Device and method for testing shear cementing performance of cement sheath under pre-axial pressure and alternating temperature

Abstract

The invention relates to a device for testing shear cementing performance of a cement sheath under pre-axial pressure and alternating temperature, the device comprises an outer sleeve, an inner sleeve, a lower end cover, an axial pressure loading mechanism and a heating unit, the inner sleeve is sleeved in the outer sleeve, the inner sleeve and the outer sleeve are both vertically and detachably arranged at the upper end of the lower end cover, the cement sheath is poured in an annular cavity between the outer sleeve and the inner sleeve, and the axial pressure loading mechanism is arranged on the lower end cover. A force sensing unit is arranged at the upper end of the inner sleeve, the axial pressure loading mechanism is arranged at the upper end of the inner sleeve, connected with the force sensing unit and used for loading axial pressure to the force sensing unit and the inner sleeve, the heating unit is arranged in the inner sleeve and connected with a heating controller through a circuit, and the force sensing unit is connected with a host terminal through a circuit. The device has the advantages that the structural design is simple and reasonable, and the shear cementing performance of the cement sheath interface after the alternating temperature action can be accurately obtained on the premise of pre-applying the axial load; the overall test is simple, the test result is direct and accurate, and an important theoretical basis can be provided for cement sheath integrity and well cementation engineering optimization design.

Description

Technical Field

[0001] This invention belongs to the field of wellbore integrity technology, and specifically relates to a device and method for testing the shear bonding performance of cement sheath under pre-axial compression and alternating temperatures. Background Technology

[0002] Domestic oil and gas development has entered an unconventional era, facing the following main challenges: First, the scale of low-permeability recoverable reserves is large, making stable production difficult. Second, medium- and high-permeability reservoirs have generally entered the dual-high-permeability stage, especially reservoirs after polymer flooding where there is no effective replacement development technology. Gas flooding, especially miscible flooding technology, has received widespread attention as one of the important means of tertiary oil recovery. However, due to the large gas injection volume, when gas channeling occurs in some production wells, a large amount of gas is produced, which gradually occupies the entire wellbore, leading to excessively high wellhead pressure. Prolonged gas channeling can also cause high-temperature thermal front intrusion, causing a sharp increase in production well temperature, affecting the integrity of the cement sheath seal, which not only affects field production but also poses production safety hazards. To ensure the safe operation of hot-assisted miscible flooding injection-production wells, research on the effect of alternating temperature on the interfacial shear bonding performance of cement sheaths under pre-axial compression load is of great significance.

[0003] To date, the bonding performance between the cement ring and the casing interface is mainly tested through experimental methods, both domestically and internationally. These methods primarily include hydraulic bonding strength, radial bonding strength, and shear bonding strength.

[0004] Hydraulic bond strength is generally obtained by air channeling test, such as the experimental device and method for evaluating the interfacial bond strength of cement ring under high temperature and high pressure conditions provided by patent CN202010024708.6, which can realize the test of hydraulic bond strength of cement ring under high temperature and high pressure environment.

[0005] Radial bond strength is generally obtained by direct tensile testing, such as the device and method for testing the tensile bond strength of the first interface of cement sheath in oil and gas well cementing provided by patent CN202110322274.2. This device and method can measure the radial bond strength of the cement sheath interface, but it is mainly applicable to normal temperature and pressure and cannot simulate the radial bond strength test under high temperature and high pressure environment.

[0006] Shear bond strength is generally obtained through quasi-static pressure testing, such as the casing cement sheath interface tangential bond parameter testing device provided in patent CN202122512311.4. This device can measure the shear bond strength of the cement sheath interface. However, due to the periodic injection and production cycles in gas storage facilities, the wellbore is often subjected to alternating temperatures, which can lead to a decrease in the shear bond strength of the cement sheath interface. Therefore, considering only the initial state of the cement sheath interface bond performance is insufficient to meet the gas storage facility's requirements for cement sheath sealing.

[0007] To address this technical challenge of directly and accurately obtaining the influence of alternating temperature on the shear bonding performance of the cement sheath interface under pre-axial load, this invention proposes a testing device and method for the shear bonding performance of the cement sheath under pre-axial load and alternating temperature. This device and method can accurately test the shear bonding performance of the cement plug interface under alternating temperature, providing a theoretical basis for the cementing mechanical properties, cement sheath integrity, and cementing optimization design of oil and gas wells. Summary of the Invention

[0008] The technical problem to be solved by the present invention is to provide a device and method for testing the shear bonding performance of cement rings under pre-axial compression and alternating temperature, which effectively overcomes the defects of the prior art.

[0009] The technical solution of the present invention to solve the above-mentioned technical problems is as follows:

[0010] A device for testing the shear bonding performance of a cement ring under pre-axial compression and alternating temperatures includes an outer sleeve, an inner sleeve, a lower end cap, an axial compression loading mechanism, and a heating unit. The inner sleeve is fitted inside the outer sleeve, and both are vertically detachably mounted on the upper end of the lower end cap. The cement ring is cast in the annular cavity between the outer sleeve and the inner sleeve. A force sensing unit is provided at the upper end of the inner sleeve. The axial compression loading mechanism is mounted at the upper end of the inner sleeve and connected to the force sensing unit for applying axial compression to the force sensing unit and the inner sleeve. The heating unit is disposed in the inner sleeve and connected to a heating controller via a circuit. The force sensing unit is connected to a host terminal via a circuit.

[0011] Based on the above technical solution, the present invention can be further improved as follows.

[0012] Furthermore, the upper end of the lower end cover is provided with a first internal thread mounting hole, the lower end of the outer surface of the outer sleeve is provided with an external thread and screwed into the first internal thread mounting hole, a positioning post is coaxially provided in the middle of the bottom wall of the first internal thread mounting hole, the lower end of the inner sleeve is sleeved in the positioning post, a wire hole is provided through the positioning post, and the heating unit is connected to the heating controller through a wire passing through the wire hole.

[0013] Furthermore, the lower end cap is provided with a first handle on its outer periphery for applying external force to rotate it.

[0014] Furthermore, it also includes an upper end cover, the lower end of which is provided with a second internal thread mounting hole, the upper outer surface of which is provided with an external thread and screwed into the second internal thread mounting hole, the axial pressure loading mechanism is mounted on the upper end cover and passes through the through hole in the middle of the upper end cover to connect with the force sensing unit.

[0015] Furthermore, the outer periphery of the aforementioned upper cover is provided with a second handle for applying external force to rotate it.

[0016] Furthermore, the aforementioned axial pressure loading mechanism includes a hollow pressure screw, a nut, and a booster bearing. The booster bearing is installed at the position corresponding to the through hole at the upper end of the aforementioned upper cover. The pressure screw vertically passes through the booster bearing and the through hole. The upper middle part of the aforementioned force sensing unit is provided with a third internal thread hole. The lower end of the aforementioned pressure screw is screwed into the aforementioned third internal thread hole. The aforementioned nut is screwed into the upper end of the aforementioned pressure screw. The aforementioned force sensing unit is connected to the aforementioned host terminal through a line passing through the inner cavity of the aforementioned pressure screw.

[0017] Furthermore, the aforementioned force sensing unit is a spoke-type force sensor.

[0018] Furthermore, the heating unit is a heating coil, and a high-temperature resistant insulating tube is sleeved in the inner sleeve, with the heating unit wound around the high-temperature resistant insulating tube.

[0019] Furthermore, the aforementioned heating controller is a variable frequency induction heating energy-saving system.

[0020] The beneficial effects of this invention are: the structural design is simple and reasonable, and it can accurately obtain the shear bonding performance of the cement sheath interface after alternating temperature under the premise of pre-applying axial load; the overall test is simple, and the test results are direct and accurate, which can provide important theoretical basis for the integrity of cement sheath and the optimized design of cementing engineering.

[0021] A method for testing the shear bonding performance of cement rings under pre-axial compression and alternating temperatures is also provided, comprising the following steps:

[0022] Step 1: Assemble the outer sleeve, inner sleeve, and lower end cap.

[0023] Step 2: Prepare cement grout by pouring cement grout into the annulus between the outer and inner sleeves;

[0024] Step 3: Install the force sensing unit and axial pressure loading mechanism, and apply an axial load Fb to the inner sleeve;

[0025] Step 4: Turn on the heating controller and set the temperature to the curing temperature to cure the cement slurry and form a cement ring;

[0026] Step 5: After the cement ring has been cured, adjust the temperature parameters of the heating controller to apply alternating temperature to the cement ring;

[0027] Step 6: After applying the alternating temperature, remove the lower end cover, take out the heating unit, and continue to apply axial load to the inner sleeve through the axial pressure loading mechanism until a certain relative displacement occurs between the cement ring and the inner sleeve interface, and record the axial load data.

[0028] Step 7: Using the axial load data recorded in Step 6, obtain the maximum axial load F during this process, and calculate the interfacial shear force Fa of the cement sheath according to the following formula:

[0029] F = Fa - Fb

[0030] The shear bond strength at the cement ring interface is σ = F / A, where A is the bond area between the cement ring and the inner sleeve. Attached Figure Description

[0031] Figure 1 This is a schematic diagram of the assembly of the outer sleeve, inner sleeve and lower end cap in the pre-axial compression and alternating temperature cement ring shear bonding performance testing device of the present invention.

[0032] Figure 2 This is a schematic diagram of the overall structure of the testing device for the shear bonding performance of cement rings under pre-axial compression and alternating temperature according to the present invention;

[0033] Figure 3 This is a schematic diagram showing the connection between the pre-axial compression and alternating temperature cement ring shear bonding performance testing device of the present invention and the heating controller and main unit terminal;

[0034] Figure 4 This is a schematic diagram of another embodiment of the testing device for the shear bonding performance of cement rings under pre-axial compression and alternating temperature according to the present invention;

[0035] Figure 5 This is a schematic diagram of the pre-axial compression and alternating temperature cement ring shear bonding performance testing device of the present invention after the lower end cover and internal heating unit have been removed.

[0036] Figure 6 This is a flowchart of the method for testing the shear bonding performance of cement rings under pre-axial compression and alternating temperatures according to the present invention.

[0037] The attached diagram lists the components represented by each number as follows:

[0038] 1. Outer sleeve; 2. Inner sleeve; 3. Lower end cover; 4. Axial pressure loading mechanism; 5. Heating unit; 6. Cement ring; 7. Force sensing unit; 8. Heating controller; 9. Main unit terminal; 10. Upper end cover; 21. High temperature resistant insulating tube; 31. First handle; 41. Pressure screw; 42. Nut; 43. Boost bearing; 101. Second handle. Detailed Implementation

[0039] The principles and features of the present invention are described below with reference to the accompanying drawings. The examples given are only for explaining the present invention and are not intended to limit the scope of the present invention.

[0040] Example: Figure 1 , 2As shown in Figures 3 and 4, the cement ring shear bonding performance testing device under pre-axial compression and alternating temperature in this embodiment includes an outer sleeve 1, an inner sleeve 2, a lower end cap 3, an axial compression loading mechanism 4, and a heating unit 5. The inner sleeve 2 is fitted inside the outer sleeve 1, and both are vertically detachably mounted on the upper end of the lower end cap 3. The cement ring 6 is poured into the annular cavity (A in the figure) between the outer sleeve 1 and the inner sleeve 2. A force sensing unit 7 is provided at the upper end of the inner sleeve 2. The axial compression loading mechanism 4 is mounted at the upper end of the inner sleeve 2 and connected to the force sensing unit 7 for applying axial compression to the force sensing unit 7 and the inner sleeve 2. The heating unit 5 is disposed in the inner sleeve 2 and is connected to the heating controller 8 via a line. The force sensing unit 7 is connected to the host terminal 9 via a line.

[0041] like Figure 6 As shown, the method for testing the shear bonding performance of cement rings under pre-axial compression and alternating temperature using the testing device of this embodiment is as follows:

[0042] Step 1: Assemble the outer sleeve 1, inner sleeve 2, and lower end cap 3;

[0043] Step 2: Prepare cement grout by pouring cement grout into the annulus between the outer sleeve 1 and the inner sleeve 2;

[0044] Step 3: Install the force sensing unit 7 and the axial pressure loading mechanism 4, and apply an axial load Fb to the inner sleeve 2;

[0045] Step 4: Turn on the heating controller 8, set the temperature to the curing temperature, and cure the cement slurry to form a cement ring 6;

[0046] Step 5: After the cement ring 6 has been cured, adjust the temperature parameters of the heating controller 8 to apply alternating temperature to the cement ring 6;

[0047] Step Six: After applying the alternating temperature, remove the lower end cap 3 (e.g. Figure 5 (As shown), remove the heating unit 5, and continue to apply an axial load to the inner sleeve 2 through the axial pressure loading mechanism 4 until a certain relative displacement occurs between the cement ring 6 and the inner sleeve 2, and record the axial load data.

[0048] Step 7: Using the axial load data recorded in Step 6, obtain the maximum axial load Fa during this process, and calculate the interfacial shear force F of cement ring 6 according to the following formula:

[0049] F = Fa - Fb

[0050] The shear bond strength of the cement ring 6 interface is σ = F / A, where A is the bond area between the cement ring 6 and the inner sleeve 2.

[0051] It should be noted that the bonding area A between the cement ring 6 and the inner sleeve 2 can be easily calculated based on the surface area of ​​the inner sleeve 2 and the height of the cement ring 6, and will not be elaborated here.

[0052] The apparatus and method in this embodiment are very simple, and can accurately obtain the shear bonding performance of the cement sheath interface after alternating temperature under the premise of pre-applying axial load. The overall test is simple, and the test results are direct and accurate, which can provide important theoretical basis for the integrity of cement sheath and the optimized design of cementing engineering.

[0053] In this embodiment, cement slurry was prepared according to standard GB / T 19139-2012.

[0054] As a preferred implementation method, such as Figure 2 As shown, the upper end of the lower end cover 3 is provided with a first internal thread mounting hole, the lower end of the outer surface of the outer sleeve 1 is provided with an external thread and screwed into the first internal thread mounting hole, a positioning post is coaxially provided in the middle of the bottom wall of the first internal thread mounting hole, the lower end of the inner sleeve 2 is sleeved in the positioning post, a wire hole is provided through the positioning post, and the heating unit 5 is connected to the heating controller 8 through a wire passing through the wire hole.

[0055] In the above implementation scheme, the lower end of the outer sleeve 1 and the lower end cap 3 are connected by a threaded connection to achieve a stable and well-sealed assembly. The lower end of the inner sleeve 2 is fitted outside the positioning post, and the two are in close contact to achieve a good setting seal. The design of the positioning post can ensure the coaxiality of the inner sleeve 2 and the outer sleeve 1, and also ensure that the assembly of the inner sleeve 2 has good sealing performance.

[0056] As a preferred implementation method, such as Figure 4 As shown, the lower end cover 3 is provided with a first handle 31 on its outer periphery for applying external force to rotate it.

[0057] In the above implementation scheme, by applying torque to the first handle 31, the lower end cover 3 can be rotated relative to the outer sleeve 1, thereby realizing the threaded installation or disassembly of the two, which is relatively convenient to operate.

[0058] In a preferred embodiment, the upper end cover 10 is also included. The lower end of the upper end cover 10 is provided with a second internal thread mounting hole. The upper outer surface of the outer sleeve 1 is provided with an external thread and is screwed into the second internal thread mounting hole. The axial pressure loading mechanism 4 is mounted on the upper end cover 10 and passes through the through hole in the middle of the upper end cover 10 to connect with the force sensing unit 7.

[0059] In the above implementation scheme, the upper end cover 10 and the upper end of the outer sleeve 1 are connected by a threaded connection, which makes disassembly and assembly relatively simple. At the same time, the design of the upper end cover 10 facilitates the assembly of the axial pressure loading mechanism 4.

[0060] As a preferred implementation method, such as Figure 4 As shown, the upper cover 10 is provided with a second handle 101 on its outer periphery for applying external force to rotate it.

[0061] In the above implementation scheme, by applying torque to the second handle 101, the upper end cover 10 can be driven to rotate relative to the outer sleeve 1, thereby realizing the threaded installation or disassembly of the two, which is relatively convenient to operate.

[0062] As a preferred implementation method, such as Figure 2 , 3 As shown in Figure 4, the axial pressure loading mechanism 4 includes a hollow pressure screw 41, a nut 42, and a booster bearing 43. The booster bearing 43 is installed at the position corresponding to the through hole at the upper end of the upper cover 10. The pressure screw 41 vertically passes through the booster bearing 43 and the through hole. The upper middle part of the force sensing unit 7 is provided with a third internal thread hole. The lower end of the pressure screw 41 is screwed into the third internal thread hole. The nut 42 is screwed into the upper end of the pressure screw 41. The force sensing unit 7 is connected to the host terminal 9 through a line passing through the inner cavity of the pressure screw 41.

[0063] In the above implementation scheme, during the test, the pre-axial load of the cement ring 6 and the shear bonding performance test of the cement ring interface after alternating temperature are achieved by turning the nut 42 to make the pressure screw 41 reciprocate in the axial direction. The operation is relatively simple and convenient.

[0064] In this embodiment, the force sensing unit 7 can be a wheel spoke type force sensor of the existing technology.

[0065] In a preferred embodiment, the heating unit 5 is a heating coil, and a high-temperature resistant insulating tube 21 is sleeved in the inner sleeve 2, with the heating unit 5 wound around the high-temperature resistant insulating tube 21.

[0066] In the above implementation scheme, the diameter of the high-temperature resistant insulating tube 21 is slightly smaller than the diameter of the inner sleeve 2, and the heating coil (heating unit 5) wound around its outside can be as close as possible to the inner wall of the inner sleeve 2. This structure allows the heating unit 5 to be quickly removed after the lower end cap 3 is removed. After testing the main tube, the heating controller 8 adjusts the output parameters of the heating unit 5 to achieve the application of alternating temperature to the cement ring 6.

[0067] In this embodiment, the heating controller 8 adopts a frequency conversion induction heating energy-saving controller of the existing technology, which can apply alternating temperature to the cement ring 6 by changing the temperature parameters of the frequency conversion induction heating energy-saving controller.

[0068] In the description of this invention, it should be understood that the terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," "counterclockwise," "axial," "radial," and "circumferential" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing this invention and simplifying the description, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0069] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this invention, "a plurality of" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0070] In this invention, unless otherwise explicitly specified and limited, the terms "installation," "connection," "linking," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components, unless otherwise explicitly limited. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0071] In this invention, unless otherwise explicitly specified and limited, "above" or "below" the second feature can mean that the first feature is in direct contact with the second feature, or that the first feature is in indirect contact with the second feature through an intermediate medium. Furthermore, "above," "over," and "on top" of the second feature can mean that the first feature is directly above or diagonally above the second feature, or simply that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature can mean that the first feature is directly below or diagonally below the second feature, or simply that the first feature is at a lower horizontal level than the second feature.

[0072] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., refer to specific features, structures, materials, or characteristics described in connection with that embodiment or example, which are included in at least one embodiment or example of the present invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of different embodiments or examples.

[0073] Although embodiments of the present invention have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting the present invention. Those skilled in the art can make changes, modifications, substitutions and variations to the above embodiments within the scope of the present invention.

Claims

1. A device for testing the shear bonding performance of cement rings under pre-axial compression and alternating temperatures, characterized in that: The device includes an outer sleeve (1), an inner sleeve (2), a lower end cap (3), an axial pressure loading mechanism (4), and a heating unit (5). The inner sleeve (2) is fitted inside the outer sleeve (1), and both are vertically detachable and mounted on the upper end of the lower end cap (3). A cement ring (6) is cast in the annular cavity between the outer sleeve (1) and the inner sleeve (2). A force sensing unit (7) is provided at the upper end of the inner sleeve (2). The axial pressure loading mechanism (4) is mounted at the upper end of the inner sleeve (2) and connected to the force sensing unit (7) for loading axial pressure on the force sensing unit (7) and the inner sleeve (2). The heating unit (5) is located in the inner sleeve (2) and is connected to a heating controller (8) via a line. The force sensing unit (7) is connected to a host terminal (9) via a line.

2. The device for testing the shear bonding performance of cement rings under pre-axial compression and alternating temperature as described in claim 1, characterized in that: The lower end cap (3) has a first internal thread mounting hole at its upper end. The outer surface of the lower end of the outer sleeve (1) has an external thread and is screwed into the first internal thread mounting hole. A positioning post is coaxially provided in the middle of the bottom wall of the first internal thread mounting hole. The lower end of the inner sleeve (2) is sleeved in the positioning post. A wire hole is provided through the positioning post. The heating unit (5) is connected to the heating controller (8) through a wire passing through the wire hole.

3. The device for testing the shear bonding performance of cement rings under pre-axial compression and alternating temperature according to claim 2, characterized in that: The lower end cap (3) is provided with a first handle (31) on its outer periphery for applying external force to rotate it.

4. The device for testing the shear bonding performance of cement rings under pre-axial compression and alternating temperature according to claim 2, characterized in that: It also includes an upper end cover (10), the lower end of which is provided with a second internal thread mounting hole, the upper outer surface of the outer sleeve (1) is provided with an external thread and screwed into the second internal thread mounting hole, the axial pressure loading mechanism (4) is mounted on the upper end cover (10) and passes through the through hole in the middle of the upper end cover (10) to connect with the force sensing unit (7).

5. The device for testing the shear bonding performance of cement rings under pre-axial compression and alternating temperature as described in claim 4, characterized in that: The upper end cap (10) is provided with a second handle (101) on its outer periphery for applying external force to rotate it.

6. The testing device for the shear bonding performance of cement rings under pre-axial compression and alternating temperature as described in claim 4, characterized in that: The axial pressure loading mechanism (4) includes a hollow pressure screw (41), a nut (42) and a booster bearing (43). The booster bearing (43) is installed at the position of the upper end of the upper cover (10) corresponding to the through hole. The pressure screw (41) vertically passes through the booster bearing (43) and the through hole. The upper middle part of the force sensing unit (7) is provided with a third internal thread hole. The lower end of the pressure screw (41) is screwed into the third internal thread hole. The nut (42) is screwed into the upper end of the pressure screw (41). The force sensing unit (7) is connected to the host terminal (9) through a line passing through the inner cavity of the pressure screw (41).

7. The testing device for the shear bonding performance of cement rings under pre-axial compression and alternating temperature as described in claim 6, characterized in that: The force sensing unit (7) is a spoke-type force sensor.

8. The device for testing the shear bonding performance of cement rings under pre-axial compression and alternating temperature according to claim 1, characterized in that: The heating unit (5) is a heating coil, and a high-temperature resistant insulating tube (21) is sleeved in the inner sleeve (2). The heating unit (5) is wound around the high-temperature resistant insulating tube (21).

9. A testing device for the shear bonding performance of cement rings under pre-axial compression and alternating temperature according to any one of claims 1 to 8, characterized in that: The heating controller (8) is a variable frequency induction heating energy-saving system.

10. A method for testing the shear bond performance of a cement ring under pre-axial compression and alternating temperatures, implemented using the testing apparatus for the shear bond performance of a cement ring under pre-axial compression and alternating temperatures as described in any one of claims 1 to 9, characterized in that... Includes the following steps: Step 1: Assemble the outer sleeve (1), inner sleeve (2), and lower end cap (3); Step 2: Prepare cement slurry by pouring cement slurry into the annulus between the outer sleeve (1) and the inner sleeve (2); Step 3: Install the force sensing unit (7) and the axial pressure loading mechanism (4), and apply an axial load Fb to the inner sleeve (2); Step 4: Turn on the heating controller (8), set the temperature to the curing temperature, and cure the cement slurry to form a cement ring (6); Step 5: After the cement ring (6) has been cured, adjust the temperature parameters of the heating controller (8) to apply alternating temperature to the cement ring (6); Step 6: After applying the alternating temperature, remove the lower end cover (3), take out the heating unit (5), and continue to apply axial load to the inner sleeve (2) through the axial pressure loading mechanism (4) until the interface between the cement ring (6) and the inner sleeve (2) produces a certain relative displacement, and record the axial load data. Step 7: Using the axial load data recorded in Step 6, obtain the maximum axial load Fa during this process, and calculate the interfacial shear force F of the cement ring (6) according to the following formula: F = Fa - Fb The shear bond strength of the cement ring (6) interface is σ=F / A, where A is the bonding area of ​​the cement ring (6) and the inner sleeve (2) interface.

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