Methods for in-situ low-temperature oxidation and channeling control of heavy oil

Abstract

This invention provides a method for sealing gas leakage channels in heavy oil through in-situ low-temperature oxidation, comprising: Step S10: determining the dominant channel or gas leakage channel between the injection well and surrounding production wells; Step S20: determining the temperature range T1 to T2 for low-temperature oxidation to coke formation in production wells with dominant or gas leakage channels to the injection well; Step S30: testing the bottom-hole temperature T and bottom-hole pressure P of the production wells with dominant or gas leakage channels to the injection well, and selecting a corresponding sealing method for sealing based on the bottom-hole temperature T and bottom-hole pressure P; Step S40: inspecting the production wells with dominant or gas leakage channels to the injection well to determine the sealing effect. This invention solves the problems of poor temperature resistance and high sealing cost after sealing gas leakage channels in the prior art.

Description

Technical Field

[0001] This invention relates to the field of heavy oil development technology, and more specifically, to a method for in-situ low-temperature oxidation and sealing of heavy oil. Background Technology

[0002] During oilfield development, three generations of technological revolutions have been achieved: steam injection, steam flooding, and SAGD (steam-assisted gravity drainage) + fire flooding, enabling the comprehensive utilization of ordinary heavy oil, extra-heavy oil, and ultra-heavy oil. Due to formation heterogeneity and steam over-coverage, serious steam channeling problems can occur with continuous steam injection. Therefore, developing efficient methods to control steam channeling is crucial for the uniform utilization of oil reservoirs and improving oil recovery.

[0003] Research began in the early 1990s on using tannin, alkali lignin, and other substances to prepare heat-resistant gels to prevent gas channeling. Among these three substances, tannin exhibits the best gelling properties, producing gels with the best stability and highest strength. It was a widely used plugging agent in China in the early days of gas channeling control. However, in recent years, the rising price of tannin has limited its application in oilfields. Another crosslinking polymer used for gas channeling control is phenolic gel prepared from synthetic polymers. Early crosslinking agents included phenol and formaldehyde, which were later gradually replaced by hydroquinone and hexamethylenetetramine combinations or water-soluble phenolic resins. The temperature resistance of this type of gel mainly depends on the polymer and fillers used. However, polymer-based gels typically gel at 200°C with a gelling time of less than 1 hour, which is insufficient to meet the requirements for deep formation gas channeling control during thermal recovery. Therefore, it is necessary to propose a low-cost, efficient, and temperature-resistant method for sealing gas channel blockages to overcome the shortcomings of existing technologies, improve the uniformity of oil layer utilization, and achieve the goal of increasing production and efficiency. Summary of the Invention

[0004] The main objective of this invention is to provide a method for sealing gas channeling in situ at low temperature, in order to solve the problems of poor temperature resistance and high sealing cost after the gas channeling is blocked in the prior art.

[0005] To achieve the above objectives, according to one aspect of the present invention, a method for sealing heavy oil in situ at low temperature oxidation is provided, comprising: step S10: determining the dominant channel or gas channel between the injection well and the production wells surrounding the injection well; step S20: determining the temperature range T1 to T2 of the low temperature oxidation to coke formation of the production wells that have a dominant channel or gas channel with the injection well; step S30: testing the bottom hole temperature T and bottom hole pressure P of the production wells that have a dominant channel or gas channel with the injection well, and selecting a corresponding sealing method for sealing based on the bottom hole temperature T and bottom hole pressure P; step S40: inspecting the production wells that have a dominant channel or gas channel with the injection well to determine the sealing effect.

[0006] Further, step S10 includes: injecting a marker substance into the injection well; periodically monitoring and recording the parameters and product composition of the injection well and the production wells surrounding the injection well; when the parameters of one or more production wells surrounding the injection well show a linkage reaction with the parameters of the injection well, or when the marker substance is detected in the product of the production well, it proves that there is a dominant channel or gas channel between one or more production wells and the injection well; determining the relationship between the location of the dominant channel or gas channel and the location of the oil layer and dynamic fluid level of the production well.

[0007] Furthermore, in determining the relationship between the location of the dominant channel or gas channel and the location of the oil layer and dynamic fluid level in the production well, the relationship between the location of the dominant channel or gas channel and the location of the oil layer and dynamic fluid level in the production well is determined by using the packer to locate the gas channel and / or by measuring the dynamic fluid level.

[0008] Furthermore, in step S10, the production wells surrounding the injection well include production wells within a range of 50 meters to 200 meters from the injection well.

[0009] Further, step S20 includes: sampling production wells that have a dominant channel or gas channel with the injection well; and measuring the temperature range T1 to T2 of low-temperature oxidation to coke under oil layer temperature and oil layer pressure in the laboratory.

[0010] Furthermore, during the sampling process of production wells that have a dominant channel or gas leakage channel with the injection well, multiple samples are taken from the production wells that have a dominant channel or gas leakage channel with the injection well.

[0011] Furthermore, during the process of measuring the temperature range T1 to T2 of low-temperature oxidation to coke under oil layer temperature and oil layer pressure, the average value of the low-temperature oxidation temperature measured multiple times was calculated.

[0012] Further, step S30 includes: if the bottom hole temperature T satisfies T1 < T < T2, then inject a first preset volume of crude oil containing heavy components and a second preset volume of air from the injection well, while controlling the bottom hole pressure P to remain constant, to form low-temperature coke and seal the gas channeling layer; if the bottom hole temperature T satisfies T < T1 or T > T2, then adjust the temperature in the gas channeling channel to be between T1 and T2, inject a first preset volume of crude oil containing heavy components and a second preset volume of air from the injection well, while controlling the bottom hole pressure P to remain constant, to seal the gas channeling layer.

[0013] Furthermore, if the bottom hole temperature T satisfies T < T1 or T > T2, the temperature within the gas channel is adjusted to be between T1 and T2. A first preset volume of crude oil containing heavy components and a second preset volume of air are injected into the injection well, while the bottom hole pressure P remains constant. The process of sealing the gas channel includes: if the bottom hole temperature T satisfies T < T1, a first preset volume of crude oil containing heavy components and a second preset volume of air are injected from the injection well, and high-temperature steam at a preset temperature is injected from the production well to control the temperature within the gas channel between T1 and T2, while maintaining the bottom hole pressure P constant, forming low-temperature coke and sealing the gas channel; if the bottom hole temperature T satisfies T > T2, a first preset volume of crude oil containing heavy components and a second preset volume of air are injected from the injection well, and a third preset volume of room-temperature water is injected from the production well to control the temperature within the gas channel between T1 and T2, while maintaining the bottom hole pressure P constant, causing a low-temperature oxidation reaction to generate dense coke and seal the gas channel.

[0014] Further, step S40 includes: injecting a marker substance into the injection well, periodically detecting and recording the injection well; periodically monitoring and recording the parameters and product composition of the injection well and the production wells around the injection well; if the production well no longer exhibits a linkage reaction or the reaction is significantly reduced or the marker substance is no longer detected, the sealing is successful; otherwise, the sealing fails.

[0015] The method for sealing heavy oil through in-situ low-temperature oxidation using the technical solution of this invention includes: Step S10: determining the dominant channel or gas channel between the injection well and the production wells surrounding the injection well; Step S20: determining the temperature range T1 to T2 for low-temperature oxidation to coke formation in the production wells that have a dominant channel or gas channel with the injection well; Step S30: testing the bottom-hole temperature T and bottom-hole pressure P of the production wells that have a dominant channel or gas channel with the injection well, and selecting a corresponding sealing method for sealing based on the bottom-hole temperature T and bottom-hole pressure P; Step S40: inspecting the production wells that have a dominant channel or gas channel with the injection well to determine the sealing effect.

[0016] The method involves identifying the dominant channel or gas channel between the injection well and surrounding production wells to determine the location for plugging. Then, the temperature range for low-temperature oxidation to coke formation in the production well is determined, along with the bottom-hole temperature T and pressure P. Based on these measurements, a suitable plugging method is selected to utilize the in-situ physicochemical reaction of crude oil to generate coke with a certain plugging capacity, reducing gas channeling, improving reservoir uniformity, enhancing reservoir development, and increasing recovery rates. This method has significant practical implications for the thermal recovery development of extra-heavy and super-heavy oil reservoirs. The in-situ low-temperature oxidation plugging method for heavy oil described in this application is low-cost, highly efficient, and has good temperature resistance. Attached Figure Description

[0017] The accompanying drawings, which form part of this application, are used to provide a further understanding of the invention. The illustrative embodiments of the invention and their descriptions are used to explain the invention and do not constitute an undue limitation of the invention. In the drawings:

[0018] Figure 1 A schematic flowchart of an optional embodiment of the present invention for in-situ low-temperature oxidation and sealing of heavy oil is shown.

[0019] Figure 2 A location distribution diagram between the injection well and the production well in Embodiment 1 of the present invention is shown;

[0020] Figure 3 A flowchart of the in-situ low-temperature oxidation and sealing method for heavy oil according to Embodiment 1 of the present invention is shown.

[0021] The above figures include the following reference numerals:

[0022] 10. Injection well; 20. Production well. Detailed Implementation

[0023] It should be noted that, unless otherwise specified, the embodiments and features described in this application can be combined with each other. The present invention will now be described in detail with reference to the accompanying drawings and embodiments.

[0024] It should be noted that, unless otherwise specified, all technical and scientific terms used in this application have the same meaning as commonly understood by one of ordinary skill in the art to which this application pertains.

[0025] In this invention, unless otherwise stated, directional terms such as "upper," "lower," "top," and "bottom" are generally used in relation to the direction shown in the accompanying drawings, or in relation to the vertical, perpendicular, or gravitational direction of the component itself; similarly, for ease of understanding and description, "inner" and "outer" refer to the inner and outer contours of each component itself, but the above directional terms are not intended to limit this invention.

[0026] To address the problems of poor temperature resistance and high sealing costs after sealing the gas channel in existing technologies, this invention provides a method for sealing gas channels in situ at low temperature through oxidation.

[0027] like Figures 1 to 3As shown, the method for sealing off channeling in in-situ low-temperature oxidation of heavy oil includes: Step S10: Determining the dominant channel or gas channel between the injection well 10 and the production wells 20 surrounding the injection well 10; Step S20: Determining the temperature range T1 to T2 for low-temperature oxidation to coke formation in the production wells 20 that have a dominant channel or gas channel with the injection well 10; Step S30: Testing the bottom hole temperature T and bottom hole pressure P of the production wells 20 that have a dominant channel or gas channel with the injection well 10, and selecting the corresponding sealing method for sealing based on the bottom hole temperature T and bottom hole pressure P; Step S40: Inspecting the production wells 20 that have a dominant channel or gas channel with the injection well 10 to determine the sealing effect.

[0028] The dominant channel or gas channel between injection well 10 and surrounding production wells 20 is determined to locate the plugging point. Then, the temperature range for low-temperature oxidation to coke formation in production well 20 is determined, and the bottom hole temperature T and bottom hole pressure P of production well 20 are measured. Based on the measured bottom hole temperature T and bottom hole pressure P, an appropriate plugging method is selected to utilize the in-situ physicochemical reaction of crude oil to generate coke with a certain plugging ability, reduce gas channeling, improve the uniformity of reservoir utilization, improve reservoir development effect, and increase recovery rate. This has significant practical implications for the thermal recovery development of extra-heavy and super-heavy oil reservoirs. The in-situ low-temperature oxidation plugging method for heavy oil in this application is low-cost, highly efficient, and has good temperature resistance.

[0029] Specifically, step S10 includes: injecting a marker substance into the injection well 10; periodically monitoring and recording the parameters and product composition of the injection well 10 and the surrounding production wells 20; when the parameters of one or more production wells 20 around the injection well 10 show a linkage reaction with the parameters of the injection well 10, or when the marker substance is detected in the product of the production well 20, it proves that there is a dominant channel or steam channel between one or more production wells 20 and the injection well 10; determining the position of the dominant channel or steam channel and its relationship with the position of the oil layer and dynamic fluid level of the production well 20. After injecting the marker substance into the injection well 10, the parameters and product composition of the injection well 10 and the surrounding production wells 20 are periodically monitored to determine which production wells 20 have a dominant channel or steam channel with the injection well 10, and to determine the position of the dominant channel or steam channel and its relationship with the position of the oil layer and dynamic fluid level of the production well 20, so as to facilitate the subsequent measurement of the temperature range for low-temperature oxidation to coke.

[0030] If the dominant channel or gas channel is located above the dynamic fluid level, crude oil needs to be injected from production well 20 for coking reaction. If the dominant channel or gas channel is located below the dynamic fluid level, crude oil does not need to be injected, or in other words, the first preset volume of the injected crude oil is zero.

[0031] It should be noted that regular monitoring refers to monitoring according to a preset cycle.

[0032] Specifically, in determining the relationship between the location of the dominant channel or gas channel and the location of the oil layer and dynamic fluid level of production well 20, the relationship between the location of the dominant channel or gas channel and the location of the oil layer and dynamic fluid level of production well 20 is determined by the method of finding the channel by lowering the packer and / or the method of measuring the dynamic fluid level.

[0033] Specifically, in step S10, the production wells 20 surrounding the injection well 10 include those within a range of 50 meters to 200 meters from the injection well 10. All production wells 20 within this range can be used for periodic monitoring; the specific range can be selected based on actual circumstances.

[0034] Specifically, step S20 includes: sampling production well 20 that has a dominant channel or gas channel with injection well 10; measuring the temperature range T1 to T2 of low-temperature oxidation to coke under oil layer temperature and oil layer pressure in the laboratory. After sampling, the sample is tested at the same temperature and pressure as the oil layer in the laboratory to test the temperature range of low-temperature oxidation to coke of the sample.

[0035] Specifically, during the sampling process of production well 20 which has a dominant channel or gas leakage channel with injection well 10, multiple samples are taken from production well 20 which has a dominant channel or gas leakage channel with injection well 10.

[0036] Specifically, during the process of measuring the temperature range T1 to T2 for low-temperature oxidation to coke under oil reservoir temperature and pressure, the average value of multiple measured low-temperature oxidation temperatures is calculated. Oil reservoir temperature and pressure refer to the temperature and pressure at the location of the dominant channel or gas channel. In other words, it is necessary to simulate the temperature and pressure environment at the location of the dominant channel or gas channel to obtain the temperature range for low-temperature oxidation to coke of the sample under this environment.

[0037] Each sample will be tested to obtain a temperature range for low-temperature oxidation to coke formation. Finally, the average of the low-temperature oxidation to coke formation temperature ranges of multiple samples can be obtained.

[0038] Specifically, step S30 includes: if the bottom hole temperature T satisfies T1 < T < T2, then inject a first preset volume of crude oil containing heavy components and a second preset volume of air from the injection well 10, while keeping the bottom hole pressure P constant to form low-temperature coke and seal the gas channeling layer; if the bottom hole temperature T satisfies T < T1 or T > T2, then adjust the temperature in the gas channeling channel to be between T1 and T2, inject a first preset volume of crude oil containing heavy components and a second preset volume of air from the injection well 10, while keeping the bottom hole pressure P constant to seal the gas channeling layer.

[0039] It should be noted that dense coke is generated during the plugging process, and the slug volume of the coke is Q.j The cross-linked pore volume Q is 10%–15%. c The volume of the pores through the passage is Q c =kπR 2 hФ, where K is a correction factor, typically 0.3–0.5 (since gas channeling mainly affects some large channels, not the entire oil layer), R is the average plugging radius, typically 1.5–2 m; h is the plugging layer thickness; and Ф is the average porosity of the oil layer. The first preset volume of crude oil is Q. y =1800Q j / (985*0.08), the second preset volume of air Q k =180Q j / 2.4, where Q j Q c Q y Q k The units are all in m 3 Cross-channeling refers to the dominant channel or channel for steam leakage.

[0040] It should be noted that R is the average sealing radius, centered on the channel; the coke sluice is a cylinder with radius R. h is the thickness of the sealing layer (the layer where the gas channel is located), which is obtained by consulting geological data after the gas channel is determined.

[0041] Specifically, if the bottom hole temperature T satisfies T < T1 or T > T2, the temperature in the gas channel is adjusted to be between T1 and T2. Injection well 10 injects a first preset volume of crude oil containing heavy components and a second preset volume of air, while simultaneously controlling the bottom hole pressure P to remain constant. The process of sealing the gas channel includes: if the bottom hole temperature T satisfies T < T1, injection well 10 injects a first preset volume of crude oil containing heavy components and a second preset volume of air, and production well 20 injects high-temperature steam at a preset temperature to control the temperature in the gas channel between T1 and T2, while simultaneously controlling the bottom hole pressure P to remain constant, forming low-temperature coke and sealing the gas channel; if the bottom hole temperature T satisfies T > T2, injection well 10 injects a first preset volume of crude oil containing heavy components and a second preset volume of air, and production well 20 injects a third preset volume of room-temperature water to control the temperature in the gas channel between T1 and T2, while simultaneously controlling the bottom hole pressure P to remain constant, causing a low-temperature oxidation reaction to generate dense coke and seal the gas channel. By adjusting the bottom hole temperature to the range of T1 to T2, after introducing crude oil and air, the dominant channel or gas channel is oxidized in a low-temperature environment to form dense coke. The porosity, permeability and other parameters of the coke are significantly reduced compared to the original oil layer, thereby blocking the dominant channel and gas channel, reducing gas channeling and improving the uniformity of oil layer utilization.

[0042] High-temperature steam refers to steam with a temperature between 200℃ and 300℃. Room temperature clean water refers to clean water with a temperature between 20℃ and 30℃.

[0043] Specifically, step S40 includes: injecting a marker substance into injection well 10; periodically monitoring and recording the parameters and product composition of injection well 10 and the surrounding production wells 20; if the production well 20 no longer exhibits a linkage reaction, or the reaction is significantly reduced, or the marker substance is no longer detected, then the sealing is successful; otherwise, the sealing has failed. After coke formation, the sealing effect needs to be verified to determine if the sealing was successful. If the sealing is unsuccessful, the above steps are repeated until the sealing is successful.

[0044] The following is a detailed description using a specific embodiment.

[0045] Example 1

[0046] The well locations of injection well 10 and surrounding production wells 20 are as follows: Figure 2 As shown, in Figure 2 In the diagram, well h000 is injection well 10, well h001 is production well 1, well h002 is production well 2, well h003 is production well 3, well h004 is production well 4, well h005 is production well 5, and well h006 is production well 6, with a spacing between wells ranging from 50 meters to 150 meters. The method for in-situ low-temperature oxidation sealing of heavy oil is as follows:

[0047] Step 1: Inject de-oiled hot water or isotopes into well h000, and regularly monitor and record the parameters and product composition of well h000 and surrounding wells h001 to h006;

[0048] If the parameters of production wells 20 around injection well 10, such as well h001, show a linkage reaction with the injection parameters of injection well 10, or if isotopes of injected substances are detected in the production of well h001, it indicates that there is a dominant channel or gas channel between well h001 and well h000. The location of the dominant channel or gas channel and its relationship with the location of the oil layer and dynamic fluid level in well h001 should be determined by methods such as packer detection and dynamic fluid level measurement.

[0049] Step 2: Determine the temperature for low-temperature oxidation to coke formation. For well h001, which has a dominant channel or gas channel with injection well 10, samples were taken three times. The range of low-temperature oxidation to coke formation temperature T1-T2 under oil layer temperature and oil layer pressure was measured in the laboratory. The average value of the three low-temperature oxidation temperatures was calculated.

[0050] Step 3: Test the bottom-hole temperature and pressure of well h001 to obtain the bottom-hole temperature T and bottom-hole pressure P. If T1 < T < T2, inject a first preset volume of crude oil containing heavy components and a second preset volume of air from well h000, controlling the bottom-hole pressure to P, to form low-temperature coke and seal the steam channeling layer. If T < T1, inject a first preset volume of crude oil containing heavy components and a second preset volume of air from well h000, and inject high-temperature steam at a preset temperature from well h001, controlling the temperature in the steam channeling channel between T1 and T2, controlling the bottom-hole pressure to P, to form low-temperature coke and seal the steam channeling layer. If T > T2, inject a first preset volume of crude oil containing heavy components and a second preset volume of air from well h000, and inject a third preset volume of room-temperature clean water from well h001, controlling the temperature in the steam channeling channel between T1 and T2, controlling the bottom-hole pressure to P, to form dense coke and seal the steam channeling layer.

[0051] This study identifies vapor channeling pathways in heavy oil reservoirs and provides a novel method for sealing these pathways. This method is characterized by low cost, high efficiency, and good temperature resistance. It can serve as an important supporting technology for the thermal recovery development of extra-heavy and ultra-heavy oils, and also provides strong support for the development of similar reservoirs. The goal is to reduce the degree of vapor channeling, improve the uniformity of reservoir utilization, and ultimately enhance the reservoir development effect.

[0052] This invention proposes a method for resolving steam channeling in heavy oil reservoirs by utilizing in-situ physicochemical reactions of crude oil. This method fills a gap that existing technologies cannot achieve and features low cost, high efficiency, and good temperature resistance. It can provide a theoretical basis for improving the uniformity of reservoir utilization, enhancing reservoir development, and increasing recovery efficiency.

[0053] Obviously, the embodiments described above are merely some, not all, embodiments of the present invention. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without inventive effort should fall within the scope of protection of the present invention.

[0054] It should be noted that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the exemplary embodiments according to this application. As used herein, the singular form is intended to include the plural form as well, unless the context clearly indicates otherwise. Furthermore, it should be understood that when the terms "comprising" and / or "including" are used in this specification, they indicate the presence of features, steps, operations, devices, components, and / or combinations thereof.

[0055] It should be noted that the terms "first," "second," etc., used in the specification, claims, and accompanying drawings of this application are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate so that the embodiments of this application described herein can be implemented in sequences other than those illustrated or described herein.

[0056] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A method for in-situ low-temperature oxidation and channeling of heavy oil, characterized in that, include: Step S10: Determine the dominant channel or gas leakage channel between the injection well (10) and the production wells (20) surrounding the injection well (10); Step S20: Determine the temperature range T1 to T2 for low-temperature oxidation coking of the production well (20) that has a dominant channel or gas channel with the injection well (10); Step S30: Test the bottom temperature T and bottom pressure P of the production well (20) that has a dominant channel or gas channel with the injection well (10), and select the corresponding sealing method to seal according to the bottom temperature T and the bottom pressure P; Step S40: The production well (20) that has a dominant channel or gas leakage channel with the injection well (10) is inspected to determine the sealing effect; Step S30 includes: If the bottom temperature T satisfies T1 < T < T2, then a first preset volume of crude oil containing heavy components and a second preset volume of air are injected from the injection well (10), while the bottom pressure P is kept constant to form low-temperature coke and seal the gas channeling layer. If the bottom temperature T satisfies T < T1 or T > T2, the temperature in the gas channel is adjusted to be between T1 and T2, and the injection well (10) injects a first preset volume of crude oil containing heavy components and a second preset volume of air, while controlling the bottom pressure P to remain unchanged to block the gas channeling layer; If the bottom hole temperature T satisfies T < T1 or T > T2, then the temperature in the gas channel is adjusted to be between T1 and T2. The injection well (10) injects a first preset volume of crude oil containing heavy components and a second preset volume of air, while controlling the bottom hole pressure P to remain constant. The process of sealing the gas channel includes: If the bottom temperature T satisfies T < T1, then a first preset volume of crude oil containing heavy components and a second preset volume of air are injected from the injection well (10), and high-temperature steam at a preset temperature is injected from the production well (20) to control the temperature in the steam channel between T1 and T2, while controlling the bottom pressure P to remain unchanged, forming low-temperature coke to block the steam channel layer. If the bottom temperature T satisfies T>T2, then a first preset volume of crude oil containing heavy components and a second preset volume of air are injected from the injection well (10), and a third preset volume of room temperature water is injected from the production well (20) to control the temperature in the gas channel between T1 and T2, while keeping the bottom pressure P constant, so that a low-temperature oxidation reaction occurs, generating dense coke and sealing the gas channeling layer.

2. The method for in-situ low-temperature oxidation and sealing of heavy oil according to claim 1, characterized in that, Step S10 includes: Inject a marker substance into the injection well (10); The parameters and product composition of the injection well (10) and the production wells (20) surrounding the injection well (10) are monitored and recorded regularly. If the parameters of one or more production wells (20) around the injection well (10) react in tandem with the parameters of the injection well (10), or if the marker substance is detected in the output of the production well (20), it proves that there is a dominant channel or gas leakage channel between one or more production wells (20) and the injection well (10). Determine the relationship between the location of the dominant channel or the gas channel and the location of the oil layer and dynamic fluid level of the production well (20).

3. The method for in-situ low-temperature oxidation and sealing of heavy oil according to claim 2, characterized in that, In determining the position of the dominant channel or the gas channel and the position of the oil layer and dynamic fluid level of the production well (20), the position of the dominant channel or the gas channel and the position of the oil layer and dynamic fluid level of the production well (20) are determined by the method of finding the gas channel by lowering the packer and / or the method of measuring the dynamic fluid level.

4. The method for in-situ low-temperature oxidation and sealing of heavy oil according to claim 1, characterized in that, In step S10, the production wells (20) surrounding the injection well (10) include the production wells (20) within a range of 50 meters to 200 meters from the injection well (10).

5. The method for in-situ low-temperature oxidation and sealing of heavy oil according to claim 1, characterized in that, Step S20 includes: Samples are taken from the production well (20) that has a dominant channel or gas channel with the injection well (10); The temperature range T1 to T2 of low-temperature oxidation to coke under oil layer temperature and oil layer pressure was measured indoors.

6. The method for in-situ low-temperature oxidation and sealing of heavy oil according to claim 5, characterized in that, During the sampling process of the production well (20) that has a dominant channel or steam channel with the injection well (10), the production well (20) that has a dominant channel or steam channel with the injection well (10) is sampled multiple times.

7. The method for in-situ low-temperature oxidation and sealing of heavy oil according to claim 6, characterized in that, During the process of measuring the temperature range T1 to T2 of low-temperature oxidation to coke under oil layer temperature and oil layer pressure indoors, the average value of the low-temperature oxidation temperature measured multiple times is calculated.

8. The method for in-situ low-temperature oxidation and sealing of heavy oil according to any one of claims 1 to 7, characterized in that, Step S40 includes: A marker substance is injected into the injection well (10), and the injection well (10) is periodically monitored and recorded. The parameters and product composition of the injection well (10) and the production wells (20) surrounding the injection well (10) are monitored and recorded regularly. If the production well (20) no longer exhibits a linkage reaction, or the reaction is significantly reduced, or the marker substance is no longer detected, then the sealing is successful; otherwise, the sealing fails.

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