A full-hole-section deflagration fracturing construction method

Abstract

The application discloses a full-well-section deflagration fracturing construction method, which comprises the following steps: drilling a horizontal well and setting a region to be fractured; lowering a screen pipe into the horizontal well and injecting a well killing fluid; pouring a liquid energetic agent into a flexible non-metallic charge barrel, then installing an ignition structure on a charge end of the charge barrel; connecting an end of a coiled tubing to an upper end of the ignition structure, then conveying the charge barrel to a set position in the horizontal well through the coiled tubing, and making the charge barrel cover all the regions to be fractured in the horizontal well; igniting the ignition structure through the coiled tubing, and making the liquid energetic agent in the charge barrel deflagrate, so that high-pressure combustion gas generated by the deflagration breaks the charge barrel and does work on rocks, and the rocks are fractured; after the fracturing is completed, the screen pipe is recovered, and the charge barrel debris is recovered with the screen pipe. The application solves the problems of complicated assembly and high failure rate in the prior art when performing a super-long well section pre-fracturing operation through a high-energy gas fracturing mode.

Description

Technical Field

[0001] This application belongs to the field of gas fracturing technology, specifically relating to a method for full-section deflagration fracturing construction. Background Technology

[0002] With the needs of oil, natural gas, coalbed methane, and coal mining and development, numerous technologies exist for drilling, fracturing, and pre-fracture in deep underground rock formations. Explosive detonation, hydraulic fracturing, and high-energy gas fracturing are three mature and commonly used techniques for pre-fracture of rock formations. High-energy gas fracturing utilizes the rapid combustion of energetic materials to generate stress waves that impact and load the rock strata. This creates multiple radial microcracks around the wellbore, unconstrained by geostress, or causes existing microcracks to expand. The high-temperature, high-pressure gas following the stress waves then rapidly opens and expands the fractures in a quasi-static manner. The most significant advantage of high-energy gas fracturing is that it does not cause the rock in the wellbore to collapse or crumble, and it allows natural fractures in the rock strata to connect with the wellbore, thereby increasing reservoir permeability and conductivity.

[0003] Currently, high-energy gas fracturing typically uses solid propellant charges, which are only 1 meter long. To achieve deflagration operations in large-span or ultra-long well sections, such as those exceeding 100 meters or even 200 meters, the on-site assembly of the propellant charge and its associated equipment is extremely cumbersome. Furthermore, the numerous connection joints may lead to leakage in a few joints, causing the entire high-energy gas fracturing ignition to fail. Summary of the Invention

[0004] This application provides a full-section deflagration fracturing construction method, which solves the problems of cumbersome assembly and high failure rate in the prior art when performing pre-fracturing operations on ultra-long well sections using high-energy gas fracturing.

[0005] To achieve the above objectives, embodiments of the present invention provide a method for full-section deflagration fracturing, comprising the following steps:

[0006] Drill a horizontal well and designate the area to be fractured;

[0007] The screen pipe is lowered into the horizontal well, and then kill fluid is injected.

[0008] A liquid energetic agent is injected into a flexible non-metallic charge cartridge, and then an ignition structure is installed on the charge end of the charge cartridge.

[0009] The end of the coiled tubing is connected to the upper end of the ignition structure, and then the charge cartridge is transported to the set position in the horizontal well through the coiled tubing, so that the charge cartridge covers the area in the horizontal well to be fracturing.

[0010] The coiled tubing ignites the ignition structure, the ignition structure makes the liquid energetic agent in the charge cylinder deflagrate, the high-pressure gas generated by deflagration breaks the charge cylinder and does work on the rock, and the rock is fractured;

[0011] After fracturing is completed, the screen pipe is recovered, and the charge cylinder debris is recovered with the screen pipe.

[0012] In a possible implementation, the extension direction of the horizontal section of the horizontal well is parallel to the direction of the minimum principal stress of the formation rock.

[0013] In a possible implementation, the ignition structure comprises a transfer tube, a primer base, a pressure initiator, and a sealing ring.

[0014] When the ignition structure is installed, the end of the transfer tube is connected to the lower end of the primer base, the pressure initiator is installed at the stepped hole in the primer base, and the primer of the pressure initiator and the end of the transfer tube are in abutment.

[0015] The end of the transfer tube is inserted into the charge cylinder through the rubber joint at the end of the charge cylinder, and at this time, the end of the transfer tube is located in the liquid energetic agent.

[0016] The primer base is screwed into the nut at the end of the rubber joint, and the two sides of the sealing ring are in abutment with the end of the primer base and the end of the rubber joint, respectively.

[0017] In a possible implementation, the liquid energetic agent is liquid nitromethane, the liquid nitromethane is passivated by an additive and its deflagration speed is reduced, and the transfer tube is filled with a composite solid propellant.

[0018] In a possible implementation, the deflagration pressure is adjusted by the decoupling coefficient of the inner diameter of the charge cylinder and the diameter of the horizontal well bore.

[0019] In a possible implementation, the diameter of the perforation site of the charge cylinder is greater than the diameter of the ignition site of the charge cylinder.

[0020] In a possible implementation, after the liquid energetic agent in the charge cylinder deflagrates, the excess energy of deflagration is released through the annulus at the ignition site.

[0021] In a possible implementation, the pressure data and temperature data in the deflagration process are collected by a collection instrument at the plugged end of the charge cylinder, and the effect of deflagration fracturing is inferred by the pressure peak value and the duration thereof, and the highest temperature.

[0022] In a possible implementation, when the ignition structure fails to make the liquid energetic agent in the charge cylinder deflagrate, the charge cylinder string is pulled out through the coiled tubing for inspection.

[0023] In a possible implementation, the charge cartridge is made of an organic polymer plastic pipe, and a rubber pipe joint is arranged at the sealing end of the charge cartridge, and a plug is arranged at the end of the rubber pipe joint, and the end of the plug is in the form of an arc-shaped sharp head.

[0024] The one or more technical solutions provided in the embodiments of the present application have at least the following technical effects or advantages:

[0025] The full-well-section deflagration fracturing construction method provided in the embodiments of the present application utilizes the flowable property of the liquid energetic agent, so that the liquid energetic agent can be filled in the charge cartridge for a long distance, the charge cartridge is not easy to be damaged by pulling, meanwhile, the well killing fluid between the charge cartridge and the screen pipe can generate a certain buoyancy on the charge cartridge, and the well killing fluid can also reduce the friction when the charge cartridge is pushed, so as to further reduce the pulling force borne by the charge end of the charge cartridge, and then the charge cartridge can still maintain a perfect structure after long-distance charging. The delivery mode of the charge cartridge can not only realize the quantitative and accurate delivery of the liquid energetic agent, but also can isolate the liquid energetic agent from the liquid in the wellbore, so that the liquid energetic agent is not polluted and dissipated by the liquid in the wellbore, and then the reliability of the liquid energetic agent during deflagration is improved. The present application adopts the pipe string structure in which the liquid energetic agent is continuously distributed in the charge cartridge, so as to solve the problems of the existing high-energy gas fracturing mode, such as complicated assembly of the propellant grain, many connection points, poor sealing of the propellant grain and easy water leakage, and the filling mode of the present application is simple, reliable and good in sealing, so as to fundamentally solve the problem of fracturing ignition failure caused by complicated assembly and poor sealing. BRIEF DESCRIPTION OF DRAWINGS

[0026] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings needed in the embodiment description will be briefly introduced. Obviously, the drawings in the following description are only some embodiments described in the present application, and other drawings can also be obtained according to these drawings without creative labor for those skilled in the art.

[0027] Figure 1 The full-well-section deflagration fracturing construction state schematic diagram provided in the embodiments of the present application.

[0028] Figure 2 The structure schematic diagram of the charge cartridge and the ignition structure provided in the embodiments of the present application.

[0029] Attached reference numerals: 1-Horizontal well; 2-Screen pipe; 3-Kill fluid; 4-Charging cartridge; 41-Perforation location; 42-Ignition location; 43-High-pressure hose; 44-Hose connector; 45-Clamping space; 46-Nut; 47-Plug; 5-Ignition structure; 51-Ignition tube; 511-Bottom plug; 512-Composite solid propellant; 52-Ignition cap base; 53-Pressure initiator; 531-Piston firing pin; 532-Bearing ring; 533-Ignition cap; 54-Sealing ring; 6-Coiled tubing. Detailed Implementation

[0030] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0031] In the description of the embodiments of the present invention, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing the embodiments of the present invention and for simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the present invention. The terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance. Furthermore, the terms "installed," "connected," and "linked" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in the embodiments of the present invention according to the specific circumstances.

[0032] like Figure 1 and Figure 2 As shown in the embodiment of the present invention, the whole-well section deflagration fracturing construction method includes the following steps:

[0033] Drill horizontal well 1 and define the area to be fractured.

[0034] Lower screen 2 into horizontal well 1, and then inject kill fluid 3.

[0035] Liquid energetic agent is injected into the flexible non-metallic charge cartridge 4, and then the ignition structure 5 is installed on the charge end of the charge cartridge 4.

[0036] The end of the coiled tubing 6 is connected to the upper end of the ignition structure 5, and then the charge cartridge 4 is delivered to a set position in the horizontal well 1 through the coiled tubing 6, and the charge cartridge 4 covers the area to be fractured in the horizontal well 1.

[0037] The ignition structure 5 is ignited through the coiled tubing 6, the ignition structure 5 makes the liquid energetic agent in the charge cartridge 4 deflagrate, the high-pressure gas generated by the deflagration breaks the charge cartridge 4 and does work on the rock, and the rock is fractured.

[0038] After the fracturing is completed, the screen pipe 2 is recovered, and the charge cartridge 4 debris is recovered with the screen pipe 2.

[0039] It should be noted that before the fracturing, different types of liquid energetic agents are selected according to the formation rock performance, the diameter and material of the screen pipe 2, and the diameter of the charge cartridge 4, and the maximum outer diameter and length of the charge cartridge 4 are determined according to the length of the whole well section to be fractured, and the length of the charge cartridge 4 is accurate to cover all the areas to be fractured in the horizontal well 1, so that the present application can achieve the purpose of operation of all the areas to be fractured through one operation. The length of the charge cartridge 4 of the present application can be up to 300 meters, so it can meet the fracturing needs of most length of the horizontal well 1.

[0040] In order to facilitate construction and transportation, the screen pipe 2 is two meters long, the adjacent screen pipes 2 are connected to each other through a threaded structure, and the end of the first screen pipe 2 is blocked when it is lowered into the well. After the screen pipe 2 is lowered into the horizontal well 1, the end of the screen pipe 2 located at the wellhead is fixed relative to the wellhead. In addition to facilitating the lowering of the charge cartridge 4 and providing protection, the screen pipe 2 also has the function of recovering the charge cartridge 4 debris after the deflagration fracturing is completed, so that there is no residue in the well after the whole operation is completed.

[0041] The charge cartridge 4 is a non-metal pipe material with sufficient strength and certain flexibility. The charge cartridge 4 can be a whole pipe material with the same diameter, or a combination of pipe materials with two different diameters. Before use, the pressure test should be carried out to ensure that there is no leakage point in the charge cartridge 4.

[0042] The present application utilizes the flowable property of the liquid energetic agent, so that the liquid energetic agent can be filled in the charge cartridge 4 for a long distance. The part of the charge cartridge 4 located in the horizontal section of the horizontal well 1 is supported on the bottom wall of the wellbore, so the charging end of the charge cartridge 4 only needs to bear the gravity of the liquid energetic agent located in the vertical section of the horizontal well 1 and part of the gravity of the build-up section, so the charge cartridge 4 is not easy to be damaged by pulling, and the well killing fluid 3 between the charge cartridge 4 and the screen pipe 2 can generate a certain buoyancy on the charge cartridge 4, and the well killing fluid 3 can also reduce the friction when the charge cartridge 4 is pushed, thereby further reducing the pulling force borne by the charging end of the charge cartridge 4, and then after the charge cartridge 4 is filled for a long distance, the charge cartridge 4 can still maintain a perfect structure.

[0043] The liquid energetic agent is continuously distributed in the tube string structure of the charging barrel 4, the problems of complicated assembly of the propellant column, many connection points, poor sealing of the propellant column and easy water leakage in long-distance deflagration operation of the existing high-energy gas fracturing method are solved, the filling method is simple, reliable and good in sealing, and the problem of ignition failure of the fracturing caused by complicated assembly and poor sealing is fundamentally solved.

[0044] The prepared charging barrel 4 is coiled on the pipe reel like the coiled tubing 6, the diameter of the pipe reel is 2-3 meters, the sealing end is outside during coiling, and the charging end with the metal transition joint is at the bottom end. When the charging barrel 4 is lowered, the charging barrel 4 is delivered into the screen pipe 2 by using the coiled tubing 6, the gooseneck pipe is used to pass through the build-up section of the horizontal well 1, the coiled tubing 6 is fixed with the wellhead device after the charging barrel 4 is lowered into the horizontal well 1, the valve of the blind ram preventer is kept half open, and the annular pipeline is introduced into the waste pool.

[0045] The liquid energetic agent is delivered to the region to be fractured by the charging barrel 4 under the protection of the screen pipe 2, when the charging barrel 4 is delivered, the liquid between the charging barrel 4 and the screen pipe 2 can generate a certain buoyancy on the charging barrel 4, so as to reduce the friction between the outer wall of the charging barrel 4 and the screen pipe 2, and the liquid between the charging barrel 4 and the screen pipe 2 can also play a certain lubricating role, so as to further reduce the friction between the outer wall of the charging barrel 4 and the screen pipe 2, therefore, the charging barrel 4 can be perfectly and smoothly pushed to the region to be fractured.

[0046] The liquid energetic agent is a non-water-soluble liquid energetic agent with low flame sensitivity and good deflagration performance, which replaces the existing water-soluble energetic agent such as ammonium nitrate-glycerol which is difficult to ignite and easily affected by underground water in the wellbore. The ignition performance and combustion performance of the water-soluble energetic agent are poor, and there is more residual explosive after deflagration, the water-soluble energetic agent is directly injected into the wellbore during use, so the water-soluble energetic agent is easily affected by the water in the wellbore and the formation water, and the performance changes, thereby causing the problem of poor fracturing effect.

[0047] The delivery mode of the charging barrel 4 can realize quantitative and accurate delivery of the liquid energetic agent, and can also isolate the liquid energetic agent from the liquid in the wellbore, so that the liquid energetic agent is not polluted and dissipated by the liquid in the wellbore, and the reliability of the liquid energetic agent during deflagration is improved. Therefore, the full-hole-section deflagration fracturing method is a method for completing the explosive rock layer modification in the wellbore by relying on the device itself, independently and efficiently and quickly without being affected by the wellbore formation water environment.

[0048] When the liquid energetic agent is detonated, the high-pressure gas generated by the detonation does work on the rock, and the detonation fracturing is beneficial to the formation of a crack network. The liquid fire agent can be continuously charged in a continuous pipeline for a long distance, and has the advantages of stable transmission of detonation, solves the continuous transmission problem of high-energy gas fracturing, realizes long-time continuous loading of the horizontal well 1, and is beneficial to the formation and expansion of cracks. The problems of complex construction process, performance of the agent and boundary of the fire agent being easily affected by formation water are solved when the liquid fire agent is fractured by using a conventional method.

[0049] The plastic cylinder containing the liquid agent has a large self-weight, and the strength of the interface between the plastic cylinder and the coiled tubing 6 has certain requirements.

[0050] In this embodiment, the extension direction of the horizontal section of the horizontal well 1 is parallel to the direction of the minimum principal stress of the formation rock.

[0051] It should be noted that the expansion of the formation crack is always along the direction of the maximum principal stress, and the direction of the maximum principal stress and the direction of the minimum principal stress are perpendicular, so the selection of the extension direction of the horizontal section of the horizontal well 1 being parallel to the direction of the minimum principal stress of the formation rock can make the detonation fracturing develop in the direction perpendicular to the wellbore to the maximum extent when the artificial cracks are formed in the whole well section, so as to achieve the purposes of directional extension of the cracks and maximum extension radius of the cracks.

[0052] In this embodiment, the ignition structure 5 includes a transmission tube 51, a primer base 52, a pressure initiator 53, and a sealing ring 54.

[0053] When the ignition structure 5 is installed, the end of the transmission tube 51 is connected to the lower end of the primer base 52, and the pressure initiator 53 is installed in the stepped hole in the primer base 52, so that the primer 533 of the pressure initiator 53 and the end of the transmission tube 51 abut.

[0054] The end of the transmission tube 51 is inserted into the high-pressure rubber tube 43 of the charging cylinder 4 through the rubber tube joint 44 at the end of the charging cylinder 4, and at this time, the end of the transmission tube 51 is located in the liquid energetic agent.

[0055] The primer base 52 is screwed into the nut 46 at the end of the rubber tube joint 44, so that the two sides of the sealing ring 54 abut against the end of the primer base 52 and the end of the rubber tube joint 44, respectively.

[0056] It should be noted that the charging cylinder 4 includes the high-pressure rubber tube 43, the rubber tube joint 44, and the nut 46, and the high-pressure rubber tube 43 is provided with the rubber tube joint 44 at both ends.

[0057] One end of the hose joint 44 is provided with an annular clamping space 45 formed by two annular bodies, and the other end of the hose joint 44 is provided with a nut 46, which is a convex edge nut 46, and the fire cap base 52 is connected to the nut 46 and the hose joint 44. The end of the high-pressure hose 43 is inserted into the annular clamping space 45 for fixation, and a sealing assembly is arranged between the inner wall of the high-pressure hose 43 and the side wall of the hose joint 44.

[0058] The pressure initiator 53 comprises a piston striker 531, a force ring 532 and a fire cap 533 arranged in sequence, the end of the piston striker 531 extends into the force ring 532 and is spaced apart from the end face of the fire cap 533. The end of the piston striker 531 strikes the fire cap 533 to realize the ignition operation of the transfer tube 51.

[0059] The transfer tube 51 is a sealed tube made of aluminum, and the end of the sealed tube is provided with a bottom plug 511, and the end of the continuous tubing 6 is connected to the upper end of the fire cap base 52. The pressure initiator 53 is ignited by the continuous tubing 6, the pressure initiator 53 ignites the transfer tube 51, and then the liquid energetic agent in the charge cylinder 4 is deflagrated. The present application transmits, initiates pressure, and uses a transfer tube to ignite, which has high controllability and good ignition effect.

[0060] In this embodiment, the liquid energetic agent is liquid nitromethane, and the liquid nitromethane is passivated by an additive and its deflagration speed is reduced. The transfer tube 51 is filled with a composite solid propellant 512.

[0061] It should be noted that nitromethane has excellent deflagration characteristics, and pure nitromethane only deflagrates stably under closed conditions without detonation. The impact and friction sensitivity of pure nitromethane itself is zero. In order to ensure safety, the present application further passivates it by an additive and reduces its deflagration speed, which is beneficial to the continuation of the deflagration process and the expansion of the crack. Therefore, by adding an oxidizing agent, aluminum powder or other additives, the deflagration speed and process of nitromethane can be greatly changed, and the corresponding liquid energetic material can be adjusted according to different rock properties.

[0062] In this embodiment, the deflagration pressure is adjusted by the uncoupling coefficient of the inner diameter of the charge cylinder 4 and the diameter of the wellbore of the horizontal well 1.

[0063] It should be noted that the appropriate deflagration pressure is selected according to the properties of the rock, so as to ensure the effect of deflagration fracturing and avoid damaging the casing.

[0064] In this embodiment, the diameter of the charge cylinder 4 at the perforation site 41 is greater than the diameter of the charge cylinder 4 at the ignition site 42.

[0065] It should be noted that the diameter of the charge cartridge 4 can be adjusted in advance. A larger diameter is selected at the perforation site 41, and a smaller diameter is selected at other non-working sites such as the transfer site 42. After the charge cartridge 4 is accurately pushed, the perforation site 41 with a larger diameter generates greater explosion energy acting on the area to be fractured, which can improve the utilization rate of the liquid energetic agent and realize accurate explosion of the whole well section.

[0066] In this embodiment, after the liquid energetic agent in the charge cartridge 4 explodes, the excess explosion energy is released through the annulus at the transfer site 42.

[0067] It should be noted that the smaller explosion energy at the other sites such as the transfer site 42 is released through the annulus.

[0068] In this embodiment, the pressure data and temperature data during the explosion process are collected by the acquisition instrument at the plugging end of the charge cartridge 4, and the explosion fracturing effect is inferred by the pressure peak value and its duration time, the maximum temperature.

[0069] The acquisition instrument is installed in the rubber pipe joint 44 at the plugging end of the charge cartridge 4.

[0070] It should be noted that by the pressure data, temperature data and corresponding time curve, the pressure peak value and its duration time, the maximum temperature are obtained, and the size of the fracture formed after the rock operation can be judged by combining the properties of the rock and the state of the existing fracture, and the explosion fracturing effect can be scientifically obtained.

[0071] In this embodiment, when the liquid energetic agent in the charge cartridge 4 fails to explode by the ignition structure 5, the charge cartridge 4 pipe string is pulled out through the coiled tubing 6 for inspection.

[0072] It should be noted that if a blind shot is encountered, the charge cartridge 4 pipe string can be directly pulled out, and then re-inspected and re-launched.

[0073] The present application can pull out the charge cartridge 4 through the screen pipe 2 for subsequent processing, thereby fundamentally solving the problem that the downhole agent cannot be recovered when the liquid gunpowder high-energy gas fracturing appears a blind shot.

[0074] In this embodiment, the charge cartridge 4 is made of organic high molecular plastic pipe material, the plugging end of the charge cartridge 4 is provided with a rubber pipe joint 44, the end of the rubber pipe joint 44 is provided with a plug 47, and the end of the plug 47 is an arc-shaped sharp structure.

[0075] It should be noted that the organic high molecular plastic pipe material can be polyethylene pipe material, and the plug 47 is an arc-shaped sharp structure to facilitate downhole operation.

[0076] In the light of the foregoing it is apparent that the application is not limited to the details of the foregoing illustrative examples, and that the application can be carried out in other specific forms without departing from the spirit or essential characteristics thereof. It is therefore considered that the present examples be illustrative only and not restrictive, the scope of the application being indicated by the appended claims rather than by the foregoing description, and all changes which come within the meaning and range of equivalency of the claims are therefore intended to be embraced therein.

Claims

1. A full- wellbore section deflagration fracturing method, characterized in that, The method comprises the following steps: Drilling a horizontal well (1) and setting a region to be fractured; Lowering a screen pipe (2) into the horizontal well (1) and then injecting a well killing fluid (3); Filling a flexible non-metallic charge cylinder (4) with a liquid energetic agent and then installing an ignition structure (5) on the charge end of the charge cylinder (4); Connecting the upper end of the ignition structure (5) to the end of a coiled tubing (6) and then conveying the charge cylinder (4) to a set position in the horizontal well (1) through the coiled tubing (6) so that the charge cylinder (4) covers the region to be fractured in the horizontal well (1); Igniting the ignition structure (5) through the coiled tubing (6), which makes the liquid energetic agent in the charge cylinder (4) deflagrate, and the high-pressure gas generated by the deflagration breaks the charge cylinder (4) and does work on the rock, thereby fracturing the rock; After the fracturing is completed, the screen pipe (2) is recovered, and the debris of the charge cylinder (4) is recovered together with the screen pipe (2).

2. The full- bore, downhole, deflagration fracturing method of claim 1, wherein: The extension direction of the horizontal section of the horizontal well (1) is parallel to the direction of the minimum principal stress of the formation rock.

3. The full- bore, downhole, deflagration fracturing method of claim 1, wherein: The ignition structure (5) comprises a transfer tube (51), a primer base (52), a pressure initiator (53), and a sealing ring (54). When the ignition structure (5) is installed, the end of the transfer tube (51) is connected to the lower end of the primer base (52), the pressure initiator (53) is installed in the stepped hole in the primer base (52), and the primer (533) of the pressure initiator (53) and the end of the transfer tube (51) abut. The end of the transfer tube (51) is inserted into the charge cylinder (4) through the rubber joint (44) at the end of the charge cylinder (4), and at this time, the end of the transfer tube (51) is located in the liquid energetic agent. The primer base (52) is screwed into the nut (46) at the end of the rubber joint (44), and the two sides of the sealing ring (54) abut the end of the primer base (52) and the end of the rubber joint (44), respectively.

4. The full- bore, downhole, auto-decommissioning, frac- out method of claim 3, wherein: The liquid energetic agent is liquid nitromethane, which is passivated by an auxiliary agent and has a reduced deflagration speed; the transfer tube (51) is filled with a composite solid propellant (512).

5. The full- bore, downhole, deflagration fracturing method of claim 1, wherein: The deflagration pressure is adjusted by the uncoupling coefficient of the inner diameter of the charge cylinder (4) and the diameter of the wellbore of the horizontal well (1).

6. The full- bore, downhole, deflagration fracturing method of claim 1, wherein: The diameter of the perforated part (41) of the charge cylinder (4) is greater than the diameter of the transfer part (42) of the charge cylinder (4).

7. The full- bore, downhole, deflagration fracturing method of claim 6, wherein: After the liquid energetic agent in the charge cylinder (4) deflagrates, the excess energy of the deflagration is released through the annulus at the transfer part (42).

8. The full- bore, downhole, deflagration fracturing method of claim 1, wherein: When the liquid energetic agent in the charge cylinder (4) fails to deflagrate due to the ignition structure (5), the charge cylinder (4) is pulled out through the coiled tubing (6) for inspection.

9. The full- bore, downhole, deflagration fracturing method of claim 1, wherein: When the liquid energetic agent in the charge cylinder (4) fails to deflagrate due to the ignition structure (5), the charge cylinder (4) is pulled out through the coiled tubing (6) for inspection.

10. The full- bore, downhole, deflagration fracturing method of claim 1, wherein: The cartridge (4) is made of organic polymer plastic pipe material, and the sealing end of the cartridge (4) is provided with a rubber pipe joint (44), the end of the rubber pipe joint (44) is provided with a plug (47), and the end of the plug (47) is in an arc-shaped sharp structure.

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