measure the coal seam gas content W ; use The gray correlation method determines the degree of correlation between S, K1 or Δh2 and the coal seam gas content W ; further measures the index that has the greatest impact on the coal seam gas content W , and simultaneously measures the coal seam gas content W ; performs regression analysis on the above two measured data to determine the two or mathematical model; to achieve rapid underground determination of coal seam gas content. The invention can quickly carry out regional outburst prediction and regional measure effect inspection; can quickly check whether the gas drainage in the working face of the outburst coal seam reaches the standard; and effectively avoid low-indicator outburst accidents.

Description

A rapid method for downhole determination of coal seam gas content

technical field

The invention relates to a coal seam gas content measurement method, in particular to a coal seam gas content fast underground measurement method.

Background technique

The gas content of coal seams is one of the important basic parameters for the calculation of mine gas reserves and the prediction of gas emission. It is one of the important indicators of whether the drainage is up to standard ("Basic Indicators of Coal Mine Gas Drainage", AQ 1026-2006), and its accurate and rapid determination is very important.

At present, there are two methods for measuring coal seam gas content: direct method and indirect method. The direct method is carried out in accordance with the "Direct Measurement Method of Coal Seam Gas Content Underground" (GB/T 23250-2009). The coal seam gas content consists of three parts: ①Naturally desorbed gas in the well—Collection of coal samples at the underground site, and quickly put them into the coal samples Tank, measured by gas desorption speed tester; ② Lost gas amount—calculated by graphical method; ③ Residual gas amount——Used vacuum degassing device laboratory measurement; it can be seen that the direct method has complicated processes and high equipment requirements, generally requiring 48 It may take more than an hour for results to be obtained. The indirect method is to measure coal seam gas pressure on site according to "Direct Measurement Method of Underground Coal Seam Gas Pressure in Coal Mine" (AQ/T 1047-2007), and to measure adsorption constant (a, b value) and industrial analysis indicators (moisture, ash, volatilization, etc.) in the laboratory. Points), coal porosity and bulk density, the coal seam gas content is calculated by the formula; the indirect method takes a long time, usually more than 20 days, and some mines do not have the conditions to directly measure the coal seam gas pressure underground.

In summary, the above methods cannot meet the needs of modern mine gas control, and it is imminent and meaningful to explore a rapid underground measurement method of coal seam gas content.

Contents of the invention

The purpose of the present invention is to provide a rapid downhole measurement method of coal seam gas content to solve the defects of the prior art.

The technical scheme of the present invention is: a kind of coal seam gas content downhole fast measuring method, as shown in Figure 1, comprises the following steps:

①. Construct a borehole with a diameter of 42mm and a depth of 14m in the coal roadway excavation face.

For coal and gas outburst mines, the outburst prediction of coal roadway working face usually adopts the cuttings index method, and the prediction index includes the cuttings gas desorption index K ₁ or Δh ₂ (K ₁ is the coal sample detached from the coal body and exposed to the atmosphere The amount of gas desorption per gram of coal sample in the first minute, _Δh2 is the gas desorption amount in the period of 4 to 5 minutes after the equilibrium pressure of the coal sample is released from the drilling of a certain sampling section) , The amount of cuttings S. In the process of outburst prediction, the same borehole is used to simultaneously test K ₁ , Δh ₂ , S and coal seam gas content W. The specific method is as follows:

At least three drill holes with a diameter of 42mm and a depth of 14m should be constructed in the near-horizontal and gently inclined coal seam working face to the front coal body, and at least two drill holes with a diameter of 42mm and a hole depth of 14m should be constructed in the inclined or steeply inclined coal seam. The drill holes should be arranged in the soft layer as much as possible. One drill hole is located in the middle of the roadway section and parallel to the direction of excavation. The end point of the other drill holes should be located 2 to 4m outside the contour line on both sides of the roadway section, as shown in the figure 2.

②. Measure the amount of cuttings S for every 1m of the borehole, measure the _K1 and _Δh2 values for every 2m of drilling, and select the maximum value of the measured data as the final measured value of each index of the borehole.

③. When the borehole is drilled to 14m, the gas content W of the coal seam is measured by the direct method.

④. Use the gray correlation method to determine the degree of correlation between S, K ₁ or Δh ₂ and the coal seam gas content W, select W as the parent factor, X ₀ , S, Δh ₂ , K ₁ as sub-factors X ₁ , X ₂ , X _3. Carry out gray relational analysis, the specific steps are as follows:

(1) Calculate the gray absolute correlation degree ε _0i , let

${\mathrm{<span\; class="notranslate">\; x</span>}}_{\mathrm{<span\; class="notranslate">\; i</span>}}^{\mathrm{<span\; class="notranslate">\; 0</span>}}<span\; class="notranslate">\; =</span><span\; class="notranslate">\; (</span>{\mathrm{<span\; class="notranslate">\; x</span>}}_{\mathrm{<span\; class="notranslate">\; i</span>}}<span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; 1</span>}<span\; class="notranslate">\; )</span><span\; class="notranslate">\; -</span>{\mathrm{<span\; class="notranslate">\; x</span>}}_{\mathrm{<span\; class="notranslate">\; i</span>}}<span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; 1</span>}<span\; class="notranslate">\; )</span><span\; class="notranslate">\; ,</span>{\mathrm{<span\; class="notranslate">\; x</span>}}_{\mathrm{<span\; class="notranslate">\; i</span>}}<span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; 2</span>}<span\; class="notranslate">\; )</span><span\; class="notranslate">\; -</span>{\mathrm{<span\; class="notranslate">\; x</span>}}_{\mathrm{<span\; class="notranslate">\; i</span>}}<span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; 1</span>}<span\; class="notranslate">\; )</span><span\; class="notranslate">\; ,</span>{\mathrm{<span\; class="notranslate">\; x</span>}}_{\mathrm{<span\; class="notranslate">\; i</span>}}<span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; 3</span>}<span\; class="notranslate">\; )</span><span\; class="notranslate">\; -</span>{\mathrm{<span\; class="notranslate">\; x</span>}}_{\mathrm{<span\; class="notranslate">\; i</span>}}<span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; 1</span>}<span\; class="notranslate">\; )</span><span\; class="notranslate">\; ,</span>{\mathrm{<span\; class="notranslate">\; x</span>}}_{\mathrm{<span\; class="notranslate">\; i</span>}}<span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; 4</span>}<span\; class="notranslate">\; )</span><span\; class="notranslate">\; -</span>{\mathrm{<span\; class="notranslate">\; x</span>}}_{\mathrm{<span\; class="notranslate">\; i</span>}}<span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; 1</span>}<span\; class="notranslate">\; )</span><span\; class="notranslate">\; )</span><span\; class="notranslate">\; =</span><span\; class="notranslate">\; (</span>{\mathrm{<span\; class="notranslate">\; x</span>}}_{\mathrm{<span\; class="notranslate">\; i</span>}}^{\mathrm{<span\; class="notranslate">\; 0</span>}}<span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; 1</span>}<span\; class="notranslate">\; )</span><span\; class="notranslate">\; ,</span>{\mathrm{<span\; class="notranslate">\; x</span>}}_{\mathrm{<span\; class="notranslate">\; i</span>}}^{\mathrm{<span\; class="notranslate">\; 0</span>}}<span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; 2</span>}<span\; class="notranslate">\; )</span><span\; class="notranslate">\; ,</span>{\mathrm{<span\; class="notranslate">\; x</span>}}_{\mathrm{<span\; class="notranslate">\; i</span>}}^{\mathrm{<span\; class="notranslate">\; 0</span>}}<span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; 3</span>}<span\; class="notranslate">\; )</span><span\; class="notranslate">\; ,</span>{\mathrm{<span\; class="notranslate">\; x</span>}}_{\mathrm{<span\; class="notranslate">\; i</span>}}^{\mathrm{<span\; class="notranslate">\; 0</span>}}<span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; 4</span>}<span\; class="notranslate">\; )</span><span\; class="notranslate">\; )</span><span\; class="notranslate">\; ,</span>$

$<span\; class="notranslate">\; |</span>{\mathrm{<span\; class="notranslate">\; the\; s</span>}}_{\mathrm{<span\; class="notranslate">\; i</span>}}<span\; class="notranslate">\; |</span><span\; class="notranslate">\; =</span><span\; class="notranslate">\; |</span>\underset{\mathrm{<span\; class="notranslate">\; k</span>}<span\; class="notranslate">\; =</span>\mathrm{<span\; class="notranslate">\; 2</span>}}{\overset{\mathrm{<span\; class="notranslate">\; 3</span>}}{\mathrm{<span\; class="notranslate">\; \&Sigma;</span>}}}{\mathrm{<span\; class="notranslate">\; x</span>}}_{\mathrm{<span\; class="notranslate">\; i</span>}}^{\mathrm{<span\; class="notranslate">\; 0</span>}}<span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; k</span>}<span\; class="notranslate">\; +</span>\frac{\mathrm{<span\; class="notranslate">\; 1</span>}}{\mathrm{<span\; class="notranslate">\; 2</span>}}{\mathrm{<span\; class="notranslate">\; x</span>}}_{\mathrm{<span\; class="notranslate">\; i</span>}}^{\mathrm{<span\; class="notranslate">\; 0</span>}}<span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; 4</span>}<span\; class="notranslate">\; )</span><span\; class="notranslate">\; |</span><span\; class="notranslate">\; ,</span><span\; class="notranslate">\; |</span>{\mathrm{<span\; class="notranslate">\; the\; s</span>}}_{\mathrm{<span\; class="notranslate">\; i</span>}}<span\; class="notranslate">\; -</span>{\mathrm{<span\; class="notranslate">\; the\; s</span>}}_{\mathrm{<span\; class="notranslate">\; 0</span>}}<span\; class="notranslate">\; |</span><span\; class="notranslate">\; =</span><span\; class="notranslate">\; |</span>\underset{\mathrm{<span\; class="notranslate">\; k</span>}<span\; class="notranslate">\; =</span>\mathrm{<span\; class="notranslate">\; 2</span>}}{\overset{\mathrm{<span\; class="notranslate">\; 3</span>}}{\mathrm{<span\; class="notranslate">\; \&Sigma;</span>}}}<span\; class="notranslate">\; (</span>{\mathrm{<span\; class="notranslate">\; x</span>}}_{\mathrm{<span\; class="notranslate">\; i</span>}}^{\mathrm{<span\; class="notranslate">\; 0</span>}}<span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; k</span>}<span\; class="notranslate">\; )</span><span\; class="notranslate">\; -</span>{\mathrm{<span\; class="notranslate">\; x</span>}}_{\mathrm{<span\; class="notranslate">\; 0</span>}}^{\mathrm{<span\; class="notranslate">\; 0</span>}}<span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; k</span>}<span\; class="notranslate">\; )</span><span\; class="notranslate">\; )</span><span\; class="notranslate">\; +</span>\frac{\mathrm{<span\; class="notranslate">\; 1</span>}}{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; (</span>{\mathrm{<span\; class="notranslate">\; x</span>}}_{\mathrm{<span\; class="notranslate">\; i</span>}}^{\mathrm{<span\; class="notranslate">\; 0</span>}}<span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; 4</span>}<span\; class="notranslate">\; )</span><span\; class="notranslate">\; -</span>{\mathrm{<span\; class="notranslate">\; x</span>}}_{\mathrm{<span\; class="notranslate">\; 0</span>}}^{\mathrm{<span\; class="notranslate">\; 0</span>}}<span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; 4</span>}<span\; class="notranslate">\; )</span><span\; class="notranslate">\; )</span><span\; class="notranslate">\; |</span><span\; class="notranslate">\; ,</span>$

${\mathrm{<span\; class="notranslate">\; \&epsiv;</span>}}_{\mathrm{<span\; class="notranslate">\; 0</span>}\mathrm{<span\; class="notranslate">\; i</span>}}<span\; class="notranslate">\; =</span>\frac{\mathrm{<span\; class="notranslate">\; 1</span>}<span\; class="notranslate">\; +</span><span\; class="notranslate">\; |</span>{\mathrm{<span\; class="notranslate">\; the\; s</span>}}_{\mathrm{<span\; class="notranslate">\; 0</span>}}<span\; class="notranslate">\; |</span><span\; class="notranslate">\; +</span><span\; class="notranslate">\; |</span>{\mathrm{<span\; class="notranslate">\; the\; s</span>}}_{\mathrm{<span\; class="notranslate">\; i</span>}}<span\; class="notranslate">\; |</span>}{\mathrm{<span\; class="notranslate">\; 1</span>}<span\; class="notranslate">\; +</span><span\; class="notranslate">\; |</span>{\mathrm{<span\; class="notranslate">\; the\; s</span>}}_{\mathrm{<span\; class="notranslate">\; 0</span>}}<span\; class="notranslate">\; |</span><span\; class="notranslate">\; +</span><span\; class="notranslate">\; |</span>{\mathrm{<span\; class="notranslate">\; the\; s</span>}}_{\mathrm{<span\; class="notranslate">\; i</span>}}<span\; class="notranslate">\; |</span><span\; class="notranslate">\; +</span><span\; class="notranslate">\; |</span>{\mathrm{<span\; class="notranslate">\; the\; s</span>}}_{\mathrm{<span\; class="notranslate">\; i</span>}}<span\; class="notranslate">\; -</span>{\mathrm{<span\; class="notranslate">\; the\; s</span>}}_{\mathrm{<span\; class="notranslate">\; 0</span>}}<span\; class="notranslate">\; |</span>}<span\; class="notranslate">\; ,</span><span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; i</span>}<span\; class="notranslate">\; =</span>\mathrm{<span\; class="notranslate">\; 0</span>}<span\; class="notranslate">\; ~</span>\mathrm{<span\; class="notranslate">\; 4</span>}<span\; class="notranslate">\; )</span>$

( ₂ ) To find the gray relative correlation degree r _0i , first find the initial value image of Xi ( _i =0~4)

${{\mathrm{<span\; class="notranslate">\; x</span>}}^{<span\; class="notranslate">\; \&prime;</span>}}_{\mathrm{<span\; class="notranslate">\; i</span>}}<span\; class="notranslate">\; =</span><span\; class="notranslate">\; (</span>\frac{{\mathrm{<span\; class="notranslate">\; x</span>}}_{\mathrm{<span\; class="notranslate">\; i</span>}}<span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; 1</span>}<span\; class="notranslate">\; )</span>}{{\mathrm{<span\; class="notranslate">\; x</span>}}_{\mathrm{<span\; class="notranslate">\; i</span>}}<span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; 1</span>}<span\; class="notranslate">\; )</span>}<span\; class="notranslate">\; ,</span>\frac{{\mathrm{<span\; class="notranslate">\; x</span>}}_{\mathrm{<span\; class="notranslate">\; i</span>}}<span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; 2</span>}<span\; class="notranslate">\; )</span>}{{\mathrm{<span\; class="notranslate">\; x</span>}}_{\mathrm{<span\; class="notranslate">\; i</span>}}<span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; 1</span>}<span\; class="notranslate">\; )</span>}<span\; class="notranslate">\; ,</span>\frac{{\mathrm{<span\; class="notranslate">\; x</span>}}_{\mathrm{<span\; class="notranslate">\; i</span>}}<span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; 3</span>}<span\; class="notranslate">\; )</span>}{{\mathrm{<span\; class="notranslate">\; x</span>}}_{\mathrm{<span\; class="notranslate">\; i</span>}}<span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; 1</span>}<span\; class="notranslate">\; )</span>}<span\; class="notranslate">\; ,</span>\frac{{\mathrm{<span\; class="notranslate">\; x</span>}}_{\mathrm{<span\; class="notranslate">\; i</span>}}<span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; 4</span>}<span\; class="notranslate">\; )</span>}{\mathrm{<span\; class="notranslate">\; x</span>}<span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; 1</span>}<span\; class="notranslate">\; )</span>}<span\; class="notranslate">\; )</span><span\; class="notranslate">\; ,</span><span\; class="notranslate">\; |</span>{{\mathrm{<span\; class="notranslate">\; the\; s</span>}}^{<span\; class="notranslate">\; \&prime;</span>}}_{\mathrm{<span\; class="notranslate">\; i</span>}}<span\; class="notranslate">\; |</span><span\; class="notranslate">\; =</span><span\; class="notranslate">\; |</span>\underset{\mathrm{<span\; class="notranslate">\; k</span>}<span\; class="notranslate">\; =</span>\mathrm{<span\; class="notranslate">\; 2</span>}}{\overset{\mathrm{<span\; class="notranslate">\; 3</span>}}{\mathrm{<span\; class="notranslate">\; \&Sigma;</span>}}}{\mathrm{<span\; class="notranslate">\; x</span>}}_{\mathrm{<span\; class="notranslate">\; i</span>}}^{<span\; class="notranslate">\; \&prime;</span>\mathrm{<span\; class="notranslate">\; 0</span>}}<span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; k</span>}<span\; class="notranslate">\; )</span><span\; class="notranslate">\; +</span>\frac{\mathrm{<span\; class="notranslate">\; 1</span>}}{\mathrm{<span\; class="notranslate">\; 2</span>}}{\mathrm{<span\; class="notranslate">\; x</span>}}_{\mathrm{<span\; class="notranslate">\; i</span>}}^{<span\; class="notranslate">\; \&prime;</span>\mathrm{<span\; class="notranslate">\; 0</span>}}<span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; 4</span>}<span\; class="notranslate">\; )</span><span\; class="notranslate">\; |</span>$

$<span\; class="notranslate">\; |</span>{{\mathrm{<span\; class="notranslate">\; the\; s</span>}}^{<span\; class="notranslate">\; \&prime;</span>}}_{\mathrm{<span\; class="notranslate">\; i</span>}}<span\; class="notranslate">\; -</span>{{\mathrm{<span\; class="notranslate">\; the\; s</span>}}^{<span\; class="notranslate">\; \&prime;</span>}}_{\mathrm{<span\; class="notranslate">\; 0</span>}}<span\; class="notranslate">\; |</span><span\; class="notranslate">\; =</span><span\; class="notranslate">\; |</span>\underset{\mathrm{<span\; class="notranslate">\; k</span>}<span\; class="notranslate">\; =</span>\mathrm{<span\; class="notranslate">\; 2</span>}}{\overset{\mathrm{<span\; class="notranslate">\; 3</span>}}{\mathrm{<span\; class="notranslate">\; \&Sigma;</span>}}}<span\; class="notranslate">\; (</span>{\mathrm{<span\; class="notranslate">\; x</span>}}_{\mathrm{<span\; class="notranslate">\; i</span>}}^{<span\; class="notranslate">\; \&prime;</span>\mathrm{<span\; class="notranslate">\; 0</span>}}<span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; k</span>}<span\; class="notranslate">\; )</span><span\; class="notranslate">\; -</span>{\mathrm{<span\; class="notranslate">\; x</span>}}_{\mathrm{<span\; class="notranslate">\; 0</span>}}^{<span\; class="notranslate">\; \&prime;</span>\mathrm{<span\; class="notranslate">\; 0</span>}}<span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; k</span>}<span\; class="notranslate">\; )</span><span\; class="notranslate">\; )</span><span\; class="notranslate">\; +</span>\frac{\mathrm{<span\; class="notranslate">\; 1</span>}}{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; (</span>{\mathrm{<span\; class="notranslate">\; x</span>}}_{\mathrm{<span\; class="notranslate">\; i</span>}}^{<span\; class="notranslate">\; \&prime;</span>\mathrm{<span\; class="notranslate">\; 0</span>}}<span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; 4</span>}<span\; class="notranslate">\; )</span><span\; class="notranslate">\; -</span>{\mathrm{<span\; class="notranslate">\; x</span>}}_{\mathrm{<span\; class="notranslate">\; 0</span>}}^{<span\; class="notranslate">\; \&prime;</span>\mathrm{<span\; class="notranslate">\; 0</span>}}<span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; 4</span>}<span\; class="notranslate">\; )</span><span\; class="notranslate">\; )</span><span\; class="notranslate">\; |</span><span\; class="notranslate">\; ,</span>$

${\mathrm{<span\; class="notranslate">\; r</span>}}_{\mathrm{<span\; class="notranslate">\; 0</span>}\mathrm{<span\; class="notranslate">\; i</span>}}<span\; class="notranslate">\; =</span>\frac{\mathrm{<span\; class="notranslate">\; 1</span>}<span\; class="notranslate">\; +</span><span\; class="notranslate">\; |</span>{{\mathrm{<span\; class="notranslate">\; the\; s</span>}}^{<span\; class="notranslate">\; \&prime;</span>}}_{\mathrm{<span\; class="notranslate">\; 0</span>}}<span\; class="notranslate">\; |</span><span\; class="notranslate">\; +</span><span\; class="notranslate">\; |</span>{{\mathrm{<span\; class="notranslate">\; the\; s</span>}}^{<span\; class="notranslate">\; \&prime;</span>}}_{\mathrm{<span\; class="notranslate">\; i</span>}}<span\; class="notranslate">\; |</span>}{\mathrm{<span\; class="notranslate">\; 1</span>}<span\; class="notranslate">\; +</span><span\; class="notranslate">\; |</span>{{\mathrm{<span\; class="notranslate">\; the\; s</span>}}^{<span\; class="notranslate">\; \&prime;</span>}}_{\mathrm{<span\; class="notranslate">\; 0</span>}}<span\; class="notranslate">\; |</span><span\; class="notranslate">\; +</span><span\; class="notranslate">\; |</span>{{\mathrm{<span\; class="notranslate">\; the\; s</span>}}^{<span\; class="notranslate">\; \&prime;</span>}}_{\mathrm{<span\; class="notranslate">\; i</span>}}<span\; class="notranslate">\; |</span><span\; class="notranslate">\; +</span><span\; class="notranslate">\; |</span>{{\mathrm{<span\; class="notranslate">\; the\; s</span>}}^{<span\; class="notranslate">\; \&prime;</span>}}_{\mathrm{<span\; class="notranslate">\; i</span>}}<span\; class="notranslate">\; +</span>{{\mathrm{<span\; class="notranslate">\; the\; s</span>}}^{<span\; class="notranslate">\; \&prime;</span>}}_{\mathrm{<span\; class="notranslate">\; 0</span>}}<span\; class="notranslate">\; |</span>}<span\; class="notranslate">\; ,</span><span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; i</span>}<span\; class="notranslate">\; =</span>\mathrm{<span\; class="notranslate">\; 0</span>}<span\; class="notranslate">\; ~</span>\mathrm{<span\; class="notranslate">\; 4</span>}<span\; class="notranslate">\; )</span>$

(3) Find the gray comprehensive correlation degree ρ _0i , take θ=0.5, ρ _0i =θε _0i +(1－θ)r _0i (i=0～4)

(4) Arrange the degree of correlation in order from large to small to form a correlation sequence, reflecting that the influence of each sub-factor on the parent factor is weakened in turn, so as to optimize the best index;

According to the above steps, the comprehensive correlation degree of each index is calculated, and the index that has the greatest impact on the gas content W of the coal seam is determined.

⑤. Further measure the index that has the greatest impact on the coal seam gas content W, and simultaneously measure the coal seam gas content W;

⑥. Carry out regression analysis on the measurement data of the above two, and determine the mathematical model of the two;

⑦. Realize rapid underground measurement of coal seam gas content.

Beneficial effects of the present invention: regional outburst prediction and regional measure effect inspection can be carried out quickly; gas drainage can be quickly inspected on outburst coal seam working faces (including stone gate (well shaft) unraveling coal face, coal roadway excavation face, coal mining face) Whether it meets the standard; when predicting the outburst of the working face, the gas content of the coal seam can be used as an auxiliary index to effectively avoid outburst accidents with _low indicators; It takes about 1 hour.

Description of drawings

Fig. 1 is a flow chart of the downhole rapid determination method of coal seam gas content;

Fig. 2 is a schematic diagram of drilling layout, in which a is a schematic diagram of drilling holes predicted by cuttings index method in tunneling working face of near horizontal and gently inclined coal seam; b is a schematic diagram of drilling hole predicted by cuttings index method in tunneling working face of inclined and steep coal seam schematic diagram;

Figure 3 is a regression analysis diagram of the relationship between W and _K1 .

Detailed ways

Below in conjunction with the specific situation of accompanying drawing and certain coal mine, the present invention will be further described:

Fig. 1 is the concrete process flow diagram of a kind of coal seam gas content down-hole fast measuring method of the present invention, and the present invention comprises the following steps:

①. Construct a borehole with a diameter of 42mm and a depth of 14m in the coal roadway excavation face.

For coal and gas outburst mines, the outburst prediction of coal roadway working face usually adopts the cuttings index method, and the prediction index includes the cuttings gas desorption index K ₁ or Δh ₂ (K ₁ is the coal sample detached from the coal body and exposed to the atmosphere The amount of gas desorption per gram of coal sample in the first minute, _Δh2 is the gas desorption amount in the period of 4 to 5 minutes after the equilibrium pressure of the coal sample is released from the drilling of a certain sampling section) , The amount of cuttings S. In the process of outburst prediction, the same borehole is used to simultaneously test K ₁ , Δh ₂ , S and coal seam gas content W. The specific method is as follows:

At least three drill holes with a diameter of 42mm and a depth of 14m should be constructed in the near-horizontal and gently inclined coal seam working face to the front coal body, and at least two drill holes with a diameter of 42mm and a hole depth of 14m should be constructed in the inclined or steeply inclined coal seam. The drill holes should be arranged in the soft layer as much as possible. One drill hole is located in the middle of the excavation roadway section and parallel to the direction of excavation. The end point of the other drill holes should be located 2-4m outside the contour line on both sides of the roadway section, as shown in the figure 2.

②. Measure the total amount of cuttings S of the 1m section every 1m of drilling, measure the K ₁ or Δh ₂ value every 2m of drilling, and select the maximum value of the actual measured data as the final measurement value of each index of the drilling .

For a certain mine, the underground measurement results of a certain mine are shown in Table 1. The total drilling length of each borehole is 14m. During this process: (1) Measure the total amount of cuttings S in the 1m section of the drillhole every 1m. A total of 14 S are measured, and the maximum value of the 14 data is selected. As the final measured value of the borehole S, for example, the maximum value of the S of the 1# borehole is 3.5; (2) The K ₁ and Δh ₂ values are measured every 2m of the borehole, and a total of 7 K ₁ values and 7 For the value of Δh ₂ , the maximum value of 7 data is selected as the final measured value of the borehole K ₁ and Δh ₂ , for example, the maximum value of K ₁ in the 1# borehole is 0.48, and the maximum value of Δh ₂ is 200.

③. When the borehole is drilled to 14m, the gas content W of the coal seam is measured by the direct method.

For a certain mine, when the borehole is drilled to 14m, the gas content W of the coal seam is measured by the direct method, and each borehole has only one W measurement value, such as the W measurement value of the 1# borehole is 5.26.

Table 1 Determination results of coal seam gas content and outburst prediction indicators in a certain mine

④. Use the gray correlation method to determine the degree of correlation between S, K1 or Δh2 and the coal seam gas content W;

Select W as the parent factor, X ₀ , S, Δh ₂ , and K ₁ as sub-factors X ₁ , X ₂ , and X ₃ respectively, and conduct gray relational analysis. See Table 2 for the values of each factor.

The specific steps of gray relational analysis are as follows:

(1) Calculate the gray absolute correlation degree

make

$\begin{array}{c}{\mathrm{<span\; class="notranslate">\; x</span>}}_{\mathrm{<span\; class="notranslate">\; i</span>}}^{\mathrm{<span\; class="notranslate">\; 0</span>}}<span\; class="notranslate">\; =</span><span\; class="notranslate">\; (</span>{\mathrm{<span\; class="notranslate">\; x</span>}}_{\mathrm{<span\; class="notranslate">\; i</span>}}<span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; 1</span>}<span\; class="notranslate">\; )</span><span\; class="notranslate">\; -</span>{\mathrm{<span\; class="notranslate">\; x</span>}}_{\mathrm{<span\; class="notranslate">\; i</span>}}<span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; 1</span>}<span\; class="notranslate">\; )</span><span\; class="notranslate">\; ,</span>{\mathrm{<span\; class="notranslate">\; x</span>}}_{\mathrm{<span\; class="notranslate">\; i</span>}}<span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; 2</span>}<span\; class="notranslate">\; )</span><span\; class="notranslate">\; -</span>{\mathrm{<span\; class="notranslate">\; x</span>}}_{\mathrm{<span\; class="notranslate">\; i</span>}}<span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; 1</span>}<span\; class="notranslate">\; )</span><span\; class="notranslate">\; ,</span><span\; class="notranslate">\; .</span><span\; class="notranslate">\; .</span><span\; class="notranslate">\; .</span><span\; class="notranslate">\; ,</span>{\mathrm{<span\; class="notranslate">\; x</span>}}_{\mathrm{<span\; class="notranslate">\; i</span>}}<span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; 10</span>}<span\; class="notranslate">\; )</span><span\; class="notranslate">\; -</span>{\mathrm{<span\; class="notranslate">\; x</span>}}_{\mathrm{<span\; class="notranslate">\; i</span>}}<span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; 1</span>}<span\; class="notranslate">\; )</span><span\; class="notranslate">\; )</span><span\; class="notranslate">\; =</span><span\; class="notranslate">\; (</span>{\mathrm{<span\; class="notranslate">\; x</span>}}_{\mathrm{<span\; class="notranslate">\; i</span>}}^{\mathrm{<span\; class="notranslate">\; 0</span>}}<span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; 1</span>}<span\; class="notranslate">\; )</span><span\; class="notranslate">\; ,</span>{\mathrm{<span\; class="notranslate">\; x</span>}}_{\mathrm{<span\; class="notranslate">\; i</span>}}^{\mathrm{<span\; class="notranslate">\; 0</span>}}<span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; 2</span>}<span\; class="notranslate">\; )</span><span\; class="notranslate">\; ,</span><span\; class="notranslate">\; .</span><span\; class="notranslate">\; .</span><span\; class="notranslate">\; .</span><span\; class="notranslate">\; ,</span>{\mathrm{<span\; class="notranslate">\; x</span>}}_{\mathrm{<span\; class="notranslate">\; i</span>}}^{\mathrm{<span\; class="notranslate">\; 0</span>}}<span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; 10</span>}<span\; class="notranslate">\; )</span><span\; class="notranslate">\; )</span>\\ <span\; class="notranslate">\; ,</span>\mathrm{<span\; class="notranslate">\; i</span>}<span\; class="notranslate">\; =</span>\mathrm{<span\; class="notranslate">\; 0,1,2,3</span>}\end{array}$

The calculation results are shown in Table 3.

$<span\; class="notranslate">\; |</span>{\mathrm{<span\; class="notranslate">\; the\; s</span>}}_{\mathrm{<span\; class="notranslate">\; i</span>}}<span\; class="notranslate">\; |</span><span\; class="notranslate">\; =</span><span\; class="notranslate">\; |</span>\underset{\mathrm{<span\; class="notranslate">\; k</span>}<span\; class="notranslate">\; =</span>\mathrm{<span\; class="notranslate">\; 2</span>}}{\overset{\mathrm{<span\; class="notranslate">\; 9</span>}}{\mathrm{<span\; class="notranslate">\; \&Sigma;</span>}}}{\mathrm{<span\; class="notranslate">\; x</span>}}_{\mathrm{<span\; class="notranslate">\; i</span>}}^{\mathrm{<span\; class="notranslate">\; 0</span>}}<span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; k</span>}<span\; class="notranslate">\; )</span><span\; class="notranslate">\; +</span>\frac{\mathrm{<span\; class="notranslate">\; 1</span>}}{\mathrm{<span\; class="notranslate">\; 2</span>}}{\mathrm{<span\; class="notranslate">\; x</span>}}_{\mathrm{<span\; class="notranslate">\; i</span>}}^{\mathrm{<span\; class="notranslate">\; 0</span>}}<span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; 10</span>}<span\; class="notranslate">\; )</span><span\; class="notranslate">\; |</span><span\; class="notranslate">\; ,</span>\mathrm{<span\; class="notranslate">\; i</span>}<span\; class="notranslate">\; =</span>\mathrm{<span\; class="notranslate">\; 0,1,2,3</span>}$

The calculation results are shown in Table 4.

$<span\; class="notranslate">\; |</span>{\mathrm{<span\; class="notranslate">\; the\; s</span>}}_{\mathrm{<span\; class="notranslate">\; i</span>}}<span\; class="notranslate">\; -</span>{\mathrm{<span\; class="notranslate">\; the\; s</span>}}_{\mathrm{<span\; class="notranslate">\; 0</span>}}<span\; class="notranslate">\; |</span><span\; class="notranslate">\; =</span><span\; class="notranslate">\; |</span>\underset{\mathrm{<span\; class="notranslate">\; k</span>}<span\; class="notranslate">\; =</span>\mathrm{<span\; class="notranslate">\; 2</span>}}{\overset{\mathrm{<span\; class="notranslate">\; 9</span>}}{\mathrm{<span\; class="notranslate">\; \&Sigma;</span>}}}<span\; class="notranslate">\; (</span>{\mathrm{<span\; class="notranslate">\; x</span>}}_{\mathrm{<span\; class="notranslate">\; i</span>}}^{\mathrm{<span\; class="notranslate">\; 0</span>}}<span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; k</span>}<span\; class="notranslate">\; )</span><span\; class="notranslate">\; -</span>{\mathrm{<span\; class="notranslate">\; x</span>}}_{\mathrm{<span\; class="notranslate">\; 0</span>}}^{\mathrm{<span\; class="notranslate">\; 0</span>}}<span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; k</span>}<span\; class="notranslate">\; )</span><span\; class="notranslate">\; )</span><span\; class="notranslate">\; +</span>\frac{\mathrm{<span\; class="notranslate">\; 1</span>}}{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; (</span>{\mathrm{<span\; class="notranslate">\; x</span>}}_{\mathrm{<span\; class="notranslate">\; i</span>}}^{\mathrm{<span\; class="notranslate">\; 0</span>}}<span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; 10</span>}<span\; class="notranslate">\; )</span><span\; class="notranslate">\; -</span>{\mathrm{<span\; class="notranslate">\; x</span>}}_{\mathrm{<span\; class="notranslate">\; 0</span>}}^{\mathrm{<span\; class="notranslate">\; 0</span>}}<span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; 10</span>}<span\; class="notranslate">\; )</span><span\; class="notranslate">\; )</span><span\; class="notranslate">\; |</span><span\; class="notranslate">\; ,</span>\mathrm{<span\; class="notranslate">\; i</span>}<span\; class="notranslate">\; =</span>\mathrm{<span\; class="notranslate">\; 0,1,2,3</span>}$

The calculation results are shown in Table 5 and Table 6.

${\mathrm{<span\; class="notranslate">\; \&epsiv;</span>}}_{\mathrm{<span\; class="notranslate">\; 0</span>}\mathrm{<span\; class="notranslate">\; i</span>}}<span\; class="notranslate">\; =</span>\frac{\mathrm{<span\; class="notranslate">\; 1</span>}<span\; class="notranslate">\; +</span><span\; class="notranslate">\; |</span>{\mathrm{<span\; class="notranslate">\; the\; s</span>}}_{\mathrm{<span\; class="notranslate">\; 0</span>}}<span\; class="notranslate">\; |</span><span\; class="notranslate">\; +</span><span\; class="notranslate">\; |</span>{\mathrm{<span\; class="notranslate">\; the\; s</span>}}_{\mathrm{<span\; class="notranslate">\; i</span>}}<span\; class="notranslate">\; |</span>}{\mathrm{<span\; class="notranslate">\; 1</span>}<span\; class="notranslate">\; +</span><span\; class="notranslate">\; |</span>{\mathrm{<span\; class="notranslate">\; the\; s</span>}}_{\mathrm{<span\; class="notranslate">\; 0</span>}}<span\; class="notranslate">\; |</span><span\; class="notranslate">\; +</span><span\; class="notranslate">\; |</span>{\mathrm{<span\; class="notranslate">\; the\; s</span>}}_{\mathrm{<span\; class="notranslate">\; i</span>}}<span\; class="notranslate">\; |</span><span\; class="notranslate">\; +</span><span\; class="notranslate">\; |</span>{\mathrm{<span\; class="notranslate">\; the\; s</span>}}_{\mathrm{<span\; class="notranslate">\; i</span>}}<span\; class="notranslate">\; -</span>{\mathrm{<span\; class="notranslate">\; the\; s</span>}}_{\mathrm{<span\; class="notranslate">\; 0</span>}}<span\; class="notranslate">\; |</span>}<span\; class="notranslate">\; ,</span>\mathrm{<span\; class="notranslate">\; i</span>}<span\; class="notranslate">\; =</span>\mathrm{<span\; class="notranslate">\; 0,1,2,3</span>}$

The calculation results are shown in Table 7.

(2) Calculate the gray relative correlation degree

First find out the initial value of Xi _i like Xi _′

${{\mathrm{<span\; class="notranslate">\; x</span>}}_{\mathrm{<span\; class="notranslate">\; i</span>}}}^{<span\; class="notranslate">\; \&prime;</span>}<span\; class="notranslate">\; =</span><span\; class="notranslate">\; (</span>\frac{{\mathrm{<span\; class="notranslate">\; x</span>}}_{\mathrm{<span\; class="notranslate">\; i</span>}}<span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; 1</span>}<span\; class="notranslate">\; )</span>}{{\mathrm{<span\; class="notranslate">\; x</span>}}_{\mathrm{<span\; class="notranslate">\; i</span>}}<span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; 1</span>}<span\; class="notranslate">\; )</span>}<span\; class="notranslate">\; ,</span>\frac{{\mathrm{<span\; class="notranslate">\; x</span>}}_{\mathrm{<span\; class="notranslate">\; i</span>}}<span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; 2</span>}<span\; class="notranslate">\; )</span>}{{\mathrm{<span\; class="notranslate">\; x</span>}}_{\mathrm{<span\; class="notranslate">\; i</span>}}<span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; 1</span>}<span\; class="notranslate">\; )</span>}<span\; class="notranslate">\; ,</span><span\; class="notranslate">\; .</span><span\; class="notranslate">\; .</span><span\; class="notranslate">\; .</span><span\; class="notranslate">\; ,</span>\frac{{\mathrm{<span\; class="notranslate">\; x</span>}}_{\mathrm{<span\; class="notranslate">\; i</span>}}<span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; 10</span>}<span\; class="notranslate">\; )</span>}{{\mathrm{<span\; class="notranslate">\; x</span>}}_{\mathrm{<span\; class="notranslate">\; i</span>}}<span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; 1</span>}<span\; class="notranslate">\; )</span>}<span\; class="notranslate">\; )</span><span\; class="notranslate">\; ,</span>\mathrm{<span\; class="notranslate">\; i</span>}<span\; class="notranslate">\; =</span>\mathrm{<span\; class="notranslate">\; 0,1,2,3</span>}$

The calculation results are shown in Table 8.

$\begin{array}{c}{\mathrm{<span\; class="notranslate">\; x</span>}}_{\mathrm{<span\; class="notranslate">\; i</span>}}^{\mathrm{<span\; class="notranslate">\; 0</span>}<span\; class="notranslate">\; \&prime;</span>}<span\; class="notranslate">\; =</span><span\; class="notranslate">\; (</span>{{\mathrm{<span\; class="notranslate">\; x</span>}}_{\mathrm{<span\; class="notranslate">\; i</span>}}}^{<span\; class="notranslate">\; \&prime;</span>}<span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; 1</span>}<span\; class="notranslate">\; )</span><span\; class="notranslate">\; -</span>{{\mathrm{<span\; class="notranslate">\; x</span>}}_{\mathrm{<span\; class="notranslate">\; i</span>}}}^{<span\; class="notranslate">\; \&prime;</span>}<span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; 1</span>}<span\; class="notranslate">\; )</span><span\; class="notranslate">\; ,</span>{{\mathrm{<span\; class="notranslate">\; x</span>}}_{\mathrm{<span\; class="notranslate">\; i</span>}}}^{<span\; class="notranslate">\; \&prime;</span>}<span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; 2</span>}<span\; class="notranslate">\; )</span><span\; class="notranslate">\; -</span>{{\mathrm{<span\; class="notranslate">\; x</span>}}_{\mathrm{<span\; class="notranslate">\; i</span>}}}^{<span\; class="notranslate">\; \&prime;</span>}<span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; 1</span>}<span\; class="notranslate">\; )</span><span\; class="notranslate">\; ,</span><span\; class="notranslate">\; .</span><span\; class="notranslate">\; .</span><span\; class="notranslate">\; .</span><span\; class="notranslate">\; ,</span>{{\mathrm{<span\; class="notranslate">\; x</span>}}_{\mathrm{<span\; class="notranslate">\; i</span>}}}^{<span\; class="notranslate">\; \&prime;</span>}<span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; 10</span>}<span\; class="notranslate">\; )</span><span\; class="notranslate">\; -</span>{{\mathrm{<span\; class="notranslate">\; x</span>}}_{\mathrm{<span\; class="notranslate">\; i</span>}}}^{<span\; class="notranslate">\; \&prime;</span>}<span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; 1</span>}<span\; class="notranslate">\; )</span><span\; class="notranslate">\; )</span><span\; class="notranslate">\; =</span><span\; class="notranslate">\; (</span>{\mathrm{<span\; class="notranslate">\; x</span>}}_{\mathrm{<span\; class="notranslate">\; i</span>}}^{\mathrm{<span\; class="notranslate">\; 0</span>}<span\; class="notranslate">\; \&prime;</span>}<span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; 1</span>}<span\; class="notranslate">\; )</span><span\; class="notranslate">\; ,</span>{\mathrm{<span\; class="notranslate">\; x</span>}}_{\mathrm{<span\; class="notranslate">\; i</span>}}^{\mathrm{<span\; class="notranslate">\; 0</span>}<span\; class="notranslate">\; \&prime;</span>}<span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; 2</span>}<span\; class="notranslate">\; )</span><span\; class="notranslate">\; ,</span><span\; class="notranslate">\; .</span><span\; class="notranslate">\; .</span><span\; class="notranslate">\; .</span><span\; class="notranslate">\; ,</span>{\mathrm{<span\; class="notranslate">\; x</span>}}_{\mathrm{<span\; class="notranslate">\; i</span>}}^{\mathrm{<span\; class="notranslate">\; 0</span>}<span\; class="notranslate">\; \&prime;</span>}<span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; 10</span>}<span\; class="notranslate">\; )</span><span\; class="notranslate">\; )</span>\\ <span\; class="notranslate">\; ,</span>\mathrm{<span\; class="notranslate">\; i</span>}<span\; class="notranslate">\; =</span>\mathrm{<span\; class="notranslate">\; 0,1,2,3</span>}\end{array}$

The calculation results are shown in Table 9.

$<span\; class="notranslate">\; |</span>{{\mathrm{<span\; class="notranslate">\; the\; s</span>}}_{\mathrm{<span\; class="notranslate">\; i</span>}}}^{<span\; class="notranslate">\; \&prime;</span>}<span\; class="notranslate">\; |</span><span\; class="notranslate">\; =</span><span\; class="notranslate">\; |</span>\underset{\mathrm{<span\; class="notranslate">\; k</span>}<span\; class="notranslate">\; =</span>\mathrm{<span\; class="notranslate">\; 2</span>}}{\overset{\mathrm{<span\; class="notranslate">\; 9</span>}}{\mathrm{<span\; class="notranslate">\; \&Sigma;</span>}}}{\mathrm{<span\; class="notranslate">\; x</span>}}_{\mathrm{<span\; class="notranslate">\; i</span>}}^{\mathrm{<span\; class="notranslate">\; 0</span>}<span\; class="notranslate">\; \&prime;</span>}<span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; k</span>}<span\; class="notranslate">\; )</span><span\; class="notranslate">\; +</span>\frac{\mathrm{<span\; class="notranslate">\; 1</span>}}{\mathrm{<span\; class="notranslate">\; 2</span>}}{\mathrm{<span\; class="notranslate">\; x</span>}}_{\mathrm{<span\; class="notranslate">\; i</span>}}^{\mathrm{<span\; class="notranslate">\; 0</span>}<span\; class="notranslate">\; \&prime;</span>}<span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; 10</span>}<span\; class="notranslate">\; )</span><span\; class="notranslate">\; |</span><span\; class="notranslate">\; ,</span>\mathrm{<span\; class="notranslate">\; i</span>}<span\; class="notranslate">\; =</span>\mathrm{<span\; class="notranslate">\; 0,1,2,3</span>}$

The calculation results are shown in Table 10.

$<span\; class="notranslate">\; |</span>{{\mathrm{<span\; class="notranslate">\; the\; s</span>}}_{\mathrm{<span\; class="notranslate">\; i</span>}}}^{<span\; class="notranslate">\; \&prime;</span>}<span\; class="notranslate">\; -</span>{{\mathrm{<span\; class="notranslate">\; the\; s</span>}}_{\mathrm{<span\; class="notranslate">\; 0</span>}}}^{<span\; class="notranslate">\; \&prime;</span>}<span\; class="notranslate">\; |</span><span\; class="notranslate">\; =</span><span\; class="notranslate">\; |</span>\underset{\mathrm{<span\; class="notranslate">\; k</span>}<span\; class="notranslate">\; =</span>\mathrm{<span\; class="notranslate">\; 2</span>}}{\overset{\mathrm{<span\; class="notranslate">\; 9</span>}}{\mathrm{<span\; class="notranslate">\; \&Sigma;</span>}}}<span\; class="notranslate">\; (</span>{\mathrm{<span\; class="notranslate">\; x</span>}}_{\mathrm{<span\; class="notranslate">\; i</span>}}^{\mathrm{<span\; class="notranslate">\; 0</span>}<span\; class="notranslate">\; \&prime;</span>}<span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; k</span>}<span\; class="notranslate">\; )</span><span\; class="notranslate">\; -</span>{\mathrm{<span\; class="notranslate">\; x</span>}}_{\mathrm{<span\; class="notranslate">\; 0</span>}}^{\mathrm{<span\; class="notranslate">\; 0</span>}<span\; class="notranslate">\; \&prime;</span>}<span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; k</span>}<span\; class="notranslate">\; )</span><span\; class="notranslate">\; )</span><span\; class="notranslate">\; +</span>\frac{\mathrm{<span\; class="notranslate">\; 1</span>}}{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; (</span>{\mathrm{<span\; class="notranslate">\; x</span>}}_{\mathrm{<span\; class="notranslate">\; i</span>}}^{\mathrm{<span\; class="notranslate">\; 0</span>}<span\; class="notranslate">\; \&prime;</span>}<span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; 10</span>}<span\; class="notranslate">\; )</span><span\; class="notranslate">\; -</span>{\mathrm{<span\; class="notranslate">\; x</span>}}_{\mathrm{<span\; class="notranslate">\; 0</span>}}^{\mathrm{<span\; class="notranslate">\; 0</span>}<span\; class="notranslate">\; \&prime;</span>}<span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; 10</span>}<span\; class="notranslate">\; )</span><span\; class="notranslate">\; )</span><span\; class="notranslate">\; |</span><span\; class="notranslate">\; ;</span>\mathrm{<span\; class="notranslate">\; i</span>}<span\; class="notranslate">\; =</span>\mathrm{<span\; class="notranslate">\; 0,1,2,3</span>}$

The calculation results are shown in Table 11 and Table 12.

${\mathrm{<span\; class="notranslate">\; r</span>}}_{\mathrm{<span\; class="notranslate">\; 0</span>}\mathrm{<span\; class="notranslate">\; i</span>}}<span\; class="notranslate">\; =</span>\frac{\mathrm{<span\; class="notranslate">\; 1</span>}<span\; class="notranslate">\; +</span><span\; class="notranslate">\; |</span>{{\mathrm{<span\; class="notranslate">\; the\; s</span>}}_{\mathrm{<span\; class="notranslate">\; 0</span>}}}^{<span\; class="notranslate">\; \&prime;</span>}<span\; class="notranslate">\; |</span><span\; class="notranslate">\; +</span><span\; class="notranslate">\; |</span>{{\mathrm{<span\; class="notranslate">\; the\; s</span>}}_{\mathrm{<span\; class="notranslate">\; i</span>}}}^{<span\; class="notranslate">\; \&prime;</span>}<span\; class="notranslate">\; |</span>}{\mathrm{<span\; class="notranslate">\; 1</span>}<span\; class="notranslate">\; +</span><span\; class="notranslate">\; |</span>{{\mathrm{<span\; class="notranslate">\; the\; s</span>}}_{\mathrm{<span\; class="notranslate">\; 0</span>}}}^{<span\; class="notranslate">\; \&prime;</span>}<span\; class="notranslate">\; |</span><span\; class="notranslate">\; +</span><span\; class="notranslate">\; |</span>{{\mathrm{<span\; class="notranslate">\; the\; s</span>}}_{\mathrm{<span\; class="notranslate">\; i</span>}}}^{<span\; class="notranslate">\; \&prime;</span>}<span\; class="notranslate">\; |</span><span\; class="notranslate">\; +</span><span\; class="notranslate">\; |</span>{{\mathrm{<span\; class="notranslate">\; the\; s</span>}}_{\mathrm{<span\; class="notranslate">\; i</span>}}}^{<span\; class="notranslate">\; \&prime;</span>}<span\; class="notranslate">\; -</span>{{\mathrm{<span\; class="notranslate">\; the\; s</span>}}_{\mathrm{<span\; class="notranslate">\; 0</span>}}}^{<span\; class="notranslate">\; \&prime;</span>}<span\; class="notranslate">\; |</span>}<span\; class="notranslate">\; ,</span>\mathrm{<span\; class="notranslate">\; i</span>}<span\; class="notranslate">\; =</span>\mathrm{<span\; class="notranslate">\; 0,1,2,3</span>}$

The calculation results are shown in Table 13.

(3) Find the gray comprehensive correlation degree

Take θ=0.5, ρ _0i =θε _oi +(1-θ)r _0i , i=0, 1, 2, 3

The calculation results are shown in Table 14.

(4) Gray comprehensive correlation degree sorting

Arranging the correlation degrees from large to small constitutes a correlation sequence, which reflects that the influence of each sub-factor on the parent factor is weakened in turn, so that the best index is selected.

Table 2 Gray relational analysis factor _Xi value table

table 3 Calculation results

Table 4 | s _i | calculation results

|s _i | |s ₀ | |s ₁ | |s ₂ | |s ₃ | Calculation results 16.75 8.65 76 0.16

table 5 $x_i^0\left(k\right)-x_0^0\left(k\right)$ Calculation results

Table 6 | s _i -s ₀ | calculation results

|s _i -s ₀ | |s ₀ -s ₀ | |s ₁ -s ₀ | |s ₂ -s ₀ | |s ₃ -s ₀ | Calculation results 0 25.4 92.75 16.59

Table 7 Calculation results of gray absolute correlation degree ε _0i

ε _0i ε ₀₀ ε ₀₁ ε ₀₂ ε ₀₃ Calculation results 1 0.509653 0.502681 0.51913

Table 8X _i 'Calculation results

X _i ′ X _i '(1) X _i '(2) X _i '(3) X _i '(4) X _i '(5) X _i '(6) X _i '(7) X _i '(8) X _i '(9) X _i '(10) X ₀ ′ 1 1.87 1.71 1.63 1.54 1.30 0.71 1.14 1.42 0.7 X ₁ ' 1 0.86 0.71 0.43 0.71 0.86 0.71 0.86 0.43 0.91 X ₂ ' 1 1.60 1.50 1.02 1 0.50 0.70 0.50 1 0.6 X ₃ ′ 1 1.54 1.23 1.15 1.35 0.92 0.50 1 0.71 0.88

Table 9 Calculation results

Table 10 |s _i ′| calculation results

|s _i ′| |s ₀ ′| |s ₁ ′| |s ₂ ′| |s ₃ ′| Calculation results 3.184411 2.471429 0.38 0.333333

Table 12|s _i ′-s ₀ ′| calculation results

|S _i ′-s ₀ ′| |S _O ′-s ₀ ′| |S1′-s ₀ ′| |S ₂ ′-S ₀ ′| |S ₃ ′-s0′| Calculation results 0 5.655839 3.564411 2.851077

Table 13 Calculation results of gray relative correlation degree r _0i

r _0i r ₀₀ r ₀₁ r ₀₂ r ₀₃ Calculation results 1 0.540612 0.56151 0.613089

Table 14 Calculation results of gray comprehensive correlation degree ρ _0i

ρ _0i ρ ₀₀ (W) ρ ₀₁ (S) ρ ₀₂ (Δh ₂ ) ρ ₀₃ (K ₁ ) Calculation results 1 0.525132 0.532095 0.56611

It can be seen from Table 14 that the order of correlation between each index and coal seam gas content W is: K ₁ >Δh ₂ >S, and for a certain mine, K ₁ has the greatest influence on W. Therefore, it is necessary to further study the relationship between W and _K1 .

⑤. Further measure the index that has the greatest impact on the coal seam gas content W, and simultaneously measure the coal seam gas content W.

For a certain mine, _K1 has the greatest impact on W. After 30 days of continuous simultaneous measurement, 30 sets of W and _K1 data were obtained, as shown in Table 15.

Table 15 Underground synchronous measurement data table of a certain mine

Drilling number K ₁ (ml/g·min ^0.5 ) W( ^m3 /t) 1# 0.54 7.63 2# 0.48 7.18 3# 0.48 6.79 4# 0.53 7.76 5# 0.52 7.66 6# 0.53 7.64 7# 0.48 7.16 8# 0.47 6.72 9# 0.46 6.82 10# 0.51 7.51 11# 0.35 6.4 12# 0.35 5.45 13# 0.38 5.42 14# 0.42 5.75 15# 0.38 5.96

16# 0.22 2.47 17# 0.19 2.96 18# 0.41 5.43 19# 0.4 5.84 20# 0.33 4.59 twenty one# 0.64 9.2 twenty two# 0.55 7.74 twenty three# 0.54 8.08 twenty four# 0.51 7.23 25# 0.52 7.39 26# 0.61 7.94 27# 0.58 7.82 28# 0.62 9.12 29# 0.62 8.89 30# 0.6 7.63

⑥. Carry out regression analysis on the measurement data of the above two, and determine the mathematical model of the two;

For a certain mine, according to Table 15, the regression analysis of the relationship between W and _K1 is shown in Figure 3. It can be seen that with the increase of K ₁ , W gradually increases, and the correlation between the two is very high, and the correlation coefficient R=0.9637. The mathematical model is established as follows:

y=8.23411+11.19943ln(x+0.41384) (1)

In the formula, y is the coal seam gas content W, m ³ /t; x is the drilling cuttings gas desorption index K ₁ , ml/(g·min ^0.5 ).

⑦. For a certain mine, through the formula (1), the rapid underground measurement of coal seam gas content can be realized.

During the excavation process of a coal roadway with a length of about 1000m, with the accumulation of measured data of W and _K1 , formula (1) can be gradually corrected.

For other mines, the biggest influence on W may be K ₁ , or Δh ₂ or S. Therefore, it is necessary to determine the order of the correlation between each index and W according to the gray correlation analysis method, and obtain the index with the highest correlation with W, and then perform regression analysis on the data of the index and W to determine the mathematical model of the two, so as to realize Downhole rapid determination of coal seam gas content.

Claims (3)

1. a coal seam gas-bearing capacity down-hole rapid assay methods, its concrete steps are:

1.. in the boring of Driving Face in Coal Tunnel construction diameter 42mm, hole depth 14m;

2.. whole coal powder quantity of bore S that 1m measures this 1m section are often crept in boring, often creep into 2m and measure a K ₁with Δ h ₂value, and choose the final measured value of maximal value as this boring indices of measured data, wherein K ₁it is the desorption of mash gas amount of a coal sample every gram of coal sample in coal body disengaging exposure in an atmosphere the 1st minute; Δ h ₂for opening a certain sampling section from boring, the desorption of mash gas amount in the time period of 4th ~ 5 minutes after coal sample equalized pressure removal;

3.. when borehole drilling proceeds to 14m, adopt Direct Determination coal seam gas-bearing capacity W;

4.. use gray relation analysis method to determine S, K ₁or Δ h ₂with the correlation degree of coal seam gas-bearing capacity W, choose W as female factor, X ₀, S, Δ h ₂, K ₁respectively as sub-factor X ₁, X ₂, X ₃, carry out grey correlation analysis, concrete steps are as follows:

(1) grey absolute correlation degree ε is asked _0i, order

$X_i^0=\left(\begin{array}{ccccc}{x}_i\left(1\right)& x_i\left(1\right),x_i\left(2\right)& x_i\left(1\right),x_i\left(3\right)& x_i\left(1\right),x_i\left(4\right)& x_i\left(1\right))\end{array},=x_i^0\left(1\right),x_i^0\left(2\right),x_i^0\left(3\right),x_i^0\left(4\right)\right),$

$\left|s_i\right|=\left|\begin{array}{c}3\\ k=2\end{array}{x}_i^0(k+\frac{1}{2}{x}_i^0\left(4\right)\right|,$ $\left|\begin{array}{cc}{s}_i& s_0\end{array}\right|={|}_{k=2}^3\left(\begin{array}{cc}{x}_i^0\left(k\right)& x_0^0\left(k\right)\end{array}\right)+\frac{1}{2}\left(\begin{array}{cc}{x}_i^0\left(4\right)& x_0^0\left(4\right)\end{array}\right)|,$

$0i=\frac{1+\left|s_0\right|+\left|s_i\right|}{1+\left|s_0\right|+\left|s_i\right|+\left|\begin{array}{cc}{s}_i& s_0\end{array}\right|}(i=0~4)$

(2) grey relative relationship degree r is asked _0i, first obtain X _i( _i=0 ~ 4) initial value picture

${X^{\&prime;}}_i=\frac{x_i\left(1\right)}{x_i\left(1\right)},\frac{x_i\left(2\right)}{x_i\left(1\right)},\frac{x_i\left(3\right)}{x_i\left(1\right)},\frac{x_i\left(4\right)}{x\left(1\right)}\underset{\&divide;}{\&divide;},$ $\left|{s^{\&prime;}}_i\right|=\left|\begin{array}{c}3\\ k=2\end{array}{x}_i^{\&prime;0}(k+\frac{1}{2}{x}_i^{\&prime;0}\left(4\right)\right|$

$\left|\begin{array}{cc}{s^{\&prime;}}_i& {s^{\&prime;}}_0\end{array}\right|={|}_{k=2}^3\left(\begin{array}{cc}{x}_i^{\&prime;0}\left(k\right)& x_0^{\&prime;0}\left(k\right)\end{array}\right)+\frac{1}{2}\left(\begin{array}{cc}{x}_i^{\&prime;0}\left(4\right)& x_0^{\&prime;0}\left(4\right)\end{array}\right)|,$

$r_{0i}=\frac{1+\left|{s^{\&prime;}}_0\right|+\left|{s^{\&prime;}}_i\right|}{1+\left|{s^{\&prime;}}_0\right|+\left|{s^{\&prime;}}_i\right|+\left|\begin{array}{cc}{s^{\&prime;}}_i& {s^{\&prime;}}_0\end{array}\right|}(=_{i}0~4)$

(3) Synthesis Relational Grade of Grey ρ is asked _0i, get θ=0.5, ρ _0i=θ ε _0i+ (1-θ) r _0i(i=0 ~ 4)

(4) degree of association is formed inteerelated order by the arrangement of descending order, reflect that the influence power of each sub-factor to female factor weakens successively, thus optimize optimal parameter;

According to above-mentioned steps, calculate the Synthesis Relational Grade of each index, determine the index that coal seam gas-bearing capacity W is had the greatest impact;

5.. estimate the index that coal seam gas-bearing capacity W is had the greatest impact further, simultaneously Simultaneous Determination

Coal seam gas-bearing capacity W;

6.. regretional analysis is carried out to both determination datas above-mentioned, determines both mathematical models;

7.. realize coal seam gas-bearing capacity down-hole Fast Measurement.

2. a kind of coal seam gas-bearing capacity down-hole as claimed in claim 1 rapid assay methods, is characterized in that: step 1. in, when coal seam, front is nearly level, gently inclined seam workplace, at least should constructs 3 and hole; When coal seam is for inclination or high_dipping face, 2 borings of at least constructing.

3. a kind of coal seam gas-bearing capacity down-hole rapid assay methods as described in claim 1 and 2, it is characterized in that: boring should be arranged in soft layering as far as possible, a boring is positioned in the middle part of digging laneway section, and being parallel to tunneling direction, the whole hole point of other borings should be positioned at the outer 2 ~ 4m place of drift section both sides outline line.