KR101225499B1 - Blasting powder structure for seismic survey using a boringhole - Google Patents

Abstract

The present invention, the first cylindrical tube filled with gunpowder therein; A second tube accommodating the first tube such that an inner wall is spaced apart from the outer wall of the first tube by a predetermined distance to have a filling space; And a blasting line having one end connected to the gunpowder and the other end exiting to the outside, wherein the filling space is filled with a filling material, and is charged with a charge structure for exploration of a borehole seismic wave. High frequency characteristics can be exhibited without.

Description

BLASTING POWDER STRUCTURE FOR SEISMIC SURVEY USING A BORINGHOLE}

The present invention relates to a charge structure for borehole seismic exploration, and to a structure for borehole seismic exploration that can exhibit high high frequency characteristics without being influenced by pressure even at long depth.

The basic purpose of seismic exploration is to identify the distribution of strata and fracture zones, and two- and three-dimensional seismic exploration is the basic approach to achieve this goal.

As shown in FIG. 1, the vertical seismic profiling (VSP) which operates the source at the surface and receives at the borehole is more effective than the ground seismic survey that operates the transceiver at the surface as shown in FIG. 1. Becomes

However, in Korea, it is difficult to secure equipment capable of performing the VSP survey at more than 1,000 m. Therefore, a reverse vertical seismic probing (RVSP) method, which is transmitted from the borehole and received at the surface, is recommended.

However, even in the case of the RVSP, there is no suitable source to operate in the borehole, and only the method using the seismic primer and the gunpowder is unique.

To date, the maximum depth of successful blasting of borehole explosives performed in Korea is only about 300m.

However, blasting at depths of more than 300m and even more than 1,000m is essential for large-depth exploration using reverse vertical seismic exploration.

The method that has been used up to now is a single tube method as shown in Fig. 2 by using a PVC tube (about 30mm) as a long barrel, filled with the inside of the seismic exploration dedicated primer and gunpowder, the top and bottom with a lid and sealed waterproof Then use it.

3 is a result of the test at 250m, 400m, 500m in this manner as shown in the example of FIG.

As a cause of such blasting failure, the problem of the water pressure and waterproof which increase as the blasting depth becomes deep can be considered. Therefore, in order to determine the effect of waterproofing, water explosives were used instead of ordinary pneumatic gunpowder. This means that the effect of high water pressure is greater than waterproofing.

The present invention has been made to solve the above-described problems, the object of the present invention is to provide a charge structure for borehole seismic exploration that can exhibit a high frequency characteristics without being affected by pressure even in long depth.

In particular, such a charge structure enables borehole blasting at depths for borehole seismic exploration and RVSP exploration.

The present invention is a means for solving the above problems, the first cylindrical tube filled with gunpowder therein; A second tube accommodating the first tube such that an inner wall is spaced apart from the outer wall of the first tube by a predetermined distance to have a filling space; And a blast line having one end connected to the gunpowder and the other end exiting to the outside, wherein the filling space is filled with a filler to provide a charge structure for borehole seismic exploration.

Preferably, the filler provides a charge structure for borehole seismic exploration, characterized in that the granulated sand.

Preferably, the filler provides a charge structure for borehole seismic exploration, characterized in that the gravel and fine sand.

Preferably, the upper and lower portions of the first tube provides a charge structure for borehole seismic exploration, characterized in that the first waterproof cap is provided.

Preferably, the upper and lower portions of the second tube provides a charge structure for the borehole seismic exploration, characterized in that the second waterproof cap is provided.

The charge structure for the borehole seismic exploration according to the present invention has the effect of being able to exhibit high high frequency characteristics without being influenced by pressure even in long depth.

In particular, such a charge structure enables borehole blasting at depths for borehole seismic exploration and RVSP exploration.

1 is a view for explaining various examples of a seismic detection method using a borehole to which the present invention is applied.
2 is a view for explaining the charge structure according to the prior art.
3 is a view showing a blasting test results (elastic wave cross-section) using a charge structure according to the prior art.
4 is a view showing a misfire state of a charge structure according to the prior art.
Figure 5 is a cross-sectional view showing a charge structure for the borehole seismic exploration according to an embodiment of the present invention.
Figure 6 is a cross-sectional view of each seismic wave for comparing the experimental results using the double-tube-shaped charge structure and the single-tube-shaped charge structure according to the prior art.
7 is a cross-sectional view showing a charge structure for borehole seismic exploration according to another embodiment of the present invention.
8 is a view for comparing the blasting performance according to an embodiment of the present invention.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings.

5 is a cross-sectional view showing a charge structure for borehole seismic exploration according to an embodiment of the present invention.

According to FIG. 5, in the charge structure according to the present invention, the gunpowder 10 is filled in the first tube 20, and the second tube 30 is firstly spaced apart from the first tube 20 by a predetermined distance in a horizontal direction. The tube 20 is embedded, and the filler 40a is filled between the first tube 20 and the second tube 30. That is, the inner wall of the second tube 30 is spaced apart from the outer wall of the first tube 20 by a predetermined interval to form the filling space 40, the filling space 40 to be filled with the filling 40a Will be.

The first tube 20 is a cylindrical tube having a predetermined inner diameter (about 30 mm), and the upper and lower portions thereof are opened. The first tube 20 may be made of polyvinyl chloride (PVC).

The gunpowder used for the explosion is densely filled in the first tube 20, and the upper and lower openings are sealed and waterproofed by being blocked by the first waterproof cap 21. At this time, the first waterproof cap 21 has a cross-sectional shape of the c-shaped to block the upper or lower portion of the first tube 20 through the bottom surface, the first tube 20 through the cylindrical side Cover the outer edge of the part will increase the sealing and waterproofing efficiency. Here, the bottom surface of the first waterproof cap 21 covering the upper portion of the first tube 20 is formed with a hole for pulling out the blast line 11 connected to the gunpowder 10 in the first tube 20 to the outside. It is desirable to be.

In this case, the first pipe 20 may be formed in a cylindrical shape in which the lower portion is blocked and the upper portion is opened as shown in FIG. have. In this case, of course, the lower first waterproof cap 21 may be omitted.

On the other hand, the second tube 30 is a cylindrical tube having a predetermined inner diameter (about 70mm) to accommodate the first tube 20, the upper and lower portions are to be opened. The second pipe 30 may be made of polyvinyl chloride (PVC).

The second tube 30 has the first tube 20 inside the central portion, and because the diameter of the second tube 30 is larger than the diameter of the first tube 20, the first tube 20 ) And the filling space 40 is formed as an empty space between the second pipe 30.

In an embodiment of the present invention, the granulated sand is filled as the filling 40a in the filling space 40 between the first tube 20 and the second tube 30.

The upper and lower opening portions of the second pipe 30 are blocked by the second waterproof cap 31 to be sealed and waterproofed. At this time, the second waterproof cap 31 has a cross-sectional shape of the c-shaped to block the upper or lower portion of the second tube 30 through the bottom surface, the second tube 30 through the cylindrical side surface Cover the outer edge of the part will increase the sealing and waterproofing efficiency. Here, the bottom surface of the second waterproof cap 31 covering the upper portion of the twenty-first tube 30 is formed with a hole for pulling out the blast line 11 connected to the gunpowder 10 in the first tube 20 to the outside. It is desirable to be.

In the charge structure of the present invention having such a structure, the charge container surrounding the gunpowder 10 is configured in the form of a double tube of the first tube 20 and the second tube 30 and is also embedded in the second tube 30. In the structure of the first tube 20, the filling space 40 between the first tube 20 and the second tube 30 is filled with coarse sand as the filling 40a, thereby releasing pressure as compared to the conventional single tube. The effect can be achieved, and even in long depths, it can achieve stable performance as a transmitting source when detonating.

6 is a comparison result of the experiment using the double-tube-shaped charge structure according to the present invention and the single-tube-shaped charge structure according to the prior art.

As a result of using the double-tubular charge structure according to the present invention, the blasting experiment was successful in 500m, 700m and 900m as well as 400m.

For example, at 400m depth, the blast test was performed using the conventional method of the single tube type and the present invention of the double tube type. 270g of gunpowder is used for the single tube method and 125g of gunpowder is used for the blast test. Although large in size, the frequency characteristics of the double tube method using less gunpowder showed higher high frequency characteristics.

In Figure 6, the left side is an acoustic wave exploration cross section obtained in the blasting test using a single tube-type charge structure according to the prior art at a depth of 700m, the right side is a blasting test using a double-tube type charge structure according to the present invention at a depth of 700m The seismic cross section obtained from.

As can be seen from this, according to the double-explosion type gunpowder blasting technology of the present invention for securing the transmission source in the long-depth borehole required for seismic exploration using the borehole as shown in the test of Figure 6 400m, 500m By successfully blasting at depths of 700m and 900m, it was possible to secure a source of long-term borehole sound source device in borehole seismic survey.

Meanwhile, according to another embodiment of the present invention, the entire double pipe structure is the same as the one embodiment, but as shown in FIG. 7, the filling space 40 between the first pipe 20 and the second pipe 30 is shown in FIG. 7. The filling 40b is filled with gravel and fine sand.

In particular, filling the gravel and coarse sand than the coarse sand of one embodiment as a filler to fill the filling space 40 in the double pipe can secure more voids and more oxygen by the air in the filling space 40. The more likely you are to succeed.

8 shows the results of comparing the blasting (depth 700m) performance according to the difference of the filling filling the filling space 40 in the double tube. As shown in FIG. 8, fine granulated sand and gravel are filled together (figure right) compared to the case where coarse sand is used as a filler to fill the filling space 40 in the double pipe at the same depth (depth 700 m) (left side of the figure). More gunpowder exploded in, it can be seen that it is more efficient to fill the fine sand and gravel in the filling space 40 in the double tube as a source of transmission as the sound source device in the borehole.

As described above, an optimal embodiment has been disclosed in the drawings and specification. Although specific terms have been employed herein, they are used for purposes of illustration only and are not intended to limit the scope of the invention as defined in the claims or the claims. Therefore, those skilled in the art will appreciate that various modifications and equivalent embodiments are possible without departing from the scope of the present invention. Therefore, the true technical protection scope of the present invention will be defined by the technical spirit of the appended claims.

10 gunpowder 11: blasting line
20: first tube 21: first waterproof cap
30: second tube 31: second waterproof cap
40: filling space 40a, 40b: filling

Claims (5)

Peony structure is installed in the borehole filled with water to generate vertical elastic waves by explosion,
A cylindrical first tube made of PVC and filled with gunpowder therein;
A second tube made of PVC material and accommodating the first tube to have a filling space spaced apart from the outer wall of the first tube by a predetermined distance; And
And a blast line connected to the gun powder and exiting the other end to the outside.
The filling space is filled with a filling consisting of gravel and coarse sand,
The upper and lower parts of the first pipe block the upper and lower openings of the first pipe through the bottom surface and cover the outer edge of the first pipe through the cylindrical side to prevent the internal powder from being wet by the infiltration of external water. Waterproof cap is provided,
The upper and lower portions of the second tube block the upper and lower openings of the second tube through the bottom surface and cover the outer edge of the second tube through the cylindrical side to prevent the internal filling from being wetted by the penetration of external water. Charge structure for borehole seismic exploration, characterized in that the waterproof cap is provided.
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