Device and method for continuously testing high-temperature dynamic settlement stability of cement slurry for well cementing

Abstract

The present invention provides a device for continuously testing the high-temperature dynamic settlement stability of cement slurry for well cementing, which includes: a sealed kettle, which includes a sealed kettle cover (1), a sealed kettle body (2), a base fixing nail (4), a rotor (5), a motor (6), a kettle bottom sealing ring (7), a fixing bolt (8), a kettle cover jack (9), a fixing pin (10), and a paddle blade slot (13); a stirring slurry cup, which includes a slurry cup body (14), a stirring paddle blade (15), and a sealing cover plate (16); a density measuring device, which includes a densitometer rod (17), a densitometer probe (18), and a densitometer signal converter (19). The present invention can test the change of the density value of the cement slurry during the dynamic stirring process and simultaneously realize the continuous measurement of the change of the cement slurry density. The present invention uses a tuning fork densitometer for testing, which overcomes the problem that when using a pressure sensor to test the density of the cement slurry by fluctuations, the density of the cement slurry cannot be accurately measured due to the change of the internal stress of the cement slurry caused by the rise in temperature.

Description

Technical Field

[0001] The present invention relates to the technical field of oilfield cementing, and specifically, to an apparatus and method for continuously testing the high-temperature dynamic sedimentation stability of cement slurry for cementing. Background Art

[0002] During cementing, the cement slurry is injected into the wellbore. Due to the density difference between the admixtures and cement particles in the cement slurry, if the sedimentation stability of the cement slurry is poor, the particles with a large density will settle severely due to gravity, resulting in a density difference between the upper and lower parts of the cement slurry column. This not only affects the safety of cementing operations but also reduces the cementing quality.

[0003] Currently, most of the methods for testing the sedimentation stability of cement slurry proposed by domestic and foreign companies, research institutions, and scholars are static discontinuous sedimentation stability tests. During the test, the cement slurry is in a static state and the test process is discontinuous, that is, the change in the density of the cement slurry cannot be measured in real time.

[0004] Moreover, the only existing apparatus for dynamically and continuously measuring the sedimentation stability of cement slurry using pressure fluctuations also has problems. This apparatus uses a pressure sensor for measurement, but the cement slurry will expand at high temperatures, resulting in changes and fluctuations in internal stress. At this time, the accuracy of the measurement results will be affected by pressure fluctuations, leading to deviations in the measurement results.

[0005] Therefore, the present invention provides an apparatus and method for continuously testing the high-temperature dynamic sedimentation stability of cement slurry for cementing. Summary of the Invention

[0006] To solve the above problems, the present invention provides an apparatus for continuously testing the high-temperature dynamic sedimentation stability of cement slurry for cementing, and the apparatus includes:

[0007] A sealing kettle, which includes a sealing kettle cover (1), a sealing kettle body (2), a base fixing nail (4), a rotor (5), a motor (6), a kettle bottom sealing ring (7), fixing bolts (8), kettle cover jacks (9), fixing pins (10), and a paddle slot (13). Among them, the sealing kettle cover (1) is fixed on the sealing kettle body (2) through the fixing bolts (8). There are at least three kettle cover jacks (9) on the sealing kettle cover (1). The rotor (5) is connected to the motor (6), and when the motor (6) rotates, it drives the rotor (5) to rotate. The kettle bottom sealing ring (7) is used to ensure the sealing performance of the sealing kettle;

[0008] A stirring slurry cup, which includes a slurry cup body (14), a stirring paddle (15), and a sealing cover plate (16). Among them, the slurry cup body (14) is fixed on the rotor (5) by the base fixing nail (4). The stirring paddle (15) is fixed through the paddle slot (13). The sealing cover plate (16) is threadedly connected to the slurry cup body (14);

[0009] A density measurement device, which includes a densitometer rod (17), a densitometer probe (18), and a densitometer signal converter (19). Among them, the densitometer rod (17) and the densitometer probe (18) are inserted into the cover socket (9) of the kettle and fixed on the sealed kettle cover (1) by fixing pins (10). The densitometer probe (18) is at least arranged in the upper, middle, and lower parts of the stirring slurry cup to measure the density of the cement slurry at the upper, middle, and lower parts of the stirring slurry cup respectively. The densitometer signal converter (19) is used to convert the electrical signals representing the density change of the cement slurry measured by the densitometer rod (17) and the densitometer probe (18) into digital signals.

[0010] According to an embodiment of the present invention, the sealed kettle further includes a heating jacket (3), which is used to wrap the sealed kettle body (2).

[0011] According to an embodiment of the present invention, the sealed kettle further includes an oil inlet pipeline and valve (11) and an oil outlet pipeline and valve (12) for respectively controlling the injection and discharge of the internal medium of the sealed kettle body (2).

[0012] According to an embodiment of the present invention, the density measurement device further includes:

[0013] A kettle body thermometer (20), which is connected to the heating jacket (3);

[0014] A kettle body pressure gauge (21), which is used to measure the pressure inside the sealed kettle;

[0015] A temperature and pressure controller (22), which is connected to the kettle body thermometer (20) and the kettle body pressure gauge (21) for controlling the pressure and temperature of the sealed kettle.

[0016] According to an embodiment of the present invention, the density measurement device further includes:

[0017] A computer (23), which is connected to the temperature and pressure controller (22) and the densitometer signal converter (19) for adjusting the control parameters of the temperature and pressure controller (22), receiving the digital signals transmitted by the densitometer signal converter (19), and displaying the curve of the change of the cement slurry density over time based on the digital signals.

[0018] According to an embodiment of the present invention, both the sealed kettle cover (1) and the sealed kettle body (2) are made of pressure-resistant steel alloy materials, and the bottom seal ring (7) of the kettle is made of high-temperature resistant polytetrafluoroethylene material.

[0019] According to an embodiment of the present invention, the cement slurry densitometer composed of the densitometer rod (17) and the densitometer probe (18) adopts a tuning fork densitometer.

[0020] According to an embodiment of the present invention, the rotational speed of the motor (6) is adjusted according to the cementing operation conditions to simulate the flow rate during the cement slurry injection and displacement process.

[0021] According to an embodiment of the present invention, the range of the cement slurry density that can be measured by the high-temperature dynamic sedimentation stability device for cementing cement slurry is 1.5 - 2.5 g / cm 3 , the operating ambient temperature range is 0 - 200 °C, and the maximum operating ambient pressure is 20 MPa.

[0022] According to another aspect of the present invention, there is also provided a method for continuously testing the high-temperature dynamic sedimentation stability of cementing cement slurry. The continuous testing of the high-temperature dynamic sedimentation stability of cementing cement slurry is carried out by using the device for continuously testing the high-temperature dynamic sedimentation stability of cementing cement slurry as described in any one of the above. The method includes the following steps:

[0023] Step 1: Configure the cement slurry and test its initial density. Pour the cement slurry into the set stirring paddle cup, and place the stirring paddle cup in the sealing kettle to complete the setting of the sealing kettle and the density measuring device.

[0024] Step 2: Turn on the motor (6), adjust the rotational speed of the motor (6) according to the working conditions, read the density of the cement slurry measured by the density meter rod (17) and the density meter probe (18), and correct it with the initial density of the cement slurry.

[0025] Step 3: Inject high-temperature curing oil into the sealing kettle body (2) so that the curing oil fills the entire sealing kettle body (2). Set the test temperature and the heating time. After starting the test, collect the density values of the cement slurry at the upper, middle, and lower parts of the stirring paddle cup, and display the curves of the upper, middle, and lower densities changing with time.

[0026] The device and method for continuously testing the high-temperature dynamic sedimentation stability of cementing cement slurry provided by the present invention can test the change of the density value of the cement slurry during the dynamic stirring process, and at the same time realize the continuous measurement of the change of the cement slurry density; the highest working temperature of the device provided by the present invention is 200 °C, which meets the test conditions for the sedimentation stability of cementing cement slurry in deep wells and ultra-deep wells; the device provided by the present invention uses a tuning fork density meter for testing, which overcomes the problem that when using a pressure sensor to test the density of cement slurry by fluctuations, the internal stress of the cement slurry changes due to the temperature rise, resulting in inaccurate measurement of the cement slurry density.

[0027] Other features and advantages of the present invention will be described in the subsequent specification, and part of them will be obvious from the specification, or understood by implementing the present invention. The objectives and other advantages of the present invention can be realized and obtained through the structures specifically pointed out in the specification, claims, and drawings. Description of the Drawings

[0028] The accompanying drawings are used to provide a further understanding of the present invention and form a part of the specification. They are used together with the embodiments of the present invention to explain the present invention and do not constitute a limitation on the present invention. In the accompanying drawings:

[0029] Figure 1 Shows the front view of the high-temperature dynamic settlement stability device for well cement slurry according to an embodiment of the present invention;

[0030] Figure 2 Shows the top view of the sealing cover plate of the stirring slurry cup according to an embodiment of the present invention;

[0031] Figure 3 Shows the flowchart of the method for continuously testing the high-temperature dynamic settlement stability of well cement slurry according to an embodiment of the present invention; and

[0032] Figure 4 Shows the schematic diagram of the cement slurry density change curve according to an embodiment of the present invention. Detailed Description of the Invention

[0033] To make the objectives, technical solutions and advantages of the present invention clearer, the following further details the embodiments of the present invention with reference to the accompanying drawings.

[0034] Figure 1 Shows the front view of the high-temperature dynamic settlement stability device for well cement slurry according to an embodiment of the present invention.

[0035] As Figure 1 shown, the high-temperature dynamic settlement stability device for well cement slurry includes a sealed autoclave, a stirring slurry cup and a density measurement device.

[0036] As Figure 1-2 shown, the sealed autoclave includes a sealed autoclave cover (1), a sealed autoclave body (2), a base fixing nail (4), a rotor (5), a motor (6), a bottom seal ring of the autoclave (7), fixing bolts (8), an insertion hole on the autoclave cover (9), a fixing pin (10) and a blade slot (13).

[0037] As Figure 1 shown, the stirring slurry cup includes a slurry cup body (14), a stirring blade (15) and a sealing cover plate (16).

[0038] As Figure 1 shown, the density measurement device includes a density meter rod (17), a density meter probe (18) and a density meter signal converter (19).

[0039] Specifically, as Figure 1-2As shown in the figure, the sealed kettle cover (1) is fixed on the sealed kettle body (2) by fixing bolts (8). There are at least three kettle cover jacks (9) on the sealed kettle cover (1). The rotor (5) is connected to the motor (6). When the motor (6) rotates, it drives the rotor (5) to rotate. The bottom kettle seal ring (7) is used to ensure the sealing performance of the sealed kettle.

[0040] Specifically, the slurry cup body (14) is fixed on the rotor (5) by the base fixing nails (4). The stirring paddle (15) is fixed through the paddle slot (13). The sealing cover plate (16) is threadedly connected with the slurry cup body (14).

[0041] The stirring principle of the stirring slurry cup is as follows: Fix the stirring paddle (15), and the lower rotor (5) drives the slurry cup body (14) to rotate, so that the stirring paddle (15) and the slurry cup body (14) perform relative motion to stir the slurry.

[0042] Specifically, the density meter rod (17) and the density meter probe (18) are inserted into the kettle cover jack (9) and fixed on the sealed kettle cover (1) by the fixing pin (10). The density meter probe (18) is arranged at least at three positions: the upper part, the middle part and the lower part of the stirring slurry cup, and is used to measure the density of the cement slurry at the upper, middle and lower parts of the stirring slurry cup respectively; the density meter signal converter (19) is used to convert the electrical signals representing the density change of the cement slurry measured by the density meter rod (17) and the density meter probe (18) into digital signals.

[0043] Furthermore, the number of the kettle cover jacks (9) is at least three. A density meter rod (17) and a density meter probe (18) for measuring the density of the cement slurry can be inserted into each kettle cover jack (9). The setting positions of the density meter probes (18) can be at the upper, middle and lower heights of the stirring slurry cup. The height setting rule of the density meter probes (18) is to be set at intervals, and the interval height is not limited.

[0044] In one embodiment, the sealed kettle further includes a heating jacket (3), which is used to wrap the sealed kettle body (2).

[0045] In one embodiment, the sealed kettle further includes an oil inlet pipeline and valve (11) and an oil outlet pipeline and valve (12), which are used to control the injection and discharge of the internal medium of the sealed kettle body (2) respectively.

[0046] In one embodiment, the density measuring device further includes: a kettle body thermometer (20), a kettle body pressure gauge (21) and a temperature and pressure controller (22).

[0047] Specifically, the kettle body thermometer (20) is connected to the heating jacket (3); the kettle body pressure gauge (21) is used to measure the pressure inside the sealed kettle; the temperature and pressure controller (22) is connected to the kettle body thermometer (20) and the kettle body pressure gauge (21) for controlling the pressure and temperature of the sealed kettle.

[0048] In one embodiment, the density measurement device further includes: a computer (23), which is connected to the temperature and pressure controller (22) and the densitometer signal converter (19), for adjusting the control parameters of the temperature and pressure controller (22), receiving the digital signals transmitted by the densitometer signal converter (19), and displaying the curve of the change of the cement slurry density over time according to the digital signals.

[0049] In one embodiment, both the sealed kettle lid (1) and the sealed kettle body (2) are made of pressure-resistant steel alloy material, and the bottom seal ring (7) of the kettle is made of high-temperature-resistant polytetrafluoroethylene material.

[0050] In the present invention, the use of pressure-resistant steel alloy material for the sealed kettle lid (1) and the sealed kettle body (2) enables the sealed kettle to have the characteristic of high pressure resistance. The bottom seal ring (7) of the kettle is made of high-temperature-resistant polytetrafluoroethylene material, so that the maximum working temperature of the well cement slurry high-temperature dynamic settlement stability device provided by the present invention is 200 °C, meeting the test conditions for the settlement stability of well cement slurry in deep wells and ultra-deep wells.

[0051] In one embodiment, the cement slurry densitometer composed of the densitometer rod (17) and the densitometer probe (18) uses a tuning fork densitometer.

[0052] The test principle of the tuning fork densitometer is: when the medium flows through the fork body, due to the change of the medium density, the resonant frequency changes, and then the medium density is calculated inversely.

[0053] Specifically, the calculation formula is D = K0 + K1T + K2T2 (D = the density of the measured medium; T = the natural frequency of the fork body; T2 = the frequency when the measured medium flows through the fork body; K0, K1, K2 = constants). According to this formula, the accurate density value of the medium can be calculated.

[0054] The device provided by the present invention uses a tuning fork densitometer for testing, overcoming the problem that when using a pressure sensor to measure the density of cement slurry fluctuatingly, due to the change of the internal stress of the cement slurry caused by the temperature rise, the density measurement of the cement slurry is inaccurate.

[0055] In one embodiment, the densitometer signal converter (19) has a preset acquisition period. Specifically, the working period of the densitometer signal converter (19) is 10 s, that is, the densitometer signal converter (19) acquires signals once every 10 s.

[0056] In one embodiment, the rotational speed of the motor (6) is adjusted according to the well cementing operation conditions to simulate the flow rate during the cement slurry injection and displacement process.

[0057] In one embodiment, the range of the cement slurry density that can be measured by the well cementing cement slurry high-temperature dynamic settlement stability device provided by the present invention is 1.5 - 2.5 g / cm3, the range of the operating environment temperature is 0 - 200 °C, and the maximum operating environment pressure is 20 MPa.

[0058] In summary, based on the characteristic that the tuning fork densitometer can continuously measure the density of the slurry, the present invention provides a device for continuously testing the high-temperature dynamic settlement stability of well cementing cement slurry, so as to evaluate the settlement stability of the well cementing cement slurry under high-temperature conditions, and can realize the continuous monitoring of the density change during the flow process of the cement slurry under the conditions of temperature rise and constant high temperature, thereby guiding the settlement stability design of the cement slurry, providing a technical means for achieving good settlement stability of the well cementing cement slurry at high temperature, and providing technical support for improving the well cementing quality of deep wells and ultra-deep wells.

[0059] Figure 3 The flowchart of the method for continuously testing the high-temperature dynamic settlement stability of well cementing cement slurry according to an embodiment of the present invention is shown.

[0060] As Figure 3 shown, in step S301, the cement slurry is configured and its initial density is tested. The cement slurry is poured into the set stirring paddle cup, and the stirring paddle cup is arranged in the sealed autoclave to complete the setting of the sealed autoclave and the density measuring device.

[0061] Specifically, in step S301, the steps of configuring the cement slurry and setting the stirring paddle cup include: putting the stirring paddle blade (15) into the body of the slurry cup (14), threading the body of the slurry cup (14), threading the sealing cover plate (16), the paddle blade rotating rod, applying high-temperature sealing grease at the contact between the body of the slurry cup (14) and the bottom of the stirring paddle blade (15), configuring the cement slurry, after testing its density, pouring it into the stirring slurry cup and making the liquid level just submerge the stirring paddle blade (15), aligning the thread of the sealing cover plate (16) with the thread of the body of the slurry cup (14), and screwing the sealing cover plate (16) into the body of the slurry cup (14).

[0062] Specifically, in step S301, the steps of completing the setting of the sealed autoclave include: putting the stirring slurry cup on the rotor (5), clamping the base of the stirring slurry cup with the fixing staple (4), fixing the stirring paddle blade (15) with the paddle blade slot (13), closing the sealed autoclave cover (1), and connecting and sealing the sealed autoclave cover (1) and the sealed autoclave body (2) with the fixing screw (8).

[0063] Specifically, in step S301, the steps for setting up the density measurement device include: inserting the density meter rod (17) and the density meter probe (18) into the kettle body through the kettle cover jack (9) above the sealed kettle cover (1), and then inserting them into the slurry cup body (14) through the jack on the sealing cover plate (16). At least three inserted density meters are respectively at the upper, middle, and lower parts of the slurry cup. Finally, use the fixing pin (10) to seal the kettle cover jack (9).

[0064] As Figure 3 shown, in step S302, turn on the motor (6), adjust the rotation speed of the motor (6) according to the working conditions, read the density of the cement slurry measured by the density meter rod (17) and the density meter probe (18), and correct it with the initial density of the cement slurry.

[0065] Specifically, in step S302, turn on the motor (6), adjust the rotation speed of the motor (6) according to the working conditions, and the stirring slurry cup starts to rotate. At this time, read the density of the cement slurry measured by the density meter rod (17) and the density meter probe (18), and correct it with the initial density when configuring the cement slurry to ensure the accuracy of the initial density value.

[0066] As Figure 3 shown, in step S303, inject high-temperature resistant curing oil into the sealed kettle body (2) so that the curing oil fills the entire sealed kettle body (2). Set the test temperature and the heating-up time. After starting the test, collect the density values of the cement slurry at the upper, middle, and lower parts of the stirring slurry cup, and display the curves of the upper, middle, and lower densities changing with time.

[0067] Specifically, in step S303, use a pump to inject high-temperature resistant curing oil into the oil inlet pipeline and valve (11) so that the curing oil fills the entire sealed kettle body (2). Turn on the density meter signal converter (19), the temperature and pressure controller (22), and the computer (23). Set the test temperature and the heating-up time on the temperature and pressure controller (22). After starting the test, turn on the data recording system on the computer (23). At this time, the computer system will continuously collect the density values of the cement slurry at the upper, middle, and lower parts of the slurry cup, and display the curves of the upper, middle, and lower densities changing with time on the computer.

[0068] Specifically, in step S303, the test is carried out for a preset time (such as 2 hours). After the test is completed, turn off the motor (6), turn off the temperature and pressure controller (22), relieve the pressure, and drive the oil through the oil outlet pipeline and valve (12). Then connect the cooling water system to the oil inlet pipeline and valve (11), inject cooling water into the cooling device, wait for the device to cool down, and remove and clean the stirring slurry cup.

[0069] In summary, the device and method for continuously testing the high-temperature dynamic settlement stability of cement slurry for well cementing provided by the present invention can measure the change in the density value of the cement slurry during the dynamic stirring process and simultaneously achieve continuous measurement of the change in the density of the cement slurry. The maximum working temperature of the device provided by the present invention is 200 °C, meeting the experimental conditions for testing the settlement stability of well cementing slurry in deep wells and ultra-deep wells. The device provided by the present invention uses a tuning fork densitometer for testing, overcoming the problem that when using a pressure sensor to measure the density of the cement slurry with fluctuations, the internal stress of the cement slurry changes due to the rise in temperature, resulting in inaccurate measurement of the density of the cement slurry.

[0070] It should be understood that the embodiments disclosed in the present invention are not limited to the specific structures, processing steps or materials disclosed herein, but should extend to equivalent alternatives of these features understood by those of ordinary skill in the relevant art. It should also be understood that the terms used herein are for the purpose of describing specific embodiments only and do not imply limitation.

[0071] The phrase "one embodiment" or "an embodiment" mentioned in the specification means that the specific features, structures or characteristics described in connection with the embodiment are included in at least one embodiment of the present invention. Therefore, the phrases "one embodiment" or "an embodiment" that appear throughout the specification do not necessarily all refer to the same embodiment.

[0072] Although the disclosed embodiments of the present invention are as above, the content described is only an embodiment for facilitating the understanding of the present invention and is not intended to limit the present invention. Any person skilled in the technical field to which the present invention pertains may make any modifications and changes in the form of implementation and details without departing from the spirit and scope disclosed by the present invention. However, the scope of patent protection of the present invention shall still be subject to the scope defined by the appended claims.

Claims

1. An apparatus for continuously testing the high-temperature dynamic sedimentation stability of cement slurry for well cementing, characterized in that, The device comprises: A sealed autoclave, which includes a sealed autoclave cover (1), a sealed autoclave body (2), base fixing nails (4), a rotor (5), a motor (6), a bottom seal ring (7), fixing bolts (8), autoclave cover jacks (9), fixing pins (10), and paddle blade slots (13). Among them, the sealed autoclave cover (1) is fixed on the sealed autoclave body (2) by the fixing bolts (8). There are at least three autoclave cover jacks (9) on the sealed autoclave cover (1). The rotor (5) is connected to the motor (6). When the motor (6) rotates, it drives the rotor (5) to rotate. The bottom seal ring (7) is used to ensure the sealing performance of the sealed autoclave. A stirring paddle cup, which includes a paddle cup body (14), a stirring paddle blade (15), and a sealed cover plate (16). Among them, the paddle cup body (14) is fixed on the rotor (5) by the base fixing nails (4). The stirring paddle blade (15) is fixed through the paddle blade slots (13). The sealed cover plate (16) is threadedly connected with the paddle cup body (14). A density measuring device, which includes a density meter rod (17), a density meter probe (18), and a density meter signal converter (19). Among them, the density meter rod (17) and the density meter probe (18) are inserted into the autoclave cover jacks (9) and fixed on the sealed autoclave cover (1) by the fixing pins (10). The density meter probe (18) is at least arranged in the upper, middle, and lower parts of the stirring paddle cup, and is used to measure the density of the cement slurry at the upper, middle, and lower parts of the stirring paddle cup respectively. The density meter signal converter (19) is used to convert the electrical signals representing the density change of the cement slurry measured by the density meter rod (17) and the density meter probe (18) into digital signals.

2. The device for continuously testing the high-temperature dynamic settlement stability of the cement slurry for well cementing according to claim 1, characterized in that, The sealed autoclave also includes a heating jacket (3), which is used to wrap the sealed autoclave body (2).

3. The device for continuously testing the high-temperature dynamic sedimentation stability of cement slurry for well cementing according to claim 1, characterized in that, The sealed autoclave also includes an oil inlet pipeline and valve (11) and an oil outlet pipeline and valve (12), which are used to control the injection and discharge of the internal medium of the sealed autoclave body (2) respectively.

4. The device for continuously testing the high-temperature dynamic settlement stability of the cement slurry for well cementing according to claim 1, characterized in that, The density measuring device also includes: A kettle body thermometer (20), which is connected to the heating jacket (3); A kettle body pressure gauge (21), which is used to measure the pressure inside the sealed autoclave; A temperature and pressure controller (22), which is connected to the kettle body thermometer (20) and the kettle body pressure gauge (21), and is used to control the pressure and temperature of the sealed autoclave.

5. The device for continuously testing the high-temperature dynamic sedimentation stability of the cement slurry for well cementing according to claim 4, characterized in that, The density measuring device also includes: A computer (23), which is connected to the temperature and pressure controller (22) and the density meter signal converter (19), and is used to adjust the control parameters of the temperature and pressure controller (22), receive the digital signals transmitted by the density meter signal converter (19), and display the curve of the change of the cement slurry density with time according to the digital signals.

6. The device for continuously testing the high-temperature dynamic sedimentation stability of the cement slurry for well cementing according to claim 1, characterized in that Both the sealed autoclave cover (1) and the sealed autoclave body (2) are made of pressure-resistant steel alloy materials, and the bottom seal ring (7) is made of high-temperature-resistant polytetrafluoroethylene materials.

7. The device for continuously testing the high-temperature dynamic settlement stability of the cement slurry for well cementing according to claim 1, characterized in that, The cement slurry density meter composed of the density meter rod (17) and the density meter probe (18) adopts a tuning fork density meter.

8. The device for continuously testing the high-temperature dynamic sedimentation stability of cement slurry for well cementing according to claim 1, characterized in that, Adjust the rotation speed of the motor (6) according to the well cementing operation conditions to simulate the flow rate during the cement slurry injection and displacement process.

9. The device for continuously testing the high-temperature dynamic settlement stability of the cement slurry for well cementing according to claim 1, characterized in that, The high-temperature dynamic settlement stability device for cement slurry in well cementing can measure the density range of cement slurry from 1.5 to 2.5 g / cm 3 , the operating ambient temperature range is from 0 to 200 °C, and the maximum operating ambient pressure is 20 MPa.

10. A method for continuously testing the high-temperature dynamic sedimentation stability of cement slurry for well cementing, characterized in that, Carry out continuous testing on the high-temperature dynamic settlement stability of the well cement slurry by using the device for continuously testing the high-temperature dynamic settlement stability of the well cement slurry as described in any one of claims 1-9. The method comprises the following steps: Step 1: Prepare the cement slurry and test its initial density. Pour the cement slurry into the set stirring paddle cup, and place the stirring paddle cup in the sealed autoclave to complete the setting of the sealed autoclave and the density measuring device; Step 2: Turn on the motor (6), adjust the rotation speed of the motor (6) according to the working conditions, read the density of the cement slurry measured by the density meter rod (17) and the density meter probe (18), and correct it with the initial density of the cement slurry; Step 3: Inject high-temperature resistant curing oil into the sealed autoclave body (2) to make the curing oil fill the entire sealed autoclave body (2). Set the test temperature and the heating time. After starting the test, collect the density values of the cement slurry at the upper, middle, and lower parts of the stirring paddle cup, and display the curves of the upper, middle, and lower densities changing with time.

Images