A device and method for simulating gas channeling of cement slurry in a closed environment

Abstract

This invention relates to the field of testing equipment technology, and in particular to a testing device and method for simulating gas channeling in cement slurry under closed conditions. The testing device includes a testing unit comprising a testing cylinder, a piston, a connecting rod, and a fixing component. The piston is slidably arranged inside the testing cylinder. The fixing component is mounted on the connecting rod and is used to control the movement of the piston. The connecting rod has an axial through-hole. The piston divides the space inside the testing cylinder into a rodless chamber and a rod chamber. The lower end of the through-hole of the connecting rod communicates with the rodless chamber, which is used to hold cement. By adjusting the piston's movement limit through the fixing component, the transmission of confining pressure can be controlled. Simultaneously, by adjusting the connection between the fixing component and the testing cylinder, the moment when the closed environment begins to close can be simulated, making the experimental environment closer to the actual downhole environment.

Description

Technical Field

[0001] This invention relates to the field of testing equipment technology, and in particular to a testing device and experimental method for simulating gas channeling in cement slurry in a closed environment. Background Technology

[0002] After cementing in oil and gas wells, the imbalance between the fluid column pressure in the annular space and the formation pressure causes fluids from the formation to enter the annular space, resulting in longitudinal flow. This phenomenon is called fluid channeling, or annular channeling for short. Annular channeling prevents permanent sealing between the formation and the casing, leading to inter-layer flow or oil and gas leakage from the wellhead, severely impacting normal production and recovery of oil and gas wells.

[0003] With the continuous development of oilfields, tailpipe cementing completion technology has developed rapidly, inevitably facing the problem of gas channeling in cement slurry within the closed environment created after the tailpipe packer is set. Compared to conventional cementing, tailpipe cementing separates the annulus after the tailpipe packer is set, and the pressure of the cement slurry column at the upper end of the annulus is no longer transmitted to the lower end, resulting in a decrease in the pressure of the cement slurry column at the lower end. This is quite different from the situation in conventional cementing where the pressure of the cement fluid column at the upper end of the annulus can be transmitted to the lower end.

[0004] Currently, there are numerous devices and experimental methods for simulating gas channeling in conventional cement slurry, but no research device has been found to study the risk of gas channeling in cement slurry under the closed environment formed by tailpipe cementing.

[0005] Currently, the most widely used cement slurry gas channeling simulation testing devices are the Chandler 7150FMA gas channeling instrument and the OWC-0480 gas channeling analyzer. Both instruments can simulate the water loss and gas channeling process of cement slurry. However, the Chandler 7150FMA gas channeling instrument, due to its cylindrical structure, cannot accurately simulate the downhole stress conditions of cement slurry. The OWC-0480 gas channeling analyzer, on the other hand, uses the weight loss of the cement slurry to identify the critical time for gas channeling. Its structure is similar to the 7150FMA gas channeling instrument, and it also cannot analyze the gas channeling risk of cement slurry in a closed environment. Northeast Petroleum University developed a gas channeling simulation device in 2010, which can analyze the impact of downhole pressure differential conditions on the anti-channeling performance of cement slurry. However, it mainly simulates formation pressure by venting and pressurizing the bottom of the vessel, allowing gas to directly penetrate the cement inside the vessel. This cannot accurately simulate the process of formation pressure invading the cement, and it is also inconvenient to observe the gas channeling path after the experiment.

[0006] In summary, existing gas channeling simulation experimental devices are mostly used to test the anti-channeling performance of conventional cementing slurry, and lack research devices and experimental methods for studying the gas channeling risk of cement slurry in the closed environment formed by tailpipe cementing. Summary of the Invention

[0007] The technical problem to be solved by the present invention is: in order to overcome the problem that the existing gas channeling simulation test devices are mostly used to test the anti-channeling performance of conventional cementing slurry, and lack research devices and experimental methods for the risk of cementing slurry gas channeling in the closed environment formed by tailpipe cementing, the present invention provides a cementing slurry gas channeling simulation test device and experimental method in a closed environment.

[0008] The technical solution adopted by this invention to solve its technical problem is: a cement slurry gas channeling simulation test device in a closed environment, comprising:

[0009] The test unit includes a test cylinder, a piston, a connecting rod, and a fixing component. The piston is slidably arranged inside the test cylinder, and the fixing component is installed on the connecting rod. The fixing component is used to control the movement of the piston. The connecting rod has an axial through hole that runs through the entire unit. The piston divides the space inside the test cylinder into a rodless chamber and a rod chamber. The lower end of the through hole of the connecting rod is connected to the rodless chamber, and the rodless chamber is used to place cement.

[0010] When the piston is in the movable state, the fixed part is located above the test cylinder;

[0011] When the piston is in a fixed position, the fixing component and the test cylinder are fixedly connected.

[0012] The simulation unit is used to inject test gas into cement, and the simulation unit is connected to the rodless cavity.

[0013] The pressurizing unit is used to apply pressure to the cement; the pressurizing unit is connected to the rod chamber.

[0014] The back pressure sampling unit is used to apply back pressure and perform sampling detection. The back pressure sampling unit and the through hole of the connecting rod are connected.

[0015] The test unit is used to detect the physical properties of cement. The test unit is installed on the test cylinder. The piston movement is restricted by the fixing component to control the transmission of confining pressure. At the same time, by adjusting the connection between the fixing component and the test cylinder, the moment when the closed environment begins to close can be simulated, making the experimental environment closer to the actual underground environment and the experimental data obtained more reliable.

[0016] Further, the connecting rod has an upper threaded section on its outer periphery, the fastener has an internal threaded hole and an external threaded section, the internal threaded hole of the fastener and the upper threaded section of the connecting rod are threadedly connected, the test cylinder has a mounting hole that matches the external threaded section of the fastener, and the external threaded section of the fastener can be threadedly connected to the mounting hole of the test cylinder.

[0017] The test cylinder further includes a cylinder body, a top cover, and a bottom cover, with the top cover installed on the top of the cylinder body and the bottom cover installed on the bottom of the cylinder body.

[0018] It further includes a filter screen arranged on the piston on the rodless chamber side.

[0019] The simulation unit further includes a servo pump and a nitrogen injection source. The output end of the servo pump is connected to the rodless chamber and is located at the bottom of the test cylinder. The output end of the nitrogen injection source is connected to the rodless chamber and is located on the side of the test cylinder. An injection pressure sensor and a flow meter are arranged on the output path of the nitrogen injection source. Rock cores are installed on the output ends of the servo pump and the nitrogen injection source.

[0020] The pressurization unit further includes a confining pressure pump, the output end of which is connected to a rod chamber, and a safety valve is installed on the output path of the confining pressure pump.

[0021] The back pressure sampling unit includes a sampling bottle and a back pressure nitrogen source. The sampling bottle is connected to the upper end of the pipe and the connecting pipe through the through hole. A pneumatic back pressure valve and a back pressure sensor are arranged sequentially on the pipe from the sampling bottle to the connecting rod. The back pressure nitrogen source is connected to the pipe, and the connection between the back pressure nitrogen source and the pipe is located between the pneumatic back pressure valve and the back pressure sensor.

[0022] The detection unit further includes a pore pressure sensor and a temperature sensor, wherein the pore pressure sensor is used to detect the pore pressure within the cement.

[0023] Further, a heating belt is arranged on the outside of the test cylinder.

[0024] An experimental method for simulating gas channeling in cement slurry under a closed environment is described below:

[0025] Step 1: Set the temperature to the required experimental temperature and turn on the heating belt switch to preheat the test cylinder;

[0026] Step 2: Once the gas channeling simulation test device has been preheated to the target temperature, fill the test cylinder with the prepared cement.

[0027] Step 3: Turn on the confining pressure pump and inject water into the rod chamber to apply a constant hydraulic pressure to the piston;

[0028] Step 4: The servo pump pressurizes the filter channel at the bottom of the cement to control the discharge pressure;

[0029] Step 5: Pressurize the rock core inside the test cylinder by injecting nitrogen gas from the nitrogen source, and maintain a constant gas pressure through the pressure relief valve;

[0030] Step 6: Apply back pressure to the top of the connecting rod from the back pressure nitrogen source, release the increased pressure during the experiment through the pneumatic back pressure valve, maintain pressure stability, and release the pressure in the pipeline through the pressure relief valve after the experiment.

[0031] Step 7: During the experiment, the flow rate of air leakage is measured by a flow meter;

[0032] Step 8: After the cement has reacted for a period of time, stop applying pressure to the piston on top of the cement, fix the fastener and the test cylinder to prevent the piston from moving;

[0033] Step 9: Collect parameters such as temperature, pressure, and gas channeling flow rate through sensors, and process the parameters by computer to analyze the factors affecting the risk of gas channeling of cement in a closed environment;

[0034] Step 10: After the experiment, cut open the test tube to observe the gas channeling channels in the cement;

[0035] Step 11: Change the pressure, cement formula, temperature and other conditions, and repeat the above steps.

[0036] The beneficial effects of this invention are: the invention provides a simulation test device and experimental method for cement slurry gas channeling in a closed environment. By adjusting the piston movement limit through the fixing component, the transmission of confining pressure can be controlled. At the same time, by adjusting the connection between the fixing component and the test cylinder, the moment when the closed environment begins to close can be simulated, making the experimental environment closer to the actual downhole environment, and the experimental data obtained are more reliable. Attached Figure Description

[0037] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0038] Figure 1 This is a schematic diagram of the structure of the present invention;

[0039] Figure 2 This is the present invention. Figure 1 Enlarged structural diagram at point A;

[0040] Figure 3 This is the present invention. Figure 2 A schematic diagram of the cross-sectional structure;

[0041] Figure 4 This is a schematic diagram of the piston of the present invention in a movable state.

[0042] In the diagram: 1. Test unit; 11. Test cylinder; 111. Rod chamber; 112. Rodless chamber; 113. Mounting hole; 114. Cylinder body; 115. Top cover; 116. Bottom cover; 12. Piston; 13. Connecting rod; 131. Through hole; 132. Upper threaded section; 14. Fixing component; 141. Internal threaded hole; 142. External threaded section; 2. Filter screen; 3. Simulation unit; 31. Servo pump; 32. Nitrogen injection source; 33. Injection pressure sensor; 34. Flow meter; 35. Rock core; 4. Pressurization unit; 41. Confining pressure pump; 42. Safety valve; 5. Back pressure sampling unit; 51. Sampling bottle; 52. Back pressure nitrogen source; 53. Pneumatic back pressure valve; 54. Back pressure sensor; 6. Detection unit; 61. Pore pressure sensor; 62. Temperature sensor; 63. Strain gauge; 7. Heating belt. Detailed Implementation

[0043] The present invention will now be described in further detail with reference to the accompanying drawings. These drawings are simplified schematic diagrams, illustrating only the basic structure of the invention, and therefore only show the components relevant to the invention.

[0044] like Figure 1 This is a schematic diagram of the structure of the present invention, a simulation test device for gas channeling in cement slurry in a closed environment, comprising:

[0045] Test unit 1 includes a test cylinder 11, a piston 12, a connecting rod 13, and a fixing member 14. The piston 12 is slidably arranged inside the test cylinder 11. The fixing member 14 is installed on the connecting rod 13 and is used to control the movement of the piston 12. The connecting rod 13 has a through hole 131 that axially penetrates the entire rod. The piston 12 divides the space inside the test cylinder 11 into a rod chamber 111 and a rodless chamber 112. The lower end of the through hole 131 of the connecting rod 13 communicates with the rodless chamber 112. The rodless chamber 112 is used to place cement. The connecting rod 13 and the piston 12 are threadedly connected. A sealing ring is provided between the piston 12 and the inner wall of the test cylinder 11.

[0046] like Figure 4 As shown, when the piston 12 is in the movable state, the fixing member 14 is located above the test cylinder 11;

[0047] like Figure 2 As shown, when the piston 12 is in a fixed state, the fixing member 14 and the test cylinder 11 are fixedly connected;

[0048] Simulation unit 3 is used to inject test gas into cement. Simulation unit 3 is connected to rodless cavity 112.

[0049] The pressurizing unit 4 is used to apply pressure to the cement, and the pressurizing unit 4 is connected to the rod chamber 111.

[0050] The back pressure sampling unit 5 is used to apply back pressure and perform sampling detection. The back pressure sampling unit 5 is connected to the through hole 131 of the connecting rod 13.

[0051] And a detection unit 6, used to detect the physical properties of cement, is installed on the test cylinder 11.

[0052] like Figure 3 As shown, the connecting rod 13 has an upper threaded section 132 on its outer periphery, and the fixing member 14 has an internal threaded hole 141 and an external threaded section 142. The internal threaded hole 141 of the fixing member 14 and the upper threaded section 132 of the connecting rod 13 are threadedly connected. The test cylinder 11 has a mounting hole 113 that matches the external threaded section 142 of the fixing member 14. The external threaded section 142 on the fixing member 14 can be threadedly connected to the mounting hole 113 of the test cylinder 11.

[0053] The test cylinder 11 includes a cylinder body 114, a top cover 115, and a bottom cover 116. The top cover 115 is installed on the top of the cylinder body 114, and the bottom cover 116 is installed on the bottom of the cylinder body 114. A sealing ring is arranged between the top cover 115 and the cylinder body 114, and a sealing ring is arranged between the cylinder body 114 and the bottom cover 116. The mounting hole 113 is located on the top cover 115.

[0054] A filter screen 2 is arranged on the piston 12 on one side of the rodless chamber 112.

[0055] The simulation unit 3 includes a servo pump 31 and a nitrogen injection source 32. The output end of the servo pump 31 is connected to the rodless chamber 112, and the output end of the servo pump 31 is located at the bottom of the test cylinder 11. The output end of the nitrogen injection source 32 is connected to the rodless chamber 112, and the output end of the nitrogen injection source 32 is located on the side of the test cylinder 11. An injection pressure sensor 33 and a flow meter 34 are arranged on the output path of the nitrogen injection source 32. Rock cores 35 are installed on the output ends of the servo pump 31 and the nitrogen injection source 32. The rock cores 35 are sandwiched between the side walls of the cylinder 114. Aeration and pressurization were used to simulate formation pressure. The filtration channel of the bottom cover 116 was pressurized, and a core 35 was fixed at the channel opening to simulate the effect of the formation on cement slurry filtration. The discharge pressure was controlled by the servo pump 31 to simulate cement slurry filtration. The nitrogen source 32 was injected to ventilate and pressurize the core 35 to simulate formation pressure. This pressure was the same as the pressure applied by the servo pump 31. The formation pressure and the pressure of the overlying slurry column together simulated the actual downhole pressure differential. During the experiment, the flow meter 34 was used to measure the gas flow rate. Pressure relief valves were installed on the output path of the servo pump 31 and the output path of the injected nitrogen source 32.

[0056] The pressurization unit 4 includes a confining pressure pump 41, the output end of which is connected to the rod chamber 111, and a safety valve 42 is installed on the output path of the confining pressure pump 41.

[0057] The back pressure sampling unit 5 includes a sampling bottle 51 and a back pressure nitrogen source 52. The sampling bottle 51 is connected to the upper end of the through hole 131 of the connecting rod through a pipe. A pneumatic back pressure valve 53 and a back pressure sensor 54 are arranged sequentially on the pipe from the sampling bottle 51 to the connecting rod 13. The pipe connected to the connecting rod 13 is a flexible hose, which can move with the connecting rod 13. The back pressure nitrogen source 52 is connected to the pipe, and the connection between the back pressure nitrogen source 52 and the pipe is located between the pneumatic back pressure valve 53 and the back pressure sensor 54. The back pressure nitrogen source 52 applies back pressure to the top of the connecting rod 13 to control the flow of fluid in the cement slurry. The increased pressure during the experiment is released through the pneumatic back pressure valve 53 to maintain pressure stability. A pressure relief valve is installed on the output path of the back pressure nitrogen source 52.

[0058] The detection unit 6 includes a pore pressure sensor 61, a temperature sensor 62, and a strain gauge 63 arranged on the test cylinder 11. The pore pressure sensor 61 is used to detect the pore pressure in the cement and monitor the cement hydration process. The strain gauge 63 collects the strain data of the test cylinder and monitors the weight loss process of the cement slurry.

[0059] A heating belt 7 is arranged on the outside of the test cylinder 11 to control the temperature of the cylinder 114 and cement to the set bottom temperature, simulating the actual temperature downhole.

[0060] The outer wall of the test cylinder 11 has strain gauges that fit against the outer wall of the test cylinder 11. The strain data of the test cylinder 11 is collected to monitor the weight loss process of the cement slurry. The aforementioned sensors transmit the collected data to the computer in real time.

[0061] Cement has different physical properties, such as setting time and initial stress after setting, under different pressures and temperatures. 1. During the initial setting of cement, the piston can move freely, transmitting the confining pressure inside the rod chamber 111 to the cement; 2. After the cement has set for a short period of time, the piston is fixed, and the confining pressure inside the rod chamber 111 is no longer transmitted to the cement; Whether or not confining pressure is transmitted to the cement during the cement setting process will affect the physical properties of the cement after setting.

[0062] During the transformation of cement from liquid to solid, it goes through three different stages: liquid, solid, and liquid-solid. In the process of transformation, the volume of cement continuously shrinks and expands. The shrinkage and expansion rates are different in open and closed environments, which will have different effects on the physical properties of cement after final setting.

[0063] An experimental method for simulating gas channeling in cement slurry under a closed environment is described below:

[0064] Step 1: Set the temperature to the required experimental temperature and turn on the heating belt 7 switch to preheat the test cylinder 11;

[0065] Step 2: When the gas channeling simulation test device has been preheated to the target temperature, fill the prepared cement into the test cylinder 11.

[0066] Step 3: Turn on the confining pressure pump 41 and inject water into the rod chamber 111 to apply a constant hydraulic pressure to the piston 12;

[0067] Step 4: The servo pump 31 pressurizes the filter channel at the bottom of the cement to control the discharge pressure;

[0068] Step 5: Pressurize the rock core 35 on the side wall of the test cylinder 11 by injecting nitrogen gas source 32, and maintain a constant gas pressure through the pressure relief valve;

[0069] Step 6: Apply back pressure to the top of the connecting rod 13 from the back pressure nitrogen source 52, release the increased pressure during the experiment through the pneumatic back pressure valve 53, and keep the pressure stable. After the experiment, release the pressure in the pipeline through the pressure relief valve, loosen the fixing part 14 on the top cover 115 to allow the piston 12 to move freely, and transmit the confining pressure to the cement simulated upper grout column pressure. After the cement reacts for a period of time, the fixing part 14 and the mounting hole 113 are threaded to prevent the piston from moving. At the same time, the confining pressure pump 41 is turned off to stop applying confining pressure to the top piston 12 of the cement. At this time, the confining pressure is no longer transmitted to the cement slurry to simulate the formation of a closed space after the tailpipe packer is set. The pressure of the cement slurry column at the upper end of the annulus is no longer transmitted to the lower end. The moment of the tailpipe packer setting can be simulated by adjusting and tightening the fixing part 14.

[0070] Step 7: During the experiment, the gas flow rate was measured by flow meter 34;

[0071] Step 8: After the cement has reacted for a period of time, stop applying pressure to the piston 12 at the top of the cement, fix the fastener 14 and the test cylinder 11 to prevent the piston 12 from moving;

[0072] Step 9: Collect parameters such as temperature, pressure, and gas channeling flow rate through sensors, and process the parameters by computer to analyze the factors affecting the risk of gas channeling of cement in a closed environment;

[0073] Step 10: After the experiment, cut open the test tube 11 to observe the gas channeling channels in the cement;

[0074] Step 11: Change the pressure, cement formula, temperature and other conditions, and repeat the above steps.

[0075] The packing system, consisting of a top cover 115, piston 12, connecting rod 13, and fixing member 14, forms a closed space with the test cylinder 11. By controlling the displacement of the piston, the transition from an open environment to a closed environment can be simulated. By adjusting the locking fixing member 14, the moment when the tailpipe packer sets can be simulated. In addition, after the experiment, the test cylinder 11 can be cut open to observe the gas channeling in the cement.

[0076] Based on the above-described preferred embodiments of the present invention, and through the foregoing description, those skilled in the art can make various changes and modifications without departing from the inventive concept. The technical scope of this invention is not limited to the contents of the specification, but must be determined according to the scope of the claims.

Claims

1. A simulation and testing device for gas channeling in cement slurry during well cementing in a closed environment, characterized in that, include: The test unit (1) includes a test cylinder (11), a piston (12), a connecting rod (13), and a fixing member (14). The piston (12) is slidably arranged inside the test cylinder (11). The fixing member (14) is installed on the connecting rod (13) and is used to control the movement of the piston (12). The connecting rod (13) has a through hole (131) that axially penetrates the entire structure. The connecting rod (13) and the piston (12) are threaded together. The piston (12) divides the space inside the test cylinder (11) into a rod chamber (111) and a rodless chamber (112). The through hole (131) of the connecting rod (13) leads to the lower... The end is connected to the rodless cavity (112), which is used to place cement. The outer periphery of the connecting rod (13) has an upper thread section (132). The fixing member (14) has an internal thread hole (141) and an external thread section (142). The internal thread hole (141) of the fixing member (14) and the upper thread section (132) of the connecting rod (13) are threadedly connected. The test cylinder (11) has a mounting hole (113) that matches the external thread section (142) of the fixing member (14). The external thread section (142) on the fixing member (14) can be threadedly connected to the mounting hole (113) of the test cylinder (11). After the cement has reacted for a period of time, stop applying pressure to the piston (12) at the top of the cement, fix the fastener (14) and the test cylinder (11) to prevent the piston (12) from moving; When the piston (12) is in a movable state, the fixing part (14) is located above the test cylinder (11); When the piston (12) is in a fixed state, the fixing member (14) and the test cylinder (11) are fixedly connected; The simulation unit (3) is used to inject test gas into cement, and the simulation unit (3) is connected to the rodless cavity (112); A pressurizing unit (4) is used to apply pressure to the cement, and the pressurizing unit (4) is connected to the rod chamber (111); The back pressure sampling unit (5) is used to apply back pressure and perform sampling detection. The back pressure sampling unit (5) is connected to the through hole (131) of the connecting rod (13). And a detection unit (6) for detecting the physical properties of cement, the detection unit (6) being mounted on the test cylinder (11).

2. The cement slurry gas channeling simulation test device in a closed environment as described in claim 1, characterized in that: The test tube (11) includes a tube body (114), a top cover (115) and a bottom cover (116). The top cover (115) is installed on the top of the tube body (114) and the bottom cover (116) is installed on the bottom of the tube body (114).

3. The well cement slurry gas channeling simulation test device in a closed environment as described in claim 1, characterized in that: A filter screen (2) is arranged on the piston (12) on one side of the rodless chamber (112).

4. The cement slurry gas channeling simulation test device in a closed environment as described in claim 2, characterized in that: The simulation unit (3) includes a servo pump (31) and a nitrogen injection source (32). The output end of the servo pump (31) is connected to the rodless chamber (112), and the output end of the servo pump (31) is located at the bottom of the test cylinder (11). The output end of the nitrogen injection source (32) is connected to the rodless chamber (112), and the output end of the nitrogen injection source (32) is located on the side of the test cylinder (11). An injection pressure sensor (33) and a flow meter (34) are arranged on the output path of the nitrogen injection source (32). Rock cores (35) are installed on the output ends of the servo pump (31) and the nitrogen injection source (32).

5. The well cement slurry gas channeling simulation test device in a closed environment as described in claim 4, characterized in that: The pressurization unit (4) includes a confining pressure pump (41), the output end of which is connected to the rod chamber (111), and a safety valve (42) is installed on the output path of the confining pressure pump (41).

6. The cement slurry gas channeling simulation test device in a closed environment as described in claim 5, characterized in that: The back pressure sampling unit (5) includes a sampling bottle (51) and a back pressure nitrogen source (52). The sampling bottle (51) is connected to the upper end of the pipe and the through hole (131) of the connecting pipe. A pneumatic back pressure valve (53) and a back pressure sensor (54) are arranged sequentially on the pipe from the sampling bottle (51) to the connecting rod (13). The back pressure nitrogen source (52) is connected to the pipe, and the connection between the back pressure nitrogen source (52) and the pipe is located between the pneumatic back pressure valve (53) and the back pressure sensor (54).

7. The cement slurry gas channeling simulation test device in a closed environment as described in claim 1, characterized in that: The detection unit (6) includes a pore pressure sensor (61), a temperature sensor (62) and a strain gauge (63) arranged on the test cylinder (11). The pore pressure sensor (61) is used to detect the pore pressure in the cement, and the strain gauge (63) is located on the outer wall of the test cylinder (11).

8. The cement slurry gas channeling simulation test device in a closed environment as described in claim 6, characterized in that: A heating band (7) is arranged on the outside of the test tube (11).

9. The experimental method for a closed-environment cement slurry gas channeling simulation test device as described in claim 8, characterized in that: The experimental steps are as follows: Step 1: Set the temperature to the required temperature for the experiment, turn on the heating belt (7) switch to preheat the test cylinder (11); Step 2: When the gas channeling simulation test device has been preheated to the target temperature, the prepared cement is loaded into the test cylinder (11); Step 3: Turn on the confining pressure pump (41) and inject water into the rod chamber (111) to apply constant hydraulic pressure to the piston (12); Step 4: The discharge pressure is controlled by the servo pump (31) pressurizing the filter channel at the bottom of the cement. Step 5: Pressurize the rock core (35) on the side wall of the test cylinder (11) by injecting nitrogen gas source (32) and maintain a constant gas pressure through the pressure relief valve; Step 6: Apply back pressure to the top of the connecting rod (13) from the back pressure nitrogen source (52), release the increased pressure during the experiment through the pneumatic back pressure valve (53), keep the pressure stable, and release the pressure in the pipeline through the pressure relief valve after the experiment; Step 7: During the experiment, the gas flow rate was measured by the flow meter (34); Step 8: After the cement has reacted for a period of time, stop applying pressure to the piston (12) at the top of the cement, fix the fastener (14) and the test cylinder (11) to prevent the piston (12) from moving; Step 9: Collect parameters such as temperature, pressure, and gas channeling flow rate through sensors, and process the parameters by computer to analyze the factors affecting the risk of gas channeling of cement in a closed environment; Step 10: After the experiment, cut open the test tube (11) and observe the gas channel in the cement; Step 11: Change the pressure, cement formula, temperature and other conditions, and repeat the above steps.

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