Device and method for testing influence of vibration on cement bonding strength in multi-factor environment

Abstract

The invention discloses a device and method for testing the influence of vibration on cement bonding strength in a multi-factor environment, and relates to the technical field of cement sheath interface bonding strength test.The device comprises a sealed tube furnace, a vibration sleeve assembly, a cement curing device, a bonding strength testing assembly and a controller, and the cement curing device is arranged in the sealed tube furnace; the vibration sleeve is arranged in the cement curing device in a sliding mode, an annular cavity used for pouring a cement sheath is formed between the vibration sleeve and the cement curing device, a gland is arranged at the top of the annular cavity, and a guide groove matched with the vibration sleeve is formed in the top in the gland; a pressure maintaining cavity is formed among the sealed tube furnace, the cement curing device and the gland; the device further comprises a feeding pipeline, a discharging pipeline, a carbon dioxide inlet pipe, a nitrogen inlet pipe and an exhaust pipe. The device is reasonable in design, and can simulate the influence of different vibration parameters on the cementing strength of the cement sheath after cement paste is injected in high-temperature and high-pressure environments. And the influence of carbon dioxide injection on the cementing strength of the cement sheath after the cement sheath is formed can be detected.

Description

Technical Field

[0001] The invention relates to the technical field of cement sheath interface bonding strength testing, and more particularly to a testing device and method for testing the influence of vibration on cement bonding strength in a multi-factor environment. Background Art

[0002] As the development of oil and gas fields progresses, the oil and gas resources in the wells are gradually exploited, resulting in the inability to effectively extract oil and gas by conventional production methods in the later stages of oil and gas well exploitation. EOR technology is needed to improve the efficiency of oil and gas well development. CO2 displacement technology is currently one of the effective methods for improving oil and gas recovery. Due to the injection of CO2 gas, the microstructure of the cement sheath changes, destroys the structure of the cement sheath, reduces the compressive strength, increases the permeability, and may also cause corrosion to the oil and gas well casing, causing the cement sheath and annulus isolation system to be damaged.

[0003] The main function of cementing sheath is to support casing, isolate oil, gas and water layers, and provide an alkaline environment to prevent corrosion of casing. In the construction industry, people use vibration waves to make cement sheath more uniform and dense, especially during the pouring of concrete, in order to improve the bonding strength between concrete and steel bars. On this basis, people began to consider applying the energy generated by vibration waves to the cementing site, using vibration waves to improve the bonding strength of cement sheath in the annular space of the sealing section. Summary of the invention

[0004] The purpose of the present invention is to solve the above technical problems and provide a testing device and method for the influence of vibration on cement bonding strength in a multi-factor environment.

[0005] In order to achieve the above-mentioned purpose, the present invention specifically adopts the following technical solutions:

[0006] One aspect of the present invention provides a testing device for the influence of vibration on cement bonding strength in a multi-factor environment, comprising a sealed tubular furnace, a vibration sleeve assembly, a cement curing device, a bonding strength testing assembly and a controller, wherein the cement curing device is arranged inside the sealed tubular furnace, the vibration sleeve is slidably arranged inside the cement curing device, an annular cavity for pouring a cement ring is formed between the vibration sleeve and the cement curing device, a gland is arranged at the top of the annular cavity, and a guide groove matching the vibration sleeve is arranged at the top of the gland; a pressure-maintaining cavity is arranged between the sealed tubular furnace, the cement curing device and the gland,

[0007] A feeding pipe and a discharging pipe communicating with the annular cavity are arranged on the side wall of the sealed tube furnace, and a carbon dioxide inlet pipe, a nitrogen inlet pipe and an exhaust pipe communicating with the inside of the pressure-maintaining cavity are arranged on the side wall of the sealed tube furnace.

[0008] In one embodiment, the sealed tube furnace comprises a sealed kettle body with an open end and a sealed lower end, a sealed kettle cover sealed on the top of the sealed kettle body, and a heating resistance wire spirally arranged on the inside of the sealed kettle body, the outer material of the sealed kettle body is a heat-insulating material, and the inner material of the sealed kettle body is a heat-resistant material;

[0009] The cement curing device and the cement ring are fixed at the inner bottom of the sealed kettle body, and the bonding strength testing component is an oil cylinder lifting mechanism.

[0010] Specifically, the sealed kettle cover is connected by a sealing thread and screwed on the top of the sealed kettle body to ensure the sealing performance of the sealed kettle body. The sealed kettle body is embedded with a resistance wire for heating; the outside of the sealed kettle body is made of insulation material to reduce heat loss, and the inside is made of materials that can withstand high temperatures.

[0011] In one embodiment, a pressure gauge for testing the air pressure in the pressure-maintaining cavity is provided on the sealed kettle cover, a carbon dioxide inlet pipe and a nitrogen inlet pipe are combined and connected to the inside of the pressure-maintaining cavity, a gas flow meter and a carbon dioxide injection port valve are provided on the carbon dioxide inlet pipe, and a nitrogen injection port valve is provided on the nitrogen inlet pipe; a material injection port valve is provided on the feed pipe, and an exhaust port valve is provided on the exhaust pipe;

[0012] The pressure gauge, gas flow meter, injection port valve, carbon dioxide injection port valve, nitrogen injection port valve and exhaust port valve are all connected to the controller signal. Other valves are also connected to the controller signal.

[0013] In one embodiment, the vibration sleeve assembly includes a vertically arranged vibration sleeve shell, an upper sleeve sealing cover arranged at the top of the vibration sleeve shell, a lower sealing cover arranged at the bottom of the vibration sleeve shell, a Bluetooth motor fixedly arranged at the top of the vibration sleeve shell, and an eccentric vibrator arranged on the output shaft of the Bluetooth motor.

[0014] In one embodiment, the eccentric vibrator includes a strength eccentric block (the strength eccentric block is used to adjust the intensity and direction of the vibration) and a centering eccentric block (the centering eccentric block is used to change the size and direction of the exciting force generated by the vibration motor). The output shaft of the Bluetooth motor is a D-type shaft. The output shaft of the Bluetooth motor is fixed to the strength eccentric block and the centering eccentric block by D-type keys in the circumferential direction, and steps and nuts are used in the axial direction. The Bluetooth motor is also connected to the controller.

[0015] In one embodiment, the vibration sleeve further includes a high temperature resistant battery, which is installed in the vibration sleeve housing and located on top of the Bluetooth motor.

[0016] Specifically, the Bluetooth motor is installed on one side of the vibration sleeve with a groove, and the strength eccentric block and the centering eccentric block are installed on the other side. The output shaft of the Bluetooth motor and the eccentric vibrator are fixed with flat keys in the circumferential direction and steps and nuts in the axial direction. The lower sealing cover of the sleeve is connected to the outer shell of the vibration sleeve through a sealing thread. During installation, after the high-temperature resistant battery and the Bluetooth motor are connected on the other side of the vibration sleeve, the upper sealing cover is tightened.

[0017] In one embodiment, the cement curing device includes a retaining frame located at the bottom of the sealed kettle body and a simulated formation installed on the retaining frame.

[0018] In one embodiment, the bonding strength testing assembly includes an oil storage tank located in a sealed kettle body, a lifting cylinder vertically arranged at the bottom of the sealed kettle body, a lifting piston slidingly sealed in the lifting cylinder, a cylinder driving assembly for driving the lifting piston to rise and fall, and a hydraulic oil safety release assembly; the top of the lifting piston is in contact with the bottom of the vibration sleeve assembly.

[0019] In one embodiment, the hydraulic oil safety release assembly includes a safety oil pipe connected to the oil storage tank and the lifting cylinder, the safety oil pipe is provided with a spring check valve and a safety release valve for controlling the opening and closing of the spring check valve, the safety release valve is provided with a safety release rod, and the safety release valve is provided with a sealing gasket.

[0020] In one embodiment, the cylinder drive assembly includes a cylinder body, an operating piston slidingly sealed in the cylinder body by a second sealing gasket, an oil suction pipe whose two ends are respectively connected to the oil storage tank and the interior of the cylinder body, an oil suction check valve arranged on the oil suction pipe, an oil outlet pipe whose two ends are respectively connected to the oil storage tank and the lifting cylinder, and a ball check valve arranged on the oil outlet pipe.

[0021] Another aspect of the present invention provides a method for testing cement bond strength under the influence of multi-factor vibration, using the above-mentioned testing device for the influence of vibration on cement bond strength in a multi-factor environment, comprising the following steps:

[0022] S1. Loosen the safety release valve, return the lifting piston to its original position, and then tighten the safety release valve. Lift the operating piston to the highest position, soak the artificial formation in water, and put it into the groove of the artificial formation fixing frame of the assembled sealing body, and connect the artificial formation with the injection pipe;

[0023] S2. After assembling the vibration casing assembly, place the vibration casing shell into the groove at the center of the tubular sealing kettle base; after injecting the drilling fluid, tighten the gland and screw the sealing kettle cover onto the sealing kettle body;

[0024] S3, open the nitrogen inlet valve and the outlet valve, ventilate for 3 minutes, close the outlet valve first and then close the nitrogen inlet valve; turn on the sealed kettle heating switch to heat to a predetermined temperature; open the nitrogen inlet valve to pressurize until the pressure gauge on the sealed kettle cover reaches a predetermined value and then close the nitrogen inlet valve;

[0025] S4. Open the injection port valve to inject drilling fluid, and open the discharge port valve to release the drilling fluid to start flushing the casing wall and the well wall; after flushing for 30 minutes, stop injecting the drilling fluid, and after the drilling fluid is completely discharged, close the discharge port valve and start injecting the configured predetermined amount of cementing slurry;

[0026] S5. After the cement slurry is injected, the computer is connected to the Bluetooth motor to start vibrating according to the predetermined frequency, amplitude and time;

[0027] S6. After the vibration is completed, the motor is turned off by Bluetooth, and the cement stone is cured under the same conditions. When the cement stone is cured, the gas outlet valve is opened to release a part of the nitrogen and then the gas outlet valve is closed. Then the carbon dioxide injection port valve is opened to inject a predetermined amount of carbon dioxide. After the carbon dioxide injection port valve is closed, the nitrogen injection port valve is opened to inject nitrogen so that the pressure in the kettle body reaches a predetermined value and then the cement ring is cured.

[0028] S7. When the cement ring curing time reaches the preset value, open the outlet valve, use external force to press the operating end piston, and the lifting end piston rises to squeeze the vibration casing, so that the vibration casing and the cement ring slide relative to each other. The computer records this value and calculates the interface bonding strength of the cement ring. Quantitatively discuss the effect of carbon dioxide concentration on the bonding strength of the cement ring.

[0029] The beneficial effects of the present invention are as follows:

[0030] 1. The design of this device is reasonable. On the one hand, it can simulate the influence of different vibration parameters on the bonding strength of cement sheath after cement slurry is injected under high temperature and high pressure environment. On the other hand, it can detect the influence of carbon dioxide injection on the bonding strength of cement sheath after the cement sheath is formed.

[0031] 2. It can accurately control the parameters of temperature, pressure, carbon dioxide concentration and vibration, and completely simulate the working environment of vibration cementing tools in the well, especially to facilitate the selection of optimal vibration parameters in high temperature and high pressure corrosion cementing operations. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following briefly introduces the drawings required for use in the embodiments. It should be understood that the following drawings only show certain embodiments of the present invention and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other related drawings can be obtained based on these drawings without creative work.

[0033] Figure 1 It is a schematic diagram of the structure of the present invention;

[0034] Figure 2 It is a structural diagram of a strength eccentric block or a centering eccentric block;

[0035] Figure numerals: 1-pressure gauge, 2-sealed kettle cover, 3-sealed kettle body, 4-pressure cover, 5-simulated formation, 6-upper sealing cover, 7-injection port valve, 8-vibration casing shell, 9-high temperature resistant battery, 10-Bluetooth motor, 11-heating resistance wire, 12-motor shaft, 13-exhaust port valve, 14-retaining frame, 15-oil storage tank, 16-safety release valve, 17-safety release rod, 18-sealing gasket, 19-spring check valve, 20-sealing ring, 21-lifting piston, 22-ball check valve, 23-lower sealing cover, 24-second sealing gasket, 25-oil suction check valve, 26-operating piston, 27-cylinder body, 28-discharge port valve, 29-nut, 30-centering eccentric block, 31-strength eccentric block, 32-carbon dioxide injection port valve, 33-gas flow meter, 34-nitrogen injection port valve, 35-computer. DETAILED DESCRIPTION

[0036] In order to make the technical problems, technical solutions and technical effects of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Generally, the components of the embodiments of the present invention described and shown in the drawings here can be arranged and designed in various different configurations.

[0037] Therefore, the following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the invention claimed for protection, but merely represents selected embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0038] It should be noted that similar reference numerals and letters represent similar items in the following drawings, so once an item is defined in one drawing, it does not need to be further defined and explained in the subsequent drawings. In addition, the terms "first", "second", etc. are only used to distinguish the description and cannot be understood as indicating or implying relative importance.

[0039] In the description of the embodiments of the present invention, it should be noted that the terms "inside", "outside", "upper", etc. indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, or are the orientations or positional relationships in which the inventive product is usually placed when used. They are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention.

[0040] like Figure 1 As shown, the present invention provides a testing device for the influence of vibration on cement bonding strength in a multi-factor environment, comprising a sealed tube furnace, a vibration sleeve assembly, a cement curing device, a bonding strength testing assembly and a controller, wherein the cement curing device is arranged inside the sealed tube furnace, the vibration sleeve is slidably arranged inside the cement curing device, an annular cavity for pouring a cement ring is formed between the vibration sleeve and the cement curing device, a gland 4 is arranged at the top of the annular cavity, and a guide groove matching the vibration sleeve is arranged at the top of the gland 4; a pressure-maintaining cavity is arranged between the sealed tube furnace, the cement curing device and the gland 4,

[0041] A feeding pipe and a discharging pipe communicating with the annular cavity are arranged on the side wall of the sealed tube furnace, and a carbon dioxide inlet pipe, a nitrogen inlet pipe and an exhaust pipe communicating with the inside of the pressure-maintaining cavity are arranged on the side wall of the sealed tube furnace.

[0042] In one embodiment, the sealed tube furnace includes a sealed kettle body 3 with openings at both ends, a sealed kettle cover 2 sealed on the top of the sealed kettle body 3, and a heating resistance wire 11 spirally arranged inside the sealed kettle body 3. The outer material of the sealed kettle body 3 is a heat-insulating material, and the inner material of the sealed kettle body 3 is a heat-resistant material.

[0043] The cement curing device and the cement ring are fixed to the bottom of the sealed kettle body 3, and the cement strength testing component is a cylinder lifting mechanism.

[0044] Specifically, the sealed kettle cover 2 is connected by a sealing thread and screwed on the top of the sealed kettle body 3 to ensure the sealing performance of the sealed kettle body 3. The sealed kettle body 3 is embedded with a resistance wire for heating; the sealed kettle body 3 is made of heat-insulating materials on the outside to reduce heat loss, and the inside is made of materials that can withstand high temperatures.

[0045] In one embodiment, a pressure gauge 1 for testing the air pressure in the pressure-maintaining cavity is provided on the sealed kettle cover 2, a carbon dioxide inlet pipe and a nitrogen inlet pipe are combined and connected to the inside of the pressure-maintaining cavity, a gas flow meter 33 and a carbon dioxide injection port valve 32 are provided on the carbon dioxide inlet pipe, and a nitrogen injection port valve 34 is provided on the nitrogen inlet pipe; a material injection port valve 7 is provided on the feed pipe, and an exhaust port valve 13 is provided on the exhaust pipe;

[0046] The pressure gauge 1, the gas flow meter 33, the injection port valve 7, the carbon dioxide injection port valve 32, the nitrogen injection port valve 34 and the exhaust port valve 13 are all connected to the controller signal.

[0047] In one embodiment, the vibration sleeve assembly includes a vertically arranged vibration sleeve shell 8, a sleeve upper sealing cover 6 arranged at the top of the vibration sleeve shell 8, a lower sealing cover 23 arranged at the bottom of the vibration sleeve shell 8, a Bluetooth motor 10 fixedly arranged at the top of the vibration sleeve shell 8, and an eccentric vibrator arranged on the output shaft of the Bluetooth motor 10.

[0048] In one embodiment, the eccentric vibrator includes a strength eccentric block 31 and an aligning eccentric block 30 , and the output shaft of the Bluetooth motor 10 is fixed to the strength eccentric block 31 and the aligning eccentric block 30 circumferentially with a flat key and axially with a step and a nut 29 .

[0049] In one embodiment, the vibration sleeve further includes a high temperature resistant battery 9 , which is installed in the vibration sleeve housing 8 and located on top of the Bluetooth motor 10 .

[0050] Specifically, the vibration sleeve has a groove on one side for installing the Bluetooth motor 10, and the strength eccentric block 31 and the centering eccentric block 30 are installed on the other side. The output shaft of the Bluetooth motor 10 is a D-type shaft. The output shaft of the Bluetooth motor 10 and the eccentric vibrator are fixed circumferentially with a D-type key, and axially with a step and a nut 29. The lower sealing cover 23 of the sleeve is connected to the vibration sleeve housing 8 through a sealing thread. During installation, after the high temperature resistant battery 9 and the Bluetooth motor 10 are connected on the other side of the vibration sleeve, the upper sealing cover 6 is tightened.

[0051] In one embodiment, the cement curing device includes a retaining frame 14 located at the bottom of the sealed kettle body 3 and a simulated stratum 5 installed on the retaining frame 14 .

[0052] In one embodiment, the bonding strength testing assembly includes an oil storage tank 15 located in the sealed kettle body 3, a lifting cylinder vertically arranged at the bottom of the sealed kettle body 3, a lifting piston 21 slidingly sealed in the lifting cylinder, a cylinder driving assembly that drives the lifting piston 21 to rise and fall, and a hydraulic oil safety release assembly; the top of the lifting piston 21 contacts the bottom of the vibration sleeve assembly.

[0053] In one embodiment, the hydraulic oil safety release assembly includes a safety oil pipe connected to the oil storage tank 15 and the lifting cylinder, and a spring check valve 19 and a safety release valve 16 for controlling the opening and closing of the spring check valve 19 are provided on the safety oil pipe, a safety release rod 17 is provided on the safety release valve 16, and a sealing gasket 18 is provided on the safety release valve 16.

[0054] The cylinder drive assembly includes a cylinder body 27, an operating piston 26 slidingly sealed in the cylinder body 27 through a second sealing gasket 24, an oil suction pipe whose two ends are respectively connected to the oil storage tank 15 and the inside of the cylinder body 27, an oil suction check valve 25 arranged on the oil suction pipe, an oil outlet pipe whose two ends are respectively connected to the oil storage tank 15 and the lifting cylinder, and a ball check valve 22 arranged on the oil outlet pipe.

[0055] Example 1

[0056] This embodiment is a test device for the effect of vibration on cement bonding strength in a multi-factor environment. The specific process is as follows:

[0057] After loosening the safety release valve 16 to release the pressure, turn the safety release rod 17 to tighten the safety release valve 16 to compress the spring check valve 19 to prevent the hydraulic oil in the oil storage tank 15 from flowing back. Raise the operating piston 26 to the highest position, and the hydraulic oil in the oil storage tank 15 flows into the cavity of the operating piston 26 through the oil suction pipe. The oil suction check valve 25 can prevent the hydraulic oil in the cavity from flowing back to the oil storage tank 15. Put the simulated formation 5 retainer 14 into the tubular sealed kettle body 3 and connect it with bolts. Then put the simulated formation 5, and then put the assembled vibration casing device into the groove at the bottom of the tubular sealed kettle body 3. After injecting drilling fluid into the annular cavity, tighten the gland 4, and finally tighten the sealing kettle cover 2. Put the Bluetooth motor 10 into the groove of the vibration casing shell 8, put the high temperature resistant battery 9, and then tighten the sealing cover 6 on the vibration casing. Then install the strength eccentric block 31 and the centering eccentric block 30 on the shaft of the Bluetooth motor 10, and then tighten the nut 29. The motor shaft 12 adopts a D-type shaft and a strength eccentric block 31, and the centering eccentric block 30 is fixed circumferentially;

[0058] The drilling fluid is injected by opening the injection port valve 7 and the drilling fluid is discharged by opening the discharge port valve 28 to simulate the flushing of the well wall by the drilling fluid. The sealed tubular furnace is heated to a predetermined temperature and the nitrogen injection port valve 34 is opened to make the pressure and temperature in the sealed tubular furnace reach a predetermined value and then maintained for 30 minutes, and then the injection port valve 7 is closed to discharge the drilling fluid;

[0059] After the drilling fluid is completely drained, the discharge port valve 28 is closed, and then the injection port valve 7 is opened to inject the standard cement slurry prepared according to the GBT19139-2012 oil well cement test method, and then the injection port valve 7 is closed; the Bluetooth motor 10 is controlled by the computer 35 to start vibration with the designed parameters; after the cement is cured, the exhaust port valve 13 is opened to release the pressure, and the hydraulic oil of the pressure-operating piston 26 enters the cavity of the lifting piston 21 through the oil discharge pipe. The hydraulic oil entering is driven by the oil pressure to push the lifting piston 21 up, and then push the vibration casing;

[0060] The bond strength can be obtained according to the following formula.

[0061] σ=(F2-G) / (2πRh),

[0062] F1×πd^2 / 4=(F2-G)×πD^2 / 4;

[0063] Where, σ is the bonding strength;

[0064] F2 is the lifting force provided by the lifting piston 21;

[0065] G is the gravity of the vibrating casing;

[0066] h is the height of the cement ring;

[0067] F1 is the force applied externally to the operating piston 26;

[0068] R is the radius of the vibration casing;

[0069] d is the diameter of the operating piston 26;

[0070] D is the diameter of the lifting piston 21 .

[0071] Example 2

[0072] This embodiment is a test device for the effect of vibration on cement bonding strength in a multi-factor environment. Regarding the effect of CO2 concentration on cement sheath performance, the specific process is as follows:

[0073] Loosen the safety release valve 16, return the lifting piston 21 to its original position, and then tighten the safety release valve 16, lift the operating piston 26 to the highest position, soak the artificial formation in water, and put it into the groove of the artificial formation fixing frame of the assembled sealing body, and connect the artificial formation with the injection pipe. After assembling the vibration casing, put the casing into the groove at the center of the tubular sealing kettle base. After injecting the drilling fluid, tighten the gland 4, and then screw the sealing kettle cover 2 onto the sealing kettle body 3. Open the nitrogen inlet valve and the outlet valve, and after ventilating for 3 minutes, close the outlet valve first and then close the nitrogen inlet valve. Turn on the heating switch of the sealing kettle body 3 and heat it to the predetermined temperature. Open the nitrogen inlet valve to pressurize, and close the nitrogen inlet valve after the pressure gauge 1 on the sealing kettle cover 2 reaches the predetermined value. Open the injection port valve 7 to inject the drilling fluid, and open the discharge port valve to release the drilling fluid to start flushing the casing wall and the well wall. After flushing for 30 minutes, stop injecting drilling fluid. After the drilling fluid is completely discharged, close the discharge port valve and start injecting the configured predetermined amount of cementing cement slurry. After the cement slurry is injected, use a computer to connect the Bluetooth motor 10 and start vibrating according to the predetermined frequency, amplitude and time. After the vibration is completed, Bluetooth turns off the motor and continues to maintain the same conditions to maintain the cement stone. When the cement stone is cured, open the outlet valve to release a part of the nitrogen and then close the outlet valve, then open the carbon dioxide injection port valve, inject a predetermined amount of carbon dioxide, close the carbon dioxide injection port valve, open the nitrogen injection valve, inject nitrogen to make the pressure in the kettle reach a predetermined value, and then continue to maintain the cement ring. When the cement ring curing time reaches the predetermined value, open the outlet valve. Use external force to press the operating end piston, the lifting end piston rises and squeezes the vibration casing, so that the vibration casing and the cement ring slide relative to each other. The computer 35 records this value and calculates the interface bonding strength of the cement ring. Quantitatively discuss the effect of carbon dioxide concentration on the bonding strength of the cement ring.

Claims

1. A testing device for the effect of vibration on cement bonding strength in a multi-factor environment, characterized in that: The invention comprises a sealed tube furnace, a vibration sleeve assembly, a cement curing device, a bonding strength test assembly and a controller, wherein the cement curing device is arranged inside the sealed tube furnace, the vibration sleeve is slidably arranged inside the cement curing device, an annular cavity for pouring a cement ring is formed between the vibration sleeve and the cement curing device, a gland (4) is arranged at the top of the annular cavity, and a guide groove cooperating with the vibration sleeve is arranged at the top of the gland (4); a pressure-maintaining cavity is arranged between the sealed tube furnace and the cement curing device and the gland (4); The sealed tube furnace side wall is provided with a feed pipe and a discharge pipe connected with the annular cavity, and the sealed tube furnace side wall is provided with a carbon dioxide inlet pipe, a nitrogen inlet pipe and an exhaust pipe connected with the inside of the pressure-maintaining cavity.

2. The testing device for the effect of vibration on cement bonding strength in a multi-factor environment according to claim 1, characterized in that: The sealed tubular furnace comprises a sealed kettle body (3) with an open upper end and a sealed lower end, a sealed kettle cover (2) sealedly arranged on the top of the sealed kettle body (3), and a heating resistance wire (11) spirally arranged inside the sealed kettle body (3), the outer material of the sealed kettle body (3) is a heat-insulating material, and the inner material of the sealed kettle body (3) is a heat-resistant material; The cement curing device and the cement ring are fixed to the bottom of the sealed kettle body (3), and the bonding strength testing component is an oil cylinder lifting mechanism.

3. The testing device for the effect of vibration on cement bonding strength in a multi-factor environment according to claim 2, characterized in that: The sealed kettle cover (2) is provided with a pressure gauge (1) for testing the air pressure in the pressure-maintaining cavity; the carbon dioxide inlet pipe and the nitrogen inlet pipe are combined and communicated with the interior of the pressure-maintaining cavity; the carbon dioxide inlet pipe is provided with a gas flow meter (33) and a carbon dioxide injection port valve (32); the nitrogen inlet pipe is provided with a nitrogen injection port valve (34); the feed pipe is provided with a feed port valve (7); and the exhaust pipe is provided with an exhaust port valve (13); The pressure gauge (1), the gas flow meter (33), the injection port valve (7), the carbon dioxide injection port valve (32), the nitrogen injection port valve (34) and the exhaust port valve (13) are all connected to the controller signal.

4. The testing device for the effect of vibration on cement bonding strength in a multi-factor environment according to claim 3, characterized in that: The vibration sleeve assembly comprises a vertically arranged vibration sleeve shell (8), a sleeve upper sealing cover (6) arranged at the top of the vibration sleeve shell (8), a lower sealing cover (23) arranged at the bottom of the vibration sleeve shell (8), a Bluetooth motor (10) fixedly arranged at the top of the vibration sleeve shell (8), and an eccentric vibration member arranged on the output shaft of the Bluetooth motor (10).

5. The testing device for the effect of vibration on cement bonding strength in a multi-factor environment according to claim 4, characterized in that: The eccentric vibrating member comprises a strength eccentric block (31) and a centering eccentric block (30); the output shaft of the Bluetooth motor (10) is a D-shaped shaft; the output shaft of the Bluetooth motor (10) is fixed to the strength eccentric block (31) and the centering eccentric block (30) in the circumferential direction by using a D-shaped key, and in the axial direction by using a step and a nut (29); the Bluetooth motor (10) is connected to the controller signal.

6. The testing device for the effect of vibration on cement bonding strength in a multi-factor environment according to claim 5, characterized in that: The vibration sleeve further comprises a high temperature resistant battery (9), wherein the high temperature resistant battery (9) is installed in the vibration sleeve housing (8) and is located on top of the Bluetooth motor (10).

7. The testing device for the effect of vibration on cement bonding strength in a multi-factor environment according to claim 6, characterized in that: The cement curing device comprises a retaining frame (14) located at the bottom of the sealed kettle body (3) and a simulated stratum (5) mounted on the retaining frame (14).

8. The testing device for the effect of vibration on cement bonding strength in a multi-factor environment according to claim 7, characterized in that: The bonding strength testing assembly comprises an oil storage tank (15) located in the sealed kettle body (3), a lifting cylinder vertically arranged at the bottom of the sealed kettle body (3), a lifting piston (21) slidingly sealed and arranged in the lifting cylinder, a cylinder driving assembly for driving the lifting piston (21) to rise and fall, and a hydraulic oil safety release assembly; the top of the lifting piston (21) is in contact with the bottom of the vibration sleeve assembly.

9. The testing device for the effect of vibration on cement bonding strength in a multi-factor environment according to claim 8, characterized in that: The hydraulic oil safety release assembly comprises a safety oil pipe connected to the oil storage tank (15) and the lifting oil cylinder, the safety oil pipe is provided with a spring check valve (19) and a safety release valve (16) for controlling the opening and closing of the spring check valve (19), the safety release valve (16) is provided with a safety release rod (17), and the safety release valve (16) is provided with a sealing gasket (18); The oil cylinder drive assembly comprises an oil cylinder body (27), an operating piston (26) slidingly sealed in the oil cylinder body (27) by a second sealing gasket (24), an oil suction pipe whose two ends are respectively connected to the oil storage tank (15) and the interior of the oil cylinder body (27), an oil suction check valve (25) arranged on the oil suction pipe, an oil outlet pipe whose two ends are respectively connected to the oil storage tank (15) and the lifting cylinder, and a ball check valve (22) arranged on the oil outlet pipe.

10. A method for testing the effect of vibration on cement bonding strength in a multi-factor environment, using the testing device for testing the effect of vibration on cement bonding strength in a multi-factor environment as claimed in any one of claims 1 to 9, characterized in that: The steps include: S1, loosen the safety release valve (16), return the lifting piston (21) to its original position, then tighten the safety release valve (16), lift the operating piston (26) to the highest position, soak the artificial formation in water and place it in the groove of the artificial formation fixing frame of the assembled sealing body, and connect the artificial formation with the injection pipe; S2. After assembling the vibration casing assembly, place the vibration casing shell (8) into the groove at the center of the tubular sealing kettle base; after injecting drilling fluid, tighten the gland (4), and then screw the sealing kettle cover (2) onto the sealing kettle body (3); S3, open the nitrogen inlet valve and the outlet valve, and after ventilation for 3 minutes, close the outlet valve first and then the nitrogen inlet valve; turn on the heating switch of the sealed kettle body (3) to heat to a predetermined temperature; open the nitrogen inlet valve to increase pressure until the pressure gauge (1) on the sealed kettle cover (2) reaches a predetermined value and then close the nitrogen inlet valve; S4, opening the injection port valve (7) to inject drilling fluid, while opening the discharge port valve to release the drilling fluid, and start flushing the casing wall and the well wall; after flushing for 30 minutes, stop injecting the drilling fluid, and after the drilling fluid is completely discharged, close the discharge port valve and start injecting the configured predetermined amount of cementing cement slurry; S5. After the cement slurry is injected, a computer is used to connect the Bluetooth motor (10) to start vibrating according to a predetermined frequency, amplitude, and time; S6. After the vibration is completed, the motor is turned off by Bluetooth, and the cement stone is cured under the same conditions. When the cement stone is cured, the gas outlet valve is opened to release a part of the nitrogen and then the gas outlet valve is closed. Then the carbon dioxide injection port valve is opened to inject a predetermined amount of carbon dioxide. After the carbon dioxide injection port valve is closed, the nitrogen injection port valve is opened to inject nitrogen so that the pressure in the kettle body reaches a predetermined value and then the cement ring is cured. S7. When the cement ring curing time reaches a predetermined value, the outlet valve is opened, and an external force is used to press the piston at the operating end. The piston at the lifting end rises to squeeze the vibration casing, so that the vibration casing and the cement ring slide relative to each other. The computer (35) records this value, and the interface bonding strength of the cement ring is obtained based on the calculation, and the influence of carbon dioxide concentration on the bonding strength of the cement ring is quantitatively discussed.

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