High-energy gas fracturing device

Abstract

The invention relates to the technical field of tunnel construction, and particularly discloses a high-energy gas fracturing device which comprises an electric ignition head, a charging paper bag and a gas producing agent filled in the charging paper bag. One end of the electric igniter is fixed at the bottom center of the charging paper bag, and the other end penetrates through the charging paper bag and extends out; the gas production powder is ignited through the electric ignition head, the gas production powder is combusted to generate high-energy gas, and the restraining body around the powder containing paper bag is fractured; wherein the gas production medicine is prepared from 5-aminotetrazole, FOX12, an oxidizing agent strontium nitrate and a process additive.

Description

Technical Field

[0001] The present invention relates to the technical field of tunnel construction, and particularly relates to a high-energy gas fracturing device. Background Art

[0002] With the rapid development of urban construction in China, the number of tunnel construction projects such as urban subways, utility tunnels, foundation pits, high-speed rail tunneling, and expressways has increased. Among them, the tunneling construction method is the most widely used in such projects. Rock-breaking machinery is the main engineering equipment in the current tunnel construction process. However, restricted by the principles of impact crushing and milling cutting, it can only achieve the highest cutting efficiency when the rock strength does not exceed 80 MPa. During tunneling construction, high-strength hard rock restricts the tunneling efficiency of rock-breaking machinery and exacerbates the wear of tunneling cutters. This situation will seriously hinder the project construction progress and lead to a significant increase in the comprehensive development cost of the project. Therefore, pre-fracturing the rock mass is the key technology to improve the project construction efficiency and reduce the construction cost.

[0003] Currently, the commonly used pre-fracturing methods include explosive blasting technology, hydraulic fracturing technology, and high-energy gas fracturing technology. Explosive blasting technology is widely used in tunnel construction projects. However, this method will bring serious hazards such as blasting vibration, surrounding rock disturbance, flying stones, and intense noise. Restricted by the complex construction environment and increasingly strict administrative control, explosive blasting technology is gradually withdrawing from the tunnel construction field; Hydraulic fracturing technology can improve safety and reduce construction vibration. However, this method has low construction efficiency, and the single rupture distance is only 1 m to 2 m. The proppants used are likely to cause groundwater pollution, and its application in actual construction projects is limited; As a new pre-fracturing method, gas fracturing technology can, to a certain extent, weaken the serious hazards brought by blasting and can also effectively solve the problem of low construction efficiency of hydraulic fracturing technology.

[0004] Currently, gas fracturing technology includes two technical routes: gasification of liquid carbon dioxide and chemical combustion to generate high-energy gas. The pre-fracturing technology of liquid carbon dioxide gasification requires pre-filling carbon dioxide in a high-strength alloy shell. Restricted by the high weight and rigidity of the shell, it is impossible to conduct deep-space embedding and tank recycling, and it is difficult to achieve large-scale application in the tunnel construction field. For the technology of using high-energy energetic materials such as propellant and propellant to generate high-energy gas by chemical combustion, there is still a detonation phenomenon during use. The shock waves and noise generated will interfere with the surrounding residents in urban construction such as subways, utility tunnels, and foundation pits, and small flying stones will be generated during the tunnel expansion of expressways, bringing risks to the driving vehicles, and it cannot be applied on a large scale in these sub-fields.

[0005] In the case of high-strength hard rock where high-energy energetic materials such as explosives, propellant, and propellant cannot be used, how to balance low disturbance, excavation efficiency, and comprehensive cost is a bottleneck problem that urgently needs to be solved. Summary of the Invention

[0006] In view of the above problems, the object of the present invention is to provide a high-energy gas fracturing device, which can eliminate shock waves, reduce noise, will not generate flying stones, and can pre-fracture hard rocks within the safe distance required by laws and regulations, generate abundant fractures, and damage the integrity of hard rocks.

[0007] The present invention provides a high-energy gas fracturing device, comprising: an electric igniter, a charge paper bag, and a gas-generating charge filling the charge paper bag;

[0008] One end of the electric igniter is fixed at the center of the bottom of the charge paper bag, and the other end passes through the charge paper bag and extends out;

[0009] The gas-generating charge is ignited by the electric igniter, and the gas-generating charge burns to generate high-energy gas to fracture the confinement around the charge paper bag;

[0010] Wherein, the gas-generating charge includes penta-aminotetrazole, FOX12, oxidizing agent strontium nitrate, and process additives.

[0011] In a possible implementation manner, by mass ratio, the penta-aminotetrazole accounts for 15% - 42%, the FOX12 accounts for 10% - 25%, the oxidizing agent strontium nitrate accounts for 25% - 70%, and the process additives account for 5% - 14%.

[0012] In a possible implementation manner, the gas-generating charge is the waste generated in the production process of pressed ignition charge grains.

[0013] In a possible implementation manner, the particle size of the waste includes greater than or equal to 8 mesh, greater than or equal to 12 mesh and less than or equal to 20 mesh, and less than or equal to 20 mesh.

[0014] In a possible implementation manner, the agent in the electric igniter is black powder.

[0015] In a possible implementation manner, the material of the charge paper bag is kraft paper.

[0016] In a possible implementation manner, an anti-static film is attached to the inner side of the charge paper bag.

[0017] In a possible implementation manner, it further includes: a plurality of serially connected electric igniters, charge paper bags, and gas-generating charges filling the charge paper bags.

[0018] The high-energy gas fracturing device provided by the present invention generates a large amount of high-energy gas through the combustion of gas-generating propellant, so as to achieve the purpose of fracturing the surrounding confining body. The structure of the present invention is simple and the cost is low. It has the characteristics of a certain gas production rate, can eliminate shock waves and reduce noise, will not generate flying rocks, and can pre-fracture hard rock within the safe distance required by laws and regulations, generate abundant fractures, and destroy the integrity of hard rock. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 It is a schematic structural diagram of the energy gas fracturing device provided for the embodiment of the present invention;

[0020] Figure 2 It is a schematic diagram of the first test effect provided for the embodiment of the present invention;

[0021] Figure 3 It is a schematic diagram of the second test effect provided for the embodiment of the present invention. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0022] The following further describes in detail the embodiments of the present invention in conjunction with the drawings. The detailed description and drawings of the following embodiments are used to exemplarily illustrate the principle of the present invention, but cannot be used to limit the scope of the present invention, that is, the present invention is not limited to the described preferred embodiments, and the scope of the present invention is defined by the claims.

[0023] In the description of the present invention, it should be noted that unless otherwise specified, the meaning of "a plurality" is two or more; the terms "first", "second", etc. are only used for descriptive purposes and cannot be understood as indicating or implying relative importance; for those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific situations.

[0024] Figure 1 It is a schematic structural diagram of the energy gas fracturing device provided for the embodiment of the present invention, as Figure 1 shown, the present invention provides a high-energy gas fracturing device, including: an electric ignition head 3, a charge paper bag 1, and a gas-generating propellant 2 filled in the charge paper bag. One end of the electric ignition head 3 is fixed at the center of the bottom of the charge paper bag 1, and the other end passes through the charge paper bag 1 and extends out. The gas-generating propellant is ignited by the electric ignition head, and the gas-generating propellant burns to generate high-energy gas to fracture the confining body around the charge paper bag.

[0025] Traditional pre-fracturing tools require a detonator to ignite the initiator and a two-stage ignition method of the initiator igniting the explosive. The present invention uses an electric ignition head to achieve one-stage ignition. Compared with the traditional two-stage ignition method, the structure is simple, easy to ignite, and the cost is low.

[0026] Among them, the gas-generating propellant includes penta-aminotetrazole, FOX12, oxidant strontium nitrate, and process aids.

[0027] In a possible implementation, by weight, penta-aminotetrazole accounts for 15% to 42%, FOX12 accounts for 10% to 25%, the oxidant strontium nitrate accounts for 25% to 70%, and the process additive accounts for 5% to 14%. Among them, penta-aminotetrazole is the main fuel and FOX12 is the auxiliary fuel.

[0028] In a possible implementation, the gas generating powder is waste material generated in the production process of compressed ignition powder particles.

[0029] In a possible implementation, the particle size of the waste includes greater than or equal to 8 mesh, greater than or equal to 12 mesh and less than or equal to 20 mesh, and less than or equal to 20 mesh.

[0030] The gas generating agent of the present invention has a certain gas production rate, can eliminate shock waves and reduce noise, will not generate flying rocks, can achieve pre-cracking of hard rock within the safe distance required by laws and regulations, generate abundant cracks, and destroy the integrity of hard rock. Cooperating with mechanical excavation, it improves construction efficiency, reduces comprehensive costs, breaks through the bottleneck problem of mechanical excavation of hard rock, and realizes low-disturbance, low-cost, and high-efficiency hard rock pre-cracking technology.

[0031] In a possible implementation, the agent in the electric ignition head is black powder.

[0032] In a possible implementation, the medicine paper bag is made of kraft paper.

[0033] In a possible implementation, an antistatic film is attached to the inner side of the medicine paper bag.

[0034] In a possible implementation, the method further includes: a plurality of electric ignition heads connected in series, a medicine-filled paper bag, and a gas-generating medicine that fills the medicine-filled paper bag.

[0035] The assembly and testing process of the high energy gas fracturing device of the present invention is as follows:

[0036] 1) The reagents are weighed and loaded according to the use requirements. The size of the fracturing device is a kraft paper tube of ф30mm×300mm, and the starter is an electric ignition head filled with black powder.

[0037] 2) Pour the medicine into the kraft paper tube according to the designed dosage and compact it with a vibrator.

[0038] 3) Install the starter into the fracturing device. Fracturing device A is made of kraft paper with a starter, and fracturing device B is made of kraft paper without a starter.

[0039] 4) Conduct pre-borehole design and layout in advance. The scheme is the three-hole layout method, with the borehole diameter ranging from 40 mm to 42 mm; the hole spacing of the boreholes is 80 cm to 100 cm; the borehole depth is 2.0 m to 2.1 m; the angle between the layout and drilling plane and the vertical plane is 40° to 45°; the linear charge density is 0.6 to 0.9; the borehole stemming is filled with 6 to 12 bags of quick-setting cement; the cement curing time is 15 min to 30 min

[0040] 5) Install the pre-splitting tools into the rock cavities at each hole position in sequence according to the requirements of each test assembly method. The initiator is installed in the second piece of kraft paper as pre-splitting tool A, with the ignition end facing inward and placed into the rock cavity. The remaining kraft papers without the initiator are pre-splitting tool B and are directly placed into the rock cavity.

[0041] 6) Use Niuyuan's quick-setting cement for sealing the holes in the test. Immerse the cement in water for 12 - 15 s and then pour it into the rock cavity. Pour the cement into cavities 1 to 3 in sequence and use a long tube to tamp the cement. After pouring the cement into cavity 3, let the cement cure for 30 min.

[0042] 7) Pull the ignition wire to 200 m away from the left mountain body. After giving the ignition command, use a blasting machine to ignite.

[0043] 8) Before the test, set up the mobile phone with a support frame and use the mobile phone to shoot a video of the ignition effect, and take photos to record the pre-splitting situation around the rock cavity of the mountain body before and after ignition. Use a decibel meter to measure the maximum vibration noise at the initiation end during the ignition process.

[0044] 9) Use an excavator to excavate the mountain body from the blast holes after blasting and analyze the pre-splitting situation of the rocks inside the mountain body after the test.

[0045] Example 1

[0046] The particle size of the gas-producing agent is 12 - 20 mesh, and the components are respectively penta-aminotetrazole, FOX12, strontium nitrate, and process additives.

[0047] The proportion of formula A-1 is respectively penta-aminotetrazole: 15%, FOX12: 25%, strontium nitrate: 46%, process additives: 14%;

[0048] The proportion of formula A-2 is respectively penta-aminotetrazole: 42%, FOX12: 10%, strontium nitrate: 43%, process additives: 5%;

[0049] The proportion of formula A-3 is respectively penta-aminotetrazole: 15%, FOX12: 10%, strontium nitrate: 70%, process additives: 5%;

[0050] The test results are as Figure 2 shown. The noise and pre-splitting gravel situation are shown in Table 1.

[0051] Figure 2Among them, a1, a2, and a3 are the conditions at 1.5 m before ignition, after ignition, and after dissection of the A-1 formulation, respectively; b1, b2, and b3 are the conditions at 1.5 m before ignition, after ignition, and after dissection of the A-2 formulation, respectively; c1, c2, and c3 are the conditions at 1.5 m before ignition, after ignition, and after dissection of the A-3 formulation, respectively.

[0052] Table 1

[0053]

[0054] The present invention utilizes the waste generated in the production process of the pressed ignition charge granule product. The formulation has three specifications of A-1, A-2, and A-3. It has low noise, good pre-splitting effect, reduces costs, and at the same time reduces the environmental pollution in the process of waste destruction, being more environmentally friendly and green.

[0055] Example 2

[0056] The gas-generating agent composition described above is penta-aminotetrazole, FOX12, strontium nitrate, and process aids.

[0057] The proportion of the B-1 formulation is penta-aminotetrazole: 42%, FOX12: 19%, strontium nitrate: 25%, and process aids: 14% respectively;

[0058] The particle size of the gas-generating agent includes three types: above 8 mesh, 12 - 20 mesh, and below 20 mesh. The effects after the test are as Figure 3 shown. The noise and pre-splitting and gravel crushing conditions are shown in Table 2.

[0059] Figure 3 Among them, d1, d2, and d3 are the conditions at 1.5 m before ignition, after ignition, and after dissection of the gunpowder granules with a particle size greater than or equal to 8 mesh respectively; e1, e2, and e3 are the conditions at 1.5 m before ignition, after ignition, and after dissection of the gunpowder granules with a particle size greater than or equal to 12 mesh and less than or equal to 20 mesh respectively; f1, f2, and f3 are the conditions at 1.5 m before ignition, after ignition, and after dissection of the gunpowder granules with a particle size less than or equal to 20 mesh respectively.

[0060] Table 2

[0061]

[0062] The present invention utilizes the waste generated in the production process of the pressed ignition charge granule product. The particle size includes three specifications: above 8 mesh, 12 - 20 mesh, and below 20 mesh. It has low noise, good pre-splitting effect, reduces costs, and at the same time reduces the environmental pollution in the process of waste destruction, being more environmentally friendly and green.

[0063] The high-energy gas fracturing device provided by the present invention generates a large amount of high-energy gas through the combustion of gas-producing explosives, so as to achieve the purpose of fracturing the surrounding confining body. The structure of the present invention is simple and the cost is low. It has the characteristics of a certain gas production rate, can eliminate shock waves and reduce noise, will not produce flying stones, and can pre-fracture hard rock within the safe distance required by laws and regulations, generate abundant fractures, and damage the integrity of hard rock.

[0064] The above is only the specific implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. Any person skilled in the art within the technical scope disclosed by the present invention can easily think of changes or substitutions, which should all be covered within the protection scope of the present invention. Therefore, the protection scope of the present invention shall be subject to the protection scope of the claims.

Claims

1. A high energy gas fracturing device, characterized in that: include: An electric ignition head, a powder-filled paper bag, and a gas-generating powder filling the powder-filled paper bag; One end of the electric ignition head is fixed to the bottom center of the medicine-filled paper bag, and the other end thereof extends through the medicine-filled paper bag; The gas generating agent is ignited by the electric ignition head, and the gas generating agent burns to generate high-energy gas, which is used to fracture the surrounding constraint body of the filling paper bag; The gas generating agent comprises pentaminotetrazolium, FOX12, oxidant strontium nitrate and process additives.

2. The high energy gas fracturing device according to claim 1, characterized in that: In terms of mass proportion, the penta-aminotetrazole accounts for 15% to 42%, the FOX12 accounts for 10% to 25%, the oxidant strontium nitrate accounts for 25% to 70%, and the process additive accounts for 5% to 14%.

3. The high energy gas fracturing device according to claim 1, characterized in that: The gas generating powder is waste material generated in the production process of compressed ignition powder particles.

4. The high energy gas fracturing device according to claim 3, characterized in that: The particle sizes of the waste materials include greater than or equal to 8 meshes, greater than or equal to 12 meshes and less than or equal to 20 meshes, and less than or equal to 20 meshes.

5. The high energy gas fracturing device according to claim 1, characterized in that: The reagent in the electric ignition head is black powder.

6. The high energy gas fracturing device according to claim 1, characterized in that: The medicine paper bag is made of kraft paper.

7. The high energy gas fracturing device according to claim 1, characterized in that: The inner side of the medicine paper bag is attached with an antistatic film.

8. The high energy gas fracturing device according to claim 1, characterized in that: Also includes: A plurality of electric ignition heads connected in series, a medicine-filled paper bag and a gas-generating medicine filling the medicine-filled paper bag.

Images