Cement slurry coagulation / thickening time testing device and method under high temperature and high pressure conditions

Abstract

The present invention discloses a cement slurry solidification / thickening time testing device and method under high temperature and high pressure conditions, and belongs to the field of oil and gas field cementing. The device includes a base, a bracket, a motor, a kettle body chuck, a kettle body and a heating and heat-insulating sleeve. The kettle cavity is provided with a guide rail, a metal slider and a floating piston. A vibration sensor is arranged outside the kettle body to receive and transmit the vibration signal generated by the slider falling and impacting the lower cover or the floating piston. The method includes: controlling the kettle body to rotate 180° to an inverted position by a motor, and pouring cement slurry into the lower cavity of the kettle body; starting a hydraulic pump, slowly filling the upper cavity of the kettle body with liquid, and applying an initial pressure of 1-2Mpa to the cement slurry in the kettle cavity; heating and heat-insulating the kettle body; starting the reciprocating motion of the kettle body by a motor, recording the vibration time, and drawing a curve of the change of the falling time of the metal slider in the cement slurry with time to obtain the cement slurry solidification / thickening time. The present invention has a novel structural design, accurate and reliable test results, and has broad market application prospects.

Description

Technical Field

[0001] The invention belongs to the field of oil and gas field cementing, and specifically relates to a device and method for simulating and testing cement slurry solidification / thickening time in oil and gas field cementing and cementing operations, which is used to evaluate the safe pumpable time of cement slurry entering the well under high temperature and high pressure conditions. Background Art

[0002] During the cementing operation of oil and gas wells, the oil and gas well cementing cement slurry prepared on the ground needs to be pumped into a predetermined position under the oil and gas wells. The oil well cement will start to hydrate after coming into contact with water, and gradually lose its flowability over time, changing from liquid to solid, that is, from cement slurry to cement stone, thereby obtaining a certain strength and achieving the desired purpose.

[0003] In order to safely pump the cement slurry for oil and gas well cementing to the predetermined position under the oil and gas well, it is necessary to keep it in good flowability within the predetermined pumping time. Therefore, it is necessary to detect and evaluate the time it can maintain good flowability before cementing operation, that is, the thickening time, to ensure that the thickening time is greater than the predetermined pumping time and has a certain safety margin.

[0004] The so-called thickening time of cement slurry refers to the time taken for the cement slurry to reach the specified value from the beginning of its preparation. It is one of the key properties of cement slurry. If the thickening time is too short, it is difficult to meet the need of pumping the cement slurry to the predetermined position. If the thickening time of cement slurry is too long, it will seriously affect the rapid setting and anti-channeling performance of cement slurry and delay the on-site waiting time. Therefore, a large number of thickening experiments are required before cementing operations to optimize the components of cement slurry system and the formula of cement slurry system, so as to obtain a thickening time that can meet the needs of safe pumping and give full play to the advantages of rapid setting and anti-channeling of cement slurry.

[0005] With the deepening of oil and gas exploration and development, the number of deep wells and ultra-deep wells is increasing. For example, the Southwest Oil and Gas Field and the Tarim Oil and Gas Field have begun to drill 10,000-meter deep wells. The downhole temperature and pressure of deep and ultra-deep wells are higher, which has a greater impact on the hydration reaction rate of cement slurry, and a greater impact on the chemical interference between cement slurry, drilling fluid and cementing pre-fluid. More cement slurry thickening experiments and pollution experiments of cement slurry, drilling fluid and spacer fluid are needed to obtain accurate supporting data.

[0006] At present, the thickening time of cement slurry under different temperatures, pressures and heating and pressure increasing speeds is tested by a high-temperature and high-pressure thickener. The specific method is as follows: the high-temperature and high-pressure environment of the oil and gas well is simulated by a high-temperature and high-pressure autoclave; the heating and pressure increasing process of the cement slurry being pumped from the ground to the predetermined position in the well is simulated by controlling the heating and pressure increasing speed of the cement slurry; a certain rotation speed is applied to the slurry cup containing the cement slurry, so that the cement slurry in the slurry cup is driven to rotate at the same speed, and relative motion is formed with the basically stationary blade in the cement slurry, so as to simulate the shear flow of the cement slurry during the pumping process and its influence on the cement hydration reaction. At the same time, the thrust of the cement slurry on the blade at the same relative motion speed is used to reflect the viscosity of the cement slurry; the thrust of the blade is converted into torque by a potentiometer, so as to drive the pointer of the potentiometer to deflect and change the resistance and current of the potentiometer. Finally, the viscosity of the cement slurry and its change are indirectly reflected by outputting the resistance / current of the potentiometer and its change, and the thickening time of the cement slurry is determined according to the change of the viscosity.

[0007] Due to the large number of conversion links in the measurement process, the structure of the high-temperature and high-pressure thickener is complex, and magnetic drive is required to achieve transmission from the outside to the inside of the high-temperature and high-pressure reactor. It is necessary to consider the influence of high temperature and high pressure on the torsion coefficient of the potentiometer spring and the resistivity of the potentiometer resistance coil, etc., resulting in high device cost and heavy maintenance workload, which is not conducive to large-scale configuration and use. In order to further improve efficiency and reduce costs, it is urgent to explore a new and efficient thickening time measurement device and method for oil and gas well cementing slurry under high temperature and high pressure conditions. Summary of the invention

[0008] The purpose of the present invention is to provide a cement slurry solidification / thickening time testing device under high temperature and high pressure conditions. The device has a novel structural design and accurate and reliable test results. The device reflects the consistency of the cement slurry and its changes by testing the falling time of the slider in the cement slurry, and the solidification / thickening time of the cement slurry is judged accordingly. The device has broad market application prospects.

[0009] Another object of the present invention is to provide a method for testing the setting / thickening time of cement slurry under high temperature and high pressure conditions using the above-mentioned device. The method has reliable principles, simple operation, controllable processes, and the test results are more in line with actual on-site working conditions.

[0010] In order to achieve the above technical objectives, the present invention adopts the following technical solutions.

[0011] The present invention indirectly measures the consistency of cement slurry and evaluates its flowability by measuring the time required for a slider to fall a certain distance in cement slurry under the same conditions. The change in the consistency of cement slurry is reflected by the change in the time required for the slider to fall. Finally, the thickening time of cement slurry is further determined based on the critical value of the time required for the slider to fall a certain distance.

[0012] The cement slurry solidification / thickening time testing device under high temperature and high pressure conditions is mainly composed of a base, a bracket, a motor, a transmission gear, a kettle body chuck, a kettle body, an electronic control system, a temperature control system, a pressure control system and a vibration sensor collection system.

[0013] The base is a thick-walled steel plate or similar material with movable, locking and positioning functions, which provides support for the device.

[0014] The bracket is a frame constructed with profiles such as steel pipes, located on the base, fixing the motor and the kettle body chuck, and the motor is connected to the kettle body chuck through a transmission gear.

[0015] The motor is a variable frequency motor with adjustable speed and clockwise / counterclockwise rotation, which provides power for the device and rotates forward or reversely as required, and drives the kettle body chuck to rotate forward or reversely through the transmission gear.

[0016] The transmission gear is connected with the motor and the chuck to transmit the rotation of the motor to the kettle body chuck, so that the rotation of the kettle body chuck is controlled by operating the motor.

[0017] The kettle body chuck is installed on the bracket and is used to fix the kettle body. Driven by the motor, it rotates clockwise or counterclockwise as required, thereby driving the kettle body to rotate accordingly.

[0018] The kettle body is a hollow thick-walled steel cylinder, which is connected with an upper cover and a lower cover by bolts to form a closed kettle cavity, and a guide rail, a metal slider and a floating piston are arranged in the kettle cavity.

[0019] The upper cover and the lower cover are provided with holes at their central positions to place the two ends of the guide rail respectively. A spring is also arranged in the hole of the upper cover to press the guide rail tightly to prevent it from moving.

[0020] The guide rail is a metal rod with a smooth surface. A spherical or spindle-shaped metal sliding block is arranged on the metal rod and slides along the guide rail under the action of gravity.

[0021] The floating piston has a center hole, the inner diameter of the center hole is slightly larger than the outer diameter of the guide rail, a sealing ring groove and a sealing ring are provided in the center hole, the guide rail passes through the center hole, and forms a seal with the floating piston through the sealing ring, a sealing ring groove and a sealing ring are also provided on the outside of the floating piston, and forms a seal with the inner wall of the kettle body through the sealing ring, the floating piston divides the inner cavity of the kettle body into an upper cavity and a lower cavity, and the metal slider slides along the guide rail in the lower cavity.

[0022] The upper cover of the kettle body is provided with a pressure-increasing and pressure-relieving port and corresponding liquid inlet pipelines, valves and pressure gauges to pressurize and relieve pressure on the upper chamber of the kettle body, and to pressurize and relieve pressure on the cement slurry in the lower chamber of the kettle body through a floating piston.

[0023] The lower cover of the kettle body is provided with an exhaust port and a corresponding plug, and the lower cavity of the kettle body is exhausted and sealed after the kettle body is inverted and cement slurry is poured into it.

[0024] The kettle body is provided with a sensor for receiving the vibration generated by the falling metal slider impacting the lower cover or floating piston, and the time when the falling metal slider impacts the lower cover or floating piston is obtained through the sensor. As the metal slider falls in the cement slurry under the action of gravity, it will be subject to the resistance of the cement slurry. The thicker the cement slurry, the greater the resistance the slider encounters, and the longer the time required to fall, so the falling time of the slider reflects the consistency of the cement slurry.

[0025] The electric control system is composed of a motor, a control switch and related circuits. The rotation speed of the kettle body is adjusted according to needs to control the kettle body to perform reciprocating movements such as inverting, flipping 180 degrees, standing upright, the slider falling, rotating 180 degrees, inverting, and the slider falling.

[0026] The temperature control system is composed of a temperature sensor, a control circuit and a heating and heat-insulating sleeve on the outer wall of the kettle body. The target temperature is set according to the needs, and the inner cavity of the kettle body is automatically heated and heat-insulated.

[0027] The pressure control system is composed of a pressure sensor, a control circuit and a hydraulic pump. The pressurization and constant pressure target value of the kettle cavity is set according to needs, and the pressurization and constant pressure of the kettle cavity are automatically performed.

[0028] The vibration sensing collection system includes a vibration sensor, a signal transmitting system, a signal receiving system and a computer control system, receives vibration signals, records the time when vibration occurs, draws the falling curve of the slider at different times, and judges the thickening time of cement slurry based on the curve.

[0029] The method for testing the setting / thickening time of cement slurry under high temperature and high pressure conditions using the above device comprises the following steps in sequence:

[0030] (1) The motor controls the kettle to rotate 180° to an inverted position, and cement slurry is poured into the lower cavity of the kettle;

[0031] (2) Start the hydraulic pump, open the valve of the liquid inlet pipeline on the upper cover of the kettle body, slowly fill the upper chamber of the kettle body with liquid, push the floating piston upward, exhaust the lower chamber of the kettle body, until cement slurry emerges from the exhaust port, block the exhaust port with a plug, and continue to apply an initial pressure of 1-2Mpa to the cement slurry in the kettle chamber through the hydraulic pump;

[0032] (3) Set the target temperature and heat and keep the kettle warm;

[0033] (4) Start the reciprocating motion of the kettle body through the motor, record the vibration time, and draw a curve of the change of the falling time of the metal slider in the cement slurry over time;

[0034] (5) As time goes by, the cement slurry gradually becomes thicker and the falling time of the slider becomes longer. When the falling time of the slider is extended to the set value, it is considered that the cement slurry has basically lost its fluidity and the motor is turned off;

[0035] (6) The solidification / thickening time of the cement slurry is obtained by plotting the change curve of the falling time of the metal slider in the cement slurry over time. The thickening performance of the cement slurry can be analyzed by judging whether the thickening process of the cement slurry is smooth based on whether the falling time of the slider fluctuates.

[0036] Compared with the prior art, the present invention has the following beneficial effects:

[0037] The test steps of the existing high-temperature and high-pressure thickener are complicated, and the conversion idea is cement slurry consistency ð blade force ð potentiometer coil spring deflection torque ð potentiometer pointer deflection angle ð potentiometer resistance ð potentiometer current, which leads to a complex internal structure of the device and faces problems such as the potentiometer coil spring torque coefficient and potentiometer resistance being significantly affected by high temperature. The present invention uses the slider falling in the cement slurry to impact the lower cover of the kettle or the floating piston to generate vibration, and measures the time required for the slider to fall the same distance in the cement slurry, thereby reflecting the flow capacity of the cement slurry and realizing non-contact testing from inside the kettle to outside the kettle. It greatly simplifies the internal measurement structure of the kettle, reduces the difficulty of device processing, construction cost and use and maintenance cost, avoids the influence of high temperature on the coil spring torque coefficient, potentiometer resistance and magnetic drive transmission efficiency, and overcomes the problem of high cost caused by easy damage to the technical components of the existing device. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] Figure 1 It is a schematic diagram of the structure of the kettle part of the cement slurry solidification / thickening time testing device.

[0039] Figure 2 It is a structural schematic diagram of the main body of the cement slurry solidification / thickening time testing device.

[0040] Description of reference numerals:

[0041] 1- kettle body; 2-upper cover; 3-lower cover; 4, 5, 21, 22-sealing ring; 6, 7, 8, 9-bolts; 10-pressure relief port; 11-valve; 12-pressure gauge; 13-spring; 14-guide rail; 15-metal slider; 16-floating piston; 17-exhaust port; 18-plug; 19-vibration sensor; 20-heating and insulation cover; 23-base; 24-bracket; 25-motor; 26-transmission gear; 27-bearing; 28-kettle body chuck. DETAILED DESCRIPTION

[0042] The present invention is further described below with reference to the accompanying drawings and examples, so that those skilled in the art can understand the present invention. However, it should be clear that the present invention is not limited to the scope of the specific embodiments, and for those skilled in the art, as long as various changes are within the spirit and scope of the present invention defined and determined by the attached claims, they are all protected.

[0043] See also Figure 1 , Figure 2 .

[0044] The cement slurry solidification / thickening time testing device under high temperature and high pressure conditions comprises a base 23, a bracket 24, a motor 25, a kettle body chuck 28, a kettle body 1, a heating and heat-insulating sleeve 20 and a vibration sensor 19.

[0045] The bracket 24 is located on the base 23, and fixes the motor 25 and the kettle body chuck 28 (through the bearing 27) respectively. The motor 25 is connected to the kettle body chuck 28 through the transmission gear 26. The kettle body chuck fixes the kettle body 1 and drives the kettle body to rotate accordingly when the motor rotates. The kettle body 1 is connected to the upper cover 2 and the lower cover 3 through bolts (6, 7) and bolts (8, 9) to form a closed kettle cavity, and the kettle cavity is provided with a guide rail 14, a metal slider 15 and a floating piston 16; the upper cover and the lower cover are opened at the center position, and the two ends of the guide rail are placed respectively. A spring 13 is also arranged in the hole of the upper cover, and the guide rail is pressed by the spring to prevent it from moving; the guide rail 14 is a metal rod with a smooth surface, and a spherical or spindle-shaped metal slider 15 is arranged on the metal rod; the floating piston 16 has a center hole, and a sealing ring groove and a sealing ring 22 are arranged in the center hole. The guide rail passes through the center hole and forms a seal with the floating piston through the sealing ring. The floating piston is provided with a sealing ring groove and a sealing ring 21 on the outside, and forms a seal with the inner wall of the kettle body through the sealing ring. The floating piston divides the inner cavity of the kettle body into an upper cavity and a lower cavity, and the metal slider 15 slides along the guide rail 14 in the lower cavity; the upper cover is provided with a pressure-injection / pressure-relief port 10 and a corresponding liquid inlet pipeline, the pressure-injection / pressure-relief port is provided with a valve 11 and a pressure gauge 12, and the liquid inlet pipeline is connected to a pressure sensor and a hydraulic pump; the lower cover is provided with an exhaust port 17 and a corresponding plug 18; the outer wall of the kettle body is covered with a heating and heat-insulating sleeve 20, and the heating and heat-insulating sleeve is connected to a temperature controller; a vibration sensor 19 is provided outside the kettle body to receive and transmit vibration signals generated by the metal slider falling and impacting the lower cover or the floating piston; the motor, pressure sensor, temperature controller and vibration sensor are all connected to a computer control system.

[0046] Furthermore, a circular boss with a radius slightly smaller than the inner diameter of the kettle body is provided at the lower end of the upper cover and the upper end of the lower cover, and a sealing ring groove and sealing rings 4 and 5 are provided outside the boss. The upper cover and the lower cover are in contact with the inner wall of the kettle body through the sealing rings to form a seal.

[0047] Furthermore, the liquid inlet pipeline of the kettle upper cover pressurizes and releases the pressure on the upper chamber of the kettle through a hydraulic pump, and pressurizes and releases the pressure on the cement slurry in the lower chamber of the kettle through a floating piston.

[0048] Furthermore, the exhaust port and the plug on the lower cover of the kettle body are used to exhaust and seal the lower cavity of the kettle body after the kettle body is inverted and poured with cement slurry.

[0049] Furthermore, the kettle body, under the control of the motor, performs reciprocating motions of inverting, flipping 180 degrees, standing upright, the slider falling, rotating 180 degrees, inverting, and the slider falling.

[0050] Furthermore, the computer control system adjusts the rotation speed of the kettle body through the motor, heats and keeps the inner cavity of the kettle body warm through the temperature controller, pressurizes and maintains a constant pressure in the inner cavity of the kettle body through the hydraulic pump, receives and transmits vibration signals through the vibration sensor, thereby drawing a curve of the change in the falling time of the metal slider over time on the display.

[0051] The method for measuring the high-temperature and high-pressure coagulation / thickening time of cement slurry using the above device comprises the following steps in sequence:

[0052] (1) Start the motor 25, and drive the kettle body chuck 28 through the transmission gear 26 to invert the kettle body 1, and the floating piston 16 is at the bottom of the inverted kettle body;

[0053] (2) Inject the cement slurry required for the experiment into the lower cavity of the kettle body, connect the kettle body and the lower cover 3 by tightening bolts 8 and 9, start the hydraulic pump to slowly inject hydraulic pressure into the upper cavity of the kettle body, push the floating piston 16 upward, exhaust the lower cavity of the kettle body, until cement slurry emerges from the exhaust port 17, then plug the exhaust port with a plug 18, and continue to apply an initial pressure of 1-2 MPa to the cement slurry in the kettle cavity through the hydraulic pump;

[0054] (3) Setting the target temperature, starting the heating and heat preservation system, and heating and heat preservation the kettle body through the heating and heat preservation sleeve 20; starting the pressure control system, and pressurizing, releasing and maintaining constant pressure in the kettle body cavity;

[0055] (4) Start the motor 25, and drive the kettle on the kettle chuck 28 to perform reciprocating motion of inverting, standing upright, and then inverting again through the transmission gear 26, so that the slider 15 is brought from the bottom of the inverted or upright kettle to a high position and then falls and impacts the floating piston 16 or the kettle lower cover 3 to generate vibration, record the time when each vibration occurs and the time between two vibrations, and draw a curve of the falling time of the slider versus time;

[0056] (5) At the beginning of the experiment, the cement slurry has good flowability and small resistance to the slider. The slider can fall quickly and the time it takes to fall from a high place to the bottom is short. As time goes by, the cement slurry gradually thickens, the resistance of the slider to fall in it becomes greater and greater, and the time it takes for the slider to fall from a high place to the bottom becomes longer and longer. The change in the slider's falling time reflects the consistency of the cement slurry. When the slider's falling time increases to the set value, it is considered that the cement slurry has basically lost its flowability and the experiment is terminated.

[0057] (6) The thickening time of cement slurry and the change of its flow capacity during the thickening process can be analyzed and judged by the curve of the change of the time required for the slider to fall versus time. Whether the thickening process of cement slurry is smooth can be judged by whether the time for the slider to fall fluctuates or is smooth.

[0058] Obviously, the above embodiments of the present invention are merely examples for clearly illustrating the present invention, and are not limitations on the implementation methods of the present invention. For ordinary technicians in the relevant field, other different forms of changes or modifications can be made on the basis of the above description. It is impossible to list all the implementation methods here. All obvious changes or modifications derived from the technical solution of the present invention are still within the protection scope of the present invention.

Claims

1. A cement slurry solidification / thickening time testing device under high temperature and high pressure conditions, comprising a base (23), a bracket (24), a motor (25), a kettle chuck (28), a kettle (1), a heating and insulation sleeve (20) and a vibration sensor (19), characterized in that: The bracket (24) is located on the base (23) and fixes the motor (25) and the kettle body chuck (28) respectively. The motor (25) is connected to the kettle body chuck (28) via a transmission gear (26). The kettle body chuck fixes the kettle body (1) and drives the kettle body to rotate accordingly when the motor rotates. The kettle body (1) is connected to the upper cover (2) and the lower cover (3) via bolts to form a closed kettle cavity. The kettle cavity contains a guide rail (14), a metal slider (15) and a floating piston (16). The upper cover and the lower cover have holes at their center positions to place the two ends of the guide rail respectively. A spring (13) is also arranged in the hole of the upper cover to press the guide rail to prevent it from moving. The guide rail (14) is a metal rod with a smooth surface. A spherical or spindle-shaped metal slider (15) is arranged on the metal rod. The floating piston (16) has a center hole, and a sealing ring is arranged in the center hole. A groove and a sealing ring are provided, wherein the guide rail passes through the center hole and contacts the floating piston through the sealing ring to form a seal. A sealing ring groove and a sealing ring are also provided on the outside of the floating piston and contacts the inner wall of the kettle body through the sealing ring to form a seal. The floating piston divides the inner cavity of the kettle body into an upper cavity and a lower cavity. The metal slider (15) slides along the guide rail (14) in the lower cavity. The upper cover is provided with a pressure-increasing / pressure-relieving port (10) and a corresponding liquid inlet pipeline, and the liquid inlet pipeline is connected to a pressure sensor and a hydraulic pump. The lower cover is provided with an exhaust port (17) and a corresponding plug (18). The outer wall of the kettle body is covered with a heating and heat-insulating sleeve (20), and the heating and heat-insulating sleeve is connected to a temperature controller. A vibration sensor (19) is provided on the outside of the kettle body to receive and transmit vibration signals generated by the metal slider falling and impacting the lower cover or the floating piston. The motor, pressure sensor, temperature controller and vibration sensor are all connected to a computer control system.

2. The cement slurry solidification / thickening time testing device under high temperature and high pressure conditions as claimed in claim 1, characterized in that: The lower end of the upper cover and the upper end of the lower cover are provided with a circular boss with a radius slightly smaller than the inner diameter of the kettle body, and a sealing ring groove and a sealing ring are provided outside the boss. The upper cover and the lower cover are respectively in contact with the inner wall of the kettle body through the sealing ring to form a seal.

3. The cement slurry solidification / thickening time testing device under high temperature and high pressure conditions as claimed in claim 1, characterized in that: The liquid inlet pipeline of the upper cover pressurizes and releases the pressure of the upper chamber of the kettle body through a hydraulic pump, and pressurizes and releases the pressure of the cement slurry in the lower chamber of the kettle body through a floating piston.

4. The cement slurry solidification / thickening time testing device under high temperature and high pressure conditions as claimed in claim 1, characterized in that: The exhaust port and the plug of the lower cover are used to exhaust and seal the lower cavity of the kettle body after the kettle body is inverted and poured with cement slurry.

5. The cement slurry solidification / thickening time testing device under high temperature and high pressure conditions as claimed in claim 1, characterized in that: The kettle body performs reciprocating motions of inverting, flipping 180 degrees, standing upright, the slider falling, rotating 180 degrees, inverting, and the slider falling under the control of the motor.

6. The cement slurry solidification / thickening time testing device under high temperature and high pressure conditions as claimed in claim 1, characterized in that: The computer control system adjusts the rotation speed of the kettle body through the motor, heats and keeps the inner cavity of the kettle body warm through the temperature controller, pressurizes and maintains constant pressure in the inner cavity of the kettle body through the hydraulic pump, receives and transmits vibration signals through the vibration sensor, and thus draws a curve of the change of the falling time of the metal slider over time on the display.

7. A method for testing the setting / thickening time of cement slurry under high temperature and high pressure conditions using the device of claim 1, 2, 3, 4, 5 or 6, comprising the following steps in sequence: (1) The motor controls the kettle to rotate 180° to an inverted position, and cement slurry is poured into the lower cavity of the kettle; (2) Start the hydraulic pump, open the valve of the liquid inlet pipeline on the upper cover of the kettle body, slowly fill the upper chamber of the kettle body with liquid, push the floating piston upward, exhaust the lower chamber of the kettle body, until cement slurry emerges from the exhaust port, block the exhaust port with a plug, and continue to apply an initial pressure of 1-2Mpa to the cement slurry in the kettle chamber through the hydraulic pump; (3) Set the target temperature and heat and keep the kettle warm; (4) Start the reciprocating motion of the kettle body through the motor, record the vibration time, and draw a curve of the change of the falling time of the metal slider in the cement slurry over time; (5) As time goes by, the cement slurry gradually becomes thicker and the falling time of the slider becomes longer. When the falling time of the slider is extended to the set value, it is considered that the cement slurry has basically lost its fluidity and the motor is turned off; (6) The solidification / thickening time of the cement slurry is obtained by plotting the change in the falling time of the metal slider in the cement slurry over time. The thickening performance of the cement slurry can be analyzed by judging whether the thickening process of the cement slurry is smooth based on whether the falling time of the slider fluctuates.

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