Continuous circulating high pressure foam cement slurry preparation device and method
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- CHINA NAT PETROLEUM CORP
- Filing Date
- 2024-11-28
- Publication Date
- 2026-05-29
Smart Images
Figure CN122100331A_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of foam cement slurry technology for cementing oil and gas wells, and is a continuous circulating high-pressure foam cement slurry preparation device and a high-pressure foam cement slurry preparation method. Background Technology
[0002] Foamed cement refers to a multiphase system in which a certain amount of foam is mixed into conventional cement slurry, forming a three-phase system of solid, liquid, and gas with high dispersion. Foamed cement cementing mainly reduces the density of the cement slurry, thereby reducing the liquid column pressure in the annular cement slurry section. This helps solve the problem of cementing leakage in low-pressure, easily leaking oil layers and also protects the oil layer.
[0003] Currently, laboratory tests primarily employ high-speed mixing (12000 rpm) at atmospheric pressure to foam cement slurry. However, in field cementing processes, high-pressure nitrogen is pumped into a foam generator to mix with the cement slurry for foaming. Furthermore, the foam generators used are conventional cementing slurry mixing cups, which produce poor foaming results and cannot be used for pressurized sampling and testing; alternatively, modified sealed mixing cups are used, which are structurally complex and also difficult to sample and test under specific pressures. In fact, field-tested foamed cement samples differ significantly from laboratory samples, primarily in smaller foam diameter and higher foam stability. Therefore, laboratory studies and testing of foamed cement slurry under atmospheric pressure cannot accurately evaluate its performance in practical applications, and thus cannot effectively guide the selection of foamed cement slurry performance required for high-pressure gas injection environments in oil and gas wells.
[0004] Chinese patent document CN109397538A discloses a foamed cement slurry generator and a pressurized aeration device for cement slurry, and their applications. This device injects high-pressure gas into the cement slurry, which is then mixed in a mixing chamber. Obviously, this results in insufficient mixing and poor foam quality. Chinese patent document CN102555055A discloses a pressurized mixing device for foamed cement slurry. Compared to a normal-pressure cement slurry preparation cup, it adds a sealed cup lid, with a high-pressure range of 0-0.5 MPa, resulting in lower pressure for preparing the foamed cement slurry. Chinese patent document CN104227846A discloses a foamed cement slurry preparation device and its applications. This device includes a magnetically driven stirring system, a pneumatically driven system, a mixing cylinder, a piston cylinder connected to a piston, and a sampler. The foamed cement slurry prepared by this device is sampled and tested using the sampler to assess its relevant properties. This device mainly suffers from complex structure, low pressure for preparing the foamed cement slurry, and complex preparation methods. Furthermore, the density of the prepared foamed cement slurry changes during the sampling process because the volume of the circulation system changes.
[0005] Therefore, it is necessary to develop a foam cement slurry preparation device with a simple structure that can help improve the aeration and foaming effect and facilitate pressurized sampling, so as to provide a basis for the study of foam cement characteristics under high-pressure aeration environment. Summary of the Invention
[0006] This invention provides a continuous circulating high-pressure foamed cement slurry preparation device and method, which overcomes the shortcomings of the prior art and can effectively solve the problems of complex structure and low pressure in the preparation of foamed cement slurry in existing foamed cement slurry preparation devices.
[0007] One of the technical solutions of this invention is achieved through the following measures: a continuous circulating high-pressure foamed cement slurry preparation device, comprising: a high-pressure slurry cup, a high-pressure gas cylinder, a mixer, and a circulating pump; a first circulating pipeline connects the first inlet at the top of the high-pressure slurry cup to the outlet of the circulating pump; a gas pressurization pipeline connects the second inlet at the top of the high-pressure slurry cup to the outlet of the high-pressure gas cylinder; a discharge pipeline connects the bottom outlet of the high-pressure slurry cup to the inlet of the mixer; and a second circulating pipeline connects the outlet of the mixer to the inlet of the circulating pump. The high-pressure slurry cup includes a cup body, a top cover installed at the upper end of the cup body, a bottom cover installed at the lower end of the cup body, a first inlet at the center of the top cover, a high-pressure nozzle with a downward-facing nozzle installed at the first inlet, a second inlet on the right side of the top cover, the first inlet connected to the first circulating pipeline, the second inlet connected to the gas pressurization pipeline, and an outlet at the center of the bottom cover connected to the discharge pipeline.
[0008] The following are further optimizations and / or improvements to one of the above-mentioned technical solutions: The mixer includes an upper diffuser and a lower diffuser. The upper diffuser is a frustum-shaped tube with a smaller upper port and a larger lower port, and the lower diffuser is a frustum-shaped tube with a larger upper port and a smaller lower port. The lower port of the upper diffuser and the upper port of the lower diffuser are detachably connected. A screen is horizontally arranged between the upper and lower diffusers. The upper port of the upper diffuser is connected to the discharge pipeline, and the lower port of the lower diffuser is connected to the second circulation pipeline.
[0009] The diameter of the lower port of the aforementioned upper diffuser is 2 to 2.5 times the diameter of its upper port, and the diameter of the upper port of the lower diffuser is 2 to 2.5 times the diameter of its lower port.
[0010] A first valve is installed near the outlet of the first circulation pipeline, and a second valve is installed on the discharge pipeline. Both the first and second valves can be disassembled and installed as needed. The first valve is installed on the first circulation pipeline near the high-pressure slurry cup.
[0011] A pressure gauge and an inlet valve are fixedly installed along the gas flow direction on the aforementioned gas pressurization pipeline.
[0012] The aforementioned high-pressure slurry cup has a cylindrical, hollow body, with threaded connections between the cup body and both the top and bottom covers. These threaded connections facilitate the loading and unloading of the cement foam slurry base within the cup body, and also facilitate the density testing and application of the high-pressure foam cement slurry.
[0013] The aforementioned circulating pump is a high-pressure plunger pump.
[0014] A pressure gauge is fixedly installed on the aforementioned second circulation pipeline.
[0015] The second technical solution of the present invention is achieved through the following measures: a method for preparing high-pressure foamed cement slurry, comprising the following steps: Determine the pressure, temperature, density, and base density of the high-pressure foamed cement slurry to be prepared, and calculate the volume of base slurry to be added. Pour the foamed cement slurry base into the high-pressure slurry cup, connect the cup body and the top cover, and connect the pipelines of the continuous circulation high-pressure foamed cement slurry preparation device. Check the airtightness of the device, open all valves, pressurize the gas supply through the high-pressure gas cylinder until the pressure gauge reaches the preset pressure value, then close the high-pressure gas cylinder and the air inlet valve. Open the first valve and the second valve, start the circulation pump, and allow the foamed cement slurry base slurry and high-pressure gas to circulate along the first circulation pipeline, the discharge pipeline and the second circulation pipeline. After the pressure gauge value stabilizes, close the circulation pump and the first and second valves to stop the circulation and complete the preparation of the high-pressure foamed cement slurry.
[0016] The following are further optimizations and / or improvements to the second technical solution of the above invention: The volume of the above-mentioned foamed cement slurry base should be calculated using the following formula: V2=(ρ-ρ 气 )×V1 / (ρ 基 -ρ 气 ) ρ 气 =(1.25P1T 标 ) / (P 标 ZT1)×10 -3 Where V2 is the volume of the foamed cement slurry base, V1 is the total volume of the first circulation pipeline, discharge pipeline, second circulation pipeline, upper diffuser, lower diffuser, and the high-pressure slurry cup of the device; ρ is the density of the high-pressure foamed cement slurry to be prepared; ρ 气 ρ is the density of the high-pressure gas. 基 P is the density of the foamed cement slurry base; P1 is the pressure of the foamed cement slurry; T1 is the temperature of the foamed cement slurry; P 标 Pressure under standard conditions; T 标 t is the temperature under standard conditions; Z is the compressibility coefficient of the high-pressure gas.
[0017] This invention provides a simple, continuous circulating high-pressure foam cement slurry preparation device that improves the aeration and foaming effect and enables pressurized sampling. It improves the preparation pressure and foam quality of high-pressure foam cement slurry, provides a basis for the study of foam cement characteristics under high-pressure gas injection environment, improves the performance of foam cement in the cementing process, and further protects the integrity of oil and gas wells. Attached Figure Description
[0018] Appendix Figure 1 This is a schematic diagram of the process flow of Embodiment 1 of the present invention.
[0019] The codes in the attached diagram are as follows: 1 is the circulating pump, 2 is the first circulating pipeline, 3 is the second circulating pipeline, 4 is the top cover, 5 is the first valve, 6 is the air inlet valve, 7 is the gas pressurization pipeline, 8 is the pressure gauge, 9 is the high-pressure gas cylinder, 10 is the cup body, 11 is the bottom cover, 12 is the second valve, 13 is the upper diffuser, 14 is the lower diffuser, 15 is the pressure gauge, 16 is the screen, 17 is the high-pressure nozzle, and 18 is the discharge pipeline.
[0020] Appendix Figure 2 Appendix to this invention Figure 1 A schematic diagram of the medium-sized screen. Detailed Implementation
[0021] This invention is not limited to the following embodiments; specific implementation methods can be determined according to the technical solutions and actual conditions of this invention. Unless otherwise specified, the equipment and apparatus used in this invention are all existing, publicly known, and commonly used equipment and apparatus in the art. In this invention, for ease of description, the description of the relative positional relationships of the components is based on the appendix to the specification. Figure 1 The layout is described using a diagrammatic method, such as the positional relationships of front, back, top, bottom, left, and right, which are based on the instructions attached. Figure 1 The orientation of the layout is determined by the direction of the map.
[0022] Unless otherwise specified, all equipment and devices used in this invention are existing and commonly known in the art.
[0023] The present invention will be further described below with reference to embodiments: Example 1: As Figure 1As shown, the continuous circulating high-pressure foamed cement slurry preparation device includes: a high-pressure slurry cup, a high-pressure gas cylinder 9, a mixer, and a circulating pump 1. A first circulating pipeline 2 connects the first inlet at the top of the high-pressure slurry cup to the outlet of the circulating pump 1. A gas pressurization pipeline 7 connects the second inlet at the top of the high-pressure slurry cup to the outlet of the high-pressure gas cylinder 9. A discharge pipeline 18 connects the bottom outlet of the high-pressure slurry cup to the inlet of the mixer. A second circulating pipeline 3 connects the outlet of the mixer to the inlet of the circulating pump 1. The high-pressure slurry cup includes a cup body 10. A top cover 4 is installed at the upper port of the cup body 10, and a bottom cover 11 is installed at the lower port of the cup body 10. A first inlet is opened at the center of the top cover 4, and a high-pressure nozzle 17 with a downward nozzle is installed at the first inlet. A second inlet is opened on the right side of the top cover 4. The first inlet is connected to the first circulating pipeline 2, and the second inlet is connected to the gas pressurization pipeline 7. An outlet is opened at the center of the bottom cover 11, and the outlet is connected to the discharge pipeline 18.
[0024] Example 2: Figure 1 As shown, as an optimization of the above embodiment, the mixer includes an upper diffuser 13 and a lower diffuser 14. The upper diffuser 13 is a frustum-shaped tube with a smaller upper port and a larger lower port, and the lower diffuser 14 is a frustum-shaped tube with a larger upper port and a smaller lower port. The lower port of the upper diffuser 13 and the upper port of the lower diffuser 14 are detachably connected. A screen 16 is horizontally arranged between the upper diffuser 13 and the lower diffuser 14. The upper port of the upper diffuser 13 is connected to the discharge pipeline 18, and the lower port of the lower diffuser 14 is connected to the second circulation pipeline 3.
[0025] As needed, the lower port of the upper diffuser tube 13 and the upper port of the lower diffuser tube 14 are connected by threads. A screen 16 is installed at the connection between the upper diffuser tube 13 and the lower diffuser tube 14 to seal the connection. The screen 16 has multiple screen holes, and the size and number of screen holes are determined according to the actual situation.
[0026] Example 3: As Figure 1 As shown, as an optimization of the above embodiment, the diameter of the lower port of the upper diffuser 13 is 2 to 2.5 times its upper port diameter, and the diameter of the upper port of the lower diffuser 14 is 2 to 2.5 times its lower port diameter. The mixer has a hollow interior with a design that is large in the middle and small at both ends, which reflects the efficiency of the mixer in mixing foamed cement slurry and high-pressure gas. The specific principle is that after the cement foamed cement slurry and high-pressure gas pass through the upper diffuser 13 with an ever-increasing diameter, they will be further mixed by turbulence. Then, the cement foamed cement slurry and high-pressure gas will flow through the lower diffuser 14 and be further sheared and mixed.
[0027] Example 4: Figure 1As shown, as an optimization of the above embodiment, a first valve 5 is installed near the outlet of the first circulation pipeline 2, and a second valve 12 is installed on the discharge pipeline 18. Both the first valve 5 and the second valve 12 can be detached and installed as needed. The first valve 5 is installed near the high-pressure slurry cup on the first circulation pipeline 2.
[0028] Example 5: Figure 1 As shown, as an optimization of the above embodiment, a pressure gauge 8 and an inlet valve 6 are fixedly installed on the gas pressurization pipeline 7 along the gas flow direction. Depending on the needs, the pressure gauge 8 can be fixedly connected to the high-pressure gas cylinder 9, i.e., an integrated design, which reduces connecting pipes and manufacturing costs. The high-pressure gas cylinder 9 can be specifically selected according to actual working conditions, and can reach a high pressure limit of forty MPa.
[0029] Example 6: As Figure 1 As shown, as an optimization of the above embodiment, the high-pressure slurry cup body 10 is cylindrical and hollow, and the cup body 10 is threadedly connected to the top cover 4 and the bottom cover 11. The threaded connection facilitates the loading and unloading of the cement foam cement slurry base in the cup body 10, and facilitates the density testing and application of the high-pressure foam cement slurry.
[0030] Example 7: As Figure 1 As shown, as an optimization of the above embodiment, the circulation pump 1 is a high-pressure plunger pump.
[0031] Example 8: As Figure 1 As shown, as an optimization of the above embodiment, a pressure gauge 15 is fixedly installed on the second circulation pipeline 3.
[0032] As needed, the continuous circulating high-pressure foamed cement slurry preparation device is equipped with instruments and valves on each pipeline to ensure its normal operation. The inner surfaces of each pipeline, high-pressure slurry cup, and mixer are coated with an anti-stick coating such as polytetrafluoroethylene (PTFE) or other non-adhesive materials to reduce cement residue adhesion and make cleaning easier. The continuous circulating high-pressure foamed cement slurry preparation device is vertically installed, allowing for easier circulation of the foamed cement slurry through gravity. The first inlet of the high-pressure slurry cup top cover 4 is threaded to the first circulation pipeline 2 and the high-pressure nozzle 17, the second inlet is threaded to the gas pressurization pipeline 7, and the outlet of the bottom cover 11 is threaded to the discharge pipeline 18. The first circulation pipeline 2, the discharge pipeline 18, and the second circulation pipeline 3 are all high-pressure pipelines. Bends in the first circulation pipeline 2 and the second circulation pipeline 3 can be connected or reversed using high-pressure elbows or high-pressure bends; the gas pressurization pipeline 7 is a high-pressure hose. The circulation pump 1, pressure gauge 15, and pressure gauge 8 can all be connected to a computer for automatic control.
[0033] Example 9: The method for preparing this high-pressure foamed cement slurry includes the following steps: Determine the pressure, temperature, density, and base density of the high-pressure foamed cement slurry to be prepared, and calculate the volume of base slurry to be added. Pour the foamed cement slurry base into the high-pressure slurry cup 10, connect the cup 10 and the top cover 4, and connect the pipelines of the continuous circulation high-pressure foamed cement slurry preparation device. Check the airtightness of the device, open all valves, pressurize and supply gas through high-pressure gas cylinder 9 until the pressure gauge 8 reaches the preset pressure value, then close high-pressure gas cylinder 9 and air inlet valve 6. Open the first valve 5 and the second valve 12, and start the circulation pump 1 to allow the foamed cement slurry base slurry and high-pressure gas to circulate along the first circulation pipeline 2, the discharge pipeline 18 and the second circulation pipeline 3. After the pressure value of the pressure gauge 15 stabilizes, close the circulation pump 1 and the first valve 5 and the second valve 12 to stop the circulation and complete the preparation of the high-pressure foamed cement slurry.
[0034] Example 10: As an optimization of the above examples, the volume of foamed cement slurry base added is calculated according to the following formula: V2=(ρ-ρ 气 )×V1 / (ρ 基 -ρ 气 ) ρ 气 =(1.25P1T 标 ) / (P 标 ZT1)×10 -3 Wherein, V2 is the volume of the foamed cement slurry base, V1 is the total volume of the first circulation pipeline 2, the discharge pipeline 18, the second circulation pipeline 3, the upper diffuser 13, the lower diffuser 14, and the high-pressure slurry cup body 10; ρ is the density of the high-pressure foamed cement slurry to be prepared; ρ 气 ρ is the density of the high-pressure gas. 基 P is the density of the foamed cement slurry base; P1 is the pressure of the foamed cement slurry; T1 is the temperature of the foamed cement slurry; P 标 Pressure under standard conditions; T 标 The temperature is denoted as ; Z is the compressibility coefficient of the high-pressure gas, which can be found in a table.
[0035] Example 11: The use of this continuous circulating high-pressure foamed cement slurry preparation device and the high-pressure foamed cement slurry preparation process are as follows: Determine the relevant parameter values for the preparation of high-pressure foamed cement slurry, including: pressure of the foamed cement slurry, temperature of the foamed cement slurry, density of the foamed cement slurry base, density of the foamed cement slurry, pressure under standard conditions, temperature under standard conditions, and compressibility coefficient of the high-pressure gas. The compressibility coefficient of the high-pressure gas can be obtained from a table.
[0036] Calculate the volume of foamed cement slurry base material added: Let the total volume of the first circulation pipeline 2, the discharge pipeline 18, the second circulation pipeline 3, the upper diffuser 13, the lower diffuser 14 and the high-pressure slurry cup body 10 of the device be V1, the volume of the foamed cement slurry base be V2, and the gas volume be V3 = V1 - V2. According to the formula ρ=m / V, it is easy to know that the density of the high-pressure foamed cement slurry is ρ=(V³ρ) / V. 气 +V2ρ 基 ) / V1; The density ρ of high-pressure gas 气 =(1.25P1T 标 ) / (P 标 ZT1)×10 -3 ; Where: P1 is the pressure of the foamed cement slurry; T1 is the temperature of the foamed cement slurry; P 标 Pressure under standard conditions; T 标 The temperature is denoted as ; Z is the compressibility coefficient of the high-pressure gas, which can be found in a table.
[0037] Combining the above formulas, the volume of foamed cement slurry base added is calculated as V2 = (ρ - ρ 气 )×V1 / (ρ 基 -ρ 气 ).
[0038] Pipelines connecting to the continuous circulation high-pressure foamed cement slurry preparation device.
[0039] Pour the required foamed cement slurry base into its high-pressure slurry cup body 10 (the bottom cover 11 and the second valve 12 have been connected), connect the cup body 10 and the top cover 4 and connect it to the circulation pump 1 through the first valve 5, and connect it to the gas pressurization pipeline 7 through the threaded hole on the right side of the top cover 4.
[0040] Check the airtightness of the device, open all valves, pressurize the gas supply through the high-pressure gas cylinder until the pressure gauge 8 reaches the preset pressure value, then close the high-pressure gas cylinder and close the high-pressure valve at the same time.
[0041] Open the first valve 5 and the second valve 12 to connect the pipeline between the high-pressure slurry cup and the circulation pump 1. At this time, turn on the circulation pump 1 to provide power for the entire circulation loop, so that the foamed cement slurry base slurry and high-pressure gas circulate clockwise. After circulating for a period of time, the pointer of the pressure gauge 15 no longer changes, then stop the circulation, close the circulation pump 1 and all valves, and obtain the prepared high-pressure foamed cement slurry.
[0042] Remove the high-pressure slurry cup and place it on the weighing platform to weigh it. Calculate the actual density according to M=ρ×V, compare it with the theoretical density, and adjust the amount of foamed cement slurry base slurry added according to the actual situation to obtain the required foamed cement slurry density.
[0043] The prepared high-pressure foamed cement slurry was subjected to performance tests, including strength, settling stability, and permeability. Based on the combined results of the foamed cement slurry density and mixing effect (i.e., the performance test results), the circulation time and gas-liquid ratio were optimized. Furthermore, the high-pressure slurry cup can be removed and used as a sampling tube for testing the compressibility of the foamed cement slurry.
[0044] After the test is completed, a cleaning agent can be added to this continuous circulating high-pressure foam cement slurry preparation device for cleaning. The cleaning agent should be a chemical specifically for cement residue, which can effectively dissolve and remove the cement.
[0045] Example 12: Before starting the preparation of high-pressure foamed cement slurry, ensure that the continuous circulating high-pressure foamed cement slurry preparation device is in good condition, cleaned, and calibrated. This includes all pipelines, cup 10, and mixer. Confirm that the total pipeline length is 100cm, inner diameter is 5cm, and volume is 28.26mL; the slurry cup is 20cm long, inner diameter is 7cm, and volume is 961.63mL; the upper diffuser 13 and lower diffuser 14 have a total length of 20cm, a maximum diameter of 5cm in the middle, and a volume of 130.83mL. The total volume is 1120.72mL.
[0046] Foamed cement slurry is a lightweight cement slurry formed by mixing foamed cement slurry base slurry with air bubbles (usually air or nitrogen). In this embodiment, nitrogen injection is used, with a designed pressure of 10 MPa and a temperature of 299.15 K (approximately 26°C). The density of the foamed cement slurry base slurry is 1.90 g / cm³, and the designed density of the final foamed cement slurry is 1.50 g / cm³.
[0047] Based on the law of conservation of mass and the definition of density (ρ=m / V), the volumes of the foamed cement slurry base and the gas can be calculated. The added volume of the foamed cement slurry base is calculated using the following formula: V2=(ρ-ρ 气 )×V1 / (ρ 基 -ρ 气 ) ρ 气 =(1.25P1T 标 ) / (P 标 ZT1)×10 -3 In this embodiment, P1 is 10 MPa; T1 is 299.15 K, P 标 0.101325 MPa; T 标 K is 273.15; Z is the compressibility coefficient of nitrogen, calculated as 1. The calculated value of V2 is 870.1 mL, which means that in this embodiment, 870.1 mL of foamed cement slurry with a density of 1.90 g / cm³ needs to be added to the high-pressure slurry cup.
[0048] Pipelines connecting to the continuous circulation high-pressure foamed cement slurry preparation device.
[0049] 870.1 mL of foamed cement slurry with a density of 1.90 g / cm³ is poured into its high-pressure slurry cup, the cup body 10 and the top cover 4 are connected, and the cup body 10 is connected to the circulation pump 1 through the first valve 5. The top cover 4 is connected to the gas pressurization pipeline 7 through the threaded hole on the right side.
[0050] Check the airtightness of the device, open all valves, pressurize the gas supply through the high-pressure gas cylinder until the pressure gauge 8 reaches 10MPa, then close the high-pressure gas cylinder and close the high-pressure valve at the same time.
[0051] Open the first valve 5 and the second valve 12 to connect the pipeline between the high-pressure slurry cup and the circulation pump 1. At this time, start the circulation pump 1 and continue for at least 5 minutes. Stop the circulation when the pointer of the pressure gauge 15 no longer changes. Close the circulation pump 1 and all valves to obtain the prepared high-pressure foamed cement slurry.
[0052] The present invention has the following advantages and effects: First, the structure is simple: the present invention uses simple components, which makes the device structure simpler and easier to operate and maintain.
[0053] Second, improve the accuracy of on-site aeration and foaming: the high-pressure gas cylinder 9 and the circulating pump 1 can help prepare high-pressure foam cement slurry with more precise density on-site, thereby improving the cementing effect.
[0054] Third, it enables pressurized sampling: sampling and testing can be conveniently carried out under high pressure conditions, thereby more accurately evaluating the performance of foamed cement slurry.
[0055] Fourth, this invention provides a foundation for research on the performance of foamed cement under high-pressure gas injection: It helps to improve the performance of foamed cement in the cementing process and further protect the integrity of oil and gas wells.
[0056] In summary, this invention provides a continuous circulating high-pressure foamed cement slurry preparation device, which can accurately prepare the foamed cement slurry density required for the on-site high-pressure gas injection foaming process and can perform pressurized sampling and testing, thereby obtaining performance parameter values of foamed cement slurry close to those required under actual application conditions. This provides a foundation for the study of foamed cement characteristics under high-pressure gas injection environment and provides reliable guidance for the application selection of foamed cement systems under high-pressure gas injection environment in oil and gas wells.
[0057] The above technical features constitute various embodiments of the present invention, which have strong adaptability and implementation effect. Unnecessary technical features can be added or removed according to actual needs to meet the needs of different situations.
Claims
1. A continuous circulating high-pressure foamed cement slurry preparation device, characterized in that it comprises: The system comprises a high-pressure slurry cup, a high-pressure gas cylinder, a mixer, and a circulating pump. A first circulating pipeline connects the first inlet at the top of the high-pressure slurry cup to the outlet of the circulating pump. A gas pressurization pipeline connects the second inlet at the top of the high-pressure slurry cup to the outlet of the high-pressure gas cylinder. A discharge pipeline connects the bottom outlet of the high-pressure slurry cup to the inlet of the mixer. A second circulating pipeline connects the outlet of the mixer to the inlet of the circulating pump. The high-pressure slurry cup includes a cup body. A top cover is installed at the upper end of the cup body, and a bottom cover is installed at the lower end of the cup body. A first inlet is located at the center of the top cover, and a high-pressure nozzle with a downward-facing nozzle is installed at the first inlet. A second inlet is located on the right side of the top cover. The first inlet is connected to the first circulating pipeline, and the second inlet is connected to the gas pressurization pipeline. An outlet is located at the center of the bottom cover and is connected to the discharge pipeline.
2. The continuous circulating high-pressure foamed cement slurry preparation device according to claim 1, characterized in that... The mixer includes an upper diffuser and a lower diffuser. The upper diffuser is a frustum-shaped tube with a smaller upper port and a larger lower port, and the lower diffuser is a frustum-shaped tube with a larger upper port and a smaller lower port. The lower ports of the upper and lower diffusers are detachably connected. A screen is horizontally arranged between the upper and lower diffusers. The upper port of the upper diffuser is connected to the discharge pipeline, and the lower port of the lower diffuser is connected to the second circulation pipeline.
3. The continuous circulating high-pressure foamed cement slurry preparation device according to claim 1 or 2, characterized in that... The diameter of the lower port of the upper diffuser is 2 to 2.5 times the diameter of its upper port, and the diameter of the upper port of the lower diffuser is 2 to 2.5 times the diameter of its lower port.
4. The continuous circulating high-pressure foamed cement slurry preparation device according to any one of claims 1 to 3, characterized in that... The first valve is installed near the outlet of the first circulation pipeline, and the second valve is installed on the discharge pipeline.
5. The continuous circulating high-pressure foamed cement slurry preparation device according to any one of claims 1 to 4, characterized in that... A pressure gauge and an inlet valve are fixedly installed on the gas pressurization pipeline along the gas flow direction.
6. The continuous circulating high-pressure foamed cement slurry preparation device according to any one of claims 1 to 5, characterized in that... The high-pressure slurry cup has a cylindrical hollow body, and the cup body is connected to the top and bottom covers by threads.
7. The continuous circulating high-pressure foamed cement slurry preparation device according to any one of claims 1 to 6, characterized in that... The circulating pump is a high-pressure plunger pump.
8. The method for preparing continuous circulating high-pressure foamed cement slurry according to any one of claims 1 to 7, characterized in that... A pressure gauge is fixedly installed on the second circulation pipeline.
9. A method for preparing high-pressure foamed cement slurry using a continuous circulating high-pressure foamed cement slurry preparation device according to any one of claims 1 to 8, characterized in that... Includes the following steps: Determine the pressure, temperature, density, and base density of the high-pressure foamed cement slurry to be prepared, and calculate the volume of base slurry to be added. Pour the foamed cement slurry base into the high-pressure slurry cup, connect the cup and the top cover, and connect the pipelines of the continuous circulation high-pressure foamed cement slurry preparation device. Check the airtightness of the device, open all valves, pressurize the gas supply through the high-pressure gas cylinder until the pressure gauge reaches the preset pressure value, then close the high-pressure gas cylinder and the air inlet valve. Open the first valve and the second valve, start the circulation pump, and allow the foamed cement slurry base slurry and high-pressure gas to circulate along the first circulation pipeline, the discharge pipeline and the second circulation pipeline. After the pressure gauge value stabilizes, close the circulation pump and the first and second valves to stop the circulation and complete the preparation of the high-pressure foamed cement slurry.
10. The method for preparing high-pressure foamed cement slurry according to claim 9, characterized in that... The volume of foamed cement slurry base material added is calculated using the following formula: V2=(ρ-ρ) 气 )×V1 / (ρ 基 -r 气 ) r 气 =(1.25P1T 标 ) / (P 标 ZT1)×10 -3 Where V2 is the volume of the foamed cement slurry base, V1 is the total volume of the first circulation pipeline, discharge pipeline, second circulation pipeline, upper diffuser, lower diffuser, and the high-pressure slurry cup of the device; ρ is the density of the high-pressure foamed cement slurry to be prepared; ρ 气 ρ is the density of the high-pressure gas. 基 P is the density of the foamed cement slurry base; P1 is the pressure of the foamed cement slurry; T1 is the temperature of the foamed cement slurry; P 标 Pressure under standard conditions; T 标 t is the temperature under standard conditions; Z is the compressibility coefficient of the high-pressure gas.