A method for directional blasting in deep, highly pressurized rock formations without an open surface

Abstract

This application provides a method for directional blasting of deep, highly confined water-bearing rock formations without free face. The method involves drilling to the reservoir to be blasted and determining the bottom depth of the borehole; raising the drill rod 30-50 cm and filling the borehole with multiple hollow bodies to a height of 30-50 cm; raising the drill rod to a height H and filling the borehole with multiple explosive charges to a height H, with a detonating charge added when the charge reaches 0.5H; repeating step S3 until the drill rod is raised to a height 10-20 cm lower than the bottom surface of the upper top plate of the reservoir; raising the drill rod 30-50 cm and filling the borehole again with multiple hollow bodies to a height of 30-50 cm; filling the upper space of the hollow bodies in the borehole with cement to form a sealing layer with a thickness of 50-100 cm; and detonating the detonating charge. By preparing collectively encapsulated explosives into separate explosives with a certain sphericity, and simultaneously preparing hollow bodies with energy-absorbing properties, and combining them with the strength differences of different deep aquifers, it can achieve directional blasting of deep aquifers without free faces.

Description

Technical Field

[0001] This application relates to the field of energy extraction, and in particular to a method for directional blasting without free face in deep, highly confined water-bearing rock strata. Background Technology

[0002] In the development of deep, low-permeability sandstone uranium deposits and the efficient extraction of fossil energy, the challenge of improving the permeability of thin reservoirs is often encountered: that is, without affecting the lower and upper plates, improving the fracturing range and uniformity of the intermediate high-content rock energy reservoir to enhance the flow, replacement, and extraction efficiency of low-permeability energy in the pores.

[0003] Current methods for controlling the uniformity of rock reservoir fracturing mainly include perforation, hydraulic fracturing, and blasting. In these techniques, perforation operates within a 2-2.5m range, with small borehole diameters and limited fracturing pathways. Perforation-assisted fracturing also creates main fracture pathways through the perforation diameter. Furthermore, single hydraulic fracturing techniques result in fractures dominated by main fractures, exhibiting poor uniformity and a high risk of penetrating the upper and lower roof and floor plates, leading to energy loss during high-pressure runoff or escape of reservoir energy through these cracks. Blasting tends to produce more uniform fractures; however, existing blasting techniques are primarily used in shallow, waterless engineering projects such as tunnel excavation with free faces. Directly applying this technology to deep-ground drilling blasting without free faces carries the risk of causing fractures in the upper and lower roof and floor plates if not handled carefully. In existing waterless blasting operations, the design for blasting parallel to the preserved rock strata mainly employs decoupled charge contour blasting technology. For borehole blasting perpendicular to the rock strata, flexible material structures or further rigid structures are used at the bottom of the borehole to allow the detonation wave impact energy to be transferred laterally. However, the effectiveness of this method in rock blasting under high-pressure water conditions is unclear. In addition, for curved and irregularly shaped boreholes, traditional strip-shaped explosive loading presents a problem of clogging.

[0004] In summary, the shortcomings of existing technologies in this field are mainly reflected in: ① the impact of high-pressure water environment on blasting effect is not considered; ② the integrity of the upper and lower top and bottom plates of the reservoir cannot be protected simultaneously under blasting conditions; ③ under concentrated charge conditions, the concentrated release of explosive energy leads to the formation of a crushing zone in the vicinity, and excessive energy dissipation restricts the expansion of the crack zone. Summary of the Invention

[0005] This application provides a method for directional blasting without free face in deep, highly confined water-bearing rock strata. It can protect the integrity of the upper and lower top and bottom plates in directional blasting without free face, based on the high-confined water environment, to adapt to different types of blast holes, and improve the efficiency of in-situ leaching mining of oil or sandstone uranium ore while improving the uniformity of rock mass cracking.

[0006] The technical solution of this application is:

[0007] A method for directional blasting of deep, highly confined water-bearing rock strata without free face includes the following steps:

[0008] S1, Drill a hole to the reservoir to be blasted and determine the bottom depth of the hole;

[0009] S2, lift the drill rod 30-50cm, pass it through the center hole of the drill rod and fill the drill hole 30-50cm high with multiple hollow bodies;

[0010] S3, raise the drill rod to height H, fill the drill hole H height range through the center hole of the drill rod with multiple explosive charges, and fill with a detonating explosive charge when the height reaches 0.5H;

[0011] S4. Repeat the operation in step S3 until the drill rod is raised to a height of 10-20cm lower than the bottom surface of the upper plate of the reservoir to be blasted. Then, raise the drill rod upward by 30-50cm and fill the borehole again by 30-50cm through the central hole of the drill rod and using multiple hollow bodies.

[0012] S5, high-strength underwater sealing cement is used to fill the upper space of the hollow body in the borehole upwards, forming a sealing layer with a thickness of 50~100cm;

[0013] S6, the detonator is used to detonate the explosive charge.

[0014] As one technical solution of this application, in step S1, the method for determining the bottom depth of the borehole includes:

[0015] When the rock strength of the upper top plate and lower bottom plate of the reservoir to be blasted is higher than the rock strength of the reservoir to be blasted, the borehole is drilled to a point 20cm away from the top surface of the lower bottom plate.

[0016] When the rock strength of the upper top plate and the lower bottom plate of the reservoir to be blasted is lower than or equal to the rock strength of the reservoir to be blasted, the borehole is drilled to the top surface of the lower bottom plate.

[0017] As one technical solution of this application, in step S3, the range of the height H of the drill pipe is 20cm≤H≤60cm.

[0018] As one technical solution of this application, the hollow body is spherical or ellipsoidal, and the sphericity of the hollow body is 0.7~1.

[0019] As one technical solution of this application, the hollow body is externally sealed and its gravity is greater than the buoyancy of the area to be filled.

[0020] As one technical solution of this application, the explosive body is spherical or ellipsoidal, and the sphericity of the explosive body is 0.7~1.

[0021] As one technical solution of this application, the spherical shell of the explosive body is made of metal material and the inner wall is covered with a layer of high-strength carbon fiber cloth, and the interior of the explosive body is filled with industrial explosives.

[0022] As one technical solution of this application, the detonating explosive is spherical or ellipsoidal, and the sphericity of the detonating explosive is 0.7~1.

[0023] As one technical solution of this application, the spherical shell of the detonating explosive is made of metal material, and the inner wall is covered with a layer of high-strength carbon fiber cloth.

[0024] As one technical solution of this application, a detonator with a lead wire is arranged at the center of the detonating explosive body, and industrial explosives are filled in the area formed by the detonator and the high-strength carbon fiber cloth in the detonating explosive body.

[0025] The beneficial effects of this application are:

[0026] This application provides a method for directional blasting of deep, highly pressurized water-bearing rock strata without free face. It employs stackable, separable spherical and ellipsoidal hollow charge structures, explosives, and detonating charges. The explosives and detonating charges can be made of high-strength steel or non-metallic materials such as carbon fiber and basalt fiber. Their circular or elliptical structures can effectively resist water pressure, are easy to transport in curved pipes, and can fill blast holes of different structural shapes. Furthermore, the separate charge unit, composed of a hollow body, explosive body, and detonating explosive body, can be stored in the drill pipe. Without removing the drill pipe, the separate spherical charge structure can be inserted into the blasting charge location through a pushing action from the drill bit opening or the pre-drilled hole in the drill pipe. This avoids the problems of concentrated release of explosive energy during integral charging, which can easily lead to the formation of a fragmentation zone in the near-field and excessive energy dissipation that restricts the expansion of the crack zone. The bundled charge spherical unit, composed of a hollow body, explosive body, and detonating explosive body, can gradually release explosive energy to expand the crack zone. In addition, the hollow body deformation buffer in this method can reduce the direct impact of the explosive energy on the weak upper and lower plates, achieving the effect of directional blasting. Furthermore, this method solves the problem of long-distance delivery by releasing explosive balls during drilling, simplifies construction procedures, and improves production efficiency. Simultaneously, the design of the clustered explosive ball unit, composed of a hollow body, explosive material, and detonating explosive material, is suitable for water-pressure environments, adaptable to delivery pipelines of different shapes, and can effectively fill irregularly shaped boreholes. Moreover, the method avoids redundant design by using hollow bodies of the same shape, thus reducing production costs. Attached Figure Description

[0027] To more clearly illustrate the technical solutions of the embodiments of this application, the drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of this application and should not be regarded as a limitation of the scope. For those skilled in the art, other related drawings can be obtained from these drawings without creative effort.

[0028] Figure 1 A schematic diagram of the explosive encapsulation and filling structure in the directional blasting method for deep, highly confined water-bearing rock strata without free face provided in the first embodiment of this application;

[0029] Figure 2 This is a schematic diagram of the detonating charge structure provided in the first embodiment of this application;

[0030] Figure 3 This is a schematic diagram of the explosive encapsulation and filling structure in the directional blasting method for deep, highly pressurized water-bearing rock strata without free face, as provided in the second embodiment of this application.

[0031] Icons: 1-Reservoir to be blasted; 2-Upper top plate; 3-Lower bottom plate; 4-Hollow body; 5-Explosive body; 6-Initiating explosive body; 7-Plugging layer; 8-Spherical shell; 9-High-strength carbon fiber cloth; 10-Industrial explosive; 11-Detonator. Detailed Implementation

[0032] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. The components of the embodiments of this application described and shown in the accompanying drawings can typically be arranged and designed in various different configurations.

[0033] Therefore, the following detailed description of the embodiments of this application provided in the accompanying drawings is not intended to limit the scope of the claimed application, but merely to illustrate selected embodiments of the application. All other embodiments obtained by those skilled in the art based on the embodiments of this application without inventive effort are within the scope of protection of this application.

[0034] First embodiment:

[0035] Please refer to Figure 1 (Refer to) Figure 2This application provides a method for directional blasting of deep, high-pressure water-bearing rock strata without free face. This method is applicable when the rock strength of the upper top plate 2 and lower bottom plate 3 of the reservoir 1 to be blasted is higher than that of the reservoir 1 itself, effectively overcoming the technical defects of high water pressure, directional blasting with a protected reservoir, and slow release of explosive energy. The method mainly includes the following steps:

[0036] S1, use drilling equipment to drill a hole to the reservoir 1 to be blasted, and use drilling equipment to drill the hole to a point 20cm away from the top surface of the bottom plate 3 of the bottom plate 3 of the reservoir 1 to be blasted;

[0037] S2, using drilling equipment to lift the drill pipe 30-50cm, through the center hole of the drill pipe and using multiple hollow bodies 4 to fill the borehole 30-50cm in height range;

[0038] S3, using drilling equipment to raise the drill pipe to a height H, filling the borehole H height range through the center hole of the drill pipe with multiple explosive charges 5, and filling with a detonating charge 6 when the height reaches 0.5H; wherein, the range of the drill pipe height H is 20cm≤H≤60cm;

[0039] S4. Repeat the operation in step S3 until the drill rod is raised to a height of 10-20cm lower than the bottom surface of the upper top plate 2 of the reservoir 1 to be blasted. Then raise the drill rod 30-50cm upward and fill the borehole 30-50cm higher by passing it through the center hole of the drill rod and using multiple hollow bodies 4.

[0040] S5, high-strength underwater sealing cement is used to fill the upper space of the hollow body 4 in the borehole upwards, and a plugging layer 7 with a sealing thickness of 50~100cm is formed;

[0041] S6 uses an initiator to detonate all the detonating explosives 6 in the explosive charge group, and ensures that one of them can detonate normally.

[0042] It should be noted that in this embodiment, the hollow body 4 is spherical or ellipsoidal, and the sphericity of the hollow body 4 is 0.7~1; at the same time, the hollow body 4 is sealed externally and its gravity is greater than the buoyancy of the area to be filled. The hollow body 4 with this structure has the function of absorbing energy.

[0043] It should be noted that in this embodiment, the explosive body 5 is spherical or ellipsoidal, and the sphericity of the explosive body 5 is 0.7~1. Meanwhile, the spherical shell 8 of the explosive body 5 is made of metal, and the inner wall is covered with a layer of high-strength carbon fiber cloth 9. The interior of the explosive body 5 is filled with industrial explosive 10.

[0044] It should be noted that in this embodiment, the detonating explosive 6 is spherical or ellipsoidal, and the sphericity of the detonating explosive 6 is 0.7~1. Meanwhile, the spherical shell 8 of the detonating explosive 6 is made of metal, and its inner wall is covered with a layer of high-strength carbon fiber cloth 9. Furthermore, a detonator 11 with a fuse is arranged at the center of the interior of the detonating explosive 6, and the area within the detonator 11 and the high-strength carbon fiber cloth 9 is filled with industrial explosive 10.

[0045] Therefore, it adopts stackable, separable spherical and ellipsoidal charge structures, hollow bodies 4, explosive bodies 5, and detonating bodies 6. The explosive bodies 5 and detonating bodies 6 can be made of high-strength steel or non-metallic materials such as carbon fiber and basalt fiber. Its circular or elliptical structure can resist water pressure well, and it is easy to transport in curved pipes and can fill blast holes of different structural shapes. Furthermore, the separate charge unit, composed of hollow body 4, explosive body 5, and detonating explosive body 6, can be stored in the drill pipe. Without removing the drill pipe, the separate spherical charge structure can be inserted into the blasting charge location from the drill bit opening or the pre-drilled hole in the drill pipe through a pushing action. This avoids the problem of concentrated release of explosive energy during overall charging, which can easily lead to the formation of a crushing zone in the near area and excessive energy dissipation that restricts the expansion of the crack zone. The bundled explosive spherical unit, composed of hollow body 4, explosive body 5, and detonating explosive body 6, can gradually release explosive energy to expand the crack zone. In addition, the method uses the deformation buffer of hollow body 4 to unload energy, which can reduce the direct impact of the explosive energy on the weak upper top plate 2 and lower bottom plate 3, thus achieving the effect of directional blasting. Furthermore, this method solves the problem of long-distance delivery by releasing the explosive charge unit while drilling, simplifies the construction process, and improves production efficiency. Simultaneously, the design of the clustered explosive charge unit, composed of a hollow body 4, an explosive charge 5, and a detonating charge 6, is suitable for water-pressure environments, adaptable to delivery pipelines of different shapes, and can effectively fill irregularly shaped boreholes. Moreover, by using hollow bodies 4 of the same shape, this method avoids redundant design and reduces production costs.

[0046] Second embodiment:

[0047] Please refer to Figure 3 This application provides a method for directional blasting of deep, high-pressure water-bearing rock formations without free face. This method is applicable when the rock strength of the upper top plate 2 and lower bottom plate 3 of the reservoir 1 to be blasted is lower than or equal to the rock strength of the reservoir 1 itself. This effectively overcomes the technical shortcomings of high water pressure, directional blasting with a protected reservoir, and slow release of explosive energy. The steps in this method are largely the same as in the first embodiment, the difference being the bottom depth of the borehole in this method, which differs from that in the first embodiment.

[0048] In this embodiment, drilling equipment is used to drill a hole to the reservoir 1 to be blasted, and the drilling equipment is used to drill the hole to the top surface of the bottom plate 3, so that subsequent construction operations can be carried out.

[0049] The above description is merely a preferred embodiment of this application and is not intended to limit this application. Various modifications and variations can be made to this application by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the protection scope of this application.

Claims

1. A method for directional blasting of deep, highly confined water-bearing rock strata without free face, characterized in that, Includes the following steps: S1, Drill a hole to the reservoir to be blasted and determine the bottom depth of the hole; S2, raise the drill rod 30-50cm, and fill the drill hole 30-50cm high by passing it through the center hole of the drill rod and using multiple hollow bodies. The hollow bodies are stored in the drill rod and are inserted into the explosive charge position from the drill bit hole or the drill rod pre-reserved hole by pushing action. The hollow bodies are spherical or ellipsoidal. S3, the drill rod is raised to a height H, and multiple explosive charges are used to fill the borehole H height range upward through the center hole of the drill rod. When the height reaches 0.5H, a detonating charge is added. The explosive charges and the detonating charge are stored in the drill rod, and the explosive charges and the detonating charge are placed into the blasting charge position from the drill bit opening or the pre-reserved opening of the drill rod by pushing action. The explosive charges are spherical or ellipsoidal, and the detonating charge is spherical or ellipsoidal. S4. Repeat the operation in step S3 until the drill rod is raised to a height of 10-20cm lower than the bottom surface of the upper plate of the reservoir to be blasted. Then, raise the drill rod upward by 30-50cm and fill the borehole again by 30-50cm through the central hole of the drill rod and using multiple hollow bodies. S5, high-strength underwater sealing cement is used to fill the upper space of the hollow body in the borehole upwards, forming a sealing layer with a thickness of 50~100cm; S6, the detonator is used to detonate the explosive charge.

2. The method for directional blasting of deep, highly confined water-bearing rock strata without free face according to claim 1, characterized in that, In step S1, the method for determining the bottom depth of the borehole includes: When the rock strength of the upper top plate and lower bottom plate of the reservoir to be blasted is higher than the rock strength of the reservoir to be blasted, the borehole is drilled to a point 20cm away from the top surface of the lower bottom plate. When the rock strength of the upper top plate and the lower bottom plate of the reservoir to be blasted is lower than or equal to the rock strength of the reservoir to be blasted, the borehole is drilled to the top surface of the lower bottom plate.

3. The method for directional blasting of deep, highly confined water-bearing rock strata without free face according to claim 1, characterized in that, In step S3, the range of the elevation H of the drill pipe is 20cm≤H≤60cm.

4. The method for directional blasting of deep, highly confined water-bearing rock strata without free face according to claim 1, characterized in that, The sphericity of the hollow body is 0.7~1.

5. The method for directional blasting of deep, highly confined water-bearing rock strata without free face according to claim 1, characterized in that, The hollow body is externally sealed and its gravity is greater than the buoyancy of the area to be filled.

6. The method for directional blasting of deep, highly confined water-bearing rock strata without free face according to claim 1, characterized in that, The sphericity of the explosive body is 0.7~1.

7. The method for directional blasting of deep, highly confined water-bearing rock strata without free face according to claim 1, characterized in that, The spherical shell of the explosive is made of metal and the inner wall is covered with a layer of high-strength carbon fiber cloth. The interior of the explosive is filled with industrial explosives.

8. The method for directional blasting of deep, highly confined water-bearing rock strata without free face according to claim 1, characterized in that, The sphericity of the detonating explosive is 0.7~1.

9. The method for directional blasting of deep, highly confined water-bearing rock strata without free face according to claim 1, characterized in that, The spherical shell of the detonator is made of metal and the inner wall is covered with a layer of high-strength carbon fiber cloth.

10. The method for directional blasting of deep, highly confined water-bearing rock strata without free face according to claim 9, characterized in that, A detonator with a lead wire is arranged at the center of the detonating explosive body, and the area in the detonator and the high-strength carbon fiber cloth is filled with industrial explosives.

Images