In-situ cement curing high temperature and high pressure leak stoppage experimental system

Abstract

The application discloses an in-situ cement maintenance high-temperature and high-pressure plugging experiment system and relates to the technical field of cement maintenance plugging test.The high-temperature and high-pressure plugging experiment system comprises a cement paste maintenance kettle body, a leakage experiment kettle body and a metering kettle body, the cement paste maintenance kettle body is provided with stirring paddles, the maintenance of cement paste in different flow states is simulated, the leakage experiment kettle body is used for plugging performance test, and the metering kettle body is used for metering leakage to reflect plugging performance.The stirring paddles in the cement paste maintenance kettle body are assembled with the maintenance kettle cover by using a rotary sealing assembly, a driving motor is connected with a transmission clutch assembly, the transmission shaft of the rotary sealing assembly is connected with the spline shaft of the transmission clutch assembly through a key matching shaft coupling, and the rotary sealing assembly is convenient to disassemble and assemble.The plugging experiment system can be used for plugging performance test of cement paste, only a gas source is used for pressure simulation, the operation is simple, the rotary sealing assembly is convenient to disassemble and assemble, the simulation effect is good, and the plugging performance test is accurate.

Description

Technical Field

[0001] The invention relates to the technical field of cement curing and leak-proofing testing, and more particularly to an in-situ cement curing high-temperature and high-pressure leak-proofing experimental system. Background Art

[0002] The invention patent application publication number is CN102518432A, and the publication date is June 27, 2012. The publication text of the invention patent application entitled "High-temperature and high-pressure leaking formation simulation plugging test device" discloses a high-temperature and high-pressure leaking formation simulation plugging test device, which is mainly composed of an air source, an oil tank, an upper kettle body, a lower kettle body, a water source, a magnetic drive, a central processing system, and a liquid collecting tank. The upper kettle body is connected to the oil tank and the air source, and the lower kettle body is connected to the water source. The upper kettle body and the lower kettle body are respectively connected to the pressure pump and the pressure relief pump, and are also respectively connected to the pressure sensor and the thermocouple. The pressure sensor and the thermocouple are connected to the central processing system; there is a paddle inside the upper kettle body, and the paddle shaft is driven to rotate by a variable frequency motor through a magnetic drive; there is a simulated rock core inside the lower kettle body and is connected to the liquid collecting tank. This invention can simulate complex working conditions such as drilling fluid at different well depths, temperatures, pressures, leakage types of formation conditions, slurry flow states, and pressure differences between the wellbore and the formation under high temperature and high pressure, test plugging-related parameters to determine the leakage plugging effect, and thus optimize the drilling fluid system.

[0003] The existing formation simulation plugging test device mentioned above is not suitable for cement slurry plugging testing. Furthermore, it is complex to operate. For example, it uses a magnetic drive as the coupling between the blades and the variable frequency motor, occupying the operating space above the upper kettle cover, which significantly affects the experimental operation. The entire experimental simulation process uses both oil pressure simulation and air pressure simulation, making the pressure simulation system complex and inconvenient to operate. Summary of the Invention

[0004] In order to overcome the defects and deficiencies in the above-mentioned prior art, the present invention provides an in-situ cement curing high-temperature and high-pressure plugging test system. The purpose of the present invention is to provide a high-temperature and high-pressure plugging test system that is easy to disassemble and install, and the pressure simulation meets the plugging test requirements, is simple to operate, and is suitable for cement slurry plugging tests. The high-temperature and high-pressure plugging test system of the present invention includes a cement slurry curing kettle body, a leakage test kettle body, and a metering kettle body. The cement slurry curing kettle body is provided with stirring blades to simulate the curing of cement slurry in different flow states. The leakage test kettle body is used to test the plugging performance, and the metering kettle body is used to measure the leakage amount to reflect the plugging performance. In the present invention, the stirring blades in the cement slurry curing kettle body are assembled together with the curing kettle cover using a rotating seal assembly, the drive motor is connected to the transmission clutch assembly, the drive motor and the transmission clutch assembly are fixed above the curing kettle cover, and the drive shaft of the rotating seal assembly and the spline shaft of the transmission clutch assembly are connected by a key-matched coupling for easy disassembly and assembly. The leak-plugging experimental system of the present invention can be used for leak-plugging performance testing of cement slurry, and only uses an air source for pressure simulation. It is simple to operate, easy to disassemble and install, has good simulation effect, and can accurately test the leak-plugging performance.

[0005] In order to solve the above problems in the prior art, the present invention is implemented through the following technical solutions.

[0006] The present invention provides an in-situ cement curing high temperature and high pressure plugging test system, which includes a cement slurry curing kettle, a leakage test kettle, a metering kettle, a control cabinet and a pressure simulation subsystem;

[0007] The cement slurry curing kettle body is assembled on a rotating base. The cement slurry curing kettle body includes a curing kettle body and a curing kettle cover. The curing kettle body is equipped with an integrated heating and cooling jacket. A stirring blade is provided in the curing kettle body. The stirring blade is assembled on the curing kettle cover through a rotating sealing assembly. The stirring shaft of the stirring blade is assembled together with the transmission shaft of the rotating sealing assembly. A thermocouple is connected to the inner cavity of the curing kettle body, and the thermocouple is data-connected to the control cabinet. An electric heater is provided on the integrated heating and cooling jacket, and the electric heater is electrically connected to the control cabinet.

[0008] A blade drive assembly is provided above the cement slurry curing kettle body, and the blade drive assembly includes a rotating frame, a drive motor and a clutch transmission assembly. The drive motor and the clutch transmission assembly are fixedly assembled on the rotating frame, and the drive motor is connected to the clutch transmission assembly in a transmission manner; the lower end of the spline shaft of the clutch transmission assembly is connected to the drive shaft in the rotary seal assembly through a key-matched coupling;

[0009] The bottom of the cement slurry curing kettle body is provided with a leakage passage communicating with the leakage test kettle body, and a detachable high-pressure needle valve for controlling the opening and closing of the leakage passage is installed at the bottom of the kettle body;

[0010] The leakage test kettle body comprises a leakage kettle body and a leakage kettle cover, wherein the leakage kettle cover is provided with a leakage joint connected to the leakage passage; a crack simulator is provided in the leakage kettle body, and the crack simulator is sealed and assembled in the leakage kettle body, dividing the internal cavity of the leakage kettle body into an upper leakage chamber and a lower leakage chamber, and the leakage passage is connected to the upper leakage chamber;

[0011] The metering kettle body includes a metering kettle body and a metering kettle cover. A metering passage is provided between the metering kettle cover and the leakage lower chamber, and a flow meter is installed on the metering passage. The bottom of the metering kettle body is connected to a conductivity meter connector, and the conductivity change of the medium in the metering kettle body is tested by the conductivity meter. The flow meter and the conductivity meter are both connected to the control cabinet data.

[0012] The pressure simulation subsystem includes a pressurizing pipeline and a pressure relief pipeline connected to the cement slurry curing kettle body, and an air source pressure pipeline connected to the leakage lower chamber of the leakage test kettle body; wherein, one end of the pressurizing pipeline is connected to the nitrogen source and the other end is connected to the inner chamber of the curing kettle body through the kettle cover joint; a pressure sensor I and a pressurizing solenoid valve are provided on the pressurizing pipeline; a pressure relief solenoid valve is provided on the pressure relief pipeline; one end of the air source pressure pipeline is connected to the nitrogen source and the other end is connected to the leakage lower chamber, and a pressure sensor II, an air source solenoid valve and an electronically controlled pressure regulating valve are provided on the air source pressure pipeline; the pressure sensor I, the pressurizing solenoid valve, the pressure relief solenoid valve, the pressure sensor II, the air source solenoid valve and the electronically controlled pressure regulating valve are all connected to the control cabinet.

[0013] The rotary seal assembly also includes a sealing seat, a sealing ring, a force transmission sleeve and a sealing gland. The maintenance kettle cover is provided with an assembly groove for assembling the rotary seal assembly. The sealing seat is assembled at the bottom of the assembly groove. An axial limiting boss that cooperates with the sealing seat is provided on the transmission shaft. The force transmission sleeve is threadedly connected to the assembly groove and presses the sealing seat against the bottom of the assembly groove. A limiting cavity for accommodating the limiting boss is formed between the force transmission sleeve and the sealing seat. Sealing rings are provided above and below the limiting boss. The sealing gland is assembled on the force transmission sleeve, and the lower end of the transmission shaft extends into the kettle body through the sealing gland, the force transmission sleeve and the sealing seat.

[0014] Further preferably, the outer wall of the sealing seat and the inner wall of the assembly groove are sealed by multiple O-rings I, a polytetrafluoroethylene gasket is provided between the sealing ring at the bottom of the limiting boss and the sealing seat, and a polytetrafluoroethylene gasket is provided between the sealing ring at the top of the limiting boss and the force transmission sleeve, and the sealing ring is a carbon graphite sealing ring.

[0015] The outer wall of the power transmission sleeve and the inner wall of the assembly groove are sealed by multiple O-rings II, and a toothed sliding ring type combined seal is provided under the sealing cover to achieve sealing of the power transmission sleeve and the transmission shaft.

[0016] Further preferably, the transmission clutch assembly also includes a clutch sleeve and a synchronous wheel, the clutch sleeve is assembled on the transmission support plate through a bearing, the transmission support plate is connected to the rotating frame, and the drive motor is fixedly assembled on the transmission support plate; the synchronous wheel sleeve is arranged on the clutch sleeve and is coaxially fixedly assembled with it, the spline shaft passes through the clutch sleeve, and a manual knob is assembled on the upper end of the spline shaft; the part of the spline shaft located in the clutch sleeve is transmitted with the clutch sleeve through a ball spline; the drive motor drives the synchronous wheel to rotate through a synchronous belt.

[0017] Further preferably, the upper end of the clutch sleeve is assembled on the transmission support plate through a bearing, the lower end of the clutch sleeve is assembled on the support seat through a bearing, the support seat is assembled on the bearing positioning seat, and the bearing positioning seat is assembled with the transmission support plate through a connecting shaft; a locking screw plug is provided at the upper end of the clutch sleeve.

[0018] More preferably, a return spring is sleeved on the lower end of the spline shaft, the upper end of the return spring contacts the clutch sleeve, the lower end of the return spring contacts the spring washer, and the spring washer is relatively fixed to the spline shaft.

[0019] Further preferably, the key-fit coupling includes a first coupling and a second coupling, the first coupling is fixedly assembled on the lower end of the spline shaft, the second coupling is fixedly assembled on the upper end of the transmission shaft, and the first coupling and the second coupling are key-fitted for transmission.

[0020] Further preferably, the detachable high-pressure needle valve is fixed to the bottom of the curing kettle body through a mounting flange; the detachable high-pressure array includes a valve body, a sealing valve needle, a valve needle positioning ring, a sealing packing, a packing fixing seat, a valve stem, a rotating handle and a threaded sleeve, and the valve body is provided with a connecting hole connected to the leakage passage, and the end of the sealing valve needle is configured to block the connecting hole, and the valve body is provided with a packing groove, and the packing groove is sequentially assembled with the valve needle positioning ring, sealing packing, packing fixing seat and threaded sleeve, and the threaded sleeve is spirally assembled on the packing groove; the end of the sealing valve needle passes through the valve needle positioning ring, sealing packing and packing fixing seat in sequence and is connected to one end of the valve stem, and the other end of the valve stem is connected to the rotating handle.

[0021] More preferably, the valve body has a convex shape, a small O-ring is sleeved on the small diameter section, a medium O-ring is provided on the end face of the large diameter section, and a large O-ring is sleeved on the large diameter section.

[0022] Compared with the prior art, the beneficial technical effects brought about by the present invention are as follows:

[0023] 1. The in-situ cement curing high-temperature and high-pressure plugging test system of the present invention uses a cement slurry curing kettle, a leakage test kettle and a metering kettle to conduct simulation experiments respectively. The cement slurry curing kettle is provided with stirring blades to simulate the curing of cement slurry in different flow states. The leakage test kettle is used to test the plugging performance, and the metering kettle is used to measure the leakage amount to reflect the plugging performance. The present invention only uses an air source for pressure simulation and plugging performance detection, which has lower experimental costs and simpler operation. At the same time, the metering kettle is connected to a conductivity meter. By testing the change in the conductivity of the metering kettle, the change in the leakage amount can be measured, thereby obtaining the plugging performance of the cement slurry. The control cabinet controls, records and simulates the parameters of each experimental stage, which can realize automated plugging simulation and facilitate operators to record experimental data and simulate experimental parameters.

[0024] 2. The present invention assembles the cement slurry curing kettle body on a rotating base. When assembling the cement slurry curing kettle body, the rotating base can drive the cement slurry curing kettle body to rotate, which is convenient for the assembly and disassembly of the cement slurry curing kettle body and more conducive to the operation of the operator. The present invention particularly adopts the cooperation of the transmission clutch assembly and the rotary seal assembly, so that the rotary seal assembly can be disassembled from the transmission clutch assembly. Compared with the magnetic drive coupling method, it can save the operating space on the upper part of the curing kettle cover, facilitate the operation and assembly of the cement slurry curing kettle body, and the structure of the transmission clutch assembly is simpler than that of the magnetic drive coupling, which is convenient for the operator to maintain. Compared with the existing sealing structure between the magnetic drive coupling and the upper kettle cover, the structure of the rotary seal assembly is simpler and has a better sealing effect.

[0025] 3. The present invention uses only an air source pipeline to test the sealing performance of cement slurry, which is much simpler to operate than existing technical solutions that require oil simulation. Furthermore, with the help of the novel air source pipeline, the sealing device of the present invention can achieve in-situ cement curing, eliminating the need for multiple experiments and simplifying the experimental procedure.

[0026] 4. The rotary seal assembly provided by the present invention has a simple structure and good transmission sealing effect. The setting of the sealing seat prevents the pressure in the curing kettle cavity from escaping into the assembly groove of the curing kettle cover. The setting of the sealing ring, on the one hand, strengthens the sealing effect, and on the other hand, can also reduce the friction between the upper limit boss of the transmission shaft and the sealing seat, reduce friction resistance, and extend the service life of the transmission shaft and the sealing life. The setting of the force transmission sleeve makes the assembly of the sealing seat and the sealing ring tighter, avoiding the existence of gaps in their assembly, and axial displacement when the transmission shaft is working, affecting the accuracy of the cement slurry flow simulation, while also avoiding affecting the sealing performance. The sealing pressure cover further increases the sealing performance, preventing the pressure in the curing kettle cavity from escaping along the transmission shaft, thereby affecting the experimental accuracy.

[0027] 5. The sealing seat of the present invention uses an O-ring I seal, which has a simple sealing structure, low cost, and good sealing effect. The PTFE gasket is placed between the sealing rings to provide a certain buffering effect, reducing wear of the sealing rings and the sealing seat, and also reducing the axial force, thereby enhancing the sealing performance and extending its service life.

[0028] 6. The transmission clutch assembly of the present invention has a simple structure and a tight fit, and can realize clutch assembly with the transmission shaft. At the same time, the setting of the rotating frame can avoid the operating space on the cement slurry curing kettle body when assembling the cement slurry curing kettle body, so as to facilitate the operation of the cement slurry curing kettle body.

[0029] 7. The clutch sleeve of the present invention is assembled on the transmission support plate through a bearing, and a bearing positioning seat and a support seat are provided at its lower end to ensure the assembly stability of the clutch sleeve and the stability of the driving electric power transmission.

[0030] 8. The present invention provides a reset spring on the spline shaft to facilitate reset when the spline shaft is disengaged from the transmission shaft.

[0031] 9. The present invention designs the coupling connecting the transmission clutch assembly and the rotary seal assembly into two key-matched transmission couplings, which can realize the separation and connection of the transmission clutch assembly and the rotary seal assembly. The connection structure is simple, the transmission is stable, and it is easy to separate and connect.

[0032] 10. The detachable high-pressure needle valve of this invention uses an O-ring seal between the valve body and the curing kettle body, making it easy to separate the curing kettle body and the needle valve, reducing overall cleaning difficulty and accessory maintenance costs. The valve stem and valve needle are designed separately, reducing the opening and closing resistance of the needle valve and extending its service life. The valve body adopts a large diameter design to reduce the risk of cement slurry clogging. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] Figure 1 This is a schematic diagram of the overall connection of the high-temperature and high-pressure leak plugging experimental system of the present invention;

[0034] Figure 2 This is a schematic structural diagram of the connection between the cement slurry curing kettle and the blade drive assembly in the high-temperature and high-pressure plugging experimental system of the present invention;

[0035] Figure 3 It is a structural schematic diagram of the rotary seal assembly of the present invention;

[0036] Figure 4 It is a structural schematic diagram of the transmission clutch assembly of the present invention;

[0037] Figure 5 This is a schematic structural diagram of the detachable high-pressure needle valve of the present invention;

[0038] Figure numerals: 1, rotating base, 2, cement slurry curing kettle body, 3, heating and cooling integrated jacket, 4, insulation sleeve, 5, kettle cover handle, 6, kettle body load-bearing ring, 7, curing kettle cover, 8, rotating sealing assembly, 9, blade drive assembly, 10, diaphragm, 11, stirring blade, 12, detachable high-pressure needle valve, 13, leakage kettle cover, 14, leakage kettle body, 15, crack simulator, 16, metering kettle cover, 17, Measuring kettle body, 18, rotating frame, 19, pressure sensor I, 20, pressurization solenoid valve, 21, pressure relief solenoid valve, 22, thermocouple, 23, electric heater quick connector, 24, gas source solenoid valve, 25, pressure sensor II, 26, electric control pressure regulating valve, 27, flow meter, 28, conductivity meter, 29, control cabinet, 30, sealing seat, 31, PTFE gasket, 32, O-ring I, 33, sealing ring, 34, O-ring II, 35, drive shaft, 36, power transmission sleeve, 37, toothed slip ring type combined seal, 38, sealing cover, 39, key-matched coupling, 40, support seat, 41, manual knob, 42, locking screw plug, 43, bearing, 44, ball spline, 45, clutch sleeve, 46, return spring, 47, spring washer, 48, transmission support plate, 49, connecting shaft, 50, bearing locating seat, 51, same Step wheel, 52, synchronous belt, 53, drive motor, 54, assembly groove, 55, first coupling, 56, second coupling, 57, spline shaft, 58, kettle cover joint; 59, valve body, 60, sealing valve needle, 61, valve needle positioning ring, 62, sealing packing, 63, packing fixing seat, 64, valve stem, 65, rotating handle, 66, threaded sleeve, 67, small O-ring, 68, medium O-ring, 69, large O-ring. DETAILED DESCRIPTION

[0039] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the drawings in the present invention specification. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0040] Example 1

[0041] As a preferred embodiment of the present invention, refer to the attached Figure 1 As shown, this embodiment discloses an in-situ cement curing high temperature and high pressure plugging test system, which includes a cement slurry curing kettle 2, a leakage test kettle, a metering kettle, a control cabinet 29 and a pressure simulation subsystem;

[0042] The cement slurry curing kettle body 2 is assembled on the rotating base 1. The cement slurry curing kettle body 2 includes a curing kettle body and a curing kettle cover 7. The curing kettle body is equipped with a heating and cooling integrated jacket 3. A stirring blade 11 is provided in the curing kettle body. The stirring blade 11 is assembled on the curing kettle cover 7 through a rotating sealing assembly 8. The stirring shaft of the stirring blade 11 is assembled with the transmission shaft 35 of the rotating sealing assembly 8. A thermocouple 22 is connected to the inner cavity of the curing kettle body, and the thermocouple 22 is data-connected to the control cabinet 29. An electric heater is provided on the heating and cooling integrated jacket, and the electric heater is electrically connected to the control cabinet 29.

[0043] like Figure 2 As shown, a blade drive assembly 9 is provided above the cement slurry curing kettle body 2. The blade drive assembly 9 includes a rotating frame 18, a drive motor 53, and a clutch transmission assembly. The drive motor 53 and the clutch transmission assembly are both fixedly mounted on the rotating frame 18. The drive motor 53 is in transmission connection with the clutch transmission assembly. The lower end of the spline shaft 57 of the clutch transmission assembly is connected to the transmission shaft 35 in the rotary seal assembly 8 through a key-fit coupling 39.

[0044] The bottom of the cement slurry curing kettle body 2 is provided with a leakage passage communicating with the leakage test kettle body, and a detachable high-pressure needle valve 12 for controlling the opening and closing of the leakage passage is installed at the bottom of the kettle body;

[0045] The leakage test kettle body includes a leakage kettle body 14 and a leakage kettle cover 13, and the leakage kettle cover 13 is provided with a leakage joint connected to the leakage passage; a crack simulator 15 is provided in the leakage kettle body, and the crack simulator 15 is sealed and assembled in the leakage kettle body, dividing the internal cavity of the leakage kettle body into a leakage upper cavity and a leakage lower cavity, and the leakage passage is connected to the leakage upper cavity;

[0046] The metering kettle body includes a metering kettle body 17 and a metering kettle cover 16. A metering passage is provided between the metering kettle cover 16 and the leakage lower chamber, and a flow meter 27 is installed on the metering passage. The bottom of the metering kettle body 17 is connected to a conductivity meter 28 connector, and the conductivity change of the medium in the metering kettle body 17 is tested by the conductivity meter 28. The flow meter 27 and the conductivity meter 28 are both connected to the control cabinet 29 for data communication.

[0047] The pressure simulation subsystem includes a pressurizing pipeline and a pressure relief pipeline connected to the cement slurry curing kettle body 2, and an air source pressure pipeline connected to the leakage lower cavity of the leakage test kettle body; wherein, one end of the pressurizing pipeline is connected to the nitrogen source and the other end is connected to the inner cavity of the curing kettle body through the kettle cover joint 58; a pressure sensor I 19 and a pressurizing solenoid valve 20 are provided on the pressurizing pipeline; a pressure relief solenoid valve 21 is provided on the pressure relief pipeline; one end of the air source pressure pipeline is connected to the nitrogen source and the other end is connected to the leakage lower cavity, and a pressure sensor II 25, an air source solenoid valve 24 and an electronically controlled pressure regulating valve 26 are provided on the air source pressure pipeline; the pressure sensor I 19, the pressurizing solenoid valve 20, the pressure relief solenoid valve 21, the pressure sensor II 25, the air source solenoid valve 24 and the electronically controlled pressure regulating valve 26 are all connected to the control cabinet 29.

[0048] In this embodiment, the rotating base 1 is a welded frame. The cement slurry curing kettle body 2 is fixed to the rotating base 1 during use. A positioning hole for installing a removable high-pressure needle valve 12 is provided at one end of the cement slurry curing kettle body 2. The removable high-pressure needle valve 12 is installed in the cement slurry curing kettle body 2 and fixed with bolts. After the cement slurry curing kettle body is installed with the kettle body bearing ring 6 and the kettle cover handle 5, the curing kettle body is lifted and installed on the rotating base 1 via the kettle cover handle 5. A fixed amount of cement slurry is poured in, and the stirring blades, diaphragm 10, curing kettle cover 7, and rotary seal assembly 8 are stirred in sequence. The position of the rotating frame 18 in the blade drive assembly 9 is adjusted to connect the blade drive assembly 9 to the drive shaft 35 of the rotary seal assembly 8. After completing the above work, the heating and cooling integrated jacket 3 is quickly fixed. The electric heater and cooling pipe inside the heating and cooling integrated jacket 3 are connected to the control cabinet 29 and the water source using the electric heater quick connector 23 and the water source connector respectively. The curing kettle body is wrapped and insulated using an integrated insulation sleeve 4.

[0049] After the above work is completed, the crack simulator 15 is placed in the leakage kettle body, the leakage kettle body is filled with water, and the leakage kettle cover 13 is tightened. Then, the metering kettle body and the leakage kettle body are connected through the flow meter 27.

[0050] Control cabinet 29 controls the target pressure within the cement curing kettle during the curing period via the pressurizing solenoid valve 20, the pressure relief solenoid valve 21, and pressure sensor I 19. Control cabinet 29 uses feedback from pressure sensor II 25 within the leaking kettle to control the electronically controlled pressure regulating valve 26, ensuring stable pressure within the leaking kettle during the curing period. After curing is complete, keep the pressurizing solenoid valve 20 open and the pressure relief solenoid valve 21 closed, and manually open the removable high-pressure needle valve 12. Two possibilities exist:

[0051] (1) The pressure of the cement curing kettle remains unchanged and the pressure difference with the leakage kettle is stable. The flow meter 27 reading is stable. At this time, the cement slurry has completed the plugging. The change in the conductivity meter 28 reading is observed to evaluate the cement plugging performance.

[0052] (2) The overflow water reading feedback through the flow meter 27 was too large, and the conductivity changed too much. The experiment was completed and no further testing was performed. It was determined that the cement slurry did not have the ability to plug leaks for this type of crack plate (crack simulator 15).

[0053] In this embodiment, a cement slurry curing kettle 2, a leakage test kettle, and a metering kettle are used to conduct simulation experiments. The cement slurry curing kettle 2 is provided with a stirring blade 11 to simulate the curing of cement slurry in different flow states. The leakage test kettle is used to test the plugging performance, and the metering kettle is used to measure the leakage amount to reflect the plugging performance. The present invention only uses an air source for pressure simulation and plugging performance testing, which reduces experimental costs and is easier to operate. At the same time, the metering kettle is connected to a conductivity meter 28. By testing the conductivity changes of the metering kettle, the changes in the leakage amount can be measured, thereby obtaining the plugging performance of the cement slurry. The control cabinet 29 controls, records, and simulates the parameters of each experimental stage, realizing automated plugging simulation and making it convenient for operators to record experimental data and simulation experimental parameters.

[0054] The cement slurry curing kettle body 2 is assembled on the rotating base 1. When the cement slurry curing kettle body 2 is assembled, the rotating base 1 can drive the cement slurry curing kettle body 2 to rotate, which is convenient for the assembly and disassembly of the cement slurry curing kettle body 2 and more conducive to the operation of the operator. The present invention particularly adopts the cooperation of the transmission clutch assembly and the rotary seal assembly 8, so that the rotary seal assembly 8 can be disassembled from the transmission clutch assembly. Compared with the magnetic drive coupling, it can save the operating space on the upper part of the curing kettle cover 7, which is convenient for the operation and assembly of the cement slurry curing kettle body 2. The structure of the transmission clutch assembly is simpler than that of the magnetic drive coupling, which is convenient for the operator to maintain. Compared with the existing sealing structure between the magnetic drive coupling and the upper kettle cover, the structure of the rotary seal assembly 8 is simpler and has a better sealing effect.

[0055] In this embodiment, the leak-proofing performance of cement slurry can be tested using only an air source pipeline, which is much simpler to operate than existing technical solutions that require oil simulation. Furthermore, with the novel air source pipeline, the leak-proofing device of the present invention can achieve in-situ cement curing, eliminating the need for multiple experiments and simplifying the experimental procedure.

[0056] Example 2

[0057] As another preferred embodiment of the present invention, this embodiment is a further detailed supplement and explanation of the technical solution of the present invention based on the above embodiment 1. Figure 3As shown, the rotary seal assembly 8 also includes a sealing seat 30, a sealing ring 3433, a force transmission sleeve 36 and a sealing gland 38. The curing kettle cover 7 is provided with an assembly groove 54 for assembling the rotary seal assembly 8. The sealing seat 30 is assembled at the bottom of the assembly groove 54. The transmission shaft 35 is provided with an axial limiting boss that cooperates with the sealing seat 30. The force transmission sleeve 36 is threadedly connected to the assembly groove 54 and presses the sealing seat 30 against the bottom of the assembly groove 54. A limiting cavity for accommodating the limiting boss is formed between the force transmission sleeve 36 and the sealing seat 30. Sealing rings 3433 are provided above and below the limiting boss; the sealing gland 38 is assembled on the force transmission sleeve 36, and the lower end of the transmission shaft 35 extends into the kettle body through the sealing gland 38, the force transmission sleeve 36 and the sealing seat 30.

[0058] Further preferably, the outer wall of the sealing seat 30 and the inner wall of the assembly groove 54 are sealed by multiple O-rings I 32, a polyfluorocarbon gasket 31 is arranged between the sealing ring 3433 at the bottom of the limiting boss and the sealing seat 30, and a polyfluorocarbon gasket 31 is arranged between the sealing ring 3433 at the top of the limiting boss and the force transmission sleeve 36, and the sealing ring 3433 is a carbon graphite sealing ring 3433.

[0059] The outer wall of the force transmission sleeve 36 and the inner wall of the assembly groove 54 are sealed by multiple O-rings II, and a toothed sliding ring type combined seal 37 is provided under the sealing cover 38 to achieve sealing of the force transmission sleeve 36 and the transmission shaft 35.

[0060] In this embodiment, the rotary seal assembly 8 is installed on the curing kettle cover 7 of the cement curing kettle body, the O-ring I 32 is placed into the curing kettle cover 7, and then the sealing seat 30 is installed. The polytetrafluoroethylene gasket 31 and the sealing ring 3433 are installed in the sealing seat 30 in sequence. The transmission shaft 35 is installed in place, and then the sealing ring 3433 and the polytetrafluoroethylene gasket 31 are inserted into the transmission shaft 35 in sequence. The power transmission sleeve 36 equipped with the O-ring II is screwed into the curing kettle cover 7 to press the polytetrafluoroethylene gasket 31 and the sealing ring 3433 to realize the rotary seal of the transmission shaft 35. The toothed sliding ring combination seal 37 and the rotary seal gland 38 are installed on the power transmission sleeve 36, and the lower half of the key-fit coupling 39 (the second coupling) is connected to the transmission shaft 35.

[0061] The rotary seal assembly 8 provided in this embodiment has a simple structure and good transmission sealing effect. The setting of the sealing seat 30 prevents the pressure in the curing kettle chamber from escaping into the assembly groove 54 of the curing kettle cover 7. The setting of the sealing ring 3433, on the one hand, strengthens the sealing effect, and on the other hand, can also reduce the friction between the upper limit boss of the transmission shaft 35 and the sealing seat 30, reducing friction resistance and extending the service life and sealing life of the transmission shaft 35. The setting of the force transmission sleeve 36 makes the assembly of the sealing seat 30 and the sealing ring 3433 tighter, avoiding the existence of gaps in their assembly, which would cause axial movement of the transmission shaft 35 when it is working, affecting the accuracy of the cement slurry flow simulation, and also avoiding affecting the sealing performance. The sealing pressure cap 38 further improves the sealing performance, preventing the pressure in the curing kettle chamber from escaping along the transmission shaft 35, thereby affecting the experimental accuracy.

[0062] Sealing seat 30 is sealed with an O-ring I 32, which features a simple, low-cost, and effective sealing structure. A PTFE gasket 31 is positioned between sealing rings 34 and 33 to provide a buffering effect, reducing wear on both rings 34 and 30 and alleviating axial stress, thereby enhancing sealing performance and extending service life.

[0063] Example 3

[0064] As another preferred embodiment of the present invention, this embodiment is a further detailed supplement and explanation of the technical solution of the present invention based on the above embodiment 1 or embodiment 2. Figure 2 and attached Figure 4 As shown, the transmission clutch assembly also includes a clutch sleeve 45 and a synchronous wheel 51. The clutch sleeve 45 is assembled on the transmission support plate 48 through a bearing 43. The transmission support plate 48 is connected to the rotating frame 18, and the drive motor 53 is fixedly assembled on the transmission support plate 48; the synchronous wheel 51 is sleeved on the clutch sleeve 45 and coaxially fixedly assembled therewith, the spline shaft 57 passes through the clutch sleeve 45, and the upper end of the spline shaft 57 is equipped with a manual knob 41; the part of the spline shaft 57 located in the clutch sleeve 45 cooperates with the clutch sleeve 45 through the ball spline 44 for transmission; the drive motor 53 drives the synchronous wheel 51 to rotate through the synchronous belt 52.

[0065] The transmission clutch assembly provided in this embodiment has a simple structure and a tight fit, and can realize clutch assembly with the transmission shaft 35. At the same time, the setting of the rotating frame 18 can avoid the operating space on the cement slurry curing kettle body 2 when assembling the cement slurry curing kettle body 2, so as to facilitate the operation of the cement slurry curing kettle body 2.

[0066] More preferably, the upper end of the clutch sleeve 45 is mounted on the transmission support plate 48 via a bearing 43, while the lower end of the clutch sleeve 45 is mounted on the support seat 40 via a bearing 43. The support seat 40 is mounted on a bearing locating seat 50, which is assembled to the transmission support plate 48 via a connecting shaft 49. A locking screw plug 42 is provided at the upper end of the clutch sleeve 45. The clutch sleeve 45 is mounted on the transmission support plate 48 via a bearing 43, and the bearing locating seat 50 and support seat 40 are provided at its lower end, ensuring the assembly stability of the clutch sleeve 45 and the stability of the driving electric power transmission.

[0067] More preferably, a return spring 46 is sleeved on the lower end of the spline shaft 57. The upper end of the return spring 46 contacts the clutch sleeve 45, and the lower end of the return spring 46 contacts the spring washer 47. The spring washer 47 is fixed relative to the spline shaft 57. The return spring 46 is provided on the spline shaft 57 to facilitate reset when it is clutched with the transmission shaft 35.

[0068] Further preferably, the keyed coupling 39 includes a first coupling member 55 and a second coupling member 56. The first coupling member 55 is fixedly assembled to the lower end of the spline shaft 57, and the second coupling member is fixedly assembled to the upper end of the transmission shaft 35. The first coupling member 55 and the second coupling member are keyed to each other. In this embodiment, the coupling connecting the transmission clutch assembly and the rotary seal assembly 8 is designed as two keyed coupling members. This allows for separation and connection between the transmission clutch assembly and the rotary seal assembly 8, resulting in a simple connection structure, stable transmission, and easy separation and connection.

[0069] In this embodiment, the transmission support plate 48 is connected to the rotating frame 18 to achieve overall rotation. The drive motor 53 (single-phase induction motor) equipped with the synchronous wheel 51 is fixed to the transmission support plate 48. The support seat 40 is fixed to the bearing positioning seat 50. Then, the bearing 43 is installed in the support seat 40. The clutch sleeve 45 is installed in the inner hole of the bearing 43. The synchronous wheel 51 is installed on the clutch sleeve 45. The ball spline 44 is inserted into the interior of the clutch sleeve 45 and locked with the locking screw plug 42. Fix the manual knob 41 to the spline shaft 57, install two connectors on the bearing locator 50, install the bearing 43 on the transmission support plate 48, connect the synchronous wheel 51 to the synchronous belt 52, install the clutch sleeve 45 into the bearing 43 on the transmission support plate 48, connect the transmission support plate 48 to the connecting shaft 49, insert the return spring 46 into the other end of the spline shaft 57, use the spring washer 47 to compress the spring, and connect the first coupling 55 of the coupling to the end of the spline shaft 57. Adjust the position of the drive motor 53 to tighten the synchronous belt 52 to complete the assembly of the clutch part.

[0070] Example 4

[0071] As another preferred embodiment of the present invention, this embodiment is a further detailed supplement and explanation of the technical solution of the present invention based on the above-mentioned embodiment 1, embodiment 2 or embodiment 3. Figure 5 As shown, the detachable high-pressure needle valve 12 is fixed to the bottom of the curing kettle body through a mounting flange; the detachable high-pressure array includes a valve body 59, a sealing valve needle 60, a valve needle positioning ring 61, a sealing packing 62, a packing fixing seat 63, a valve stem 64, a rotating handle 65 and a threaded pressing sleeve 66. The valve body 59 is provided with a connecting hole connected to the leakage passage, and the end of the sealing valve needle 60 is configured to block the connecting hole. The valve body 59 is provided with a packing groove, and the packing groove is sequentially assembled with the valve needle positioning ring 61, the sealing packing 62, the packing fixing seat 63 and the threaded pressing sleeve 66, and the threaded pressing sleeve 66 is spirally assembled on the packing groove; the end of the sealing valve needle 60 passes through the valve needle positioning ring 61, the sealing packing 62 and the packing fixing seat 63 in sequence and is connected to one end of the valve stem 64, and the other end of the valve stem 64 is connected to the rotating handle 65. The valve body 59 has a convex shape, with a small O-ring 67 sleeved on the small diameter section, a medium O-ring 68 set on the end face of the large diameter section, and a large O-ring 69 sleeved on the large diameter section.

[0072] The valve body 59 of the removable high-pressure needle valve 12 provided in this embodiment is sealed with an O-ring to the curing kettle body, making it easy to separate the curing kettle body from the needle valve, reducing overall cleaning difficulty and accessory maintenance costs. The valve stem 64 and valve needle are designed separately, reducing the opening and closing resistance of the needle valve and extending its service life. The large diameter of the valve body 59 reduces the risk of cement slurry clogging.

Claims

1. An in-situ cement curing high temperature and high pressure plugging experimental system, characterized by: It includes a cement slurry curing kettle (2), a leakage test kettle, a metering kettle, a control cabinet (29) and a pressure simulation subsystem; The cement slurry curing kettle body (2) is assembled on the rotating base (1), and the cement slurry curing kettle body (2) includes a curing kettle body and a curing kettle cover (7). The curing kettle body is equipped with a heating and cooling integrated jacket (3). A stirring blade (11) is provided in the curing kettle body. The stirring blade (11) is assembled on the curing kettle cover (7) through a rotating sealing component (8). The stirring shaft of the stirring blade (11) is assembled with the transmission shaft (35) of the rotating sealing component (8). The inner cavity of the curing kettle body is connected to a thermocouple (22), and the thermocouple (22) is data-connected to a control cabinet (29). An electric heater is provided on the heating and cooling integrated jacket, and the electric heater is electrically connected to the control cabinet (29). A blade drive assembly (9) is provided above the cement slurry curing kettle body (2), the blade drive assembly (9) comprising a rotating frame (18), a drive motor (53) and a clutch transmission assembly, the drive motor (53) and the clutch transmission assembly being fixedly mounted on the rotating frame (18), the drive motor (53) being in transmission connection with the clutch transmission assembly; the lower end of the spline shaft (57) of the clutch transmission assembly is detachably connected to the transmission shaft (35) in the rotary seal assembly (8) via a key-matched coupling (39); The bottom of the cement slurry curing kettle body (2) is provided with a leakage passage communicating with the leakage test kettle body, and a detachable high-pressure needle valve (12) for controlling the opening and closing of the leakage passage is installed at the bottom of the kettle body; The leakage test kettle body comprises a leakage kettle body (14) and a leakage kettle cover (13), wherein the leakage kettle cover (13) is provided with a leakage joint connected to the leakage passage; a crack simulator (15) is provided in the leakage kettle body, and the crack simulator (15) is sealed and assembled in the leakage kettle body, dividing the internal cavity of the leakage kettle body into a leakage upper cavity and a leakage lower cavity, and the leakage passage is connected to the leakage upper cavity; The metering kettle body comprises a metering kettle body (17) and a metering kettle cover (16); a metering passage is provided between the metering kettle cover (16) and the leakage lower chamber, and a flow meter (27) is mounted on the metering passage; the bottom of the metering kettle body (17) is connected to a conductivity meter (28) connector, and the conductivity change of the medium in the metering kettle body (17) is tested by the conductivity meter (28); the flow meter (27) and the conductivity meter (28) are both connected to the control cabinet (29) for data connection; The pressure simulation subsystem includes a pressurizing pipeline and a pressure relief pipeline connected to the cement slurry curing kettle body (2), and an air source pressure pipeline connected to the leakage lower cavity of the leakage test kettle body; wherein one end of the pressurizing pipeline is connected to the nitrogen source, and the other end is connected to the inner cavity of the curing kettle body through the kettle cover joint (58); a pressure sensor I (19) and a pressurizing solenoid valve (20) are provided on the pressurizing pipeline; a pressure relief solenoid valve (21) is provided on the pressure relief pipeline; one end of the air source pressure pipeline is connected to the nitrogen source, and the other end is connected to the leakage lower cavity, and a pressure sensor II (25), an air source solenoid valve (24) and an electric control pressure regulating valve (26) are provided on the air source pressure pipeline; the pressure sensor I (19), the pressurizing solenoid valve (20), the pressure relief solenoid valve (21), the pressure sensor II (25), the air source solenoid valve (24) and the electric control pressure regulating valve (26) are all connected to the control cabinet (29).

2. The in-situ cement curing high temperature and high pressure plugging test system according to claim 1, characterized in that: The rotary seal assembly (8) further comprises a sealing seat (30), a sealing ring (33), a force transmission sleeve (36) and a sealing gland (38); an assembly groove (54) for assembling the rotary seal assembly (8) is provided on the curing kettle cover (7); the sealing seat (30) is assembled at the bottom of the assembly groove (54); an axial limiting boss cooperating with the sealing seat (30) is provided on the transmission shaft (35); the force transmission sleeve (36) is threadedly connected to the assembly groove (54) and presses the sealing seat (30) against the bottom of the assembly groove (54); a limiting cavity for accommodating the limiting boss is formed between the force transmission sleeve (36) and the sealing seat (30); sealing rings (33) are provided above and below the limiting boss; the sealing gland (38) is assembled on the force transmission sleeve (36); the lower end of the transmission shaft (35) passes through the sealing gland (38), the force transmission sleeve (36) and the sealing seat (30) and extends into the kettle body.

3. The in-situ cement curing high temperature and high pressure plugging test system according to claim 2, characterized in that: The outer wall of the sealing seat (30) and the inner wall of the assembly groove (54) are sealed by multiple O-rings I (32). A polyfluorocarbon gasket (31) is provided between the sealing ring (33) at the bottom of the limiting boss and the sealing seat (30). A polyfluorocarbon gasket (31) is provided between the sealing ring (33) at the top of the limiting boss and the force transmission sleeve (36). The sealing ring (33) is a carbon graphite sealing ring.

4. The in-situ cement curing high temperature and high pressure plugging test system according to claim 2, characterized in that: The outer wall of the power transmission sleeve (36) and the inner wall of the assembly groove (54) are sealed by multiple O-rings II (34), and a toothed sliding ring type combined seal (37) is provided under the sealing cover (38) to achieve sealing of the power transmission sleeve (36) and the transmission shaft (35).

5. An in-situ cement curing high temperature and high pressure plugging test system according to any one of claims 1 to 4, characterized in that: The clutch transmission assembly further comprises a clutch sleeve (45) and a synchronous wheel (51), wherein the clutch sleeve (45) is assembled on a transmission support plate (48) through a bearing (43), wherein the transmission support plate (48) is connected to the rotating frame (18), and the driving motor (53) is fixedly assembled on the transmission support plate (48); the synchronous wheel (51) is sleeved on the clutch sleeve (45) and fixedly assembled coaxially therewith, wherein a spline shaft (57) passes through the clutch sleeve (45), and a manual knob (41) is assembled on the upper end of the spline shaft (57); the portion of the spline shaft (57) located in the clutch sleeve (45) cooperates with the clutch sleeve (45) for transmission through a ball spline (44); and the driving motor (53) drives the synchronous wheel (51) to rotate through a synchronous belt (52).

6. The in-situ cement curing high temperature and high pressure plugging test system according to claim 5, characterized in that: The upper end of the clutch sleeve (45) is assembled on the transmission support plate (48) through the bearing (43), the lower end of the clutch sleeve (45) is assembled on the support seat (40) through the bearing (43), the support seat (40) is assembled on the bearing positioning seat (50), and the bearing positioning seat (50) is assembled with the transmission support plate (48) through the connecting shaft (49); a locking screw plug (42) is provided at the upper end of the clutch sleeve (45).

7. The in-situ cement curing high temperature and high pressure plugging test system according to claim 5, characterized in that: A return spring (46) is sleeved on the lower end of the spline shaft (57), the upper end of the return spring (46) contacts the clutch sleeve (45), and the lower end of the return spring (46) contacts the spring washer (47), and the spring washer (47) is relatively fixed to the spline shaft (57).

8. An in-situ cement curing high temperature and high pressure plugging test system according to any one of claims 1 to 4, characterized in that: The key-matched coupling (39) comprises a first coupling (55) and a second coupling (56), wherein the first coupling (55) is fixedly assembled on the lower end of the spline shaft (57), and the second coupling is fixedly assembled on the upper end of the transmission shaft (35), and the first coupling (55) and the second coupling are key-matched for transmission.

9. An in-situ cement curing high temperature and high pressure plugging test system according to any one of claims 1 to 4, characterized in that: The detachable high-pressure needle valve (12) is fixed to the bottom of the curing kettle body through a mounting flange; the detachable high-pressure needle valve comprises a valve body (59), a sealing valve needle (60), a valve needle positioning ring (61), a sealing packing (62), a packing fixing seat (63), a valve stem (64), a rotating handle (65) and a threaded pressing sleeve (66); a connecting hole connected to the leakage path is provided on the valve body (59); the end of the sealing valve needle (60) is configured to block the connecting hole; a packing groove is provided on the valve body (59); the packing groove is sequentially assembled with the valve needle positioning ring (61), the sealing packing (62), the packing fixing seat (63) and the threaded pressing sleeve (66); the threaded pressing sleeve (66) is spirally assembled on the packing groove; the end of the sealing valve needle (60) passes through the valve needle positioning ring (61), the sealing packing (62) and the packing fixing seat (63) in sequence and is connected to one end of the valve stem (64); the other end of the valve stem (64) is connected to the rotating handle (65).

10. The in-situ cement curing high temperature and high pressure plugging test system according to claim 9, characterized in that: The valve body (59) has a convex shape, a small O-ring (67) is provided on the small diameter section, a medium O-ring (68) is provided on the end face of the large diameter section, and a large O-ring (69) is provided on the large diameter section.

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