Test device and method for evaluating volume change rate of cement slurry during cementing waiting-on-cement stage

Abstract

The application provides a kind of test device and method for evaluating volume change rate of cement slurry in cementing waiting-on-phase, and belongs to the technical field of oil and gas well cementing engineering.The test device comprises a curing kettle body, a cement slurry cup is arranged in the curing kettle body, a supporting assembly is used to suspend the cement slurry cup in the curing kettle body, and an adjusting assembly is used to assist in taking the cement slurry cup.The cement slurry cup can be suspended by the supporting assembly and the adjusting assembly, the remaining space in the curing kettle body forms a continuous flow cavity, which is beneficial to simulate temperature conditions and pressure environment closer to the actual downhole environment, the cement slurry cup can be easily taken out or put into the curing kettle body without the help of additional tools, the operation time is saved, the liquid medium in the cement slurry cup can be easily emptied, and the subsequent processing work after the test is completed is simplified.

Description

Technical Field

[0001] This invention relates to the field of oil and gas well cementing engineering technology, and in particular to a testing device and method for evaluating the volume change rate of cement slurry during the setting stage. Background Technology

[0002] Cementing is a crucial step in oil drilling. After the casing is run into the well, cementing operations are required. As the cement slurry is injected into the wellbore annulus to form cement stone, its volume changes due to physical and chemical reactions. If the volume expands, it may damage the casing. If the volume shrinks, it may create gaps at the cementing interface or cause annular pressure and other hazards. To ensure cementing quality and the safety of oil and gas well production, it is necessary to accurately evaluate the volume change performance of the cement slurry.

[0003] Currently, the testing method for cement slurry volume change performance involves placing a cement slurry cup filled with cement slurry inside a curing vessel equipped with a sensor system. Specifically, a liquid medium is injected into the curing vessel, which is then heated and pressurized. The volume change of the cement slurry cup is monitored through a corresponding control system. This method can monitor and evaluate the cement slurry volume change performance to a certain extent. However, existing cement slurry cups are suspended inside the curing vessel, with the suspension frame fixed to a hanging edge on the top inner side of the vessel. While the hanging edge and the suspension frame work together to suspend and fix the steel cup, ensuring effective monitoring of cement slurry volume change, in actual operation, due to the limited internal space of the curing vessel and the fixed position of the suspension frame, workers need to use additional tools to retrieve the cement slurry cup, making the operation cumbersome and affecting the testing efficiency of cement slurry volume change performance.

[0004] Therefore, the present invention provides a testing device for evaluating the volume change rate of cement slurry during the setting stage to meet the requirements. Summary of the Invention

[0005] The technical problem to be solved by this invention is to provide a testing device for evaluating the volume change rate of cement slurry during the curing stage. By setting up a support component and an adjustment component, the cement slurry cup can be suspended in the air, so that the remaining space inside the curing vessel forms a continuous flow cavity. This is beneficial for simulating temperature and pressure conditions that are closer to the actual downhole environment. It allows the operator to easily remove or place the cement slurry cup from or into the curing vessel without the need for additional tools, saving operation time. It also facilitates the emptying of the liquid medium in the cement slurry cup and simplifies the subsequent processing work after the test. The above settings can solve the problem that the fixed suspension frame in the prior art is inconvenient for operators to take the cement slurry cup.

[0006] To solve the above-mentioned technical problems, the present invention provides the following technical solution: A testing device for evaluating the volume change rate of cement slurry during the setting stage includes a curing vessel, a lid on top of the vessel, a storage tank and a recovery tank connected to both sides of the vessel, a pressure sensor on the side wall of the vessel, a cement slurry cup inside the vessel, a temperature sensor on the lid extending into the cement slurry cup, a support assembly for suspending the cement slurry cup inside the vessel, and an adjustment assembly for assisting in handling the cement slurry cup, the adjustment assembly being connected to the support assembly.

[0007] Optionally, the supporting assembly includes a bracket, a placement groove is provided on the top of the inner wall of the curing vessel, the bracket is engaged with the placement groove, an upper bracket is provided at the bottom of the bracket, the top of the upper bracket is in contact with the bottom edge of the cement slurry cup, a vertical rod is provided at the bottom of the upper bracket, there is a gap between the vertical rod and the cement slurry cup, and a lower bracket is provided at the bottom of the vertical rod, which is in contact with the bottom of the cement slurry cup.

[0008] Optionally, the adjustment assembly includes two brackets, the tops of which are engaged with the placement slot, and the bottoms of which are provided with sliding rods. There is a gap between the sliding rods and the cement slurry cup. The tops of the two sliding rods are in contact with the bottom edge of the cement slurry cup, and the bottoms of the two sliding rods are slidably connected to the lower bracket. Support plates are slidably provided inside the two sliding rods, and the two support plates are engaged. The temperature sensor can pass through the space between the two support plates, and the upper bracket is slidably connected to the sliding rods.

[0009] Optionally, the lower bracket has a corresponding insert rod at its top, and the slide rod has a slot at its bottom end, with the insert rod slidably connected to the slot.

[0010] Optionally, a longitudinal groove is provided on one side of the slide rod, and a slider is provided on the upper bracket, the slider sliding in the longitudinal groove.

[0011] Optionally, the bottom of the second bracket is provided with a transverse sliding groove, and an adjusting rod is slidably disposed in the transverse sliding groove. The top end of the adjusting rod is hinged to the support plate.

[0012] Optionally, a sealing block is provided on one side of the adjusting rod, and a notch is provided on the top of the cement slurry cup, with the sealing block being inserted into the notch.

[0013] Optionally, the bottom of the cement slurry cup is provided with an opening, and the top of the inner wall of the lower bracket is provided with a sealing block two, which is inserted and engaged with the opening.

[0014] Optionally, a sliding groove is provided in one of the support plates, a limiting block is provided in the sliding groove, a pushing block is slidably provided on one side of the sliding groove, a button is provided on one side of the pushing block, an insert block is slidably provided in the sliding groove, a locking block is provided on one side of the insert block, the locking block engages with the limiting block, the locking block abuts against the pushing block, a deformation part is provided between the insert block and the locking block, and the end of the insert block away from the sliding groove is connected to the other support plate.

[0015] This invention also provides a method for evaluating the volume change rate of cement slurry during the setting stage, comprising the following steps: Step 1: Apply sealant evenly to the connection between the curing vessel body and the vessel lid, as well as to the inner wall of the cement slurry cup; Step 2: Place the cement slurry cup on the top of the lower bracket so that the second sealing block is inserted into the through-hole. Slide the two adjusting rods so that the first sealing block is inserted into the notch. At the same time, the two support plates are engaged to complete the initial placement of the cement slurry cup. Step 3: Inject the cement slurry to be tested into the cement slurry cup, lift the support plate to suspend the cement slurry cup in the curing vessel, cover the vessel with the lid, and control the liquid medium in the storage tank to flow into and fill the curing vessel through the control system. Heat and pressurize the curing vessel, adjust the pressure in the curing vessel and collect the monitoring data of the temperature sensor and the pressure sensor in real time. Obtain the volume change and volume change rate of the cement slurry during the curing stage based on the monitoring data of the temperature sensor and the pressure sensor. Step 4: Discharge the liquid medium in the curing vessel into the recovery tank through the control system, open the vessel lid, if the volume expands, press the button to release the locking fit of the support plate, push the two adjusting rods away from each other, release the insertion fit of the sealing block one with the notch, if the volume shrinks, press down the support one and lift the support plate upward, release the insertion fit of the sealing block two with the port, and empty the liquid medium in the cement slurry cup; Step 5: Lift the support plate to remove the cement slurry cup from the curing vessel, pour out the cement block from the cement slurry cup, and complete a test of the volume change rate of cement slurry during the setting stage.

[0016] Compared with the prior art, the present invention has at least the following beneficial effects: In the above scheme, by setting up a support component and an adjustment component, the support component can suspend the cement slurry cup in the air, so that the remaining space inside the curing vessel forms a continuous flow cavity, which is conducive to simulating temperature and pressure conditions that are closer to the actual downhole environment. The adjustment component allows the operator to easily remove or place the cement slurry cup from or into the curing vessel without the need for additional tools, saving operation time and facilitating the emptying of the liquid medium in the cement slurry cup, simplifying the subsequent processing work after the test. At the same time, it can also limit the temperature sensor, ensuring that the temperature sensor can stably obtain the temperature information inside the cement slurry cup, which is conducive to improving the accuracy and reliability of the test results.

[0017] By setting up a support frame, an upper bracket, and a lower bracket, the cement slurry cup can be suspended in mid-air, allowing the remaining space inside the curing vessel to form a continuous flow cavity. This continuous flow cavity provides a smooth flow channel for the liquid medium, which helps to simulate temperature and pressure conditions that are closer to the actual downhole environment.

[0018] By setting up a second support, a sliding rod, and a support plate, the support plate can act as a handle, allowing workers to easily remove or place the cement slurry cup from the curing vessel without the need for additional tools, saving operation time. The support plate can also work with the vessel lid to limit the temperature sensor, ensuring that the temperature sensor can stably obtain temperature information inside the cement slurry cup. The combination of the second support and the sliding rod facilitates the emptying of the liquid medium inside the cement slurry cup, simplifying the subsequent processing work after the test and further improving work efficiency.

[0019] By monitoring and collecting sensor data through the control system and calculating the volume change rate of the cement slurry, a reliable data reference is provided for evaluating the addition of expanding agent in the cement slurry, which is beneficial to improving cementing quality. Attached Figure Description

[0020] The accompanying drawings, which are incorporated herein and form part of the specification, illustrate embodiments of the invention and, together with the specification, further serve to explain the principles of the invention and enable those skilled in the art to practice and use the invention.

[0021] Figure 1 A three-dimensional structural diagram of a testing device for evaluating the volume change rate of cement slurry during the setting stage. Figure 2 A schematic diagram of the three-dimensional structure of the internal side section of the curing vessel; Figure 3 A magnified three-dimensional structural diagram of a cement slurry cup; Figure 4 A three-dimensional structural diagram showing the fit between the support component and the cement grout cup; Figure 5 A schematic diagram of the three-dimensional structure of the supporting components; Figure 6 A schematic diagram of the three-dimensional structure of the adjustment component; Figure 7 A side-section three-dimensional structural diagram of the adjustment component and the cement slurry cup; Figure 8 for Figure 7 Enlarged structural diagram at point A in the middle; Figure 9 This is a schematic diagram of the three-dimensional structure of the support plate, viewed from top and partially sectional. Figure 10 for Figure 9 Enlarged structural diagram at point B; Figure 11 A three-dimensional structural diagram showing the adjustment component and cement slurry cup being pulled away from the supporting component.

[0022] Figure label: 1. Curing vessel body; 2. Vessel lid; 3. Storage tank; 4. Recovery tank; 5. Cement slurry cup; 6. Temperature sensor; 7. Pressure sensor; 8. Placement slot; 9. Support 1; 10. Upper bracket; 11. Vertical rod; 12. Lower bracket; 13. Insert rod; 14. Sliding rod; 15. Slot; 16. Longitudinal slide groove; 17. Sliding block; 18. Support 2; 19. Adjusting rod; 20. Sealing block 1; 21. Transverse slide groove; 22. Notch; 23. Support plate; 24. Sliding groove; 25. Insert block; 26. Locking block; 27. Deformation part; 28. Limiting block; 29. ​​Pushing block; 30. Button; 31. Through port; 32. Sealing block 2.

[0023] As shown in the figure, specific structures and devices are marked in the figure to clearly illustrate the structure of the embodiments of the present invention. However, this is only for illustrative purposes and is not intended to limit the present invention to this specific structure, device and environment. Those skilled in the art can adjust or modify these devices and environments according to specific needs. Detailed Implementation

[0024] The following is a detailed description of a testing device and method for evaluating the volume change rate of cement slurry during the setting stage, provided by the present invention, with reference to the accompanying drawings and specific embodiments. It should be noted that, to make the embodiments more detailed, the following embodiments are the best and preferred embodiments; those skilled in the art can also use other alternative methods to implement some known technologies; and the accompanying drawings are only for more specific description of the embodiments and are not intended to specifically limit the present invention.

[0025] It should be noted that the use of terms such as "an embodiment," "an embodiment," "an exemplary embodiment," and "some embodiments" in the specification indicates that the described embodiment may include a specific feature, structure, or characteristic, but not every embodiment necessarily includes that specific feature, structure, or characteristic. Furthermore, when a specific feature, structure, or characteristic is described in connection with an embodiment, implementing such a feature, structure, or characteristic in conjunction with other embodiments (whether explicitly described or not) should be within the knowledge of those skilled in the art.

[0026] Generally, terms can be understood at least partly from their use in context. For example, depending at least partly on the context, the term "one or more" as used herein can be used to describe any feature, structure, or characteristic in a singular sense, or a combination of features, structures, or characteristics in a plural sense. Additionally, the term "based on" can be understood not necessarily to convey an exclusive set of factors, but rather, alternatively, depending at least partly on the context, to allow for the presence of other factors that are not necessarily explicitly described.

[0027] It is understood that the meanings of “on”, “above”, and “above” in this invention should be interpreted in the broadest manner, such that “on” means not only “directly on” something, but also includes the meaning of being “on” something with an intervening feature or layer, and that “above” or “above” means not only “on” something, but also includes the meaning of being “on” something without an intervening feature or layer.

[0028] Furthermore, spatially related terms such as “below,” “under,” “lower,” “above,” and “upper” are used herein for convenience to describe the relationship of one element or feature to one or more other elements or features, as illustrated in the accompanying drawings. Spatially related terms are intended to cover different orientations in the use or operation of the device other than those depicted in the accompanying drawings. The device may be oriented in other ways, and the spatially related descriptive terms used herein can be interpreted similarly.

[0029] like Figures 1 to 11As shown, an embodiment of the present invention provides a test device for evaluating the volume change rate of cement slurry during the setting stage, including a curing vessel 1, a lid 2 on the top of the curing vessel 1, a storage tank 3 and a recovery tank 4 connected to both sides of the curing vessel 1. It is understood that the storage tank 3, the recovery tank 4 and the curing vessel 1 are all connected to each other by pipes, and hydraulic pumps and valves are connected to the pipes to control the inflow and outflow of liquid medium in the curing vessel 1. A pressure sensor 7 is provided on the side wall of the curing vessel 1, a cement slurry cup 5 is provided inside the curing vessel 1, a temperature sensor 6 is installed on the lid 2, and the bottom end of the temperature sensor 6 extends into the cement slurry cup 5. The exterior of the curing vessel 1 is also covered with a heating jacket and insulation cotton. It should be noted that the operation of the entire testing device, including the data acquisition and transmission from temperature sensor 6 and pressure sensor 7, is controlled by a control system. The control system can be either a built-in microcontroller or an external control computer. The control system and the components to be controlled are electrically connected. The control and operating principles are disclosed as prior art and will not be elaborated upon here. Of course, those skilled in the art can also choose to operate each component manually.

[0030] A sealing gasket is provided between the curing vessel body 1 and the vessel cover 2, and the connection is made by threads to ensure the sealing during testing. Temperature sensor 6 and pressure sensor 7 can work with the curing vessel body 1 to simulate the temperature and pressure environment downhole. During use, the cement slurry to be tested is injected into the cement slurry cup 5, the vessel cover 2 is opened, the cement slurry cup 5 is placed into the curing vessel body 1, the vessel cover 2 is closed, the control system controls the valve to open, and starts the hydraulic pump to fill the curing vessel body 1 with liquid medium. The control system controls the start of the heating jacket to heat and pressurize the inside of the curing vessel body 1, and collects the monitoring data of temperature sensor 6 and pressure sensor 7 in real time. The system calculates the volume change and volume change rate of cement slurry during the curing stage, realizing the evaluation of the volume change rate of cement slurry during the setting stage.

[0031] The support assembly suspends the cement slurry cup 5 inside the curing vessel 1. Connected to the curing vessel 1, the support assembly allows the cement slurry cup 5 to be suspended. The remaining space inside the curing vessel 1 forms a continuous flow cavity, providing a smooth flow channel for the liquid medium, allowing it to circulate freely within the curing vessel 1. When the curing vessel 1 is heated, heat is rapidly transferred to the area around the cement slurry cup 5 through the liquid medium, ensuring uniform heating of the cement slurry within the cup and simulating temperature conditions closer to the actual downhole environment. During pressurization, due to the incompressibility of the liquid medium, it applies uniform pressure to the cement slurry cup 5, helping to accurately simulate the pressure environment experienced by the cement slurry in the downhole annulus, thus more realistically reflecting the volume change of the cement slurry under pressure.

[0032] The adjusting component, which assists in handling the cement slurry cup 5, is connected to the supporting component. This component allows operators to easily remove or place the cement slurry cup 5 from the curing vessel 1 without additional tools, saving operation time and improving the testing efficiency of cement slurry volume change performance. While assisting in handling the cement slurry cup 5, the adjusting component also facilitates the emptying of the liquid medium inside, allowing it to flow out smoothly and simplifying post-test processing, thus improving work efficiency. Furthermore, the adjusting component limits the temperature sensor 6, ensuring that it can stably acquire temperature information from the cement slurry cup 5, providing reliable temperature data support for accurately evaluating cement slurry volume change performance and further improving the accuracy and reliability of the test results.

[0033] As one implementation method in this embodiment, such as Figure 2 , Figure 4 , Figure 5 and Figure 11 As shown, the supporting component includes a bracket 9, a placement groove 8 is provided on the top of the inner wall of the curing vessel 1, the bracket 9 is engaged with the placement groove 8, an upper bracket 10 is provided at the bottom of the bracket 9, the top of the upper bracket 10 is in contact with the bottom edge of the cement slurry cup 5, a vertical rod 11 is provided at the bottom of the upper bracket 10, there is a gap between the vertical rod 11 and the cement slurry cup 5, a lower bracket 12 is provided at the bottom of the vertical rod 11, and the lower bracket 12 is in contact with the bottom of the cement slurry cup 5; The placement slot 8 provides a space for the support 9. The upper bracket 10 supports the bottom edge of the cement slurry cup 5, and the lower bracket 12 supports the bottom of the cement slurry cup 5. The upright 11 serves as a connector. In use, the cement slurry cup 5 is placed on the lower bracket 12, so that the upper bracket 10 simultaneously supports the bottom edge of the cement slurry cup 5, ensuring the initial stability of the cement slurry cup 5. The cement slurry to be tested is injected into the cement slurry cup 5, and the support 9 and the cement slurry cup 5 are placed into the curing vessel 1. This allows the cement slurry cup 5 to be suspended, so that the remaining space inside the curing vessel 1 forms a continuous flow cavity. The continuous flow cavity provides a smooth flow channel for the liquid medium, allowing the liquid to circulate freely in the curing vessel 1, which is beneficial for simulating temperature and pressure conditions that are closer to the actual downhole environment. When the vessel cover 2 is closed, the bottom of the vessel cover 2 abuts against the top of the support 9, so that the cement slurry cup 5 can be stably placed in the curing vessel 1.

[0034] In this embodiment, as Figures 2 to 5 , Figure 11As shown, the adjustment assembly includes two brackets 18, which are symmetrically arranged. The top of each bracket 18 is engaged with the placement groove 8. The bottom of each bracket 18 is provided with a sliding rod 14. There is a gap between the sliding rod 14 and the cement slurry cup 5. The top of each sliding rod 14 is in contact with the bottom edge of the cement slurry cup 5. The bottom of each sliding rod 14 is slidably connected to the lower bracket 12. A support plate 23 is slidably provided inside each sliding rod 14. The two support plates 23 are engaged. The temperature sensor 6 can pass through the space between the two support plates 23. Two supports, 18 and 9, are circumferentially distributed on the placement groove 8 to provide stable support for the cement slurry cup 5. The top of the lower bracket 12 is provided with a rod 13 corresponding to the slide rod 14. The bottom of the slide rod 14 is provided with a slot 15. The rod 13 and the slot 15 are slidably connected. The sliding connection between the slide rod 14 and the lower bracket 12 provides adjustment space for the bottom of the cement slurry cup 5 to move away from the lower bracket 12. The two support plates 23 are engaged to act as handles, allowing the operator to easily remove or place the cement slurry cup 5 from the curing vessel 1 without the need for additional tools, saving operation time. When the two support plates 23 are engaged, the temperature sensor 6 can pass between the two support plates 23, thereby working with the vessel lid 2 to limit the temperature sensor 6, ensuring that the temperature sensor 6 can stably obtain the temperature information inside the cement slurry cup 5, providing reliable temperature data support for accurately evaluating the performance of cement slurry volume change.

[0035] In this embodiment, as Figures 3 to 8 As shown, the upper bracket 10 is slidably connected to the slide rod 14. A longitudinal slide groove 16 is provided on one side of the slide rod 14. A slider 17 is provided on the upper bracket 10. The slider 17 slides in the longitudinal slide groove 16. A through-hole 31 is provided at the bottom of the cement slurry cup 5. A sealing block 32 is provided on the top of the inner wall of the lower bracket 12. The sealing block 32 is inserted into the through-hole 31. It can be understood that in order to further ensure the sealing effect of the sealing block 32, a sealing ring is also provided on the surface of the sealing block 32. When the cement slurry cup 5 is placed on the lower support 12, the sealing block 2 32 and the opening 31 are inserted and engaged to ensure the bottom of the cement slurry cup 5 is sealed. After the test is completed, the lid 2 is opened. If the cement block in the cement slurry cup 5 is in a contracted state, the worker holds down the support 1 9 with one hand and lifts the two interlocking support plates 23 with the other hand to pull them upward along the length of the longitudinal slide groove 16. This causes the support 2 18 and the slide rod 14 to move the cement slurry cup 5 upward, thereby releasing the insertion and engagement of the sealing block 2 32 and the opening 31. This allows the excess liquid medium in the cement slurry cup 5 to flow out from the opening 31, simplifying the subsequent processing work after the test and improving work efficiency. At the same time, the opening 31 also facilitates the demolding of the hardened cement block in the cement slurry cup 5, further improving work efficiency.

[0036] In this embodiment, as Figures 3 to 8 As shown, the bottom of the bracket 2 18 is provided with a transverse sliding groove 21, and an adjusting rod 19 is slidably provided in the transverse sliding groove 21. The top of the adjusting rod 19 is hinged to the support plate 23. A sealing block 20 is provided on one side of the adjusting rod 19. A notch 22 is provided on the top of the cement slurry cup 5. The sealing block 20 is inserted into the notch 22. A sealing ring is also provided on the surface of the sealing block 20 to ensure the sealing effect of the sealing block 20 on the mouth of the cement slurry cup 5. When the cement slurry cup 5 is placed on the lower bracket 12, the operator pushes the two adjusting rods 19 closer together along the length of the transverse sliding groove 21 until the sealing block 20 and the notch 22 are engaged, thus sealing the mouth of the cement slurry cup 5. At this time, the two support plates 23 are simultaneously engaged, which can also serve as handles, allowing the operator to easily remove or place the cement slurry cup 5 from the curing vessel 1 without the need for additional tools, saving operation time. At this time, the temperature sensor 6 can pass between the two support plates 23, thus working with the vessel lid 2 to limit the temperature sensor 6 and ensure the stability of the temperature sensor 6. After the test is completed, open the lid 2. If the cement block in the cement slurry cup 5 is in an expanded state, the staff manually releases the locking fit of the two support plates 23 and pushes the two adjusting rods 19 away from each other along the length of the transverse sliding groove 21, thereby releasing the insertion fit between the sealing block 20 and the notch 22, allowing the excess liquid medium in the cement slurry cup 5 to flow out through the notch 22. This simplifies the subsequent processing work after the test and improves work efficiency.

[0037] In this embodiment, as Figure 9 and Figure 10 As shown, there are two support plates 23 as described above. One support plate 23 has a sliding groove 24, a limiting block 28 in the sliding groove 24, a pushing block 29 slidingly on one side of the sliding groove 24, a button 30 on one side of the pushing block 29, and the pushing block 29 and the button 30 are connected by a connecting post. A spring is sleeved on the surface of the connecting post. One support plate 23 has a limiting groove for limiting the spring on one side. A baffle is also provided at one end of the connecting post to abut against one side of the limiting groove. An insert block 25 slides in the sliding groove 24. A locking block 26 is provided on one side of the insert block 25. The locking block 26 engages with the limiting block 28 and abuts against the pushing block 29. A deformation part 27 is provided between the insert block 25 and the locking block 26. The end of the insert block 25 away from the sliding groove 24 is connected to the other support plate 23. Insert block 25 is inserted into sliding groove 24 until locking block 26 engages with limiting block 28, thereby achieving the locking engagement of two support plates 23. When it is necessary to release the locking engagement of the two support plates 23, the operator manually presses button 30, which causes push block 29 to push locking block 26 under the action of connecting column. Under the deformation action of deformation part 27, locking block 26 is released from engagement with limiting block 28, thereby releasing the locking engagement of the two support plates 23.

[0038] This invention also provides a method for evaluating the volume change rate of cement slurry during the setting stage, comprising the following steps: Step 1: Apply sealant evenly to the joint between the curing vessel body 1 and the vessel cover 2, as well as the inner wall of the cement slurry cup 5. Applying sealant to the inside of the cement slurry cup 5 is to facilitate demolding after the cement stone is formed. Step 2: Place the cement slurry cup 5 on the top of the lower bracket 12 so that the sealing block 2 32 and the opening 31 are inserted and matched to seal the bottom of the cement slurry cup 5. Slide the two adjusting rods 19 so that the sealing block 1 20 and the notch 22 are inserted and matched to seal the mouth of the cement slurry cup 5. At the same time, the two support plates 23 are engaged and matched to serve as handles to pick up the cement slurry cup 5, thus completing the initial placement of the cement slurry cup 5. Step 3: Inject the cement slurry to be tested into the cement slurry cup 5, lift the support plate 23 to suspend the cement slurry cup 5 in the curing vessel 1, cover the vessel with the lid 2, open the control valve, and start the hydraulic pump to fill the curing vessel 1 with liquid medium. The control system controls the start of the heating jacket to heat and pressurize the inside of the curing vessel 1, and collect the monitoring data of the temperature sensor 6 and pressure sensor 7 in real time. The system calculates the volume change and volume change rate of the cement slurry during the curing stage, and realizes the evaluation of the volume change rate of the cement slurry during the setting stage. It should be noted that the capacity of cement slurry cup 5 is 500mL, and the cement slurry to be tested injected into cement slurry cup 5 is 400mL. It should be further noted that the liquid medium, AK-50 silicone oil, can withstand high temperatures of 200°C and has a low cost. The volume of cement paste under temperature T and pressure P can be calculated using the following formula: in, The volume of cement grout injected; (T, P) represents the volume of cement paste at temperature T and pressure P; P is the initial pressure of the cement slurry, and P is the set curing pressure. T represents the initial temperature of the cement slurry, and T represents the set curing temperature; △ (T, P) represents the volume change of the cement slurry inside the reactor during the heating and pressurization stage; α is the coefficient of thermal expansion of the cement slurry, taking a value of... β is the compressibility coefficient of cement paste, and its value is... ; The volume occupied by the liquid inside the vessel can be calculated using the following formula: in, The volume of silicone oil to be filled into the high-temperature and high-pressure reactor; This refers to the total volume of the vessel. The amount of liquid substance inside the vessel can be calculated using the following formula: in, M represents the amount of liquid substance introduced into the reactor; M is the molar mass of the liquid, and the molar mass of the silicone oil is 5000 g / mol. The mass of the liquid filled into the vessel is also equal to the change in mass of the storage tank Δ during the heating and pressurization phase. ; The density of the liquid inside the vessel at temperature T and pressure P can be calculated using the following formula: in, Let be the density of the liquid at temperature T and pressure P. Step 4: Discharge the liquid medium in the curing vessel 1 into the recovery tank 4 through the control system. Open the vessel lid 2. If the volume expands, press button 30 to release the locking fit of the support plate 23. Push the two adjusting rods 19 away from each other to release the insertion fit between the sealing block 1 20 and the notch 22. If the volume shrinks, press down the support 1 9 and lift the support plate 23 upward to release the insertion fit between the sealing block 2 32 and the opening 31, and empty the liquid medium in the cement slurry cup 5. It should be noted that when the pressure inside the curing vessel 1 is lower than the curing pressure P, the cement slurry is in a contracted state. The control system controls the opening of the valve of the storage tank 3 to inject liquid medium into the curing vessel 1 to replenish the pressure. After the pressure is restored, the control system controls the closing of the valve of the storage tank 3. When the pressure inside the curing vessel 1 is higher than the curing pressure P, the cement slurry is in an expanded state. The control system controls the opening of the valve of the recovery tank 4 to depressurize the liquid medium into the recovery tank 4. After the pressure is restored, the control system controls the closing of the valve of the recovery tank 4. It should be further explained that both the storage tank 3 and the recovery tank 4 are equipped with mass sensors at their bottoms. When the mass of the liquid medium in the storage tank 3 and the recovery tank 4 changes, the control system will collect the mass sensor data in real time during the pressure replenishment or pressure relief phases. The change in mass of the storage tank at a certain moment Δ Change in the mass of the recycling tank Δ ; Volume change Δ during cement grout curing stage The volume change rate η can be calculated using the following formula: Among them, ΔV is the change in the total volume of cement slurry; Δ This represents the volume change of the cement slurry inside the reactor during the curing stage; Δ The change in liquid volume inside the vessel during the curing stage; Δ Let g be the change in mass of storage tank 3 at a certain moment; Δ η represents the mass change of recovery tank 4 at a certain moment; η is the volume change rate of cement slurry; if η is positive, it indicates that the cement slurry expands, and if η is negative, it indicates that the cement slurry contracts.

[0039] Step 5: Lift the support plate 23 to remove the cement slurry cup 5 from the curing vessel 1, pour out the cement block in the cement slurry cup 5, and complete a test of the volume change rate of cement slurry during the setting stage.

[0040] The device was then tested using the steps outlined above. The test and calculation results are shown in Table 1. Known: Effective space inside the cement slurry curing autoclave The volume of the cement slurry cup is 500 mL, and the cement slurry to be tested is poured in. =400mL, the coefficient of thermal expansion α of the cement grout is taken as: The compressibility coefficient β of the cement grout is taken as: Initial temperature 25℃, initial pressure 1×10 5 The molar mass of the liquid medium silicone oil is 5000 g / mol.

[0041] Table 1. Test data and calculation results under high temperature and high pressure. As shown in Table 1, when the curing temperature and curing pressure are constant, the volume change rate of cement slurry is negative, indicating that the cement slurry shrinks.

[0042] A certain amount of cement slurry expansion agent was added to the cement slurry used in Table 1. Other operations were the same as in the experiment in Table 1. The device was then tested using the above steps. The test and calculation results are shown in Table 2. Table 2. Test data and calculation results under high temperature and high pressure. As shown in Table 2, when the curing temperature and curing pressure are constant, the volume change rate of the cement slurry is positive, indicating that the cement slurry expands.

[0043] In summary, this device can obtain the volume change rate of cement slurry in oil and gas wells by collecting data through the control system and calculating according to the above formula. Then, an appropriate amount of cement slurry expansion agent can be added according to the actual engineering needs, which is beneficial to improving the cementing quality.

[0044] The working principle of the technical solution provided by this invention is as follows: During use, the operator evenly applies sealant to the connection between the curing vessel body 1 and the vessel lid 2, as well as the inner wall of the cement slurry cup 5. The cement slurry cup 5 is then placed on top of the lower support 12, allowing the sealing block 2 32 to engage with the opening 31, thus sealing the bottom of the cement slurry cup 5. The two adjusting rods 19 are slid to engage the sealing block 1 20 with the notch 22, sealing the opening of the cement slurry cup 5. Simultaneously, the two support plates 23 engage to act as handles for lifting the cement slurry cup 5, thus achieving initial placement. Afterward, the cement slurry to be tested is injected into the cement slurry cup 5. The support plates 23 are then lifted to place the support 1 9 and the cement slurry cup 5 into the curing vessel body. Within the curing vessel 1, the cement slurry cup 5 can be suspended, creating a continuous flow chamber within the remaining space. The vessel lid 2 is then placed on top, its bottom abutting against the top of the support 9, ensuring the cement slurry cup 5 is stably positioned within the curing vessel 1. The operator uses the control system to open the valve and activate the hydraulic pump to fill the curing vessel 1 with liquid silicone oil. The control system also activates the heating jacket to heat and pressurize the inside of the curing vessel 1, while simultaneously collecting monitoring data from the temperature sensor 6 and pressure sensor 7. The system calculates the volume change and volume change rate during the cement slurry curing stage, thus achieving the desired volume change during the cement slurry setting stage. The evaluation of the volume change rate is achieved by discharging the liquid medium in the curing vessel 1 into the recovery tank 4 through the control system. If the volume change rate of the cement slurry is positive, it indicates that the cement slurry has expanded. The vessel lid 2 is opened, and the operator manually presses button 30. Under the action of the connecting column, the pushing block 29 pushes the locking block 26. Under the deformation of the deforming part 27, the locking block 26 is released from engagement with the limiting block 28, thereby releasing the engagement of the two support plates 23. This pushes the two adjusting rods 19 away from each other, releasing the insertion engagement of the sealing block 20 with the notch 22, allowing excess liquid medium in the cement slurry cup 5 to flow out through the notch 22. If the cement slurry volume change rate is positive... A negative rate indicates cement slurry shrinkage. The worker holds down the support 1 9 with one hand and lifts the two interlocking support plates 23 with the other hand, pulling them upwards along the length of the longitudinal slide groove 16. This causes the support 2 18 and the slide rod 14 to move the cement slurry cup 5 upwards, thereby releasing the interlocking fit between the sealing block 2 32 and the opening 31. This allows excess liquid medium in the cement slurry cup 5 to flow out through the opening 31, simplifying the subsequent processing work after the test. After the liquid medium is drained, the support plate 23 is lifted to remove the cement slurry cup 5 from the curing vessel 1, and the cement blocks in the cement slurry cup 5 are poured out, completing a test of the volume change rate of cement slurry during the setting stage.

[0045] This invention encompasses any substitutions, modifications, equivalent methods, and solutions made within the spirit and scope of this invention. To provide the public with a thorough understanding of this invention, specific details are described in detail in the following preferred embodiments; however, those skilled in the art will fully understand the invention even without these details. Furthermore, to avoid unnecessary misunderstanding of the essence of this invention, well-known methods, processes, procedures, components, and circuits are not described in detail.

[0046] The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the principle of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A testing device for evaluating the volume change rate of cement slurry during the setting stage, comprising a curing vessel, characterized in that, The top of the curing vessel is provided with a lid, and a storage tank and a recovery tank are connected to both sides of the curing vessel. A pressure sensor is provided on the side wall of the curing vessel. A cement slurry cup is provided inside the curing vessel. A temperature sensor is installed on the lid, and the bottom end of the temperature sensor extends into the cement slurry cup. A support assembly for suspending the cement slurry cup inside the curing vessel, the support assembly being connected to the curing vessel; An adjustment component, which is used to assist in picking up the cement slurry cup, is connected to a support component; The supporting component includes a bracket, a placement groove is provided on the top of the inner wall of the curing vessel, the bracket is snapped into the placement groove, an upper bracket is provided at the bottom of the bracket, the top of the upper bracket is in contact with the bottom edge of the cement slurry cup, a vertical rod is provided at the bottom of the upper bracket, there is a gap between the vertical rod and the cement slurry cup, and a lower bracket is provided at the bottom of the vertical rod, which is in contact with the bottom of the cement slurry cup. The adjustment assembly includes two brackets, the tops of which are engaged with the placement slot, and the bottoms of each bracket are provided with sliding rods. There is a gap between the sliding rods and the cement slurry cup. The tops of the two sliding rods are in contact with the bottom edge of the cement slurry cup, and the bottoms of the two sliding rods are slidably connected to the lower bracket. Support plates are slidably provided inside each of the two sliding rods, and the two support plates are engaged. The temperature sensor can pass through the space between the two support plates, and the upper bracket is slidably connected to the sliding rods.

2. The testing device for evaluating the volume change rate of cement slurry during the setting stage according to claim 1, characterized in that, The lower bracket has a corresponding insert rod at its top, and the bottom of the slide rod has a slot, with the insert rod slidably connected to the slot.

3. The testing device for evaluating the volume change rate of cement slurry during the setting stage according to claim 1, characterized in that, A longitudinal groove is provided on one side of the slide bar, and a slider is provided on the upper bracket, the slider sliding in the longitudinal groove.

4. The testing device for evaluating the volume change rate of cement slurry during the setting stage according to claim 1, characterized in that, The bottom of the second bracket is provided with a transverse sliding groove, and an adjusting rod is slidably disposed in the transverse sliding groove. The top end of the adjusting rod is hinged to the support plate.

5. The testing device for evaluating the volume change rate of cement slurry during the setting stage according to claim 4, characterized in that, A sealing block is provided on one side of the adjusting rod, and a notch is provided on the top of the cement slurry cup. The sealing block is inserted into the notch.

6. The testing device for evaluating the volume change rate of cement slurry during the setting stage according to claim 1, characterized in that, The bottom of the cement slurry cup has an opening, and the top of the inner wall of the lower bracket has a sealing block two, which is inserted into the opening.

7. The testing device for evaluating the volume change rate of cement slurry during the setting stage according to claim 1, characterized in that, A sliding groove is provided in one of the support plates, a limiting block is provided in the sliding groove, a pushing block is slidably provided on one side of the sliding groove, a button is provided on one side of the pushing block, an insert block is slidably provided in the sliding groove, a locking block is provided on one side of the insert block, the locking block engages with the limiting block, the locking block abuts against the pushing block, a deformation part is provided between the insert block and the locking block, and the end of the insert block away from the sliding groove is connected to the other support plate.

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