Device and method for improving the ignition success rate of light oil reservoir fire drive

Abstract

The application discloses a method and device for improving the ignition success rate of fire flooding of light oil reservoirs, the device comprises an adiabatic layer, a heating rod and a multi-stage metal cartridge, wherein the heating rod penetrates through the adiabatic layer and forms a heat preservation cavity with the adiabatic layer; the multi-stage metal cartridge comprises a first-stage metal cartridge and a second-stage metal cartridge; the first-stage metal cartridge and the second-stage metal cartridge are fixed outside the heating rod and located inside the heat preservation cavity. Different catalysts are added in the multi-stage metal cartridge. The catalyst in the first-stage metal cartridge promotes low-temperature oxidation of thin oil and increases coking amount, and the catalyst in the second-stage metal cartridge promotes high-temperature combustion of coke. According to the understanding of fire flooding of thick oil, based on the combustion deposition amount and with the help of catalysts, low-temperature oxidation coking is first realized for thin oil ignition, then coke ignition combustion is realized on the basis of a certain combustion deposition amount, and stable high-temperature ignition combustion is formed.

Description

Technical Field

[0001] This invention relates to the field of fire-driven oil reservoir applications, and more particularly to an apparatus and method for improving the success rate of fire-driven ignition in light oil reservoirs. Background Technology

[0002] Fire-driven oil recovery is an important thermal oil recovery technology. Its principle involves using coke, a pyrolysis product of a small portion of the oil reservoir, as fuel. An external oxygen source and artificial heating ignite the reservoir, creating a stable, propagating combustion front. The resulting high temperature and pressure reduce viscosity and displace the oil, thus achieving oil recovery. Compared to other extraction technologies, fire-driven oil recovery offers advantages such as high recovery rates and a wide range of applications.

[0003] Ignition technology is crucial in fire-driven oil recovery. Currently, commonly used ignition methods both domestically and internationally include chemical ignition and electric ignition. Chemical ignition is more widely used and is not limited by well depth; however, it suffers from poor vertical ignition performance, low-temperature oxidation, and the risk of runaway reactions from the ignition reagents. Electric ignition, on the other hand, uses a surface control system to supply electrical energy to the heating elements of a heating rod, generating the heat required for reservoir ignition. This heat is then carried into the reservoir by air injected through an air compressor, thus igniting the reservoir. Electric ignition offers advantages such as high safety and reliability, high ignition success rate, and controllable temperature, representing a new direction for the development of fire-driven oil recovery ignition technology.

[0004] For light oil reservoirs, the success rate of electric ignition is not high. This is because the crude oil in light oil reservoirs is relatively light, with low viscosity and good fluidity. At the same time, the water saturation near the injection well is relatively high. In the initial stage of ignition, water evaporation takes away a large portion of the heat. Therefore, a long low-temperature oxidation reaction is required to reach the ignition temperature. During this process, some wells fail to reach the ignition temperature of the oil layer due to the excessively long low-temperature oxidation time and thus extinguish. Summary of the Invention

[0005] The purpose of this invention is to provide an apparatus and method for improving the ignition success rate of fire-driven oil recovery in light oil reservoirs, overcoming the shortcomings of existing technologies. This method offers a high ignition success rate and, by adding different catalyst functions at a fixed ignition temperature, can be applied to light oil reservoirs with a high ignition success rate. Because crude oil in light oil reservoirs is lighter, has lower viscosity, and better fluidity, it exhibits lower combustion deposition in oxidation kinetics experiments compared to heavy oil, leading to insufficient fuel supply and difficulty in ignition.

[0006] To achieve the above objectives, the present invention provides the following technical solution:

[0007] An apparatus for improving the ignition success rate of fire flooding in light oil reservoirs, the apparatus comprising an insulation layer, a heating rod, and a multi-stage metal cartridge, wherein the heating rod penetrates the insulation layer and forms an insulated cavity with the insulation layer; the multi-stage metal cartridge includes a primary metal cartridge and a secondary metal cartridge; the primary metal cartridge and the secondary metal cartridge are fixed to the outside of the heating rod and located inside the insulated cavity.

[0008] Specifically, the primary metal cartridge is connected to the heating rod via a polycarbonate material, and is used to melt and automatically release the catalyst at a certain low temperature; the secondary metal cartridge is connected to the heating rod via a polyimide material, and is used to melt and automatically release the catalyst at a high temperature.

[0009] Specifically, the multi-level metal pillbox is composed of a high-temperature resistant metal shell and a polymer sheet with a fixed melting point. The metal pillbox shell is made of titanium alloy, a high-temperature resistant and oxidation-resistant material, and the polymer sheet with a fixed melting point is made of either polycarbonate or polyimide.

[0010] Specifically, the catalysts in the primary metal cartridge and the secondary metal cartridge are fluid catalysts of different types. The catalyst in the primary metal cartridge is a low-carbon alkane dehydrogenation fluid catalyst, which is used to promote coking of thin oil and accelerate the formation of coke through low-temperature oxidation of thin oil. The catalyst in the secondary metal cartridge is a high-temperature resistant oxidation-promoting fluid catalyst, which is used to promote coke combustion.

[0011] Specifically, the fluid catalyst is composed of a mixture of fuel oil and catalyst particles, wherein,

[0012] The fuel oil in the primary metal pillbox includes C. 10 H 22 C 12 H 26 C 14 H 30 C 10 H 22 Content is 10-25%, C 12 H 26 The content is 20-30%, and the rest is C. 14 H 30 ;

[0013] The fuel oil in the secondary metal pillbox includes light hydrocarbons (C5H). 12 C7H 16 C9H 20 Among them, C5H 12 Content is 5-10%, C7H 16 The content is 10-20%, and the rest is C9H. 20 .

[0014] Specifically, the heating rod includes a heating resistor, wherein the heating resistor is located inside the heating rod.

[0015] Specifically, the heat insulation layer includes a reflective layer, a heat-containing layer, and a heat-insulating layer, wherein the reflective layer is the innermost layer, the heat-insulating layer is the outermost layer, and the heat-containing layer is located between the reflective layer and the heat-insulating layer.

[0016] Specifically, the reflective layer is composed of nano-evaporated aluminum mirror reflectors to reduce heat radiation; the heat-containing layer is composed of porous graphene gel to stabilize the temperature; and the heat-insulating layer is composed of glass fiber to reduce heat exchange between the inside and outside of the heating rod.

[0017] A method for improving the ignition success rate of fire flooding in light oil reservoirs, the method comprising the following steps:

[0018] Ignite the heating rod and introduce it into the insulation cavity at a speed of 30m. 3 / h~45m 3 / h of air, temperature controlled at 230℃-260℃, so that the first-stage metal box releases low-temperature oxidation fluid catalyst. After several days of low-temperature oxidation, the thin oil near the heating rod is oxidized at low temperature to form coke.

[0019] Ignite the heating rod and introduce it into the insulation cavity at a speed of 90m. 3 / h~120m 3 / h of air, temperature controlled at 500℃-520℃, ignites the coke formed by low-temperature oxidation, and causes the secondary metal cartridge to release a high-temperature resistant oxidation-promoting fluid catalyst. After several days of continuous combustion of coke, the thin oil layer is successfully ignited.

[0020] The heating rod penetrates the insulation layer and forms a heat-insulating cavity with the insulation layer; the multi-stage metal medicine box includes a primary metal medicine box and a secondary metal medicine box, which are fixed to the outside of the heating rod and located inside the heat-insulating cavity.

[0021] Specifically, the multi-level metal pillbox is composed of a high-temperature resistant metal shell and a composite material of a fixed-melting-point polymer sheet. The shell of the multi-level metal pillbox is made of titanium alloy, a high-temperature resistant and oxidation-resistant material. The composite material of the fixed-melting-point polymer sheet includes either polycarbonate or polyimide.

[0022] Specifically, the primary metal medicine box is connected to the inner wall of the heating rod by a polycarbonate material. The polycarbonate is melted at a certain low temperature. After being heated, the fluid catalyst expands and is released into the inner wall of the heating rod, promoting the low-temperature oxidation of thin oil into coke.

[0023] The secondary metal cartridge is connected to the inner wall of the heating rod through a polyimide material. When the polyimide melts at a certain high temperature, the fluid catalyst expands and is automatically released into the inner wall of the heating rod, accelerating the formation of coke from the high-temperature combustion of thin oil and low-temperature oxidation.

[0024] Specifically, the fluid catalyst is composed of a mixture of fuel oil and catalyst particles. The catalyst in the primary metal cartridge is a low-carbon alkane dehydrogenation fluid catalyst, which can promote coking of thin oil and accelerate the formation of coke through low-temperature oxidation of thin oil. The catalyst in the secondary metal cartridge is a high-temperature resistant oxidation-promoting fluid catalyst, which can promote coke combustion.

[0025] Specifically, the fuel oil in the primary metal pillbox includes C 10 H 22 C 12 H 26 C 14 H 30 C 10 H 22 Content is 10-25%, C 12 H 26 The content is 20-30%, and the rest is C. 14 H 30 The fuel oil in the secondary metal pillbox includes light hydrocarbons (C5H). 12 C7H 16 C9H 20 Among them, C5H 12 Content is 5-10%, C7H 16 The content is 10-20%, and the rest is C9H. 20 .

[0026] Specifically, the ignition of the heating rod involves the heating rod including a heating resistor located inside the heating rod, and the ignition temperature of the heating rod being controlled by controlling the current flowing through the heating resistor.

[0027] Specifically, the insulation layer comprises, from the inside out, a reflective layer, a heat-containing layer, and a heat-insulating layer. The reflective layer is composed of nano-evaporated aluminum mirror reflectors, which can reduce heat radiation. The heat-containing layer is composed of porous graphene gel, which can stabilize the temperature. The heat-insulating layer is composed of glass fiber, which can reduce heat exchange between the inside and outside of the heating rod.

[0028] The technical effects and advantages of this invention are as follows:

[0029] 1. The insulation layer is composed of multiple layers of heat insulation material. From the inside to the outside, they are a reflective layer, a heat-containing layer, and a heat insulation layer. The insulation layer and the middle section of the heating rod form a heat preservation zone, which can accurately ensure that heat is not lost. The temperature set for the heating rod is the same as the temperature inside the insulation body. This is beneficial for the characteristic of multi-stage drug delivery at specific temperatures in the later stage. The insulation layer makes the radial direction of the heating rod and the oil pipe almost the same temperature, with no heat conduction phenomenon, reducing heat loss of the ignition head and improving the ignition success rate.

[0030] 2. The multi-stage automatic release metal cartridge is integrally molded with the ignition heating rod. By adding a multi-stage metal cartridge to the outside of the heating rod, when a fixed ignition temperature is reached, the polymer material at the outlet of the metal cartridge melts, automatically releasing the pre-set low-temperature oxidation and high-temperature combustion catalyst, thereby improving the ignition success rate.

[0031] 3. Different catalysts are added to the multi-stage metal cartridges. The catalyst in the first-stage metal cartridge promotes low-temperature oxidation of the thin oil and increases the amount of coking, while the catalyst in the second-stage metal cartridge promotes high-temperature combustion of the coke.

[0032] 4. Based on the understanding of heavy oil fire flooding, and relying on combustion deposition and a catalyst, the light oil is first ignited to achieve low-temperature oxidation and coking. Then, based on a certain amount of combustion deposition, the coke is ignited and combusted to form a stable high-temperature ignition and combustion.

[0033] Other features and advantages of the invention will be set forth in the description which follows, and will be apparent in part from the description, or may be learned by practicing the invention. The objects and other advantages of the invention may be realized and obtained by means of the structures pointed out in the description, claims and drawings. Attached Figure Description

[0034] Figure 1 A schematic diagram of the heating rod insulation design is shown;

[0035] Figure 2 A schematic diagram of a device for improving the ignition success rate of fire flooding in light oil reservoirs is shown. Detailed Implementation

[0036] 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 embodiments of the present invention, and not all embodiments. 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.

[0037] To address the shortcomings of existing technologies, this invention discloses an apparatus and method for improving the ignition success rate of fire-driven combustion in light oil reservoirs. The apparatus of this invention incorporates the function of releasing different catalysts at a fixed ignition temperature, enabling it to be applied to light oil reservoir conditions and achieving a high ignition success rate. Because crude oil in light oil reservoirs is relatively light, has low viscosity, and good fluidity, it exhibits lower combustion deposition compared to heavy oil in oxidation kinetic experiments, leading to insufficient fuel supply and difficulty in ignition. This invention improves the ignition success rate by refining the electric ignition process and the electric ignition heating device.

[0038] Figure 1 A schematic diagram of the heating rod insulation design is shown. Figure 2 A schematic diagram of a device for improving the ignition success rate of fire flooding in light oil reservoirs is shown, combined with... Figure 1 and Figure 2 As can be seen, the device of the present invention includes an insulation layer, a heating rod, and a multi-stage metal medicine box. The multi-stage metal medicine box is integrally formed with the ignition heating rod and located inside the insulation layer. The insulation layer and the middle section of the ignition heating rod form a cavity, called the heat preservation zone. The insulation layer is composed of multiple layers of heat-insulating materials. From the inside to the outside, the insulation layer includes a reflective layer, a heat-capacitating layer, and a heat-insulating layer. The reflective layer is composed of nano-aluminum vapor-coated mirror reflectors, which have the characteristics of high temperature resistance and significantly reduced heat radiation. The heat-capacitating layer is composed of porous graphene gel, which has the characteristics of phase change heat release and temperature stabilization. The heat-insulating layer is composed of glass fiber, which can reduce heat exchange between the inside and outside of the heating rod.

[0039] This invention improves the heat insulation performance of the heating rod's insulation layer. Ordinary heating rods either lack an insulation layer or use asbestos or other similar materials. The improved insulation layer in this patent incorporates a nano-liquid material, exhibiting adaptive capabilities of high-temperature heat absorption and energy storage, and low-temperature heat release, thus better stabilizing the internal temperature of the heating rod's insulation layer. This also allows for more precise temperature control, facilitating subsequent modifications for multi-stage drug delivery. The insulation layer significantly enhances insulation performance, reducing heat loss and increasing heating efficiency. The insulation layer is designed to form a cavity (insulation zone) with the middle section of the heating rod. This zone precisely prevents heat loss; the internal temperature of the insulation zone is directly proportional to the temperature set on the heating rod. This is beneficial for subsequent multi-stage drug delivery at specific temperatures. By improving the heating rod's insulation material, there is almost no temperature difference between the radial direction of the heating rod and the oil pipe, eliminating heat conduction and reducing heat loss from the ignition head, thereby increasing the ignition success rate.

[0040] The heating rod contains an internal heating resistor. By controlling the current flowing through the resistor, the ignition temperature of the heating rod can be controlled. The heating rod temperature is set between 200 and 300°C (250°C in this embodiment). Air is injected to increase the viscosity of the crude oil, causing it to oxidize and coke at low temperatures, artificially forming a coke-like substance. The temperature is maintained so that the tar cannot burn (it does not reach its ignition point). This allows for the accumulation of coke (combustion deposits). Because light oil has fewer heavy components than heavy oil, less coke is formed during combustion, which is not conducive to sustained high-temperature combustion and makes it easy to extinguish the flame. Coke is essentially a reserve fuel for combustion; sufficient combustion deposits can maintain stable combustion after ignition. Therefore, ensuring sufficient coke during the ignition of light oil is of great significance. The heating rod temperature is then set to above 500°C to ignite the coke. The igniter design of this invention greatly improves the insulation performance of the heating rod, reducing heat loss.

[0041] Furthermore, Figure 2 A schematic diagram of a device for improving the ignition success rate of fire flooding in light oil reservoirs is shown, combined with... Figure 2 As can be seen, the heating rod of the device of the present invention is equipped with a multi-stage metal cartridge. The metal cartridge is connected to the igniter heating rod, and the cartridge outlet is a polymer with a fixed melting point. When there is no temperature, the internal spaces of the multi-stage cartridge and the heating rod are not connected. Under certain temperature conditions, the polymer with the fixed melting point melts, connecting the metal cartridge and the heating rod. Utilizing the property of fluid thermal expansion, a specially formulated thin oil ignition fluid catalyst is automatically released, promoting combustion and increasing the ignition success rate.

[0042] A multi-stage metal pillbox is incorporated into the heating rod. The metal pillbox is located within the insulation layer and attached to the outer wall of the heating rod. See the attached diagram for details. Figure 2 The composite material consists of a high-temperature resistant metal shell and a fixed-melting-point polymer sheet, wherein the metal shell is made of titanium alloy, a high-temperature resistant and oxidation-resistant material, and the composite material of the fixed-melting-point polymer sheet includes either polycarbonate or polyimide.

[0043] The multi-stage metal cartridge includes a primary metal cartridge and a secondary metal cartridge. The primary cartridge is connected to the heating rod by polycarbonate (melting point 220°C). The secondary cartridge is connected to the heating rod by polyimide (melting point approximately 500°C). It can release fluid catalysts at low temperatures (250°C) and high temperatures (500°C), respectively. The fluid catalyst is composed of a mixture of fluid (fuel oil) and catalyst particles. The fuel oil in the primary metal cartridge includes C... 10 H 22 C 12 H 26 C 14 H 30 C 10H 22 Content is 10-25%, C 12 H 26 The content is 20-30%, and the rest is C. 14 H 30 The fuel oil in the secondary metal pillbox includes light hydrocarbons (C5H). 12 C7H 16 C9H 20 Among them, C5H 12 Content is 5-10%, C7H 16 The content is 10-20%, and the rest is C9H. 20 When the temperature reaches above 220℃, the melting point of polycarbonate is reached, causing the material to melt and connecting the primary cartridge to the inner wall of the heating rod. Upon heating, the fluid catalyst expands and is released onto the inner wall of the heating rod, participating in the catalysis of the low-temperature oxidation process. When the temperature reaches above 500℃, the melting point of polyimide is reached, causing the material to melt and connecting the secondary cartridge to the inner wall of the heating rod. Upon heating, the fluid catalyst expands and is released onto the inner wall of the heating rod, participating in the catalysis of the high-temperature oxidation process. The primary cartridge contains a low-carbon alkane dehydrogenation catalyst, and the secondary cartridge contains a high-temperature resistant oxidation-promoting catalyst. Ignition at 250℃ takes 2 weeks, and ignition at 500℃ takes 2 days.

[0044] The catalysts in the primary and secondary metal cartridges are fluid catalysts of different types. The fluid catalysts are composed of a mixture of fuel oil and catalyst particles.

[0045] The catalyst in the primary metal cartridge is a low-carbon alkane dehydrogenation fluid catalyst, used to promote coking of thin oil and accelerate the formation of coke through low-temperature oxidation of thin oil; the fuel oil in the primary metal cartridge includes C 10 H 22 C 12 H 26 C 14 H 30 , where C 10 H 22 Content is 10-25%, C 12 H 26 The content is 20-30%, and the rest is C. 14 H 30 ;

[0046] The catalyst in the secondary metal cartridge is a high-temperature resistant, oxidation-promoting fluid catalyst used to promote coke combustion. The fuel oil in the secondary metal cartridge includes light hydrocarbons (C5H). 12 C7H 16 C9H 20 Among them, C5H 12 Content is 5-10%, C7H 16The content is 10-20%, and the rest is C9H. 20 .

[0047] A method for improving the ignition success rate of fire flooding in light oil reservoirs, specifically,

[0048] This invention features a heating rod design that significantly improves its insulation performance and reduces heat loss. A multi-stage, automatically releasing metal cartridge is integrally molded with the ignition heating rod. The heating rod tube head incorporates a multi-stage metal cartridge, consisting of a primary cartridge and a secondary cartridge. The primary cartridge is connected to the heating rod via polycarbonate (melting point 220°C). The secondary cartridge is connected to the heating rod via polyimide (melting point approximately 500°C). This design enables the release of fluid catalysts at both low (250°C) and high (500°C) temperatures.

[0049] The electric controller ignites the heating rod and introduces low-speed air into the insulation zone, maintaining a speed of 30m. 3 / h~45m 3 At a controlled ignition time of / h, low-speed air is supplied, maintaining the temperature at 230℃-260℃ (250℃ in this embodiment), causing low-temperature oxidation and coking of the thin oil near the heating rod. Simultaneously, the conditions for releasing the first-stage metal cartridge are met, releasing the first low-carbon alkane dehydrogenation catalyst fluid catalyst. This catalyst effectively promotes thin oil coking. After several days of low-temperature oxidation, sufficient combustion deposits form near the heating rod. Due to the effect of the low-temperature oxidation catalyst, the coking rate is accelerated. After approximately one week of ignition at 250℃, sufficient coking to sustain the next stage is formed near the ignition rod.

[0050] The electric control ignites the heating rod and introduces air into the insulation zone, with the air introduction speed controlled at 90m. 3 / h~120m 3 The temperature is maintained at 500℃-520℃ per hour, with 500℃ used in this embodiment. The coke formed during the previous low-temperature oxidation is ignited using a method similar to heavy oil fire-driven ignition (heavy oil ignition, due to its high content of heavy oil, easily forms coke during combustion, and can continue combustion as fuel even after ignition stops). Simultaneously, the conditions for releasing the secondary metal cartridge are met, releasing a second type of high-temperature resistant oxidation-promoting fluid catalyst. This catalyst effectively promotes coke combustion. After several days of continuous combustion, the thin oil layer is successfully ignited.

[0051] The insulation zone is the cavity formed between the insulation layer and the heating rod.

[0052] Furthermore, the primary metal cartridge is connected to the inner wall of the heating rod by a polycarbonate material. The polycarbonate is melted at a certain low temperature, and the fluid catalyst expands and is released onto the inner wall of the heating rod after being heated, promoting the low-temperature oxidation of the thin oil into coke. The secondary metal cartridge is connected to the inner wall of the heating rod by a polyimide material. The polyimide is melted at a certain high temperature, and the fluid catalyst expands and is automatically released onto the inner wall of the heating rod after being heated, accelerating the high-temperature combustion of the thin oil and the low-temperature oxidation of the coke.

[0053] Furthermore, the fluid catalyst is composed of a mixture of fuel oil and catalyst particles. The catalyst in the primary metal cartridge is a low-carbon alkane dehydrogenation fluid catalyst, which can promote coking of thin oil and accelerate the formation of coke through low-temperature oxidation of thin oil. The catalyst in the secondary metal cartridge is a high-temperature resistant oxidation-promoting fluid catalyst, which can promote coke combustion.

[0054] This invention improves the insulation material of the heating rod, resulting in almost no temperature difference between the radial direction of the heating rod and the oil pipe, eliminating heat conduction, reducing heat loss from the ignition head, and increasing the ignition success rate. A multi-stage automatic release metal cartridge is integrally formed with the ignition heating rod. By adding a multi-stage metal cartridge to the igniter heating rod, when a fixed ignition temperature is reached, the polymer material at the outlet of the metal cartridge melts, automatically releasing a pre-placed low-temperature oxidation and high-temperature combustion catalyst, thus improving the ignition success rate. Different catalysts are added to the multi-stage metal cartridges. The catalyst in the first-stage metal cartridge promotes low-temperature oxidation of light oil, increasing coking; the catalyst in the second-stage metal cartridge promotes high-temperature combustion of coke. Based on the understanding of heavy oil fire flooding, and relying on combustion deposition and catalysts, low-temperature oxidation and coking are first achieved for light oil ignition, and then coke ignition and combustion are aided based on a certain amount of combustion deposition, forming stable high-temperature ignition and combustion. Therefore, this invention can significantly improve the ignition success rate of fire flooding in light oil reservoirs.

[0055] Finally, it should be noted that the above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A device for improving the ignition success rate of fire flooding in light oil reservoirs, characterized in that, The device includes an insulation layer, a heating rod, and a multi-stage metal medicine box, wherein... The heating rod penetrates the insulation layer and forms a heat-insulating cavity with the insulation layer; The multi-level metal pillbox includes a primary metal pillbox and a secondary metal pillbox; The primary metal medicine box and the secondary metal medicine box are fixed to the outside of the heating rod and located inside the heat preservation cavity; The primary metal cartridge is connected to the heating rod via polycarbonate material and is used to melt and automatically release the catalyst at a temperature of 230℃-260℃; the secondary metal cartridge is connected to the heating rod via polyimide material and is used to melt and automatically release the catalyst at a temperature of 500℃-520℃. The multi-level metal pillbox is composed of a high-temperature resistant metal shell and a composite material of a fixed-melting-point polymer sheet. The metal pillbox shell is made of titanium alloy, a high-temperature resistant and oxidation-resistant material. The composite material of the fixed-melting-point polymer sheet includes either polycarbonate or polyimide. The catalysts in the primary metal cartridge and the secondary metal cartridge are fluid catalysts and are of different types. The catalyst in the primary metal cartridge is a low-carbon alkane dehydrogenation fluid catalyst, which is used to promote coking of thin oil and accelerate the formation of coke by low-temperature oxidation of thin oil. The catalyst in the secondary metal cartridge is a high-temperature resistant, oxidation-promoting fluid catalyst used to promote coke combustion.

2. The apparatus according to claim 1, characterized in that, The fluid catalyst is composed of a mixture of fuel oil and catalyst particles, wherein, The fuel oil in the primary metal pillbox includes C. 10 H 22 C 12 H 26 C 14 H 30 C 10 H 22 Content is 10-25%, C 12 H 26 The content is 20-30%, and the rest is C. 14 H 30 ; The fuel oil in the secondary metal pillbox includes light hydrocarbons (C5H). 12 C7H 16 C9H 20 Among them, C5H 12 Content is 5-10%, C7H 16 The content is 10-20%, and the rest is C9H. 20 .

3. The apparatus according to claim 1, characterized in that, The heating rod includes a heating resistor, wherein the heating resistor is located inside the heating rod.

4. The apparatus according to claim 1, characterized in that, The insulation layer includes a reflective layer, a heat-containing layer, and a heat-insulating layer, wherein, The reflective layer, heat-containing layer, and heat-insulating layer are arranged sequentially from the inside out.

5. The apparatus according to claim 4, characterized in that, The reflective layer is composed of nano-evaporated aluminum mirror reflectors, used to reduce heat radiation; The heat-containing layer is composed of porous graphene gel and is used to stabilize the temperature; The insulation layer, made of glass fiber, is used to reduce heat exchange between the inside and outside of the heating rod.

6. A method for improving the ignition success rate of fire flooding in light oil reservoirs, characterized in that, The method includes the following steps: Ignite the heating rod and introduce it into the insulation cavity at a speed of 30m. 3 / h~45m 3 / h of air, temperature controlled at 230℃-260℃, so that the first-stage metal box releases low-temperature oxidation fluid catalyst. After several days of low-temperature oxidation, the thin oil near the heating rod is oxidized at low temperature to form coke. Ignite the heating rod and introduce it into the insulation cavity at a speed of 90m. 3 / h~120m 3 / h of air, temperature controlled at 500℃-520℃, ignites the coke formed by low-temperature oxidation, and causes the secondary metal cartridge to release a high-temperature resistant oxidation-promoting fluid catalyst. After several days of continuous combustion of coke, the thin oil layer is successfully ignited. The heating rod penetrates the insulation layer and forms a heat-insulating cavity with the insulation layer; the multi-stage metal pillbox includes a primary metal pillbox and a secondary metal pillbox, which are fixed to the outside of the heating rod and located inside the heat-insulating cavity; The multi-level metal pillbox is composed of a high-temperature resistant metal shell and a composite material of a fixed-melting-point polymer sheet. The shell of the multi-level metal pillbox is made of titanium alloy, a high-temperature resistant and oxidation-resistant material. The composite material of the fixed-melting-point polymer sheet includes either polycarbonate or polyimide. The primary metal medicine box is connected to the inner wall of the heating rod by a polycarbonate material. The polycarbonate is melted at a temperature of 230℃-260℃. After being heated, the fluid catalyst expands and is released into the inner wall of the heating rod, promoting the low-temperature oxidation of thin oil into coke. The secondary metal cartridge is connected to the inner wall of the heating rod through a polyimide material. When the polyimide melts at a temperature of 500℃-520℃, the fluid catalyst expands and is automatically released into the inner wall of the heating rod after being heated, which accelerates the coke formed by high-temperature combustion of thin oil and low-temperature oxidation. The fluid catalyst is composed of a mixture of fuel oil and catalyst particles, wherein, The catalyst in the primary metal cartridge is a low-carbon alkane dehydrogenation fluid catalyst, which can promote coking of thin oil and accelerate the formation of coke by low-temperature oxidation of thin oil. The catalyst in the secondary metal cartridge is a high-temperature resistant, oxidation-promoting fluid catalyst that can promote coke combustion.

7. The method according to claim 6, characterized in that, The fuel oil in the primary metal pillbox includes C. 10 H 22 C 12 H 26 C 14 H 30 C 10 H 22 Content is 10-25%, C 12 H 26 The content is 20-30%, and the rest is C. 14 H 30 ; The fuel oil in the secondary metal pillbox includes light hydrocarbons (C5H). 12 C7H 16 C9H 20 Among them, C5H 12 Content is 5-10%, C7H 16 The content is 10-20%, and the rest is C9H. 20 .

8. The method according to claim 6, characterized in that, The ignition of the heating rod specifically refers to... The heating rod includes a heating resistor located inside the heating rod. The ignition temperature of the heating rod is controlled by controlling the current flowing through the heating resistor.

9. The method according to claim 6, characterized in that, The insulation layer, from the inside out, comprises a reflective layer, a heat-containing layer, and a heat-insulating layer, wherein, The reflective layer is composed of nano-evaporated aluminum mirror reflectors, which can reduce heat radiation; The heat-containing layer is composed of porous graphene gel, which can stabilize the temperature; The insulation layer, made of glass fiber, reduces heat exchange between the inside and outside of the heating rod.

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