Deep high-pressure-bearing underwater explosive package detonation method and fracture area calculation method

Abstract

The invention provides a deep high-pressure-bearing underwater explosive package detonating method and a fissure area calculation method. The method comprises the steps that drilling is conducted and stopped when the drilling is close to an impermeable bottom plate of a rock stratum; drilling and chambering are conducted from bottom to top till a chambering area is close to an impervious roof of a rock stratum; a hose filled with the medicine balls extends into the reaming section, and high-pressure gas is introduced into the hose when the hose is close to the bottom of the drilled hole; after the medicine balls start to be continuously flushed out of the hose, the hose is lifted up till the end of the hose is flush with the upper portion of the reaming section, and then the hose is closed and lifted out; a detonating structure is put down into a clustered explosive unit composed of the multiple explosive balls through a connecting rod, and detonating is conducted; and calculating the radius of the fissure area after detonation. The detonating method can overcome the waterproof and pressure-resistant sealing problem of the explosive in the vertical shaft under the action of high water pressure, so that the explosive can sink to a target reservoir; meanwhile, the calculation method can improve the calculation precision of the radius of the fissure area.

Description

Technical Field

[0001] The present application relates to the field of energy extraction, and in particular to a method for detonating a deep and high-pressure underwater explosive package and a method for calculating a fracture zone. Background Art

[0002] During the mining of deep low-permeability sandstone uranium, the rock mass needs to be fractured evenly to increase the contact surface between the in-situ leaching liquid and the rock, thereby improving the efficiency of in-situ leaching. Blasting is an effective method to improve the uniformity of fracturing, but blasting in underground projects will face the problem of high groundwater pressure. Conventional explosives have poor pressure resistance, and there are also problems of limited explosive force or difficulty in charging during high-pressure underwater use. Therefore, it is necessary to solve the problem of packaging, placement and detonation of deep well high-pressure underwater explosive packages to serve the development of deep low-permeability sandstone uranium resources.

[0003] The pressure bearing capacity of ordinary emulsion explosives cannot meet the requirements of water depths of 50m and above. In terms of waterproof packaging of explosives under high pressure, existing research mainly adopts the method of integral packaging and then lowering the explosives into the well. However, the integral packaging is difficult to meet the requirements of complete filling of drugs in the expansion hole or irregular shaped blasting areas, resulting in all charges being uncoupled charges, which can easily lead to problems such as insufficient explosive force and poor fracturing effect. At the same time, the excessively large packaging volume is also difficult to meet the requirements of dropping drugs inside the drill pipe, which greatly affects the scope of construction application of the project.

[0004] In summary, the existing technical difficulties in this field are mainly reflected in: ① How to package medicines under high water pressure to solve the problem of compression and dilution of emulsion explosives in the underwater pressure environment, and ensure that the buoyancy of the medicines is not too large so that they can sink to the target reservoir; ② How to achieve coupled charging in the expansion area of ​​the well to solve the problem of charging and filling in a small opening but a large blasting area; ③ How to lower the packaged medicines in a narrow pipe into the well to solve the problem that the overall package size is too large to enter the narrow space through the drill pipe into the target expansion area. Summary of the invention

[0005] The present application provides a method for detonating a deep, high-pressure underwater explosive package and a method for calculating a fracture zone. Based on the consideration of the high-pressure water environment, the method can enter the stratum to be blasted through a smaller hole, thereby improving the uniformity of rock fracturing and the efficiency of in-situ leaching of uranium ore, and can also improve the accuracy of calculating the radius of the fracture zone after detonation.

[0006] The technical solution of this application is:

[0007] A method for detonating a deep and high-pressure underwater explosive package comprises the following steps:

[0008] S1, drilling with a first drill bit, stopping drilling when approaching the impermeable bottom plate of the rock formation; then drilling and expanding the hole from bottom to top, until the expanded hole area approaches the impermeable top plate of the rock formation, and then stopping expanding the hole;

[0009] S2, using the second drill bit to spray water at low pressure to clean the borehole and pull out the drill rod;

[0010] S3, extending the hose containing the medicine ball into the expansion section, and introducing high-pressure gas into the hose when the hose is close to the bottom of the drill hole;

[0011] S4, when the medicine balls start to continuously rush out of the hose, the hose is lifted up until the end of the hose is flush with the upper part of the expansion section, and the valve at the end of the hose is closed to prevent the remaining medicine balls in the hose from leaking out; and then the hose is lifted out;

[0012] S5, encapsulating the detonation structure in a connecting rod with a packer, and lowering the detonation structure into a cluster explosive unit composed of a plurality of the medicine balls through the connecting rod;

[0013] S6, using the packer to seal the cluster explosive unit of the rock formation;

[0014] S7, detonating the cluster explosive unit.

[0015] As a technical solution of the present application, in step S1, the first drill bit with a diameter of 89 mm is used to drill a hole, and the drilling is stopped when it is 1.5 to 2.5 m away from the impermeable bottom plate; then, hydraulic cutting is used to drill and expand the hole from bottom to top until the expanded hole area is 1.5 to 2.5 m away from the impermeable top plate.

[0016] As a technical solution of the present application, in step S3, high-pressure gas with a pressure of P is introduced into the hose at a distance of 20 to 30 cm from the bottom of the borehole, where P satisfies:

[0017] P ≥ P0 + ΔP;

[0018] In the formula: P is the input pressure of high-pressure gas; P0 is the bottom hole water pressure; ΔP is the incremental gas pressure, which is 0.1~0.2MPa.

[0019] As a technical solution of the present application, in step S4, after the medicine balls begin to continuously rush out of the hose, the hose is lifted up at a uniform speed of 3 to 5 cm / s.

[0020] As a technical solution of the present application, in step S5, the detonating structure is sealed and connected to the connecting rod with the seal, and the wires of the detonators in the detonating structure and the control wires of the seal are connected to the ground from the inside of the connecting rod, and the detonating structure is slowly placed into the cluster explosive unit through the connecting rod.

[0021] As a technical solution of the present application, the medicine ball includes an outer shell, a sealing cover, a plurality of weighted balls and emulsion explosive; the outer shell is a spherical structure made of plastic material; the sealing cover is arranged on the opening of the outer shell; the plurality of weighted balls are installed in the inner cavity of the outer shell; the emulsion explosive is arranged in the inner cavity of the outer shell.

[0022] As a technical solution of the present application, the mass of the emulsion explosive is m y , where m y satisfy:

[0023] m y >ρ q V q -m p -nm w ;

[0024] Where: m y is the mass of the emulsion explosive; ρ q is the density of water; V q is the volume of water displaced by the medicine ball when it is submerged in water; m p is the mass of the shell; n is the number of the weighted balls; m w is the weight of the counterweight ball.

[0025] As a technical solution of the present application, the detonation structure includes a detonating cord and a detonator; the detonating cord is packaged at the bottom of the inner cavity of the connecting rod; and the two ends of the detonator are respectively connected to the detonating cord and the surface detonator.

[0026] As a technical solution of the present application, the diameter of the expansion area is 200 mm, and the distance between the bottom and the impermeable bottom plate is 1.5 to 2.5 m, and the distance between the top and the impermeable top plate is 1.5 to 2.5 m; the packer is arranged at the top of the expansion area.

[0027] A method for calculating the fracture zone after detonation using the deep high-pressure underwater explosive package detonation method as described above, the method comprising the following steps:

[0028] S1, the calculation formula for the impact load generated by the detonation of deep high-pressure underwater explosive packages is as follows:

[0029]

[0030] Where: P d is the impact load generated after detonation; ρ0 is the equivalent charge density of the explosive; D is the detonation velocity of the explosive; γ is the expansion adiabatic index of the detonation product; ρ m is the equivalent charge density of the explosive; Cp is the sound velocity of the rock; where the equivalent charge density ρ0 of the explosive is calculated using the following formula:

[0031]

[0032] Where: ρ0 is the equivalent charge density of the explosive; R is the radius of the blast hole; r is the radius of the medicine ball; π is the circumference; ρ Z is the density of the explosive;

[0033] S2, the radius R of the crack zone T The calculation is done using the following formula:

[0034]

[0035] Where: r b is the radius of the blast hole; P d is the impact load generated after detonation; A=[(1+λ) 2 +(1+λ 2 )-2μ(1-μ)(1-λ 2 ) 0.5 ,λ=μ / (1-μ);σ cd is the dynamic compressive strength of rock; ɑ=2+μ / (1-μ); σ td is the dynamic tensile strength of rock; β = 2-μ / (1-μ); μ is the dynamic Poisson's ratio of rock.

[0036] Beneficial effects of this application:

[0037] (1) The present application provides a method for detonating a deep, high-pressure underwater explosive package, which can overcome the problem of waterproof and pressure-resistant sealing of explosives in a vertical shaft under high water pressure. The method adopts a buoyancy-gravity equivalence method to ensure that the explosives can sink to the target reservoir; at the same time, the method adopts a dispersed charging structure, which can solve the problem that the overall charging cannot be applied to a charging environment with a small opening and a large storage capacity;

[0038] (2) The present application provides a method for calculating the fracture zone after detonation using a deep high-pressure underwater explosive package detonation method. The proposed method can minimize the difficulty of implementing borehole blasting in deep high-porosity and high-pressure rock formations, and can also improve the calculation accuracy of the fracture zone radius. It has important engineering value for achieving the conditions of large fracture area and high fracture uniformity required for in-situ leaching of uranium resources. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] In order to more clearly illustrate the technical solutions of the implementation methods of the present application, the drawings required for use in the implementation methods will be briefly introduced below. It should be understood that the following drawings only show certain embodiments of the present application and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other related drawings can be obtained based on these drawings without paying creative work.

[0040] Figure 1 A schematic diagram of a medicine ball provided in the first embodiment of the present application;

[0041] Figure 2 A schematic diagram of a cluster explosive unit provided in the first embodiment of the present application.

[0042] Icons: 1-medicine ball; 2-outer shell; 3-sealing cover; 4-weighted ball; 5-emulsion explosive; 6-detonating cord; 7-detonator; 8-connecting rod; 9-packer. DETAILED DESCRIPTION

[0043] In order to make the purpose, technical solution and advantages of the embodiments of the present application clearer, the technical solution in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are part of the embodiments of the present application, not all of the embodiments. The components of the embodiments of the present application described and shown in the drawings here can be arranged and designed in various different configurations.

[0044] Therefore, the following detailed description of the embodiments of the present application provided in the accompanying drawings is not intended to limit the scope of the present application for which protection is sought, but merely represents selected embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in the field without creative work are within the scope of protection of the present application.

[0045] First embodiment:

[0046] Please refer to Figure 1 , with reference Figure 2 In the embodiment of the present application, a method for detonating a deep high-pressure underwater explosive package is provided, which, on the basis of considering the high-pressure water environment, can enter the stratum to be blasted through a smaller hole, thereby improving the uniformity of rock fracturing and the efficiency of in-situ leaching of uranium ore; it mainly includes the following steps:

[0047] S1, use the first drill bit with a diameter of 89 mm to drill, and stop drilling when it is 1.5 to 2.5 m away from the impermeable bottom plate; then use hydraulic cutting to drill and expand the hole from bottom to top until the expanded hole area is 1.5 to 2.5 m away from the impermeable top plate;

[0048] S2, using a second drill bit to perform low-pressure water spraying to clean the borehole and remove the drill rod; specifically, the second drill bit can be a hydraulic cutting drill bit;

[0049] S3, extend the hose containing the medicine ball 1 into the expansion section, and start to introduce high-pressure gas with a pressure of P into the hose when it is 20 to 30 cm away from the bottom of the drill hole, where P satisfies:

[0050] P ≥ P0 + ΔP;

[0051] Where: P is the input pressure of high-pressure gas; P0 is the bottom water pressure; ΔP is the incremental gas pressure, which is 0.1~0.2Mpa;

[0052] S4, when the medicine balls 1 start to rush out of the hose continuously, the hose is lifted up at a uniform speed of 3 to 5 cm / s until the end of the hose is flush with the upper part of the expanded hole section, and then the valve at the end of the hose is closed to prevent the remaining medicine balls 1 in the hose from leaking out; then the hose is pulled out;

[0053] S5, sealingly connecting the detonating structure to the connecting rod 8 with the packer 9, connecting the wire of the detonator 7 in the detonating structure and the control wire of the packer 9 from the inside of the connecting rod 8 to the ground, and slowly lowering the detonating structure into the cluster explosive unit through the connecting rod 8;

[0054] S6, using the packer 9 to seal the cluster explosive unit of the rock formation; protecting the wellhead on the ground, guarding the site, and evacuating personnel and important equipment;

[0055] S7, turn on the existing automatic monitoring equipment, connect the wires of the detonator 7 and check them online, and after confirming that they are correct, detonate the cluster explosive unit.

[0056] It should be noted that, in this embodiment, the medicine ball 1 includes an outer shell 2, a sealing cover 3, a plurality of weighted balls 4 and an emulsion explosive 5; wherein the outer shell 2 is a spherical structure made of plastic material; the sealing cover 3 is covered on the opening of the outer shell 2; at the same time, the plurality of weighted balls 4 are installed in the inner cavity of the outer shell 2; and the emulsion explosive 5 is arranged in the inner cavity of the outer shell 2. In addition, the mass of the emulsion explosive 5 is m y , where m y satisfy:

[0057] m y >ρ q V q -m p -nm w ;

[0058] Where: m y is the mass of emulsion explosive 5; ρ q is the density of water; V q is the volume of water displaced by medicine ball 1 when it is submerged in water; m p is the mass of the housing 2; n is the number of weighted balls 4; m w is the weight of the counterweight ball 4.

[0059] It should be noted that, in this embodiment, the detonation structure includes a detonating cord 6 and a detonator 7; the detonating cord 6 is encapsulated at the bottom of the inner cavity of the connecting rod 8; the bottom of the detonator 7 is connected to the detonating cord 6, and the top is connected to the surface detonator.

[0060] It should be noted that, in this embodiment, the diameter of the expansion area is 200 mm, the distance between the bottom and the impermeable bottom plate is 1.5-2.5 m, and the distance between the top and the impermeable top plate is 1.5-2.5 m; the packer 9 is arranged at the top of the expansion area.

[0061] In summary, the present application provides a method for detonating a deep, high-pressure underwater explosive package, which can overcome the problem of waterproof and pressure-resistant sealing of explosives in a vertical shaft under high water pressure, and adopts a buoyancy-gravity equivalent method to ensure that the drugs can sink to the target reservoir; at the same time, it adopts a dispersed charging structure, which can solve the problem that the overall charging cannot be applied to a charging environment with a small opening and a large storage capacity;

[0062] Second embodiment:

[0063] The present application provides a method for calculating the fracture zone after detonation using the deep high-pressure underwater explosive package detonation method described in the first embodiment. The method comprises the following steps:

[0064] S1, the calculation formula for the impact load generated by the detonation of deep high-pressure underwater explosive packages is as follows:

[0065]

[0066] Where: P d is the impact load generated after detonation; ρ0 is the equivalent charge density of the explosive; D is the detonation velocity of the explosive; γ is the expansion adiabatic index of the detonation product; ρ m is the equivalent charge density of the explosive; Cp is the sound velocity of the rock; where the equivalent charge density ρ0 of the explosive is calculated using the following formula:

[0067]

[0068] Where: ρ0 is the equivalent charge density of the explosive; R is the radius of the blast hole; r is the radius of the medicine ball 1; π is the circumference; ρ Z is the density of the explosive;

[0069] S2, radius R of the crack zone T The calculation is done using the following formula:

[0070]

[0071] Where: r b is the radius of the blast hole; P d is the impact load generated after detonation; A=[(1+λ) 2 +(1+λ 2 )-2μ(1-μ)(1-λ 2 ) 0.5,λ=μ / (1-μ);σ cd is the dynamic compressive strength of rock; ɑ=2+μ / (1-μ); σ td is the dynamic tensile strength of rock; β = 2-μ / (1-μ); μ is the dynamic Poisson's ratio of rock.

[0072] In summary, the present application provides a method for calculating the fracture zone after detonation using a deep high-pressure underwater explosive package detonation method. The proposed method can reduce the difficulty of implementing borehole blasting in deep high-porosity and high-pressure rock formations to the greatest extent, and can also improve the calculation accuracy of the fracture zone radius. It has important engineering value for achieving the conditions of large fracture area and high fracture uniformity required for in-situ leaching of uranium resources.

[0073] The above description is only the preferred embodiment of the present application and is not intended to limit the present application. For those skilled in the art, the present application may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A method for detonating a deep, high-pressure underwater explosive package, characterized in that: The following steps are involved: S1, drilling with a first drill bit, stopping drilling when approaching the impermeable bottom plate of the rock formation; then drilling and expanding the hole from bottom to top, until the expanded hole area approaches the impermeable top plate of the rock formation, and then stopping expanding the hole; S2, using the second drill bit to spray water at low pressure to clean the borehole and pull out the drill rod; S3, extending the hose containing the medicine ball into the expansion section, and introducing high-pressure gas into the hose when the hose is close to the bottom of the drill hole; S4, when the medicine balls start to continuously rush out of the hose, the hose is lifted up until the end of the hose is flush with the upper part of the expansion section, and the valve at the end of the hose is closed to prevent the remaining medicine balls in the hose from leaking out; and then the hose is lifted out; S5, encapsulating the detonation structure in a connecting rod with a packer, and lowering the detonation structure into a cluster explosive unit composed of a plurality of the medicine balls through the connecting rod; S6, using the packer to seal the cluster explosive unit of the rock formation; S7, detonating the cluster explosive unit.

2. The method for detonating a deep, high-pressure underwater explosive package according to claim 1, characterized in that: In step S1, the first drill bit with a diameter of 89 mm is used for drilling, and the drilling is stopped when the distance from the waterproof bottom plate is 1.5 to 2.5 m; then the hole is drilled and expanded from bottom to top by hydraulic cutting, and the expansion is stopped when the expanded area is 1.5 to 2.5 m away from the waterproof top plate.

3. The method for detonating a deep and high-pressure underwater explosive package according to claim 1, characterized in that: In step S3, high pressure gas with a pressure of P is introduced into the hose at a distance of 20 to 30 cm from the bottom of the borehole, where P satisfies: P ≥ P0 + ΔP; In the formula: P is the input pressure of high-pressure gas; P0 is the bottom hole water pressure; ΔP is the incremental gas pressure, which is 0.1~0.2MPa.

4. The method for detonating a deep and high-pressure underwater explosive package according to claim 1, characterized in that: In step S4, after the medicine balls start to rush out of the hose continuously, the hose is lifted up at a uniform speed of 3 to 5 cm / s.

5. The method for detonating a deep and high-pressure underwater explosive package according to claim 1, characterized in that: In step S5, the detonating structure is sealed and connected to the connecting rod with the packer, and the wires of the detonators in the detonating structure and the control wires of the packer are connected to the ground from the inside of the connecting rod, and the detonating structure is slowly placed into the cluster explosive unit through the connecting rod.

6. The method for detonating a deep and high-pressure underwater explosive package according to claim 1, characterized in that: The medicine ball includes an outer shell, a sealing cover, a plurality of weighted balls and emulsion explosive; the outer shell is a spherical structure made of plastic material; the sealing cover is arranged on the opening of the outer shell; the plurality of weighted balls are installed in the inner cavity of the outer shell; the emulsion explosive is arranged in the inner cavity of the outer shell.

7. The method for detonating a deep and high-pressure underwater explosive package according to claim 6, characterized in that: The mass of the emulsion explosive is m y , where m y satisfy: m y >ρ q V q -m p -nm w ; Where: m y is the mass of the emulsion explosive; ρ q is the density of water; V q is the volume of water displaced by the medicine ball when it is submerged in water; m p is the mass of the shell; n is the number of the weighted balls; m w is the weight of the counterweight ball.

8. The method for detonating a deep and high-pressure underwater explosive package according to claim 1, characterized in that: The detonation structure comprises a detonating cord and a detonator; the detonating cord is packaged at the bottom of the inner cavity of the connecting rod; and the two ends of the detonator are respectively connected to the detonating cord and the surface detonator.

9. The method for detonating a deep, high-pressure underwater explosive package according to claim 1, characterized in that: The diameter of the expansion area is 200 mm, the distance between the bottom and the waterproof bottom plate is 1.5-2.5 m, and the distance between the top and the waterproof top plate is 1.5-2.5 m; the packer is arranged at the top of the expansion area.

10. A method for calculating the fracture zone after detonation using the method for detonating a deep high-pressure underwater explosive package according to any one of claims 1 to 9, characterized in that: The Method The following steps are involved: S1, the calculation formula for the impact load generated by the detonation of deep high-pressure underwater explosive packages is as follows: Where: P d is the impact load generated after detonation; ρ0 is the equivalent charge density of the explosive; D is the detonation velocity of the explosive; γ is the expansion adiabatic index of the detonation product; ρ m is the equivalent charge density of the explosive; Cp is the sound velocity of the rock; where the equivalent charge density ρ0 of the explosive is calculated using the following formula: Where: ρ0 is the equivalent charge density of the explosive; R is the radius of the blast hole; r is the radius of the medicine ball; π is the circumference; ρ Z is the density of the explosive; S2, the radius R of the crack zone T The calculation is done using the following formula: Where: r b is the radius of the blast hole; P d is the impact load generated after detonation; A=[(1+λ) 2 +(1+λ 2 )-2μ(1-μ)(1-λ 2 ) 0.5 ,λ=μ / (1-μ);σ cd is the dynamic compressive strength of rock; ɑ=2+μ / (1-μ); σ td is the dynamic tensile strength of rock; β = 2-μ / (1-μ); μ is the dynamic Poisson's ratio of rock.

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