Burning explosion fracturing anti-reflection device and method

Abstract

The invention discloses a combustion explosion fracturing anti-reflection device which is applied to an L-shaped drilling well (200) in a reservoir stratum, the L-shaped drilling well (200) comprises a vertical well section (201) and a horizontal well section (202), the anti-reflection device (100) comprises a first gas injection pump station (110), a second gas injection pump station (110) and a third gas injection pump station (110), the first gas injection pump station (110) is communicated with the L-shaped drilling well (200) through a first gas injection guide pipe (111) and is configured to inject oxygen-methane mixed gas containing combustion improvers into the horizontal well section (202) of the L-shaped drilling well (200); the at least one burning and explosion assembly (120) comprises an impacting mechanism (121) and a charging chamber (122), a mixture of sodium chlorate and aluminum powder is loaded in the charging chamber (122), the impacting mechanism (121) is arranged close to the charging chamber (122), and the impacting mechanism (121) is configured to be used for impacting the charging chamber (122) and generating explosion to generate fracturing in the L-shaped drilling well (200).

Description

Technical Field

[0001] This invention relates to the field of coal seam fracturing technology, and in particular to a combustion-explosion fracturing and permeability enhancement device and method. Background Technology

[0002] With increasing coal mining depth, the complexity of geological conditions significantly increases the difficulty of gas control. Therefore, the concept of in-situ methane combustion explosion has emerged. This technology involves initiating a methane combustion explosion in situ within the coal seam, using the resulting shock wave and high temperature to effectively break up the coal mass and expand and connect fractures. The challenge of in-situ combustion explosion typically lies in insufficient explosion pressure, making it difficult to effectively fracture the coal seam; traditional electric spark detonators are easily affected by the complex underground environment. Therefore, there is a need for an in-situ combustion explosion fracturing and permeability enhancement device with superior fracturing effect and a simpler mechanical structure. Summary of the Invention

[0003] This solution addresses the problems and needs raised above by proposing a combustion-induced fracturing and permeability enhancement device and method. Due to the adoption of the following technical features, it can achieve the above-mentioned technical objectives and bring about several other technical effects.

[0004] One object of the present invention is to provide a combustion-induced fracturing and permeability enhancement device for use in L-type wells in reservoirs, wherein the L-type well includes a vertical section and a horizontal section, and the permeability enhancement device includes: The gas injection pump station is connected to the L-shaped well via the first gas injection conduit and is configured to inject a mixture of oxygen and methane containing a combustion-supporting agent into the horizontal section of the L-shaped well. At least one combustion and detonation component includes: an impact mechanism and a charge chamber, the charge chamber being filled with a mixture of sodium chlorate and aluminum powder, the impact mechanism being disposed close to the charge chamber and configured to impact the charge chamber to cause an explosion and generate a fracturing fracture in an L-shaped well. The second gas injection pump station is connected to the L-type well via the second gas injection conduit and is configured to inject high-purity nitrogen into the horizontal section of the L-type well to drive the combustible gas. The working pump station is connected to the L-shaped well via a negative pressure pipe and is configured to extract gas from the horizontal section of the L-shaped well under negative pressure.

[0005] In addition, the combustion-induced fracturing and penetration-enhancing device and method according to the present invention may also have the following technical features: In one example of the invention, at least one combustion and explosion component comprises a plurality of components arranged sequentially along a horizontal section of an L-shaped well, and the plurality of combustion and explosion components explode one by one from the side closer to the gas injection pump station toward the side away from the gas injection pump station.

[0006] In one example of the invention, it further includes: a pressure sensor located in each combustion and explosion assembly, with the pressure sensor in each combustion and explosion assembly positioned close to another adjacent combustion and explosion assembly; when the pressure sensor detects that its corresponding combustion and explosion assembly has exploded and the pressure generated in the L-shaped well reaches a threshold pressure, it triggers the explosion of another adjacent combustion and explosion assembly.

[0007] In one example of the invention, it further includes: at least one screen tube, one end of which is disposed near the charging chamber and the other end of which extends away from the combustion and explosion assembly, and the screen tube is provided with screen holes, the configuration being for conducting the high-temperature and high-pressure gas generated by the combustion and explosion assembly to form directional fractures in the horizontal well section.

[0008] In one example of the invention, the screen tube includes: at least one main pipe and at least one secondary pipe connected to the at least one main pipe, wherein the secondary pipe extends away from the loading chamber and forms an acute angle with the main pipe.

[0009] In one example of the invention, the sieve tube further includes at least one microchannel connected to the at least one secondary channel, the microchannel extending away from the loading chamber and forming an acute angle with the secondary channel.

[0010] In one example of the invention, at least one of the main pipeline and the secondary pipeline is a tapering orifice, and gradually decreases in size from the end near the charge chamber to the end away from the charge chamber.

[0011] In one example of the present invention, the impact mechanism includes: An elastic element, located near the loading chamber, is capable of switching between a compressed state and an extended state. An impact block is provided at one end of the elastic element near the loading chamber. When the elastic element is in the extended state, it can drive the impact block to impact the loading chamber and generate an explosion. A limiting member, which is connected to the impact block, is configured to switch between a locking position that limits the elastic member to a compressed state and a release position that releases the elastic member to an extended state.

[0012] Another object of the present invention is to provide a method for enhancing the penetration of the combustion-induced fracturing device as described above, comprising the following steps: S10: Based on the specific geological conditions of the reservoir area, determine the strata and distance of L-type well 200, and install at least one combustion and explosion component in the horizontal well section; S20: The gas injection pump station injects a mixture of oxygen and methane containing a combustion-supporting agent into the horizontal well section through the first gas injection conduit; S30: The impact mechanism pushes the impact block to impact the charge chamber. The mixture of sodium chlorate and aluminum powder explodes upon impact. High temperature, high pressure and high oxygen induce in-situ combustion of methane. The high temperature and high pressure gas generated by the combustion creates fissures in the horizontal well section. The combustion component will trigger the next stage combustion component to explode under the pressure generated by the combustion. S40: After the staged combustion and explosion, the second gas injection pump station continuously injects high-purity nitrogen through the second gas injection conduit to displace the combustible gas. The working pump station performs negative pressure extraction of the reservoir area through the negative pressure pipe and monitors the nitrogen concentration in the extracted gas in real time. When the nitrogen concentration increases significantly, the injection of nitrogen is stopped. S50: Stop extraction when no gas is detected or very little gas is detected. The extracted gas is collected through the ground working pump station and pushed to the next working section to repeat steps S10-S40.

[0013] In one example of the present invention, in step S30, at least one screen pipe is provided near the charging chamber, and when the combustion and explosion component detonates, the high-temperature and high-pressure gas generated forms directional fractures in the horizontal well section through at least one screen pipe.

[0014] Compared with the prior art, the present invention has the following beneficial effects: This device uses NaClO3 particles as a combustion accelerant, which can significantly increase the explosion overpressure. Compared to KMnO4, NaClO3 produces a single reaction product without heavy metal contamination, and the NaClO3 particles can provide support for some micro-cracks. Traditional staged combustion detonation devices generally use electric sparks to ignite explosives, but the underground environment is complex, and if the electric spark comes into contact with flammable and explosive materials, it can easily cause an accident. This device uses an impact method to initiate staged combustion detonation, which is safer than electric spark devices, has a simpler structure, and is easier to maintain. The sieve aperture is gradually... Constricted pores, through the Venturi effect, accelerate gas flow and concentrate shock wave energy, reducing ineffective energy consumption; the guiding pathways within the pores mimic the fractal structure of plant roots, directionally forming a regular fracture network, reducing energy dispersion and increasing the fracture propagation rate through natural mechanical optimization; the use of high-purity nitrogen to displace gas can further improve the gas extraction rate; the extraction wells are arranged concentrically with the combustion and explosion well as the center, making full use of the isotropic transmission property of the shock wave after combustion and explosion in the coal seam, resulting in a wide extraction coverage and high efficiency.

[0015] The preferred embodiments of the invention will be described in more detail below with reference to the accompanying drawings, so as to facilitate an understanding of the features and advantages of the invention. Attached Figure Description

[0016] To more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings of the embodiments of the present invention will be briefly described below. The drawings are merely illustrative of some embodiments of the present invention and are not intended to limit the scope of the present invention to all embodiments.

[0017] Figure 1 This is a schematic diagram of an L-shaped well in a reservoir according to an embodiment of the present invention; Figure 2 This is a schematic diagram of the structure of the combustion-induced fracturing and permeability enhancement device according to an embodiment of the present invention; Figure 3 This is a schematic diagram of the structure of a combustion and explosion assembly according to an embodiment of the present invention; Figure 4 This is a schematic diagram of the structure of a sieve tube according to an embodiment of the present invention; Figure 5 This is a schematic diagram of the connection structure between two adjacent combustion and explosion components according to an embodiment of the present invention; Figure 6 This is a schematic diagram of the connection structure between the limiting member and the impact block according to an embodiment of the present invention; Figure 7 This is a control principle diagram of the combustion-induced fracturing and permeability enhancement device according to an embodiment of the present invention.

[0018] List of reference numerals in the attached diagram: Anti-reflective device 100; First air injection pump station 110; First gas injection conduit 111; Safety valve 112; Explosion-propellant assembly 120; Impact mechanism 121; Elastic component 1211; Impact block 1212; Limiting component 1213; Cylinder block 12131; Lock block 12132; Tension spring 12133; Solenoid directional valve 12134; Explosive loading chamber 122; Pressure sensor 130; 140mm sieve tube; 141 Guanzhi Road; Secondary piping 142; Micro-pipeline 143; Fixed plate structure 150; First fixing plate 151; Second fixing plate 152; Gasket 153; Bolt 154; Gasket 153; Bolt 154; Electrochemical sensor 160; Casing size 170; Working pump station 180; Negative pressure pipe 181; Controller 190; L-type drilling 200; Shaft section 201; Horizontal well section 202; Second air injection pump station 210; Second gas injection conduit 211. Detailed Implementation

[0019] To make the objectives, technical solutions, and advantages of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. The same reference numerals in the drawings represent the same components. It should be noted that the described embodiments are only some, not all, of the embodiments of the present invention. All other embodiments obtained by those skilled in the art based on the described embodiments of the present invention without creative effort are within the scope of protection of the present invention.

[0020] Unless otherwise defined, the technical or scientific terms used herein shall have the ordinary meaning understood by one of ordinary skill in the art to which this invention pertains. The terms “first,” “second,” and similar terms used in this patent application specification and claims do not indicate any order, quantity, or importance, but are merely used to distinguish different components. Similarly, “an” or “a” and similar terms do not necessarily indicate a quantity limitation. Terms such as “comprising” or “including” mean that the element or object preceding the word encompasses the element or object listed following the word and its equivalents, without excluding other elements or objects. Terms such as “connected” or “linked” are not limited to physical or mechanical connections, but can include electrical connections, whether direct or indirect. Terms such as “upper,” “lower,” “left,” and “right” are used only to indicate relative positional relationships; these relative positional relationships may change accordingly when the absolute position of the described object changes.

[0021] According to a first aspect of the present invention, a combustion-induced fracturing and penetration-enhancing device 100, such as... Figure 1 and Figure 2 As shown, an L-shaped well 200 is used in a reservoir, wherein the L-shaped well 200 includes a vertical well section 201 and a horizontal well section 202, and the permeability enhancement device 100 includes: The first gas injection pump station 110 is connected to the L-shaped well 200 through the first gas injection conduit 111. It is configured to inject an oxygen-methane mixture containing a combustion accelerant into the horizontal section 202 of the L-shaped well 200. For example, the combustion accelerant is NaClO3 particles. The ratio of the contents of the oxygen-methane mixture containing NaClO3 particles injected into the horizontal section 202 of the L-shaped well 200 needs to be reasonably designed according to the specific geological conditions of the reservoir area to ensure that the combustion and explosion effect reaches the optimal level.

[0022] At least one combustion and detonation assembly 120 includes: an impact mechanism 121 and a charge chamber 122, wherein the charge chamber 122 is filled with a mixture of sodium chlorate and aluminum powder. The impact mechanism 121 is located close to the charge chamber 122 and is configured to impact the charge chamber 122 to cause an explosion and create a fracturing fracture in the L-shaped well 200. For example, the charge chamber 122 is cylindrical in shape to reduce the risk of stress concentration; it is made of stainless steel with thin walls but good sealing and strength. Another example is that the charge chamber 122 contains sodium chlorate (NaClO3) and aluminum powder in a mass ratio controlled between 5:1 and 5.5:1.

[0023] The second gas injection pump station 210 is connected to the L-type well 200 through the second gas injection conduit 211 and is configured to inject high-purity nitrogen into the horizontal section 202 of the L-type well 200 to drive the combustible gas. The working pump station 180 is connected to the L-shaped well 200 through the negative pressure pipe 181 and is configured to perform negative pressure extraction of gas in the horizontal section 202 of the L-shaped well 200.

[0024] The specific working principle of the permeability enhancement device 100 is as follows: Based on the specific geological conditions of the reservoir area, the formation and distance of the vertical and horizontal wells are determined. At least one combustion and explosion component 120 is installed in the horizontal well section 202. The first gas injection pump station 110 injects an oxygen-methane mixture containing an oxidizer into the horizontal well section 202 through the first gas injection conduit 111. The impact mechanism 121 pushes the impact block 1212 to impact the charging chamber 122. The sodium chlorate and aluminum powder mixture explodes upon impact. The high temperature, high pressure, and high oxygen induce in-situ combustion and explosion of methane. The high temperature and high pressure gas generated by the combustion and explosion in the horizontal well section 202... A fissure forms within 02, simultaneously triggering the next-stage combustion and explosion component 120. After the staged combustion and explosion, the second gas injection pump station 210 continuously injects high-purity nitrogen through the second gas injection conduit 211 to displace methane and other combustible gases. The working pump station 180 performs negative pressure extraction in the reservoir area. The electrochemical sensor 160 monitors the nitrogen concentration in the extracted gas in real time. When the nitrogen concentration increases significantly, nitrogen injection is stopped. When the electrochemical sensor 160 detects no or very little gas, extraction is stopped. The extracted gas is collected through the ground working pump station 180 and advanced to the next working section to repeat the above steps.

[0025] In other words, methane in the well is ignited by an explosion caused by the impact of a mixture of sodium chlorate (NaClO3) and aluminum powder. Simultaneously, sodium chlorate (NaClO3) acts as a combustion accelerant, effectively increasing the explosion overpressure and more efficiently disrupting the surrounding rock mass and expanding the fracture network. High-purity nitrogen is used to displace the gas, and a concentric circle arrangement of extraction wells further enhances gas extraction efficiency. This invention effectively improves reservoir permeability, increases gas extraction efficiency, and features a simplified structure and high safety.

[0026] This device uses NaClO3 particles as a combustion accelerant, which can significantly increase the explosion overpressure. Compared to KMnO4, NaClO3 produces a single reaction product without heavy metal contamination, and the NaClO3 particles can provide support for some micro-cracks. Traditional staged combustion detonation devices generally use electric sparks to ignite explosives, but the underground environment is complex, and if the electric spark comes into contact with flammable and explosive materials, it can easily cause an accident. This device uses an impact method to initiate staged combustion detonation, which is safer than electric spark devices, has a simpler structure, and is easier to maintain. The sieve aperture is gradually... Constricted pores, through the Venturi effect, accelerate gas flow and concentrate shock wave energy, reducing ineffective energy consumption; the guiding pathways within the pores mimic the fractal structure of plant roots, directionally forming a regular fracture network, reducing energy dispersion and increasing the fracture propagation rate through natural mechanical optimization; the use of high-purity nitrogen to displace gas can further improve the gas extraction rate; the extraction wells are arranged concentrically with the combustion and explosion well as the center, making full use of the isotropic transmission property of the shock wave after combustion and explosion in the coal seam, resulting in a wide extraction coverage and high efficiency.

[0027] It should be noted that the optimal explosion concentration for methane is generally 9.5%, so injection should be stopped when the methane concentration reaches 9-10%, and combustion and explosion treatment can then be carried out. The injection concentration of the oxygen-methane mixture depends on the actual reservoir geological conditions. For example, if the measured geological methane concentration is 5%, then the corresponding oxygen-methane mixture should be injected to bring the methane concentration to 9%-10%.

[0028] Preferably, the system further includes a housing 170, which is installed in the horizontal well section 202, and the combustion and explosion assembly 120 is installed in the housing 170; the housing 170 facilitates the installation of the combustion and explosion assembly 120. For example, the housing 170 is made of ultra-high strength alloy steel.

[0029] It is understandable that it also includes: a working pump station 180, which is arranged in the L-shaped well 200 through a negative pressure pipe 181 and extends into its horizontal well section 202, configured to perform negative pressure extraction of the reservoir area, monitor the nitrogen concentration in the extracted gas in real time, and stop injecting nitrogen when the nitrogen concentration increases significantly; both the working pump station 180 and the second gas injection pump station 210 operate after the staged combustion explosion is completed, the second gas injection pump station 210 continuously injects high-purity nitrogen through the second gas injection conduit 211 to drive the methane and other combustible gases, while the working pump station 180 performs negative pressure extraction of the reservoir area.

[0030] In one example of the present invention, at least one combustion and explosion component 120 includes a plurality of components and is arranged sequentially along the horizontal well section 202 of the L-shaped well 200, and the plurality of combustion and explosion components 120 explode one by one from the side closer to the first gas injection pump station 110 toward the side away from the first gas injection pump station 110. Specifically, each combustion and explosion assembly 120 includes an impact mechanism 121, a charging chamber 122, and a sieve tube 140 arranged in sequence. The tail end of the sieve tube 40 is connected to another combustion and explosion assembly 120, that is, the end of the previous combustion and explosion assembly 120 is connected to the front end of the next combustion and explosion assembly 120.

[0031] In other words, multiple combustion and explosion components 120 are sequentially and spaced apart within the horizontal well section 202. During the fracturing process, the combustion and explosion components 120 closest to the vertical well section 201 and in the direction away from the vertical well section 201 explode sequentially, thereby fracturing the well step by step. This device uses an impact method to initiate the step-by-step combustion and explosion, which is safer, simpler in structure, and easier to maintain compared to electric spark devices.

[0032] In one example of the invention, a pressure sensor 130 is further included, located in each combustion-explosion assembly 120, with the pressure sensor 130 in each combustion-explosion assembly 120 positioned close to the adjacent combustion-explosion assembly 120. When the pressure sensor 130 detects an explosion in its corresponding combustion-explosion assembly 120, and the pressure generated in the L-shaped drilling rig 200 reaches a threshold pressure, it triggers the explosion of the adjacent combustion-explosion assembly 120. It is understood that the pressure sensor 130 is not required in the last combustion-explosion assembly 120 to explode.

[0033] For example, when the pressure sensor 130 detects 3 standard atmospheres, the trigger circuit immediately activates the next-stage combustion and explosion component 120, and its response time from detecting the pressure signal to outputting the trigger pulse does not exceed 0.01 seconds.

[0034] By setting up a pressure sensor 130, fracturing can be effectively achieved through step-by-step combustion based on the pressure inside the well.

[0035] Preferably, the system also includes an electrochemical sensor 160, which is used to monitor the concentrations of nitrogen and methane in the extracted gas in real time. When the nitrogen concentration is detected to be significantly increased, the injection of nitrogen is stopped. When the electrochemical sensor 160 detects no or very little methane, the extraction is stopped, and the extracted gas is collected by a ground working pump station 180 and advanced to the next working section to repeat the above steps.

[0036] Based on the specific geological conditions of the reservoir area, the strata and distances of the vertical and horizontal wells are determined. Multiple combustion and explosion components 120 are installed within the horizontal well section 202. The first gas injection pump station 110 injects an oxygen-methane mixture containing an oxidizer into the horizontal well section 202 through the first gas injection conduit 111. The impact mechanism 121 of the first combustion and explosion component 120 pushes the impact block 1212 to impact the charging chamber 122. The sodium chlorate and aluminum powder mixture explodes upon impact, and the high temperature, high pressure, and high oxygen induce in-situ combustion and explosion of methane. The high temperature and high pressure gas generated by the combustion and explosion forms fractures within the horizontal well section 202. After the pressure sensor 130 senses that the pressure generated in the L-shaped well 200 reaches the threshold pressure, it triggers the next adjacent... The impact mechanism 121 of the combustion and explosion component 120 pushes the impact block 1212 to impact the charging chamber 122 to produce an explosion, which is triggered by the pressure sensor 130 to trigger the next stage combustion and explosion component 120. After the staged combustion and explosion is completed, the second gas injection pump station 210 continuously injects high-purity nitrogen gas through the second gas injection conduit 211 to displace methane and other combustible gases. The working pump station 180 performs negative pressure extraction in the reservoir area. The electrochemical sensor 160 monitors the nitrogen concentration in the extracted gas in real time. When the nitrogen concentration increases significantly, the injection of nitrogen gas is stopped. When the electrochemical sensor 160 detects no gas or very little gas, the extraction is stopped. The extracted gas is collected through the ground working pump station 180 and pushed to the next working section to repeat the above steps.

[0037] In one example of the present invention, such as Figure 3 As shown, it also includes: at least one screen tube 140, one end of the at least one screen tube 140 is disposed near the charging chamber 122, and the other end extends away from the combustion and explosion assembly 120, and the screen tube 140 is provided with screen holes 1401, and the screen tube 140 is configured to conduct the high temperature and high pressure gas generated by the combustion and explosion assembly 120 to form directional fractures in the horizontal well section 202; In other words, by setting at least one screen pipe 140 at the charging chamber 122, the high-temperature and high-pressure gas generated by the re-ignition component 120 after impact and explosion can be conducted through at least one screen pipe 140 to a designated location in the horizontal well section 202, thereby forming a directional fracture in the horizontal well section 202.

[0038] For example, a pressure sensor 130 is provided inside the screen tube 140 and near the next combustion and explosion assembly 120.

[0039] Preferably, the screen tube 140 is made of silicon carbide material with a thickness of 20 mm; several round holes are evenly distributed in the horizontal direction of the screen tube 140 to guide high-temperature and high-pressure gas to the area around the horizontal well for fracturing, while simultaneously triggering the pressure sensor 130.

[0040] Preferably, the screen pipe 140 includes a plurality of screen pipes, which are arranged along the extension direction of the horizontal section 202 of the L-shaped well 200 and spaced apart along the circumferential direction of the horizontal section 202; by setting a plurality of screen pipes 140, the fracturing effect of the combustion and explosion component 120 during the combustion and explosion process can be further improved.

[0041] In one example of the present invention, such as Figure 4 As shown, the sieve tube 140 includes: at least one main pipe 141 and at least one secondary pipe 142 connected to the at least one main pipe 141, and the micro pipe 143 extends away from the loading chamber 122 and forms an acute angle with the main pipe 141. In short, the internal structure of the screen pipe 140 is a root system structure. The high-temperature and high-pressure gas can be transmitted to the designated location in the form of multiple pipelines through the connection between the main pipeline 141 and the secondary pipeline 142. The secondary pipeline 142 extends away from the charging chamber 122 and forms an acute angle with the main pipeline 141, which allows the high-temperature and high-pressure gas to be transmitted in the designated direction, thereby forming directional fractures in the horizontal well section 202.

[0042] In one example of the present invention, the sieve tube 140 further includes: at least one microchannel 143 connected to the at least one secondary channel 142, wherein the secondary channel 142 extends away from the loading chamber 122 and forms an acute angle with the secondary channel 142. In other words, the structure of sieve tube 140 is a three-level fractal branch, which further guides the shock wave to expand along a predetermined path, thereby further improving the effect of directional fracture. In short, the guiding pathway inside the pore mimics the fractal structure of plant roots, and fractal grooves are etched on the surface of the sieve tube to guide the shock wave to expand along a predetermined path, using a three-level fractal branch (main groove → secondary groove → micro groove).

[0043] In one example of the present invention, at least one of the main pipeline 141 and the secondary pipeline 142 is a tapering orifice, and gradually decreases in size from one end near the charge chamber 122 to the end away from the charge chamber 122; The sieve apertures are tapered, which accelerate gas flow and concentrate shock wave energy through the Venturi effect, reducing ineffective energy consumption. The internal guiding pathways mimic the fractal structure of plant roots, forming a regular network of fissures. Through natural mechanical optimization, energy dispersion is reduced and the fissure expansion rate is increased.

[0044] In one example of the present invention, such as Figure 5 As shown, two adjacent combustion and explosion components 120 are connected by a fixing plate structure 150. The fixing plate structure 150 includes a first fixing plate 151 and a second fixing plate 152 that are fixedly connected. The first fixing plate 151 is fixedly connected to the screen tube 140 of one of the combustion and explosion components 120, and the second fixing plate 152 is fixedly connected to the impact mechanism 121 of the other combustion and explosion component 120. The end of the previous stage combustion and explosion assembly 120 is connected to the front end of the next stage combustion and explosion assembly 120 through a fixing plate structure 150. The connection includes a first fixing plate 151, a second fixing plate 152, a gasket 153, and a bolt 154. A high-temperature and high-pressure resistant carbon fiber sealing gasket is embedded between the first fixing plate 151 and the second fixing plate 152 and is fastened with bolts to prevent gas leakage and ensure sealing.

[0045] The aforementioned fixed plate structure can greatly improve the reliability of the connection between two adjacent combustion and explosion components.

[0046] In one example of the present invention, the impact mechanism 121 includes: An elastic element 1211, disposed near the charge chamber 122, is capable of switching between a compressed state and an extended state. An impact block 1212 is disposed at one end of the elastic element 1211 near the charge chamber 122. When the elastic element 1211 is in the extended state, it can drive the impact block 1212 to impact the charge chamber 122, causing an explosion. For example, an impact cavity is provided between the impact block 1212 and the charge chamber 122. Preferably, the impact block 1212 is conical in shape, generating sufficient pressure upon impact and directing the energy to a designated area. For example, the impact block 1212 is made of titanium alloy.

[0047] The limiting member 1213, which is connected to the impact block 1211, is configured to switch between a locking position that limits the elastic member 1211 to a compressed state and a release position that releases the elastic member 1211 to an extended state.

[0048] Specifically, such as Figure 6As shown, the limiting component 1213 is an electro-hydraulic drive device, which includes: a cylinder body 12131, a locking block 12132, a tension spring 12133, and a solenoid directional valve 12134. The locking block 12132 is retractably disposed within the cylinder body 12131. One end of the tension spring 12133 is connected to the cylinder body 12131, and the other end is connected to the locking block 12132. The solenoid directional valve 12134 is located on one side of the cylinder body 12131 and is configured to achieve the filling and releasing of hydraulic oil within the cylinder body 12131 through reversing. In other words, the locking block 12132 is locked and the tension spring 12133 is released by switching between a first state and a second state using the solenoid directional valve 12134. When the electromagnetic reversing valve 12134 is in the first state, the hydraulic oil filling cylinder pushes the locking block 12132 towards the impact block 1212, and it engages with the groove on the impact block. That is, the locking block 12132 is in the locked position, locking the impact block 1212, causing the elastic element 1213 to be in a compressed state. When the electromagnetic reversing valve 12134 is in the second state, the hydraulic oil is depressurized from the cylinder 12131, causing the locking block 12132 to move away from the impact block along the cylinder 12131 and separate from the groove on the impact block. The locking block 12132 is in the released position, releasing the elastic element 1213, allowing the elastic element 1213 to return to its extended state and drive the impact block 1212 to impact the charging chamber 122, causing an explosion. The locking and releasing states of the locking block 12132 are achieved through the reversing action of the electromagnetic reversing valve 12134. For example, multiple electro-hydraulic drive devices are arranged at intervals along the circumferential direction of the impact block.

[0049] Preferably, the elastic element 1211 is a compression spring with an elastic coefficient of 5000 N / m, pre-compressed to 0.8 meters. A buffer pad made of rubber and polyurethane composite material with a thickness of 5 cm is provided between the spring and the impact block 1212 to reduce the impact of spring rebound on the equipment.

[0050] In one example of the present invention, such as Figure 7 As shown, it also includes a controller 190, which is coupled to the pressure sensor 130, electrochemical sensor 160, limiter 1213, ground working pump station 180, safety valve 112, etc., so that the controller 190 can control the limiter 1213, ground working pump station 180, first gas injection pump station 110, second gas injection pump station 210, safety valve 112, etc. to perform corresponding operations based on the information obtained by the pressure sensor 130 and electrochemical sensor 160.

[0051] Specifically, based on the specific geological conditions of the reservoir area, the formation and distance of the vertical and horizontal drilling sites are determined. Multiple combustion and explosion components 120 are installed within the horizontal well section 202, and the elastic element 1211 is pre-positioned in a compressed locked state by the limiting member 1213. The controller 190 controls the first gas injection pump station 110 to inject an oxygen-methane mixture containing an oxidizer into the horizontal well section 202 through the first gas injection conduit 111 (the controller 190 controls the safety valve 112 to open). After the mixed gas concentration reaches the required level, the controller 190 controls the limiting member 1213 of the first combustion and explosion component 120 to release the elastic element 1211, switching it from the locked position to the released position. This causes the elastic element 1211 to push the impact block 1212 to impact the charging chamber 122. The sodium chlorate and aluminum powder mixture explodes upon impact, and the high temperature, high pressure, and high oxygen induce in-situ combustion and explosion of methane. The high temperature and high pressure gas generated by the explosion forms a fracture within the horizontal well section 202, which is then ignited by the combustion and explosion component 1211. After the pressure sensor 130 in section 20 senses that the pressure generated by the explosion reaches the threshold pressure, it triggers the impact mechanism 121 of the adjacent next combustion and explosion component 120 to push the impact block 1212 to impact the charging chamber 122 and generate an explosion. That is, the pressure sensor 130 triggers the next stage combustion and explosion component 120. After the staged combustion and explosion is completed, the controller 190 controls the second gas injection pump station 210 to continuously inject high-purity nitrogen gas through the second gas injection conduit 211 to displace methane and other combustible gases (the controller 190 controls the safety valve 112 to open). The controller 190 controls the working pump station 180 to perform negative pressure extraction in the reservoir area (the controller 190 controls the safety valve 112 to open). The electrochemical sensor 160 monitors the nitrogen concentration in the extracted gas in real time. When the nitrogen concentration increases significantly, the injection of nitrogen gas is stopped. When the electrochemical sensor 160 detects no gas or very little gas, the extraction is stopped. The extracted gas is collected by the ground working pump station 180 and pushed to the next working section to repeat the above steps.

[0052] According to a second aspect of the present invention, a method for enhancing the penetration of the combustion-induced fracturing penetration enhancement device 100 as described above includes the following steps: S10: Based on the specific geological conditions of the reservoir area, determine the strata and distance of the L-shaped well 200, and install at least one combustion and explosion component 120 in the horizontal well section 202; for example, the screen pipe 140 and the vertical well section 201 are equipped with guide pipes, the screen pipe 140 is equipped with a pressure sensor 130, and the connection between the vertical well section 201 and the first gas injection pump station 110 is equipped with a safety valve 112 to control the connection and disconnection between the first gas injection pump station 110 and the vertical well section 201; the drilling arrangement adopts a concentric circle form, with the well at the center of the circle being used for combustion and explosion, and the extraction wells are arranged concentrically around it; S20: The first gas injection pump station 110 injects a mixture of oxygen and methane containing a combustion-supporting agent into the horizontal well section 202 through the first gas injection conduit 111; S30: The impact mechanism 121 pushes the impact block 1212 to impact the charging chamber 122. The sodium chlorate and aluminum powder mixture explodes upon impact. The high temperature, high pressure and high oxygen induce in-situ combustion and explosion of methane. The high temperature and high pressure gas generated by the combustion and explosion forms a fracture in the horizontal well section 202 and is guided by the screen holes of the screen pipe 140 to form a directional fracture. The combustion and explosion component 120 will trigger the next stage combustion and explosion component 120 to explode when the combustion and explosion pressure is generated. For example, when the pressure sensor 130 detects that the combustion and explosion pressure reaches the threshold, the controller 190 issues a command through remote control to control the release of the elastic element of the limit member 1213 of one combustion and explosion component 120.

[0053] S40: After the staged combustion and explosion, the second gas injection pump station 210 continuously injects high-purity nitrogen through the second gas injection conduit 211 to displace combustible gases such as methane. The working pump station 180 performs negative pressure extraction of the reservoir area through the negative pressure pipe 181. The electrochemical sensor 160 monitors the nitrogen concentration in the extracted gas in real time. When the nitrogen concentration increases significantly, the injection of nitrogen is stopped. For example, the high-purity nitrogen has a purity of 97%-99.99%.

[0054] S50: When the electrochemical sensor 160 detects no gas or very little gas, stop the extraction. The extracted gas is collected through the ground working pump station 180 and pushed to the next working section to repeat steps S10-S40. Based on the specific geological conditions of the reservoir area, the formation and distance of the vertical and horizontal wells are determined. Multiple combustion and explosion components 120 are installed within the horizontal well section 202, and the elastic element 1211 is pre-positioned in a compressed state by the limiting member 1213. The first gas injection pump station 110 injects an oxygen-methane mixture containing an oxidizer into the horizontal well section 202 through the first gas injection conduit 111. Once the mixed gas concentration reaches the required level, the limiting member 1213 of the first combustion and explosion component 120 releases the elastic element 1211, switching it from the locked position to the released position. This causes the elastic element 1211 to push the impact block 1212 to impact the charging chamber 122. The sodium chlorate and aluminum powder mixture explodes upon impact, and the high temperature, high pressure, and high oxygen induce in-situ combustion and explosion of methane. The high temperature and high pressure gas generated by the explosion forms fractures within the horizontal well section 202. When the pressure sensor 130 inside the combustion and explosion assembly 120 senses that the pressure generated by the explosion reaches the threshold pressure, it triggers the impact mechanism 121 of the adjacent next combustion and explosion assembly 120 to push the impact block 1212 to impact the charging chamber 122 to produce an explosion. That is, the pressure sensor 130 triggers the next stage combustion and explosion assembly 120. After the staged combustion and explosion is completed, the second gas injection pump station 210 continuously injects high-purity nitrogen gas through the second gas injection conduit 211 to displace combustible gases such as methane. The working pump station 180 performs negative pressure extraction in the reservoir area. The electrochemical sensor 160 monitors the nitrogen concentration in the extracted gas in real time. When the nitrogen concentration increases significantly, the injection of nitrogen gas is stopped. When the electrochemical sensor 160 detects no gas or very little gas, the extraction is stopped. The extracted gas is collected through the ground working pump station 180 and advanced to the next working section to repeat the above steps.

[0055] This permeation enhancement method uses NaClO3 particles as a combustion aid, which can significantly increase the explosion overpressure. Compared to KMnO4, NaClO3 has a single reaction product and no heavy metal contamination. NaClO3 particles can also provide support for some micro-fractures. Traditional staged combustion detonation devices generally use electric sparks to ignite explosives, but the underground environment is complex. If the electric spark comes into contact with flammable and explosive materials, it can easily cause an accident. This device uses an impact method to initiate staged combustion detonation, which is safer than electric spark devices, has a simpler structure, and is easier to maintain. The sieve aperture type is... The tapered orifice, through the Venturi effect, accelerates gas flow and concentrates shock wave energy, reducing ineffective energy consumption; the guiding pathway within the orifice mimics the fractal structure of plant roots, directionally forming a regular fracture network, reducing energy dispersion and increasing the fracture propagation rate through natural mechanical optimization; the use of high-purity nitrogen to displace the gas can further improve the gas extraction rate; the extraction wells are arranged concentrically with the combustion well as the center, making full use of the isotropic transmission property of the shock wave after combustion in the coal seam, resulting in a wide extraction coverage and high efficiency.

[0056] In one example of the present invention, in step S30, at least one screen pipe 140 is provided near the charging chamber 122. When the combustion and explosion component 120 is combusted, the high temperature and high pressure gas generated forms directional fractures in the horizontal well section 202 via the at least one screen pipe 140.

[0057] In other words, by setting at least one screen pipe 140 at the charging chamber 122, the high-temperature and high-pressure gas generated by the re-ignition component 120 after impact and explosion can be conducted through at least one screen pipe 140 to a designated location in the horizontal well section 202, thereby forming a directional fracture in the horizontal well section 202.

[0058] Preferably, the screen pipe 140 includes a plurality of screen pipes, which are arranged along the extension direction of the horizontal section 202 of the L-shaped well 200 and spaced apart along the circumferential direction of the horizontal section 202; by setting a plurality of screen pipes 140, the fracturing effect of the combustion and explosion component 120 during the combustion and explosion process can be further improved.

[0059] The foregoing description, with reference to preferred embodiments, details exemplary implementations of the combustion-induced fracturing and permeability enhancement device 100 and method proposed in this invention. However, those skilled in the art will understand that various modifications and alterations can be made to the above specific embodiments without departing from the concept of this invention, and various combinations can be made to the various technical features and structures proposed in this invention without exceeding the protection scope of this invention, which is determined by the appended claims.

Claims

1. A combustion-induced fracturing and permeability enhancement device, characterized in that, In an L-type well (200) used in a reservoir, wherein the L-type well (200) includes a vertical section (201) and a horizontal section (202), and the permeability enhancement device (100) includes: The first gas injection pump station (110) is connected to the L-type well (200) through the first gas injection conduit (111) and is configured to inject an oxygen-methane mixture containing a combustion-supporting agent into the horizontal section (202) of the L-type well (200); At least one combustion and detonation assembly (120) includes: an impact mechanism (121) and a charge chamber (122) containing a mixture of sodium chlorate and aluminum powder, the impact mechanism (121) being disposed close to the charge chamber (122) and configured to impact the charge chamber (122) to cause an explosion and create a fracturing fracture in an L-shaped borehole (200); The second gas injection pump station (210) is connected to the L-type well (200) through the second gas injection conduit (211) and is configured to inject high-purity nitrogen into the horizontal section (202) of the L-type well (200) to drive the combustible gas. The working pump station (180) is connected to the L-shaped well (200) via a negative pressure pipe (181) and is configured to perform negative pressure extraction of gas in the horizontal section (202) of the L-shaped well (200).

2. The combustion-induced fracturing and permeability enhancement device according to claim 1, characterized in that, At least one combustion and explosion component (120) comprises multiple components and is arranged sequentially along the horizontal well section (202) of the L-shaped borehole (200), and the multiple combustion and explosion components (120) explode one by one from the side closer to the first gas injection pump station (110) toward the side away from the first gas injection pump station (110).

3. The combustion-induced fracturing and permeability enhancement device according to claim 2, characterized in that, It also includes: a pressure sensor (130) located in each combustion component (120), and the pressure sensor (130) in each combustion component (120) is set close to the other combustion component (120) adjacent to it; when the pressure sensor (130) detects that its corresponding combustion component (120) has exploded and the pressure generated in the L-shaped well (200) reaches the threshold pressure, it triggers the explosion of the other combustion component (120) adjacent to it.

4. The combustion-induced fracturing and permeability enhancement device according to claim 1, characterized in that, It also includes: at least one screen tube (140), one end of which is located near the charging chamber (122), and the other end of which extends away from the combustion and explosion assembly (120), and the screen tube (140) is provided with screen holes (1401), and the screen tube (140) is configured to conduct the high temperature and high pressure gas generated by the combustion and explosion assembly (120) to form directional fractures in the horizontal well section (202).

5. The combustion-induced fracturing and permeability enhancement device according to claim 4, characterized in that, The screen tube (140) includes at least one main pipe (141) and at least one secondary pipe (142) connected to the at least one main pipe (141), wherein the secondary pipe (142) extends away from the loading chamber (122) and forms an acute angle with the main pipe (141).

6. The combustion-induced fracturing and permeability enhancement device according to claim 5, characterized in that, The screen tube (140) further includes at least one microchannel (143) which is connected to the at least one secondary channel (142), and the microchannel (143) extends away from the loading chamber (122) and forms an acute angle with the secondary channel (142).

7. The combustion-induced fracturing and permeability enhancement device according to claim 5, characterized in that, At least one of the main pipeline (141) and the secondary pipeline (142) is a tapered orifice, and gradually decreases in size from the end near the charge chamber (122) to the end away from the charge chamber (122).

8. The combustion-induced fracturing and permeability enhancement device according to claim 1, characterized in that, The impact mechanism (121) includes: An elastic element (1211) is disposed near the charge chamber (122) and is capable of switching between a compressed state and an extended state. An impact block (1212) is disposed at one end of the elastic element (1211) near the charge chamber (122). When the elastic element (1211) is in the extended state, it can drive the impact block (1212) to impact the charge chamber (122) to generate an explosion. The limiting member (1213), which is connected to the impact block (1211), is configured to switch between a locking position that limits the elastic member (1211) to a compressed state and a release position that releases the elastic member (1211) to an extended state.

9. A method for enhancing the penetration of a combustion-induced fracturing device as described in any one of claims 1 to 8, characterized in that, Includes the following steps: S10: Based on the specific geological conditions of the reservoir area, determine the stratum and distance of the L-type well (200), and set at least one combustion and explosion component (120) in the horizontal well section (202). S20: The first gas injection pump station (110) injects a mixture of oxygen and methane containing a combustion-supporting agent into the horizontal well section (202) through the first gas injection conduit (111); S30: The impact mechanism (121) pushes the impact block (1212) to impact the charging chamber (122). The sodium chlorate and aluminum powder mixture explodes upon impact. High temperature, high pressure and high oxygen induce in-situ combustion and explosion of methane. The high temperature and high pressure gas generated by the combustion and explosion forms a fracture in the horizontal well section (202). The combustion and explosion component (120) will trigger the next stage combustion and explosion component (120) to explode under the pressure generated by the combustion and explosion. S40: After the explosion is completed, the second gas injection pump station (210) continuously injects high-purity nitrogen through the second gas injection conduit (211) to displace the combustible gas. The working pump station (180) performs negative pressure extraction of the reservoir area through the negative pressure pipe (181) and monitors the nitrogen concentration in the extracted gas in real time. When the nitrogen concentration increases significantly, the injection of nitrogen is stopped. S50: Stop extraction when no gas is detected or very little gas is detected. The extracted gas is collected through the ground working pump station (180) and pushed to the next working section to repeat steps S10-S40.

10. The method for enhancing penetration using the combustion-induced fracturing and penetration-enhancing device according to claim 9, characterized in that, In step S30, at least one screen pipe (140) is provided near the charging chamber (122). When the combustion and explosion assembly (120) is combusted, the generated high-temperature and high-pressure gas forms a directional fracture in the horizontal well section (202) through at least one screen pipe (140).

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