A method and device for simulating casing annulus air channeling

Abstract

The present application relates to natural gas mining technical field, more particularly, it relates to a kind of casing annular gas channeling simulation test method and device, method includes the following steps: S1: to cement plug along radial seam, select certain permeability core plug, fill cement plug and core plug into gas channeling passage;S2: into annular cavity in completion fluid, into the bottom of core plug in high-pressure gas, make high-pressure gas sequentially through the internal porosity of core plug and cement plug and enter annular cavity;S3: in combination with the liquid level and pressure in annular cavity change with time law, simulate analysis casing annular gas channeling situation.Through the liquid level and pressure in annular cavity change with time law, the characteristics and law of casing annular gas channeling are analyzed, to guide the selection of casing annular well control opportunity and the formulation of treatment scheme.The device of the present application is used in combination with the above method, to effectively and reliably carry out casing annular gas channeling simulation experiment test.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of natural gas exploitation, and more particularly to a casing annulus gas channeling simulation test method and device. BACKGROUND

[0002] In the process of natural gas development, the problem of casing annulus pressure increase occurs more and more with the increase of exploitation time. The reasons for causing the casing annulus pressure increase are mainly two kinds: one is that the temperature of the oil casing annulus and the casing annulus increases, and the fluid in the limited space expands due to heating, resulting in the increase of the annulus pressure. The other is that the casing annulus pressure increases due to natural gas leakage, mainly including the sealing failure of the tubing string, the sealing failure of the casing string and the sealing failure of the cement ring. Among them, the casing annulus pressure caused by the thermal expansion of the fluid in the annulus can be solved by reducing the production, using heat insulation materials or appropriately releasing pressure. For the casing annulus pressure caused by the sealing failure of the oil casing, the leakage test, engineering logging and other means can be used to analyze the leakage situation, and the corresponding treatment measures can be developed.

[0003] However, for the casing annulus pressure caused by the sealing failure of the cement ring, the existing experimental or engineering test means cannot accurately analyze the gas channeling rule of the cement ring and the gas channeling situation at different stages, and it is difficult to form targeted treatment measures. The related simulation test method and device have not been disclosed in the prior art. SUMMARY

[0004] In order to overcome the problem that the casing annulus pressure caused by the sealing failure of the cement ring cannot be simulated and analyzed in the prior art, the present application provides a casing annulus gas channeling simulation test method.

[0005] Another object of the present application is to provide a device for realizing the above method.

[0006] In order to solve the above technical problems, the technical scheme adopted by the present application is as follows: a casing annulus gas channeling simulation test method is provided, which is tested by using a casing annulus gas channeling simulation test device. The device has an annular cavity at the upper end and a gas channeling channel at the lower end. The annular cavity is in communication with the gas channeling channel. The method comprises the following steps:

[0007] S1: radially forming a joint on the cement plug, selecting a core plug with a certain permeability, and filling the cement plug and the core plug into the gas channeling channel;

[0008] S2: injecting completion fluid into the annular cavity, and introducing high-pressure gas into the bottom of the core plug, so that the high-pressure gas enters the annular cavity through the inside pores of the core plug and the cement plug in turn;

[0009] S3: combining the liquid level and pressure variation law in the annular cavity with time, and simulating and analyzing the casing annulus gas channeling situation.

[0010] In the technical scheme of the present application, the cement plug and the core plug after being cut simulate the structure of the gas channeling layer in the actual mining process, the annular cavity filled with the completion fluid simulates the annular state in the well, the high-pressure gas passing through the core plug and the cement plug enters the simulated casing annular gas channeling state, and the liquid level and pressure in the annular cavity change with time to analyze the characteristics and rules of the casing annular gas channeling, thereby guiding the selection of the treatment opportunity and the development of the treatment scheme for the casing annular pressure control well.

[0011] Preferably, in step S1, the cement plug is irregularly cut in the radial direction, and quartz sand of a certain mesh size is filled in the cracks and then fixed.

[0012] Preferably, in step S1, the core plug has a permeability close to that of the gas channeling reservoir, and the core plug is saturated with simulated formation water.

[0013] Preferably, the simulated formation water is configured according to the components of the gas channeling formation water.

[0014] Preferably, the gas channeling channel is further surrounded by a filling cavity, and in step S2, a fluid is injected into the filling cavity to pressurize the gas channeling channel, so that the side wall of the gas channeling channel tightly abuts the outer circumferential surface of the cement plug and the core plug.

[0015] Preferably, the fluid pressure in the filling cavity is greater than the high-pressure gas pressure introduced into the bottom of the core plug.

[0016] Preferably, the completion fluid is configured according to the components of the cementing slurry spacer fluid.

[0017] Preferably, the method further comprises the following step: when the pressure in the annular cavity rises to a certain value, the annular cavity is depressurized, and the liquid level and pressure in the cavity change with time to simulate the on-site depressurization.

[0018] Preferably, the annular cavity is repeatedly depressurized, and the liquid level and pressure in the cavity change with time to simulate the on-site repeated depressurization.

[0019] Preferably, the repeated depressurization comprises the following steps: the top of the annular cavity is connected to the atmosphere to depressurize, and then the annular cavity is closed, and the depressurization is repeated when the pressure reaches a certain value.

[0020] The application further provides a casing annular air channeling simulation test device for implementing the method, which comprises a casing assembly and an air channeling simulation assembly connected to the bottom of the casing assembly, an internal part of the casing assembly is vertically formed with a closed annular cavity, and the casing assembly is connected with a liquid injection pump through a pipeline, the liquid injection pump is communicated with the annular cavity, the air channeling simulation assembly comprises a cylinder body and a high-pressure gas source device, an internal part of the cylinder body is vertically formed with an air channeling channel, the top of the cylinder body is connected with the bottom of the casing assembly and the air channeling channel is communicated with the annular cavity, the bottom of the air channeling channel is connected with the high-pressure gas source device, the cylinder body comprises a confining pressure cylinder and a rubber cylinder, the internal part of the rubber cylinder is formed with the air channeling channel, the confining pressure cylinder is sleeved outside the rubber cylinder, a closed filling cavity is formed between the confining pressure cylinder and the rubber cylinder, the filling cavity is connected with a fluid pump through a pipeline, the casing assembly is connected with a first pressure gauge for measuring the pressure of the annular cavity, the air channeling simulation assembly is connected with a second pressure gauge for measuring the pressure of the high-pressure gas source device, the air channeling simulation assembly is connected with a third pressure gauge for measuring the internal pressure of the filling cavity, and the upper end of the annular cavity is provided with a pipeline communicated with the outside, and a pressure relief valve is arranged on the pipeline.

[0021] Compared with the prior art, the application has the following beneficial effects:

[0022] Firstly, the casing annular air channeling simulation test method can analyze the characteristics and rules of casing annular air channeling through the change rules of the liquid level and pressure in the annular cavity with time, thereby guiding the selection of the treatment opportunity and the development of the treatment scheme for the casing annular well with pressure.

[0023] Secondly, the casing annular air channeling simulation test method can simulate the influence of the pressure rise caused by temperature rise after well shut-in and production recovery on the casing annular air channeling, simulate the influence of field pressure relief on the casing annular air channeling, and simulate and analyze the influence of repeated well opening and closing or pressure relief on the casing annular air channeling, thereby guiding the selection of the treatment opportunity and the development of the treatment scheme for the casing annular well with pressure.

[0024] Thirdly, the casing annular air channeling simulation test device is used for implementing the above test method, thereby effectively and reliably performing the casing annular air channeling simulation test. BRIEF DESCRIPTION OF DRAWINGS

[0025] Figure 1 is the overall structure schematic view of the casing annular air channeling simulation test device of the application;

[0026] Figure 2 is the annular cavity pressure and liquid level change curve graph of example 1.

[0027] In the drawings: 1, casing assembly; 11, annular cavity; 12, inner layer pipe; 13, outer layer pipe; 14, upper cover; 15, lower cover; 2, gas channeling simulation assembly; 21, barrel; 211, confining pressure cylinder; 212, rubber cylinder; 213, filling cavity; 22, high-pressure gas source device; 23, gas channeling channel; 24, plug; 25, end cover; 26, compression part; 251, gas injection channel; 27, intermediate container; 3, liquid injection pump; 4, fluid pump; 5, first pressure gauge; 6, second pressure gauge; 7, third pressure gauge; 8, pressure relief valve; 100, cement piston; 200, core piston. DETAILED DESCRIPTION

[0028] The drawings are only used for illustrative description, and should not be understood as limiting the patent; in order to better illustrate the embodiment, some components in the drawings may be omitted, enlarged or reduced, and do not represent the actual product size; for those skilled in the art, it is understandable that some well-known structures and their descriptions in the drawings may be omitted. The positional relationship described in the drawings is only used for illustrative description, and should not be understood as limiting the patent.

[0029] The same or similar reference numerals in the drawings of the embodiments of the present application correspond to the same or similar components; in the description of the present application, it should be understood that if the terms "upper", "lower", "left", "right", "long", "short" and the like indicate the orientation or positional relationship, it is based on the orientation or positional relationship shown in the drawings, and is only for the convenience of describing the present application and simplifying the description, and does not indicate or imply that the device or element referred to must have a particular orientation, be constructed and operated in a particular orientation, therefore the terms describing the positional relationship in the drawings are only used for illustrative description, and should not be understood as limiting the patent, for those skilled in the art, the specific meaning of the above terms can be understood according to the specific situation.

[0030] The technical solutions of the present application will be further described below through specific embodiments and in conjunction with the drawings:

[0031] Embodiment 1

[0032] The embodiment discloses a casing annulus gas channeling simulation test method, which is tested by using a casing annulus gas channeling simulation test device, and refers to Figure 1 The device has an annular cavity 11 at the upper end and a gas channeling channel 23 at the lower end, and the annular cavity 11 is in communication with the gas channeling channel 23.

[0033] The method of the embodiment comprises the following steps:

[0034] S1: radially irregularly split the cement plug 100 along the crack, fill a certain mesh size of quartz sand in the crack and fix it, to obtain a jointed cement plug 100; select a similar permeability to the gas channeling reservoir, make the core plug 200 absorb saturated simulated formation water, and the simulated formation water is configured according to the composition of the gas channeling formation water; fill the cement plug 100 and the core plug 200 into the gas channeling channel 23 of the barrel 21, wherein the cement plug 100 is located above the core plug 200.

[0035] S2: inject the completion fluid into the annular cavity 11 through the liquid injection pump 3, and the completion fluid is configured according to the composition of the cementing slurry spacer fluid; inject the fluid into the filling cavity 213 through the fluid pump 4 to pressurize, so that the side wall of the gas channeling channel 23 tightly abuts the outer circumferential surface of the cement plug 100 and the core plug 200; introduce high-pressure gas into the bottom of the core plug 200 through the high-pressure gas source device 22, so that the high-pressure gas enters the annular cavity 11 in sequence through the internal pores of the core plug 200 and the cement plug 100, wherein the fluid pressure in the filling cavity 213 is higher than the gas pressure provided by the high-pressure gas source device 22.

[0036] S3: record the liquid level and pressure change law in the annular cavity 11 over time.

[0037] Through the above method, the influence of the pressure rise caused by the temperature rise after the well is shut in and production is restored on the annular gas channeling is simulated, and the obtained experimental data is used to guide the casing annulus pressure well treatment.

[0038] Further, the above method can further include step S4: when the pressure in the annular cavity 11 rises to a certain value, open the pressure relief valve to relieve the pressure in the annular cavity 11, and record the liquid level and pressure change law in the annular cavity 11 over time, thereby simulating the influence of field pressure relief on annular gas channeling.

[0039] Further, the above method can further include step S5: after the pressure relief is completed, close the pressure relief valve, repeat step S4, repeatedly relieve the pressure in the annular cavity 11, and record the liquid level and pressure change law in the annular cavity 11 over time, thereby simulating the influence of repeated well opening and closing or pressure relief on annular gas channeling.

[0040] Example 2

[0041] This example is an experiment according to the method of example 1 combined with actual production conditions, and the obtained data and results are used to propose a corresponding treatment scheme.

[0042] M well casing annulus pressure 2.2 MPa, according to the annulus gas sample analysis for production layer gas extravascular channeling caused annulus pressure, channeling gas containing 26% CO2, no H2S, there is a certain casing corrosion risk. Currently, the production layer pressure is 7.5 MPa, the average permeability is 48.6 md. Field pressure relief test, the annulus pressure can be discharged to zero, stop the pressure relief after 26 h pressure recovery to 2.2 MPa stable. In order to analyze the effect of pressure relief operation on annulus gas channeling, the casing annulus gas channeling simulation test is carried out.

[0043] 1. Drill diameter 2.5 cm, length 10 cm cement plug, longitudinal section, fill a layer of 230 mesh ~ 200 mesh quartz sand between the cracks, and fix the cement plug.

[0044] 2. According to the permeability of gas channeling layer and the core inventory, select the diameter of 2.5 cm, length of 8.3 cm, permeability of 47.5 md core for simulation experiment. According to the ion composition of gas channeling layer water, the simulated formation water is prepared, and the core plug is saturated with simulated formation water.

[0045] 3. The processed cement plug and core plug are sequentially loaded into the test device rubber tube, and the test device is assembled. The liquid injection pump is used to add 2 MPa to the filling cavity.

[0046] 4. The liquid in the gas channeling annulus is cement slurry spacer fluid. According to the spacer fluid formula, the simulation test liquid is prepared, and the liquid injection pump is used to pump the simulation test liquid between the inner cylinder and the outer cylinder until the annulus is filled.

[0047] 5. The liquid injection pump increases the confining pressure in the filling cavity to 4.2 MPa, and the high-pressure gas source device is used to inject gas into the middle container to 2.2 MPa.

[0048] 6. Slowly open the valve between the plug and the middle container and time, observe and record the change of the pressure and liquid level of the annular cavity with time; discharge the annular cavity pressure three times at 30 min, 60 min, 90 min, each time for 0.5 min, record the pressure and liquid level change before and after pressure relief.

[0049] 7. After 120 min, the high-pressure gas source device is closed, the pressure is relieved and the experimental equipment is cleaned.

[0050] The experimental data is shown in the following table, and the pressure and liquid level of the annular cavity with time curve is shown in Figure 2 .

[0051]

[0052] From the experimental results, with the increase of annulus pressure relief times, the leakage rate gradually increases, therefore, the M well annulus pressure management suggestions are: maintain production, strengthen annulus pressure monitoring, avoid annulus relief pressure as much as possible during production, and regularly supplement alkaline corrosion liquid to control annulus CO2 corrosion.

[0053] Example 3

[0054] Reference Figure 1 The casing annulus gas channeling simulation test device comprises a casing assembly 1 and a gas channeling simulation assembly 2, the gas channeling simulation assembly 2 is connected to the bottom of the casing assembly 1, the inside of the casing assembly 1 is vertically formed with a closed annular cavity 11, the casing assembly 1 is connected with a liquid injection pump 3 through a pipeline, the liquid injection pump 3 is in communication with the annular cavity 11, the gas channeling simulation assembly 2 comprises a cylinder body 21 and a high-pressure gas source device 22, the inside of the cylinder body 21 is vertically formed with a gas channeling channel 23, the top of the cylinder body 21 is connected with the bottom of the casing assembly 1 and the gas channeling channel 23 is in communication with the annular cavity 11, the bottom of the gas channeling channel 23 is connected with the high-pressure gas source device 22, the cylinder body 21 comprises a confining pressure cylinder 211 and a rubber cylinder 212, the inside of the rubber cylinder 212 is formed with the gas channeling channel 23, the confining pressure cylinder 211 is sleeved outside the rubber cylinder 212, a closed filling cavity 213 is formed between the confining pressure cylinder 211 and the rubber cylinder 212, the filling cavity 213 is connected with a fluid pump 4 through a pipeline, the casing assembly 1 is connected with a first pressure gauge 5 for measuring the pressure of the annular cavity 11, the gas channeling simulation assembly 2 is connected with a second pressure gauge 6 for measuring the pressure of the high-pressure gas source device 22, the gas channeling simulation assembly 2 is connected with a third pressure gauge 7 for measuring the pressure inside the filling cavity 213, the upper end of the annular cavity 11 is provided with a pipeline in communication with the outside, and a pressure relief valve 8 is arranged on the pipeline.

[0055] The casing annulus gas channeling simulation test device of the embodiment is used for injecting completion fluid into the annular cavity 11 inside the casing assembly 1 through the liquid injection pump 3 to simulate the annulus state in the well. The gas channeling channel 23 formed by the cylinder body 21 is used for filling the cement plug 100 and the core plug 200, wherein the cement plug 100 is located at the upper end of the gas channeling channel 23 and the core plug 200 is located below the cement plug 100. The high-pressure gas source device 22 is used for injecting high-pressure gas below the core plug 200, so that the high-pressure gas seeps into the annular cavity 11 through the core plug 200 and the cracks of the cement plug 100 to simulate the annulus gas channeling condition.

[0056] Reference Figure 1The barrel 21 comprises a surrounding pressure barrel 211 and a rubber barrel 212, the surrounding pressure barrel 211 is sleeved outside the rubber barrel 212, and a sealed filling cavity 213 is formed between the surrounding pressure barrel 211 and the rubber barrel 212. By injecting high-pressure fluid into the filling cavity 213 through the fluid pump 4, the rubber barrel 212 can be tightly attached to the outer circumferential surface of the core plug 200 and the cement plug 100. In this way, when high-pressure gas is injected into the bottom of the core plug 200 through the high-pressure gas source device 22, the gas can be prevented from escaping from the gas channeling passage 23 and the circumferential gap between the core plug 200 and the cement plug 100, thereby improving the accuracy of the simulation test.

[0057] The first pressure gauge 5, the second pressure gauge 6 and the third pressure gauge 7 are respectively used for monitoring the pressure of the annular cavity 11, the pressure of the high-pressure gas and the pressure of the filling cavity 213. During the test, the pressure of the filling cavity 213 should be greater than the pressure of the high-pressure gas, that is, the value of the third pressure gauge 7 is greater than the value of the second pressure gauge 6, so that the rubber barrel 212 can be tightly attached to the outer circumferential surface of the cement plug 100 and the core plug 200. The pressure relief valve 8 is arranged at the upper end of the casing assembly 1 and communicates with the upper end of the annular cavity 11. By opening and closing the pressure relief valve 8, the annular cavity 11 can be depressurized.

[0058] Reference Figure 1 The gas channeling simulation assembly 2 further comprises a plug 24, an end cover 25 and a pressing member 26. The upper end of the end cover 25 is fixedly connected to the bottom of the barrel 21, the plug 24 is arranged in the end cover 25, one end of the pressing member 26 is adjustably connected to the end cover 25, and the other end of the pressing member 26 abuts against the bottom of the plug 24. The plug 24 is provided with a gas injection passage 251, one end of the gas injection passage 251 is opposite to the core plug 200, and the other end of the gas injection passage 251 is connected to the high-pressure gas source device 22. The pressing member 26 can be a threaded jack, and the bottom of the end cover 25 is provided with a threaded hole. The threaded jack is threadedly connected to the bottom of the end cover 25. By threadedly connecting the threaded jack to the bottom of the end cover 25, the plug 24 can be pressed against the bottom of the core plug 200. By injecting high-pressure gas into one end of the gas injection passage 251 of the core plug 200 through the high-pressure gas source device 22, the high-pressure gas enters the core plug 200 through the gas injection passage 251 and then channels out of the cracks of the cement plug 100 and enters the annular cavity 11.

[0059] Reference Figure 1In the embodiment, the axial section of the plug 24 can be substantially inverted T-shaped, the upper end of the plug 24 can be substantially cylindrical and matched with the lower end inlet of the gas channel 23, and the lower end of the plug 24 can be disc-shaped with a slightly larger diameter. The upper end of the plug 24 can be fixedly connected to the lower end of the gas channel 23 or abut against the lower end of the gas channel 23 through other components to block the lower end inlet of the gas channel 23. The plug 24 is provided with a substantially L-shaped gas injection channel 251, which communicates the upper end face of the plug 24 and the lower end side face of the plug 24. The upper end face of the plug 24 is in abutment with the bottom of the core plug 200, and the gas flow channel of the lower end side face of the plug 24 is connected to the external high-pressure gas source device 22. The high-pressure gas can enter the core plug 200 through the gas injection channel 251 in the plug 24 by the high-pressure gas source device 22. Since the plug 24 can block the lower end inlet of the gas channel 23, the high-pressure gas can enter the core plug 200, reducing the gas leakage.

[0060] With reference to Figure 1 The end cover 25 can be composed of an inlet cover and a compression dome. The inlet cover is substantially annular, and the upper end of the inlet cover is sleeved outside the bottom of the barrel 21, for example, through threaded connection, to fix the inlet cover to the barrel 21. The compression dome is a cap-shaped structure with an open top end, and the upper end of the compression dome is fixedly connected to the lower end of the inlet cover. For example, the bottom of the inlet cover is provided with an annular groove in the circumferential direction, and the upper end opening of the compression dome is provided with a protrusion on the radially inner side, and the inlet cover and the compression dome are connected by clamping the protrusion in the annular groove. The plug 24 is axially through the inlet cover and assembled at the lower end of the plug 24 in the dome cap. The upper end of the plug 24 can be interference-fitted with the inlet cover to improve the tightness of the connection.

[0061] With reference to Figure 1 The gas channeling simulation assembly 2 further comprises an intermediate container 27, one end of the intermediate container 27 is connected to the gas injection channel 251 through a pipeline, and the other end of the intermediate container 27 is connected to the high-pressure gas source device 22 through a pipeline. The intermediate container 27 can store the completion fluid flowing out of the annular cavity 11. The third pressure gauge 7 can be connected to the inner cavity of the intermediate container 27, and the pressure value of the high-pressure gas can be obtained by measuring the pressure value in the intermediate container 27. Corresponding valves are arranged on each pipeline.

[0062] With reference to Figure 1The sleeve assembly 1 comprises an inner tube 12, an outer tube 13, an upper cover 14 and a lower cover 15, the outer tube 13 is sleeved on the outer side of the inner tube 12, the upper cover 14 is fixedly connected to the upper ends of the inner tube 12 and the outer tube 13, the lower cover 15 is fixedly connected to the lower ends of the inner tube 12 and the outer tube 13, an annular cavity 11 is formed between the inner tube 12, the outer tube 13, the upper cover 14 and the lower cover 15, the lower cover 15 is provided with a hole communicating with the annular cavity 11, and the hole is communicated with the top of the gas channel 23.

[0063] With reference to Figure 1 A rubber sealing ring can be arranged between the inlet cover and the cylinder 21 to improve the air tightness of the connection. The rubber sealing ring can comprise a first sealing section in the axial direction at the upper end and a second sealing section in the radial direction at the lower end. The first sealing section can be matched and fitted on the inner wall of the bottom opening of the gas channel 23, and the upper end of the plug 24 is tightly fitted with the first sealing section, so as to improve the air tightness. The second sealing section is arranged in the radial direction between the shoulder formed by the upper end of the inlet cover and the lower end of the cylinder 21, so as to improve the air tightness of the connection between the inlet cover and the cylinder 21. Sealing rings are arranged at the positions where the inner tube 12, the outer tube 13, the upper cover 14 and the lower cover 15 contact each other, so as to effectively improve the sealing performance of the sleeve assembly 1.

[0064] With reference to Figure 1 In the embodiment, a valve is arranged on the pipeline connected between the liquid injection pump 3 and the annular cavity 11, a valve is arranged on the pipeline connected between the fluid pump 4 and the filling cavity 213, a valve is arranged on the pipeline connected between the intermediate container 27 and the plug 24, a valve is arranged on the pipeline connected between the intermediate container 27 and the outside, and a valve is arranged on the pipeline connected between the high-pressure gas source device 22 and the intermediate container 27.

[0065] Obviously, the above embodiments of the present application are merely exemplary for clearly illustrating the present application, and are not intended to limit the implementation modes of the present application. Based on the above description, other different forms of changes or variations can be made by those skilled in the art. Here, all the implementation modes are not required or can not be exhausted. Any modification, equivalent replacement and improvement made within the spirit and principle of the present application shall be included in the protection scope of the claims of the present application.

Claims

1. A method for testing casing annular channeling simulation by using a casing annular channeling simulation testing device, characterized in that: The device has an annular cavity (11) at the upper end and a gas channel (23) at the lower end, the annular cavity (11) is communicated with the gas channel (23), the method comprises the following steps: S1: radially cracking the cement plug (100), selecting a core plug (200) with a certain permeability, filling the cement plug (100) and the core plug (200) into the gas channel (23); S2: injecting completion fluid into the annular cavity (11), and injecting high-pressure gas into the bottom of the core plug (200), so that the high-pressure gas enters the annular cavity (11) through the internal pores of the core plug (200) and the cement plug (100) in turn; the side wall of the gas channel (23) is further surrounded by a filling cavity (213), and the filling cavity (213) is filled with fluid under pressure, so that the side wall of the gas channel (23) tightly adheres to the outer circumferential surface of the cement plug (100) and the core plug (200); the fluid pressure in the filling cavity (213) is greater than the high-pressure gas pressure injected into the bottom of the core plug (200); the completion fluid is configured according to the components of the cementing slurry spacer fluid; S3: combining the liquid level and pressure change rule of the annular cavity (11) with time, simulating and analyzing the casing annulus gas channeling condition.

2. The casing annulus channeling analog test method of claim 1, wherein: In step S1, the cement plug (100) is irregularly cracked in the radial direction, and a certain mesh size of quartz sand is filled in the crack and fixed.

3. The casing annulus channeling analog test method of claim 1, wherein: In step S1, the core plug (200) is similar to the permeability of the gas channeling reservoir, and the core plug (200) absorbs saturated simulated formation water.

4. The casing annulus channeling analog test method of claim 3, wherein: The simulated formation water is configured according to the components of the gas channeling formation water.

5. The casing annulus channeling analog test method of claim 1, wherein: The method further comprises the following steps: when the pressure in the annular cavity (11) rises to a certain value, the annular cavity (11) is depressurized, and the liquid level and pressure change rule of the cavity after depressurization with time are simulated to simulate the on-site depressurization condition.

6. The casing annulus channeling analog test method of claim 5, wherein: The annular cavity (11) is repeatedly depressurized, and the liquid level and pressure change rule of the cavity during the repeated depressurization process with time are simulated to simulate the on-site repeated depressurization condition.

7. An annulus air channeling simulation test apparatus for implementing the method of any one of claims 1 to 6, characterized by: The utility model relates to a casing assembly (1) and gas channeling simulation assembly (2) are connected in casing assembly (1) bottom, casing assembly (1) inside vertical formation has the closed annular cavity (11), casing assembly (1) is connected with liquid injection pump (3) through pipeline, liquid injection pump (3) is communicated with annular cavity (11), gas channeling simulation assembly (2) includes cylinder (21) and high pressure gas source device (22), cylinder (21) inside vertical formation has gas channeling channel (23), cylinder (21) top is connected with casing assembly (1) bottom and gas channeling channel (23) is communicated with annular cavity (11), gas channeling channel (23) bottom is connected with high pressure gas source device (22), cylinder (21) includes confining pressure cylinder (211) and rubber cylinder (212), rubber cylinder (212) inside forms gas channeling channel (23), confining pressure cylinder (211) is sleeved in rubber cylinder (212) outside, and the closed filling cavity (213) is formed between confining pressure cylinder (211) and rubber cylinder (212), filling cavity (213) is connected with fluid pump (4) through pipeline, casing assembly (1) is connected with first pressure gauge (5) for measuring annular cavity (11) pressure, gas channeling simulation assembly (2) is connected with second pressure gauge (6) for measuring high pressure gas source device (22) pressure, gas channeling simulation assembly (2) is connected with third pressure gauge (7) for measuring filling cavity (213) inside pressure, the upper end of annular cavity (11) is equipped with the pipeline that communicates outside, is equipped with pressure relief valve (8) on the pipeline.

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