Experimental device for simulating and repairing integrity casing damage of shaft and application of experimental device

Abstract

The invention discloses a wellbore integrity casing damage simulation and repair experimental device, which comprises a heating temperature control box, the interior of the heating temperature control box is divided into an upper part and a lower part, the upper part forms a first cavity for accommodating liquid, and the lower part forms a second cavity for placing a casing damage simulation module or a cement column damage simulation module; the liquid injection and pressurization equipment is communicated with the first cavity and is used for injecting a plugging agent or formation water into the first cavity and pressurizing the plugging agent or the formation water so as to drive the plugging agent or the formation water to enter the casing damage simulation module or the cement column damage simulation module; and the ball valve is arranged at the bottom of the heating temperature control box, is communicated with the second cavity and is used for controlling opening and closing of an outlet of the casing damage simulation module or the cement column damage simulation module. According to the invention, the field environment of the oil and gas well can be simulated more accurately, and a repair experiment can be carried out on a damaged sleeve or a cement column, so that not only can experimental data support be provided for researchers, but also a more accurate repair scheme can be provided for field operators.

Description

Technical Field

[0001] The invention belongs to the technical field of oil and gas well development engineering, and in particular relates to an experimental device capable of simulating casing damage and evaluating plugging and repairing capabilities. Background Art

[0002] In the process of oil and gas well development, due to the complex geological environment and harsh operating conditions, it is easy to have casing and tubing seal failure (casing and tubing corrosion and perforation caused by fluid corrosion, casing deformation and breakage caused by formation stress change and extrusion), poor cementing quality, and damage to the integrity of the post-cementing sealing system (cement ring failure). These damages will cause annular pressure, which will not only affect the production and mining safety of oil and gas wells, but also cause the oil and gas wells to be scrapped in serious cases, resulting in huge losses. Therefore, timely and effective repair of damaged casing or cement ring is an important measure to ensure the safe operation of oil wells.

[0003] However, existing research methods lack an effective simulation device to simulate actual casing or cement sheath damage, resulting in the inability to fully verify the repair effect. Summary of the invention

[0004] The present invention aims to solve at least one of the technical problems existing in the prior art. To this end, the present invention provides an experimental device for simulating and repairing casing damage of wellbore integrity, which is designed to simulate high temperature and high pressure conditions on site, effectively repair and evaluate casing and cement damage, so as to improve the pertinence and effectiveness of the repair plan.

[0005] To achieve the above object, the present invention adopts the following technical solutions: In a first aspect, the present invention provides an experimental device for casing damage simulation and repair of wellbore integrity, comprising: a heating temperature control box, wherein the internal space of the heating temperature control box is divided into an upper and lower part by a partition, wherein the upper part forms a first cavity for accommodating liquid, and the lower part forms a second cavity for placing a casing damage simulation module or a cement column damage simulation module; a liquid injection and pressurizing device, which is connected to the first cavity and is used to inject a plugging agent or formation water into the first cavity and pressurize it to drive the plugging agent or formation water into the casing damage simulation module or the cement column damage simulation module; a ball valve, which is arranged at the bottom of the heating temperature control box and is connected to the second cavity, and is used to control the opening and closing of the outlet of the casing damage simulation module or the cement column damage simulation module; The casing damage simulation module is used to simulate casing damage, and includes a first outer casing and a semi-through perforating casing. The semi-through perforating casing is arranged in the first outer casing, and the open end of the semi-through perforating casing is connected to the first cavity. The plugging agent or formation water can flow into the semi-through perforating casing through the channel therebetween. A casing damage simulation point is formed on the semi-through perforating casing, and a first ball valve connector is arranged at the bottom of the first outer casing. The cement column damage simulation module is used to simulate the damage of the cement column, and includes a second outer casing and a full-through steel pipe. The full-through steel pipe is arranged in the second outer casing. The first open end of the full-through steel pipe is connected to the first cavity. The plugging agent or formation water can flow into the full-through steel pipe through the channel therebetween. The second open end of the full-through steel pipe is provided with a rubber gasket through a connecting piece, and a second ball valve connecting piece is provided at the bottom of the second outer casing.

[0006] Preferably, a temperature sensor is provided in the first cavity of the heating temperature control box, and the heating temperature control box can be controlled by the temperature sensor to heat the plugging agent or formation water to a set temperature.

[0007] Preferably, an agitator is arranged in the first cavity of the heating temperature control box, the agitator comprises a stirring motor and a stirring blade, the stirring motor is arranged on the upper part of the heating temperature control box, the stirring blade is arranged in the first cavity and connected to the stirring motor through a stirring shaft.

[0008] Preferably, a pressure sensor is provided on the connecting pipe between the injection and pressurizing equipment and the first cavity, for monitoring the hydraulic pressure applied by the injection and pressurizing equipment to the casing damage simulation module or the cement column damage simulation module.

[0009] Preferably, the device further comprises a pressure relief valve connected to the first cavity, wherein the pressure relief valve is used to release the hydraulic pressure applied to the first cavity by the injection and pressurizing equipment.

[0010] Preferably, the second open end of the full-through steel pipe is provided with a rubber gasket via a connecting piece.

[0011] In a second aspect, the present invention provides an application of the experimental device as described in the first aspect of the present invention in a simulated casing damage plugging agent repair experiment, comprising the following steps: S100. The outer side of the casing damage simulation point on the semi-through perforating casing is sealed with heat-resistant plastic paper, and the semi-through perforating casing is placed in the first outer casing, and then the first outer casing is placed in the second cavity, and a plugging agent is injected into the semi-through perforating casing through a liquid injection and pressurizing device, and the amount of the plugging agent is ensured to cover the casing damage simulation point; S200. solidify the plugging agent at the set temperature and pressure, open the pressure relief valve to release the pressure after the plugging agent solidifies, close the heating temperature control box and the injection and pressurization equipment, and take out the semi-through perforation casing in the first outer casing after the casing damage simulation module returns to normal temperature and pressure, drill the plugging agent in the semi-through perforation casing with a drill bit, drill to the point where the casing damage simulation leaks out, and remove the heat-resistant plastic paper; S300. Install the semi-through perforating casing back into the first outer casing and put it back into the second cavity, then open the ball valve, inject formation water into the casing damage simulation module through the injection and pressurization equipment, slowly apply hydraulic pressure, and always pay attention to the ball valve outlet to observe whether there is liquid flowing out: when the first drop of liquid flows out, record the pressure value displayed by the pressure sensor at this time, which is the plugging strength of the plugging agent; when the injection pressure reaches the rated pressure, if no liquid flows out, it proves that the plugging strength of the plugging agent is greater than the rated pressure.

[0012] In a third aspect, the present invention provides an application of the experimental device as described in the first aspect of the present invention in a repair experiment of a plugging agent for simulating cement column damage, comprising the following steps: S100. The second open end of the full-length steel pipe is sealed with heat-resistant plastic paper and placed in the second cavity, and then cement slurry is injected into the full-length steel pipe, and cured at a set temperature and pressure to obtain a cement module; S200. Restore the device to normal temperature and pressure, take out the full-through steel pipe, remove the heat-resistant plastic paper, put the full-through steel pipe back into the second outer casing, close the ball valve, use formation water as the pressurizing medium, increase the temperature and pressure to the set values, and maintain for 72 hours; then open the pressure relief valve to release the pressure, open the ball valve, slowly inject water into the cement column damage simulation module to increase the pressure, if liquid flows out, it proves that the cement module is damaged, then use the plugging agent to replace the formation water and inject it into the cement column damage simulation module, when the plugging agent flows out from the bottom of the cement column damage simulation module, it means that the plugging agent has filled the internal cracks of the cement module; S300. Take out the full-through steel pipe and seal the lower part of the full-through steel pipe with heat-resistant plastic paper, solidify the plugging agent at the set temperature and pressure, open the pressure relief valve to release the pressure after the plugging agent solidifies, turn off the heating temperature control box and the injection and pressurizing equipment, and take out the full-through steel pipe in the second outer casing after the cement column damage simulation module returns to normal temperature and pressure, and remove the heat-resistant plastic paper; S400. Install the full-through steel pipe back into the second outer casing and put it back into the second cavity, then open the ball valve, inject formation water into the cement column damage simulation module through the injection and pressurization equipment, slowly apply hydraulic pressure, and always pay attention to the ball valve outlet to observe whether there is liquid flowing out: when the first drop of liquid flows out, record the pressure value displayed by the pressure sensor at this time, which is the plugging strength of the plugging agent; when the injection pressure reaches the rated pressure, if no liquid flows out, it proves that the plugging strength of the plugging agent is greater than the rated pressure.

[0013] The present invention adopts the above technical solution, which has the following advantages: The experimental device provided by the present invention can more accurately simulate the on-site environment of oil and gas wells, and carry out repair experiments on damaged casing or cement columns under these conditions, which can not only provide experimental data support for researchers, but also provide on-site operators with more accurate repair plans, significantly improving the safety and economy of oil and gas well operations. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Various other advantages and benefits will become apparent to those of ordinary skill in the art by reading the detailed description of the preferred embodiments below. The accompanying drawings are only for the purpose of illustrating the preferred embodiments and are not to be considered as limiting the present invention. Throughout the accompanying drawings, the same reference numerals are used to represent the same components. In the accompanying drawings: Figure 1 A schematic diagram of the structure of an experimental device for simulating and repairing casing damage of wellbore integrity provided by the present invention; Figure 2 A schematic diagram of the structure of a casing damage simulation module provided by the present invention; Figure 3 This is a structural schematic diagram of the cement column damage simulation module provided by the present invention. DETAILED DESCRIPTION

[0015] In order to make the purpose, technical scheme and advantages of the present invention clearer, the specific embodiments of the present invention are further described below in conjunction with the accompanying drawings. Although the exemplary embodiments of the present invention are shown in the accompanying drawings, it should be understood that the present invention can be implemented in various forms and should not be limited by the embodiments described herein. On the contrary, these embodiments are provided in order to enable a more thorough understanding of the present invention and to fully convey the scope of the present invention to those skilled in the art.

[0016] In the description of the present invention, it is to be understood that the terms “center”, “longitudinal”, “lateral”, “length”, “width”, “thickness”, “up”, “down”, “front”, “back”, “left”, “right”, “vertical”, “horizontal”, “top”, “bottom”, “inside”, “outside”, “clockwise”, “counterclockwise”, “axial”, “radial”, “circumferential”, etc., indicating orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as limiting the present invention.

[0017] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include one or more of the features. In the description of the present invention, the meaning of "plurality" is more than two, unless otherwise clearly and specifically defined.

[0018] In the present invention, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0019] In the present invention, unless otherwise clearly specified and limited, a first feature being "above" or "below" a second feature may mean that the first and second features are in direct contact, or the first and second features are in indirect contact through an intermediate medium. Moreover, a first feature being "above", "above" or "above" a second feature may mean that the first feature is directly above or obliquely above the second feature, or simply means that the first feature is higher in level than the second feature. A first feature being "below", "below" or "below" a second feature may mean that the first feature is directly below or obliquely below the second feature, or simply means that the first feature is lower in level than the second feature.

[0020] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art may combine and combine the different embodiments or examples described in this specification and the features of the different embodiments or examples, without contradiction.

[0021] The experimental device for casing damage simulation and repair of wellbore integrity provided by the present invention comprises: a heating temperature control box, the interior of which is divided into two parts, the upper part forms a first cavity for accommodating liquid, and the lower part forms a second cavity for placing a casing damage simulation module or a cement column damage simulation module; a liquid injection and pressurizing device, which is connected to the first cavity and is used to inject plugging agent or formation water into the first cavity and pressurize it to drive the plugging agent or formation water into the casing damage simulation module or the cement column damage simulation module; a ball valve, which is arranged at the bottom of the heating temperature control box and is connected to the second cavity, and is used to control the opening and closing of the outlet of the casing damage simulation module or the cement column damage simulation module. The present invention can simulate the on-site environment of the oil and gas well more accurately, and perform repair experiments on damaged casing or cement columns, which can not only provide experimental data support for researchers, but also provide more accurate repair solutions for on-site operators.

[0022] Next, the experimental device for simulating and repairing casing damage of wellbore integrity provided by the embodiment of the present invention will be described in detail with reference to the accompanying drawings.

[0023] Example 1 See also Figures 1 to 3 The present embodiment provides an experimental device for casing damage simulation and repair of wellbore integrity, comprising: a heating temperature control box 1, wherein the internal space of the heating temperature control box 1 is divided into an upper and lower part by a partition, wherein the upper part forms a first cavity 11 for accommodating liquid, and the lower part forms a second cavity 12 for placing a casing damage simulation module 4 or a cement column damage simulation module 5; a liquid injection and pressurizing device 2, which is connected to the first cavity 11 and is used to inject a plugging agent or formation water into the first cavity 11 and pressurize it, so as to drive the plugging agent or formation water into the casing damage simulation module 4 or the cement column damage simulation module 5; and a ball valve 3, which is arranged at the bottom of the heating temperature control box 1 and is connected to the second cavity 12, and is used to control the opening and closing of the outlet of the casing damage simulation module 4 or the cement column damage simulation module 5.

[0024] Among them, the casing damage simulation module 4 is used to simulate casing damage, including a first outer casing 41 and a half-through perforating casing 42. The half-through perforating casing 42 is arranged in the first outer casing 41. The open end of the half-through perforating casing 42 is connected to the first cavity 11. The plugging agent or formation water can flow into the half-through perforating casing 42 through the channel therebetween. A casing damage simulation point 43 is formed on the half-through perforating casing 42. A first ball valve connector 44 is arranged at the bottom of the first outer casing 41.

[0025] The cement column damage simulation module 5 is used to simulate the damage of the cement column, and includes a second outer casing 51 and a full-through steel pipe 52. The full-through steel pipe 52 is arranged in the second outer casing 51. The first open end of the full-through steel pipe 52 is connected to the first cavity 11. The plugging agent or formation water can flow into the full-through steel pipe 52 through the channel between the two. A second ball valve connector 54 is arranged at the bottom of the second outer casing 51.

[0026] In the above embodiment, preferably, a temperature sensor 6 is provided in the first cavity 11 of the heating temperature control box 1, and the heating temperature control box 1 can be controlled by the temperature sensor 6 to heat the plugging agent or formation water to a set temperature.

[0027] In the above embodiment, preferably, an agitator 7 is arranged in the first cavity 11 of the heating temperature control box 1, and the agitator 7 includes a stirring motor 71 and a stirring blade 72. The stirring motor 71 is arranged on the upper part of the heating temperature control box 1, and the stirring blade 72 is arranged in the first cavity 11 and is connected to the stirring motor 71 through a stirring shaft 73. The agitator 7 is used to fully mix the plugging agent when the plugging agent needs to be injected.

[0028] In the above embodiment, preferably, a pressure sensor 8 is provided on the connecting pipe between the injection and pressurizing device 2 and the first cavity 11 to monitor the hydraulic pressure applied by the injection and pressurizing device 2 to the casing damage simulation module or the cement column damage simulation module.

[0029] In the above embodiment, preferably, a pressure relief valve 9 connected to the first cavity 11 is further included, and the pressure relief valve 9 is used to release the hydraulic pressure applied to the first cavity 11 by the injection and pressurizing device 2 .

[0030] In the above embodiment, preferably, the second open end of the full-through steel pipe 52 is provided with a rubber gasket 55 through a connector 53 to prevent wear caused by direct contact of metal parts and to play a sealing role.

[0031] Example 2 Based on the experimental device for simulating and repairing casing damage of wellbore integrity provided in Example 1, it is applied to simulate the casing damage plugging agent repair experiment, including the following steps: S100. The outer side of the casing damage simulation point 43 (a circular hole with a diameter of 1 mm) on the semi-through perforating casing 42 is sealed with heat-resistant plastic paper, and the semi-through perforating casing 42 is placed in the first outer casing 41, and then the first outer casing 41 is placed in the second cavity 12, and a plugging agent is injected into the semi-through perforating casing 42 through the injection and pressurizing device 2, and the amount of the plugging agent is ensured to cover the casing damage simulation point 43; S200. The plugging agent is solidified at the set temperature and pressure. After the plugging agent is solidified, the pressure relief valve 9 is opened to release the pressure, the heating temperature control box 1 and the injection and pressurizing device 2 are closed, and after the casing damage simulation module 4 returns to normal temperature and pressure, the semi-through perforated casing 42 in the first outer casing 41 is taken out, and the plugging agent in the semi-through perforated casing 42 is drilled out with a drill bit until the casing damage simulation point 43 leaks out, and the heat-resistant plastic paper is removed; S300. Install the semi-through perforating casing 42 back into the first outer casing 41 and put it back into the second cavity 12, then open the ball valve 3, inject formation water into the casing damage simulation module 4 through the injection and pressurizing equipment 2, slowly apply hydraulic pressure, and always pay attention to the outlet of the ball valve 3 to observe whether there is liquid flowing out: when the first drop of liquid flows out, record the pressure value displayed by the pressure sensor 8 at this time, which is the plugging strength of the plugging agent; when the injection pressure reaches the rated pressure, if no liquid flows out, it proves that the plugging strength of the plugging agent is greater than the rated pressure.

[0032] Example 3 Based on the experimental device for simulating and repairing casing damage of wellbore integrity provided in Example 1, it is applied to simulate the cement column damage plugging agent repair experiment, including the following steps: S100. The second open end of the full-through steel pipe 52 is closed with heat-resistant plastic paper and placed in the second cavity 12, and then cement slurry is injected into the full-through steel pipe 52, and cured at a set temperature and pressure to obtain a cement module; S200. Restore the device to normal temperature and pressure, take out the full-through steel pipe 52, remove the heat-resistant plastic paper, and then put the full-through steel pipe 52 back into the second outer casing 51, close the ball valve 3, use formation water as the pressurizing medium, increase the temperature and pressure to the set values, and maintain for 72 hours, then open the pressure relief valve 9 to release the pressure, open the ball valve 3, slowly inject water into the cement column damage simulation module 5 to increase the pressure, if there is liquid flowing out, it proves that the cement module is damaged, at this time, use the plugging agent to replace the formation water and inject it into the cement column damage simulation module 5, when the plugging agent flows out from the bottom of the cement column damage simulation module 5, it means that the plugging agent has filled the internal cracks of the cement module; S300. Take out the full-through steel pipe 52 and seal the lower part of the full-through steel pipe 52 with a heat-resistant plastic paper, solidify the plugging agent at the set temperature and pressure, open the pressure relief valve 9 to release the pressure after the plugging agent solidifies, close the heating temperature control box 1 and the injection and pressurizing equipment 2, and take out the full-through steel pipe 52 in the second outer casing 51 after the cement column damage simulation module 5 returns to normal temperature and pressure, and remove the heat-resistant plastic paper; S400. Install the full-through steel pipe 52 back into the second outer casing 51, and put it back into the second cavity 12, then open the ball valve 3, inject formation water into the cement column damage simulation module 5 through the injection and pressurizing equipment 2, slowly apply hydraulic pressure, and always pay attention to the outlet of the ball valve 3 to observe whether there is liquid flowing out: when the first drop of liquid flows out, record the pressure value displayed by the pressure sensor 8 at this time, which is the plugging strength of the plugging agent; when the injection pressure reaches the rated pressure, if no liquid flows out, it proves that the plugging strength of the plugging agent is greater than the rated pressure.

[0033] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present application, rather than to limit them; although the present application has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or replace some or all of the technical features therein by equivalents; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments of the present application, and they should all be included in the scope of the claims and specification of the present application. In particular, as long as there is no structural conflict, the various technical features mentioned in the various embodiments can be combined in any way. The present application is not limited to the specific embodiments disclosed herein, but includes all technical solutions that fall within the scope of the claims.

Claims

1. An experimental device for simulating and repairing casing damage of wellbore integrity, characterized in that: include: A heating temperature control box, wherein the internal space of the heating temperature control box is divided into two parts, the upper part forms a first cavity for containing liquid, and the lower part forms a second cavity for placing a casing damage simulation module or a cement column damage simulation module; A liquid injection and pressurizing device, which is in communication with the first cavity and is used to inject a plugging agent or formation water into the first cavity and pressurize it to drive the plugging agent or formation water into the casing damage simulation module or the cement column damage simulation module; A ball valve, which is arranged at the bottom of the heating temperature control box and is connected to the second cavity, and is used to control the opening and closing of the outlet of the casing damage simulation module or the cement column damage simulation module; The casing damage simulation module is used to simulate casing damage, and includes a first outer casing and a semi-through perforating casing. The semi-through perforating casing is arranged in the first outer casing, and the open end of the semi-through perforating casing is connected to the first cavity. The plugging agent or formation water can flow into the semi-through perforating casing through the channel therebetween. A casing damage simulation point is formed on the semi-through perforating casing, and a first ball valve connector is arranged at the bottom of the first outer casing. The cement column damage simulation module is used to simulate the damage of the cement column, and includes a second outer casing and a full-through steel pipe. The full-through steel pipe is arranged in the second outer casing. The first open end of the full-through steel pipe is connected to the first cavity. The plugging agent or formation water can flow into the full-through steel pipe through the channel therebetween. The second open end of the full-through steel pipe is provided with a rubber gasket through a connecting piece, and a second ball valve connecting piece is provided at the bottom of the second outer casing.

2. The experimental device according to claim 1, characterized in that: A temperature sensor is arranged in the first cavity of the heating temperature control box, and the heating temperature control box can be controlled by the temperature sensor to heat the plugging agent or formation water to a set temperature.

3. The experimental device according to claim 1, characterized in that: An agitator is arranged in the first cavity of the heating temperature control box, and the agitator includes a stirring motor and a stirring blade. The stirring motor is arranged on the upper part of the heating temperature control box, and the stirring blade is arranged in the first cavity and connected to the stirring motor through a stirring shaft.

4. The experimental device according to claim 2, characterized in that: A pressure sensor is provided on the connecting pipe between the injection and pressurizing equipment and the first cavity, for monitoring the hydraulic pressure applied by the injection and pressurizing equipment to the casing damage simulation module or the cement column damage simulation module.

5. The experimental device according to claim 4, characterized in that: It also includes a pressure relief valve connected to the first cavity, and the pressure relief valve is used to release the hydraulic pressure applied to the first cavity by the injection and pressurizing equipment.

6. The experimental device according to claim 1, characterized in that: The second open end of the full-through steel pipe is provided with a rubber gasket via a connecting piece.

7. An application of the experimental device as claimed in claim 5 in a simulated casing damage plugging agent repair experiment, characterized in that: The following steps are involved: S100. The outer side of the casing damage simulation point on the semi-through perforating casing is sealed with heat-resistant plastic paper, and the semi-through perforating casing is placed in the first outer casing, and then the first outer casing is placed in the second cavity, and a plugging agent is injected into the semi-through perforating casing through a liquid injection and pressurizing device, and the amount of the plugging agent is ensured to cover the casing damage simulation point; S200. solidify the plugging agent at the set temperature and pressure, open the pressure relief valve to release the pressure after the plugging agent solidifies, close the heating temperature control box and the injection and pressurization equipment, and take out the semi-through perforation casing in the first outer casing after the casing damage simulation module returns to normal temperature and pressure, drill the plugging agent in the semi-through perforation casing with a drill bit, drill to the point where the casing damage simulation leaks out, and remove the heat-resistant plastic paper; S300. Install the semi-through perforating casing back into the first outer casing and put it back into the second cavity, then open the ball valve, inject formation water into the casing damage simulation module through the injection and pressurization equipment, slowly apply hydraulic pressure, and always pay attention to the ball valve outlet to observe whether there is liquid flowing out: when the first drop of liquid flows out, record the pressure value displayed by the pressure sensor at this time, which is the plugging strength of the plugging agent; when the injection pressure reaches the rated pressure, if no liquid flows out, it proves that the plugging strength of the plugging agent is greater than the rated pressure.

8. An application of the experimental device as claimed in claim 5 in a simulated cement column damage plugging agent repair experiment, characterized in that: The following steps are involved: S100. The second open end of the full-length steel pipe is sealed with heat-resistant plastic paper and placed in the second cavity, and then cement slurry is injected into the full-length steel pipe, and cured at a set temperature and pressure to obtain a cement module; S200. Restore the device to normal temperature and pressure, take out the full-through steel pipe, remove the heat-resistant plastic paper, put the full-through steel pipe back into the second outer casing, close the ball valve, use formation water as the pressurizing medium, increase the temperature and pressure to the set values, and maintain for 72 hours; then open the pressure relief valve to release the pressure, open the ball valve, slowly inject water into the cement column damage simulation module to increase the pressure, if liquid flows out, it proves that the cement module is damaged, then use the plugging agent to replace the formation water and inject it into the cement column damage simulation module, when the plugging agent flows out from the bottom of the cement column damage simulation module, it means that the plugging agent has filled the internal cracks of the cement module; S300. Take out the full-through steel pipe and seal the lower part of the full-through steel pipe with heat-resistant plastic paper, solidify the plugging agent at the set temperature and pressure, open the pressure relief valve to release the pressure after the plugging agent solidifies, turn off the heating temperature control box and the injection and pressurizing equipment, and take out the full-through steel pipe in the second outer casing after the cement column damage simulation module returns to normal temperature and pressure, and remove the heat-resistant plastic paper; S400. Install the full-through steel pipe back into the second outer casing and put it back into the second cavity, then open the ball valve, inject formation water into the cement column damage simulation module through the injection and pressurization equipment, slowly apply hydraulic pressure, and always pay attention to the ball valve outlet to observe whether there is liquid flowing out: when the first drop of liquid flows out, record the pressure value displayed by the pressure sensor at this time, which is the plugging strength of the plugging agent; when the injection pressure reaches the rated pressure, if no liquid flows out, it proves that the plugging strength of the plugging agent is greater than the rated pressure.

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