Simulation apparatus and method for evaluating the effect of perforating impact loads on cement integrity

Abstract

The application discloses a simulation device and method for evaluating the influence of perforation impact load on cement ring integrity, which comprises the following steps: placing cement slurry into a cement curing experimental device to form a cement ring; performing a perforation impact load experiment on the cement ring by using a simulation perforation impact load device; and detecting the integrity of the cement ring after the perforation impact load experiment is completed. The simulation device can simulate the perforation impact load on the cement ring sealing integrity experiment, the impact load caused by the perforation impact is considered in the simulation device, the influence of the perforation impact load on the cement ring sealing integrity can be truly reflected, and the simulation is not limited to software. By setting double-layer fixed supports and a control inclined angle support, the simulation device can simulate and evaluate the influence of the perforation impact load on the cement ring sealing integrity under different well inclination angles, and the blank of the prior art is made up.

Description

Technical Field

[0001] This invention belongs to the field of cementing in petroleum engineering, and specifically relates to a simulation device and method for evaluating the impact of perforation impact load on the integrity of cement sheath. Background Technology

[0002] Current research on cement sheath sealing integrity mainly focuses on the structure of the cement sheath itself and the evaluation of its bonding with the casing and surrounding rock at the first and second interfaces. Both domestic and international research has been conducted on experimental devices for cement sheath sealing integrity. For example, Chinese invention patent (CN 104500034A) discloses a device and method for evaluating the impact of pressure changes on cement sheath integrity. This patent simulates the impact of wellbore pressure and formation pressure changes on cement sheath sealing integrity under actual working conditions by loading and unloading the inner and outer annulus. Another Chinese invention patent (CN 108361024A) proposes an experimental device and method for evaluating the impact of tubing impact load on cement sheath integrity. This device has a heating hood outside the vessel, forming a simulated surrounding rock-cement sheath-casing assembly inside the vessel. The casing contains a vibrator, the upper vessel cover has an internal pressure increasing / decreasing valve, the lower vessel cover has a confining pressure increasing / decreasing valve, and gas inlet and outlet pipelines are also provided. The gas inlet on the lower end face of the cement sheath is connected to a nitrogen cylinder, and the gas outlet on the upper end face of the cement sheath is connected to a gas flow meter. The method includes: changing the experimental temperature and pressure, turning on the vibrator, causing the vibrator to continuously impact the inner wall of the casing, and evaluating whether the cement ring has experienced sealing failure at the end face of the cement ring. However, neither of the above two patents considered the impact of the perforation operation on the cement ring.

[0003] Perforation is a crucial step in oil and gas extraction, essential for normal well production after casing completion. Specifically, it involves a perforating projectile directly penetrating the casing and cement sheath. This impact not only damages the cement sheath at the perforation location but also disrupts the seal integrity of the upper cement sheath. The impact can cause the cement sheath to crack, resulting in micro-fractures. Currently, there is no laboratory-scale device to realistically simulate the impact of perforation impact loads on the cement sheath's seal integrity. Most studies rely on finite element method (FEM) software to simulate the destructive effects of perforation on the cement sheath, which has limitations. Therefore, it is essential to develop an experimental device and evaluation method capable of simulating the impact of perforation impact loads on the cement sheath's seal integrity and to conduct corresponding research. Summary of the Invention

[0004] To address the above problems, this invention proposes a simulation device for evaluating the impact of perforation impact loads on the integrity of the cement sheath. The simulation device includes:

[0005] A cement curing experimental apparatus is used to cure cement slurry to form a cement ring.

[0006] A simulated perforation impact load device is used to conduct perforation impact load experiments on cured cement rings.

[0007] The perforation integrity testing device is used to test the integrity of the cement ring after the perforation impact load test is completed.

[0008] The cement curing experimental device, the simulated perforation impact load device, and the post-perforation integrity testing device all include a vessel body and an upper vessel cover, with the upper end face of the vessel body and the upper vessel cover being connected in a fitting manner.

[0009] Furthermore, the cement curing device also includes a high-temperature and high-pressure curing autoclave and a type-1 lower autoclave cover; the autoclave body is a hollow stainless steel cylinder, installed inside the high-temperature and high-pressure curing autoclave;

[0010] The lower end face of the type-I vessel cover and vessel body is detachably connected;

[0011] The upper lid is equipped with a valve for controlling the pressure inside and outside the vessel.

[0012] Furthermore, the simulated perforation impact load device also includes a control tilt angle bracket, a base, and a Hopkinson rod mounted on the base;

[0013] A control tilt angle bracket is installed above the Hopkinson rod, and the control tilt angle bracket fixes the vessel body through the fixing buckle of the double-layer fixing bracket;

[0014] The Hopkinson rod includes an incident rod and a transmission rod, which are respectively disposed on both sides of the exposed cement ring at the lower end of the vessel body.

[0015] Furthermore, the fixing buckle consists of an upper fixing buckle and a lower fixing buckle;

[0016] The control tilt angle bracket is equipped with a control tilt angle bracket slide rail; a damping device is correspondingly provided at the end of the transmission rod away from the vessel body.

[0017] An impact rod is provided at the end of the incident rod away from the vessel body, and the incident rod and the transmission rod are symmetrically arranged about the vessel body.

[0018] Furthermore, the post-perforation integrity detection device also includes a type II lower vessel cover, which is fixedly attached to the lower end of the vessel body.

[0019] The type II lower vessel cover is equipped with a type II lower vessel cover valve for controlling the gas source;

[0020] The upper cover valve of the vessel body is provided with an installation port for installing a gas flow detector.

[0021] Furthermore, the upper lid, the type I lower lid, the type II lower lid, and the vessel body are all made of stainless steel, and the vessel body is a hollow cylinder.

[0022] Furthermore, the simulation device also includes connecting components and sealing elements between the vessel body and the upper vessel cover, and between the type I lower vessel cover and the type II lower vessel cover;

[0023] The connecting component includes threads, nuts, and pressure rings;

[0024] The sealing component includes a gasket and an O-ring, and the material of the sealing component is tetrafluoroethylene.

[0025] This invention also proposes a simulation method for evaluating the impact of perforation impact loads on the integrity of the cement sheath, the method comprising:

[0026] Cement slurry is placed in a cement curing experimental device for curing to form a cement ring;

[0027] A perforation impact load test was conducted on a cement sheath using a simulated perforation impact load device.

[0028] Integrity testing was performed on the cement ring after the perforation impact load test was completed.

[0029] Furthermore, the step of placing the cement slurry into the cement curing experimental device for curing to form a cement ring includes the following steps:

[0030] Install the type I lower lid onto the lower end face of the vessel body and evenly apply butter to the inside of the type I lower lid;

[0031] Prepare cement slurry and pour it into the reactor body space, then connect the reactor lid with threads;

[0032] Place the vessel body into the high-temperature and high-pressure curing vessel, open the valve of the upper vessel cover to ensure that the pressure inside and outside the vessel is consistent, set the parameters of the high-temperature and high-pressure curing vessel to cure the cement slurry into a cement ring, and remove the lower vessel cover.

[0033] Furthermore, the perforation impact load test on the cement sheath using a simulated perforation impact load device includes the following steps:

[0034] The cured vessel body is vertically fixed on a double-layer fixed bracket that controls the tilt.

[0035] The incident and transmission rods of the Hopkinson rod were placed on both sides of the exposed cement ring at the lower end of the vessel. The impact rod parameters were adjusted according to the required impact load to conduct a simulated perforation impact load experiment.

[0036] Furthermore, the integrity testing of the cement sheath after the perforation impact load test includes the following steps:

[0037] Install a type II lower vessel cover on the lower end face of the vessel body, and connect a nitrogen source through the type II lower vessel cover valve;

[0038] Connect the gas flow detector and data acquisition computer to the valve on the upper lid;

[0039] Nitrogen gas at a certain pressure is introduced into the upper and lower lid valves, and gas flow data at the upper lid is collected.

[0040] The cement ring sample was removed for microscopic testing, and the impact of the perforation impact load on the sealing integrity of the cement ring was analyzed based on the test results.

[0041] Furthermore, the microscopic inspection includes detecting whether microcracks and micro-annular gaps are generated inside the cement ring.

[0042] The beneficial effects of this invention are:

[0043] This invention utilizes a cement curing experimental device, a simulated perforation impact load device, and a post-perforation integrity testing device to accurately simulate the impact load on the cement sheath seal integrity. The simulation device considers the impact load caused by perforation impact, thus realistically reflecting the influence of perforation impact load on the cement sheath seal integrity, rather than being limited to software simulation. By setting up a double-layer fixed support and a support for controlling the inclination angle, the simulation device can simulate and evaluate the impact of perforation impact load on the cement sheath seal integrity under different well inclination angles, filling a gap in existing technologies.

[0044] Other features and advantages of the invention will be set forth in the description which follows, and will be apparent in part from the description, or may be learned by practicing the invention. The objects and other advantages of the invention may be realized and obtained by means of the structures pointed out in the description, claims and drawings. Attached Figure Description

[0045] Figure 1 A schematic diagram of the cement slurry curing simulation device in an embodiment of the present invention is shown;

[0046] Figure 2 A schematic diagram of the structure of the simulated perforation impact load device in an embodiment of the present invention is shown;

[0047] Figure 3 A schematic diagram of the perforation integrity detection device in an embodiment of the present invention is shown.

[0048] Figure 4 A schematic diagram of the control tilt angle part of the simulated perforation impact load device in an embodiment of the present invention is shown.

[0049] Figure 5 A schematic diagram of the fixing buckle part in the simulated perforation impact load device in an embodiment of the present invention is shown.

[0050] In the diagram: 1. Kettle body; 2. Upper kettle cover; 3. Upper kettle cover valve; 4. Cement ring 4; 5. Type I lower kettle cover; 6. High-temperature and high-pressure curing kettle; 7. Base; 8. Hopkinson rod; 9. Impact rod; 10. Incident rod; 11. Transmission rod; 12. Damping device; 13. Double-layer fixed bracket; 14. Control tilt angle bracket; 15. Gas flow detector; 16. Type II lower kettle cover; 17. Type II lower kettle cover valve; 18. Nitrogen source; 19. Data acquisition computer; 20. Control tilt angle bracket slide rail; 21. Fixing buckle; 22. Fixing buckle connecting screw. Detailed Implementation

[0051] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0052] The purpose of this invention is to provide a simulation device for evaluating the impact of perforation impact loads on the cement sheath seal integrity. This device can simulate the effect of perforation impact loads on the cement sheath at different downhole inclination angles, providing support for exploring the damage mechanism of perforation impact loads on the cement sheath seal integrity under actual downhole conditions, and addressing the shortcomings of current cementing testing methods and devices.

[0053] This embodiment uses Figure 1 - Figure 5 The simulation device is illustrated in the attached diagram. It includes a cement curing experimental device, a simulated perforation impact load device, and a post-perforation integrity testing device. The cement curing experimental device is used to cure the cement slurry into a cement ring 4; the simulated perforation impact load device is used to conduct a perforation impact load test on the cured cement ring 4; and the post-perforation integrity testing device is used to test the integrity of the cement ring 4 after the perforation impact load test. These three devices are used at different stages. Each device involves the vessel body 1 and the upper vessel cover 2, while the remaining components are used at different stages of application.

[0054] like Figure 1As shown, the cement curing experimental apparatus includes a high-temperature and high-pressure curing vessel 6. The high-temperature and high-pressure curing vessel 6 can independently control its internal temperature and pressure. The vessel body 1 is used to hold cement slurry. The vessel body 1, after being filled with cement slurry, is installed inside the high-temperature and high-pressure curing vessel 6 for curing the cement slurry. The vessel body 1 is a hollow stainless steel cylinder. An upper vessel cover 2 and a type-I lower vessel cover 5 are detachably connected to the upper and lower ends of the vessel body 1, respectively. Both the upper vessel cover 2 and the type-I lower vessel cover 5 are made of stainless steel. The dimensions of the upper vessel cover 2 and the type-I lower vessel cover 5 match the vessel body 1. They are connected to the vessel body 1 via external threads and a sealing gasket is provided at the connection point, providing good sealing performance and better curing of the cement slurry. An upper vessel cover valve 3 is installed on the upper vessel cover 2, which is used to control the pressure inside and outside the high-temperature and high-pressure curing vessel 6. During the curing of cement slurry, grease is applied to the inside of the lower kettle cover 5; cement slurry is poured into the kettle body 1, and the cement slurry solidifies into a cement ring 4 after curing for a set time, at which point the curing is complete.

[0055] like Figure 2 As shown, after curing, the vessel body 1 is removed, and the lower vessel cover 5 is disassembled. The vessel body 1 is then fixed to the control tilt angle support 14 via a double-layer fixing bracket 13 for a perforation impact load test. The simulated perforation impact load device includes the control tilt angle support 14, a base 7, and a Hopkinson rod 8 mounted on the base 7. The Hopkinson rod 8 includes an incident rod 10 and a transmission rod 11. One end of the incident rod 10 and one end of the transmission rod 11 are respectively located on both sides of the exposed cement ring 4 at the lower end of the vessel body 1. The other end of the transmission rod 11 is correspondingly provided with a damping device 12, which acts as a buffer. The incident rod 10 and the transmission rod 11 are symmetrically arranged about the vessel body 1. The other end of the incident rod 10 is correspondingly provided with an impact rod 9. The parameters of the impact rod 9 are adjusted according to the required impact load to conduct a simulated perforation impact load test. When the impact rod 9 springs into the incident rod 10 at a certain speed, an incident pulse is generated in the incident rod 10. The stress wave reaches the specimen through the elastic incident rod 10, and the specimen undergoes high-speed deformation under the action of the stress pulse, thereby simulating a perforation impact load experiment. Furthermore, the tilt angle of the well can be realistically simulated through the control tilt angle bracket 14; for example... Figure 4 As shown, a double-layer fixed support 13 is provided below the control tilt angle support 14. The vessel body 1 is fixed in the simulated perforation impact load device by the fixing buckles 21 of the double-layer fixed support 13. The double-layer fixed support 13 includes two layers of fixing buckles 21, which can ensure the reliability of the experiment. At the same time, the upper fixing buckle can slide and be fixed along the slide rail 20 of the control tilt angle support, thereby realizing the adjustment of different tilt angles.

[0056] like Figure 5As shown, the fixing buckle 21 consists of two semi-circular structures. The upper semi-circle is connected to the double-layer fixing bracket 13 at its left and right ends, and the lower semi-circle is connected to the upper semi-circle through the fixing buckle connecting screw 22 to fix the vessel body 1.

[0057] After completing the simulated perforation impact load experiment, the integrity of the cement ring 4 was tested using a post-perforation integrity testing device. The structure of the post-perforation integrity testing device is as follows: Figure 3 As shown, the apparatus includes a gas flow detector 15 and a data acquisition computer 19. After the simulated perforation impact load experiment, a type II lower vessel cover 16 is installed at the lower end of the vessel body 1. A type II lower vessel cover valve 17 for controlling the inflow of gas is installed on the type II lower vessel cover 16; the gas source can be nitrogen. The upper vessel cover valve 3 of the vessel body 1 has a data acquisition interface for installing the gas flow detector 15. The gas flow detector 15 is connected to the data acquisition computer 19, which can collect the gas flow data detected by the gas flow detector 15 for subsequent judgment. The upper vessel cover valve 3 is opened, and nitrogen gas at a certain pressure is introduced, and the gas flow data at the upper vessel cover 2 is collected. Both the pipes connecting the gas source and the pipes connecting the gas flow detector 15 are high-pressure stainless steel pipelines.

[0058] The device is equipped with connecting components and sealing elements. The connecting components are threads, nuts, and pressure rings; the sealing elements are gaskets and O-rings, and the material is polytetrafluoroethylene (PTFE). For example, the vessel body 1 and the upper vessel cover 2 are connected by threads, and a gasket is installed at the top of the threads of the upper vessel cover 2; or as... Figure 5 The fixed fastener 22 consists of threads, nuts, washers and O-rings. The above-mentioned connecting components and seals are not fixed, as long as they can achieve connection and sealing in the corresponding environment.

[0059] like Figure 1 - Figure 5 The simulation device shown can not only simulate the impact load of the perforating projectile on the sealing integrity of the cement sheath 4 during perforation, but also simulate the impact of perforation on the sealing integrity of the cement sheath 4 under different well inclination angles according to the actual well conditions. The internal structure of the device can be adjusted according to the actual situation to make the downhole conditions and working conditions studied more extensive.

[0060] The experimental method for evaluating the effect of perforation impact load on the sealing integrity of cement ring 4 using the above-mentioned simulation device includes the following steps:

[0061] After installing the lower lid 5 and evenly applying grease inside the lower lid, prepare the cement slurry required for the experiment according to API (American Petroleum Institute) standards, pour it into the space of the vessel body 1, and connect the upper lid 2 via threads.

[0062] Place the vessel body 1 into the high-temperature and high-pressure curing vessel 6, open the valve 3 of the upper vessel cover to ensure that the pressure inside and outside the vessel body 1 is consistent, determine the experimental curing conditions according to the required temperature, pressure and other working conditions, set the parameters of the high-temperature and high-pressure curing vessel 6, and cure the cement slurry into a cement ring 4.

[0063] After the curing is completed, remove the lower lid 5 of the vessel body 1 and fix the vessel body 1 on the tilt control bracket 14 through the double-layer fixed bracket 13. Adjust the tilt angle of the vessel body 1 according to the required tilt angle.

[0064] After adjusting the tilt angle, place the incident rod 10 and transmission rod 11 of the Hopkinson rod 8 on both sides of the exposed cement ring 4 at the lower end of the vessel body 1. Adjust the parameters of the impact rod 9 according to the required impact load and conduct a simulated perforation impact load experiment.

[0065] After simulating the impact load of the perforation, a type II lower vessel cover 16 is installed at the lower end of the vessel body 1, and a nitrogen source 18 is connected through the type II lower vessel cover valve 17. A gas flow detector 15 and a data acquisition computer 19 are connected to the upper vessel cover valve 3. At the same time, the upper vessel cover valve 3 and the lower vessel cover valve are opened to introduce nitrogen at a certain pressure and collect the gas flow data at the upper vessel cover 2.

[0066] After the experiment, cement ring 4 sample was removed and subjected to microscopic testing to detect whether microcracks or micro-annular gaps were generated inside cement ring 4, and to analyze the failure mechanism of the perforation impact load on the sealing integrity of cement ring 4.

[0067] The experiment on the effect of perforation impact load on the sealing integrity of cement sheath 4 was conducted under the condition that the wellbore has no inclination angle, and was carried out by the following method:

[0068] After installing the lower lid 5 and evenly applying grease inside, prepare the cement slurry required for the experiment according to API standards, pour it into the space of the vessel body 1, and connect the upper lid 2 via threads. Place the vessel body 1 into the high-temperature and high-pressure curing vessel 6, open the valve 3 of the upper lid to ensure that the pressure inside and outside the vessel body 1 is consistent, determine the experimental curing conditions according to the required temperature, pressure and other working conditions, set the parameters of the high-temperature and high-pressure curing vessel 6, and cure the cement slurry into a cement ring 4 for the set time. After curing, remove the vessel body 1 and remove the lower lid 5. Vertically fix the vessel body 1 on the double-layer fixed bracket 13 of the control tilt angle bracket 14. Place the incident rod 10 and the transmission rod 11 of the Hopkinson rod 8 on both sides of the exposed cement ring 4 at the lower end of the vessel body 1. Adjust the parameters of the impact rod 9 according to the required impact load and conduct a simulated perforation experiment. After perforation, a type II lower vessel cover 16 is installed at the lower end of the vessel body 1, and a nitrogen source 18 is connected through the type II lower vessel cover valve 17. A gas flow detector 15 and a data acquisition computer 19 are connected to the upper vessel cover valve 3. The upper vessel cover valve 3 and the lower vessel cover valve are opened, and nitrogen gas at a certain pressure is introduced. Gas flow data at the upper vessel cover 2 is collected. After the experiment, the cement ring 4 sample is taken out for microscopic inspection to detect whether microcracks or micro-annular gaps are generated inside the cement ring 4, and to analyze the failure mechanism of the perforation impact load on the sealing integrity of the cement ring 4.

[0069] The experiment on the effect of perforation impact load on the sealing integrity of cement sheath 4 under the condition of well inclination was conducted according to the following method:

[0070] After installing the lower lid 5 and evenly applying grease inside, prepare the cement slurry required for the experiment according to API standards, pour it into the space of the vessel body 1, and connect the upper lid 2 via threads. Place the vessel body 1 into the high-temperature and high-pressure curing vessel 6, open the upper lid valve 3 to ensure consistent pressure inside and outside the vessel body 1, determine the experimental curing conditions according to the required temperature, pressure, and other working conditions, set the parameters of the high-temperature and high-pressure curing vessel 6, and cure the cement slurry into a cement ring 4 for the set time. After curing, remove the vessel body 1 and remove the lower lid 5. Adjust the control tilt angle bracket 14 to simulate the well inclination angle. After adjustment, fix the vessel body 1 at a specific angle using the fixing buckle 21 of the double-layer fixing bracket 13 for the test. Place the incident rod 10 and transmission rod 11 of the Hopkinson rod 8 on both sides of the exposed cement ring 4 at the lower end of the vessel body 1, adjust the parameters of the impact rod 9 according to the required impact load, and conduct a simulated perforation experiment. After perforation, a type II lower vessel cover 16 is installed at the lower end of the vessel body 1, and a nitrogen source 18 is connected through the type II lower vessel cover valve 17. A gas flow detector 15 and a data acquisition computer 19 are connected to the valve on the upper vessel cover 2. The valves of the upper and lower vessel covers are opened, and nitrogen gas at a certain pressure is introduced. Gas flow data at the upper vessel cover 2 is collected. After the experiment, the cement ring 4 sample is taken out for microscopic inspection to detect whether microcracks or micro-annular gaps are generated inside the cement ring 4, and to analyze the failure mechanism of the perforation impact load on the sealing integrity of the cement ring 4.

[0071] Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A simulation device for evaluating the effect of perforation impact load on cement sheath integrity, characterized in that, The simulation device includes: Cement curing experimental device, used to cure cement slurry to form cement ring (4); A simulated perforation impact load device is used to conduct a perforation impact load test on a cured cement ring (4). The post-perforation integrity testing device is used to test the integrity of the cement ring (4) after the perforation impact load test is completed. The cement curing experimental device, the simulated perforation impact load device, and the post-perforation integrity testing device all include a vessel body (1) and an upper vessel cover (2), with the upper end face of the vessel body (1) and the upper vessel cover (2) being connected in a fitment. The simulated perforation impact load device also includes a control tilt angle bracket (14), a base (7), and a Hopkinson rod (8) mounted on the base (7); A control tilt angle bracket (14) is installed above the Hopkinson rod (8), and the control tilt angle bracket (14) fixes the vessel body (1) by the fixing buckle (21) of the double-layer fixing bracket (13); The Hopkinson rod (8) includes an incident rod (10) and a transmission rod (11), which are respectively located on both sides of the exposed cement ring (4) at the lower end of the vessel body (1); The fixing buckle (21) consists of an upper fixing buckle and a lower fixing buckle; The control tilt angle bracket (14) is equipped with a control tilt angle bracket slide rail (20); A damping device (12) is provided at the end of the transmission rod (11) away from the vessel body (1); an impact rod (9) is provided at the end of the incident rod (10) away from the vessel body (1); the incident rod (10) and the transmission rod (11) are symmetrically arranged about the vessel body (1). The perforation integrity detection device also includes a type II lower vessel cover (16), which is fixed to the lower end of the vessel body (1). The type II lower vessel cover (16) is equipped with a type II lower vessel cover valve (17) for controlling the gas source; The upper cover valve (3) of the vessel body (1) is provided with an installation port for installing a gas flow detector (15); The upper lid (2), type I lower lid (5), type II lower lid (16) and the vessel body (1) are all made of stainless steel, and the vessel body (1) is a hollow cylinder; The simulation device also includes connecting and sealing components between the vessel body (1) and the upper vessel cover (2), and between a type I lower vessel cover (5) or a type II lower vessel cover (16); The connecting component includes threads, nuts, and pressure rings; The sealing component includes a gasket and an O-ring, and the material of the sealing component is tetrafluoroethylene.

2. The simulation device for evaluating the effect of perforation impact load on cement sheath integrity according to claim 1, characterized in that, The cement curing experimental device also includes a high temperature and high pressure curing kettle (6) and a type I lower kettle cover (5); the kettle body (1) is a hollow stainless steel cylinder, which is installed inside the high temperature and high pressure curing kettle (6); The lower end faces of the type-above lid (5) and the vessel body (1) are detachably connected; The upper lid (2) is equipped with an upper lid valve (3) for controlling the pressure inside and outside the vessel.

3. A simulation method for evaluating the impact of perforation impact load on the integrity of the cement sheath, characterized in that, The simulation apparatus for evaluating the effect of perforation impact load on cement sheath integrity as described in claim 1 or 2 includes the following steps: Cement slurry was placed in a cement curing experimental device for curing to form a cement ring (4); The cement ring (4) was subjected to a perforation impact load test using a simulated perforation impact load device. The cement ring (4) after the perforation impact load test was completed was subjected to integrity testing using a post-perforation integrity testing device.

4. The simulation method for evaluating the influence of perforation impact load on cement sheath integrity according to claim 3, characterized in that, The cement slurry is placed in a cement curing experimental device for curing to form a cement ring (4) including the following steps: Install the type-1 lower lid (5) on the lower end face of the pot body (1) and evenly apply butter inside the type-1 lower lid (5); Pour the prepared cement slurry into the space of the reactor body (1) and connect the reactor lid (2) by thread; Place the vessel body (1) into the high temperature and high pressure curing vessel (6), open the upper vessel cover valve (3), ensure that the pressure inside and outside the vessel body (1) is consistent, set the parameters of the high temperature and high pressure curing vessel (6) to cure the cement slurry into a cement ring (4), and remove the lower vessel cover (5).

5. The simulation method for evaluating the influence of perforation impact load on cement sheath integrity according to claim 4, characterized in that, The perforation impact load test on the cement ring (4) using a simulated perforation impact load device includes the following steps: The cured vessel body (1) is vertically fixed on the double-layer fixed bracket (13) of the tilt control bracket; The incident rod (10) and transmission rod (11) of the Hopkinson rod (8) are placed on both sides of the exposed cement ring (4) at the lower end of the vessel body (1). The parameters of the impact rod (9) are adjusted according to the required impact load to conduct a simulated perforation impact load experiment.

6. The simulation method for evaluating the influence of perforation impact load on cement sheath integrity according to claim 3, characterized in that, The integrity test of the cement ring (4) after the perforation impact load test includes the following steps: Install a type II lower vessel cover (16) on the lower end face of the vessel body (1), and connect a nitrogen source (18) through a type II lower vessel cover valve (17); Connect the gas flow detector (15) and the data acquisition computer (19) to the valve (3) on the upper lid; Nitrogen gas at a certain pressure is introduced into the upper lid valve (3) and the lower lid valve, and gas flow data at the upper lid (2) is collected; The cement ring (4) sample was removed, and microscopic inspection was performed. The impact of the perforation impact load on the sealing integrity of the cement ring (4) was analyzed based on the inspection results.

7. The simulation method for evaluating the influence of perforation impact load on cement sheath integrity according to claim 6, characterized in that, The microscopic inspection includes detecting whether microcracks and microring gaps are generated inside the cement ring (4).

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