Analog wellbore high temperature and high pressure foam liquid carrying evaluation device and method

Abstract

The application relates to the technical field of oil and gas engineering, in particular to a simulation wellbore high-temperature high-pressure foam liquid carrying evaluation device and method. The simulation wellbore high-temperature high-pressure foam liquid carrying evaluation device provided by the application comprises the following: a simulation wellbore, which is provided with a second gas-liquid mixing outlet, and the angle of the simulation wellbore relative to the vertical direction is adjustable; a mixing container; a water supply container; a foaming agent solution production device; a gas supply device; a liquid level detection device, which is arranged at a preset liquid level of the simulation wellbore; a pressure stabilizing device; and a liquid carrying detection device, which is used for opening the second gas-liquid mixing outlet when the pressure in the simulation wellbore reaches a preset pressure, and calculating the liquid carrying efficiency of the system by detecting the liquid carrying amount. The simulation wellbore high-temperature high-pressure foam liquid carrying evaluation device and method can evaluate the liquid carrying effect of different foaming agents under the simulation of real wellbore environment, help to quickly and accurately optimize the foaming agent formula, and thus improve the gas well liquid carrying efficiency and the gas production.

Description

Technical Field

[0001] This application relates to the field of oil and gas engineering technology, and in particular to a device and method for evaluating high-temperature and high-pressure foam-carrying liquid in simulated wells. Background Technology

[0002] In oil and gas field development projects, processes such as well drainage and gas production, and foam sand flushing rely on the evaluation of the liquid-carrying capacity of gas-liquid two-phase foam to optimize fluid design and predict operational results. Testing equipment that simulates real wellbore conditions and simultaneously acquires multi-parameter dynamic data is a key requirement for improving process reliability and efficiency.

[0003] Existing testing devices mostly use vertical static reactors to simulate the wellbore environment and conduct gas-liquid mixing experiments inside the reactor to measure the liquid-carrying capacity of the foam.

[0004] However, traditional testing equipment cannot reproduce complex wellbore environments, resulting in low accuracy of measurement data. Summary of the Invention

[0005] In view of the above problems, this application provides a device and method for simulating high-temperature and high-pressure foam liquid-carrying evaluation in wellbore, which helps to simulate the real wellbore environment, thereby improving the accuracy of measurement data and the reliability of the device.

[0006] In a first aspect, this application provides a simulated wellbore high-temperature and high-pressure foam-carrying liquid evaluation device, comprising: a simulated wellbore for mixing gas-liquid two-phase fluids to simulate a drainage and gas production process, the simulated wellbore having a mixed solution inlet, a gas inlet, a first gas-liquid mixing outlet, and a second gas-liquid mixing outlet, wherein the mixed solution inlet is located at the bottom of the simulated wellbore, the gas inlet is located at the bottom of the simulated wellbore, and the angle of the simulated wellbore relative to the vertical direction is adjustable; a mixing container for in-situ mixing of formation water and foaming agent solution to form a mixed solution to simulate bottom-hole liquid accumulation, the mixing container having a water inlet and a foaming agent solution inlet, the mixing container and the mixed solution inlet The system comprises: a connection to the simulated wellbore via the mixed solution inlet; a water supply container connected to the water inlet; a foaming agent solution production device connected to the foaming agent solution inlet; a gas supply device connected to the gas inlet; a liquid level detection device located at a preset liquid level in the simulated wellbore for detecting the liquid level in the simulated wellbore; a pressure stabilizing device for adjusting the pressure inside the simulated wellbore to keep the pressure within a preset pressure range; and a liquid carrying detection device connected to the second gas-liquid mixture outlet, which is used to open the second gas-liquid mixture outlet when the pressure inside the simulated wellbore reaches the preset pressure and to detect the liquid carrying efficiency.

[0007] In one possible implementation, the second gas-liquid mixing outlets are a plurality of outlets spaced apart along the height direction of the simulated wellbore; the pressure stabilizing device includes: a plurality of first back pressure valves, each corresponding to one of the second gas-liquid mixing outlets, the first back pressure valves being located at the corresponding second gas-liquid mixing outlets, the first back pressure valves being configured to open when the pressure inside the simulated wellbore reaches a first opening pressure; the liquid carrying detection device includes: a first gas-liquid separator, each connected to one of the plurality of first back pressure valves, the first gas-liquid separator having a first exhaust port and a first liquid discharge port; and a liquid carrying detector, connected to the first liquid discharge port, for detecting the foam liquid carrying rate.

[0008] In one possible implementation, the simulated wellbore high-temperature and high-pressure foam-carrying liquid evaluation device further includes a second gas-liquid separator, which is connected to the second back pressure valve. The second gas-liquid separator has a second exhaust port and a second liquid discharge port. The pressure stabilizing device further includes: a second back pressure valve located at the first gas-liquid mixing outlet, which is configured to open when the pressure inside the simulated wellbore reaches a second valve opening pressure; and a liquid container connected to the second liquid discharge port.

[0009] In one possible implementation, the pressure stabilizing device further includes a pressure detection device disposed between the second back pressure valve and the first gas-liquid mixture outlet, for detecting the pressure inside the simulated wellbore.

[0010] In one possible implementation, the simulated wellbore high-temperature and high-pressure foam-carrying liquid evaluation device further includes a heating device located on the outside of the simulated wellbore, the heating device being used to heat the simulated wellbore.

[0011] In one possible implementation, the simulated wellbore high-temperature and high-pressure foam-carrying liquid evaluation device further includes: a flow guide, which is spirally disposed inside the simulated wellbore to cause the fluid inside the simulated wellbore to spiral forward.

[0012] In one possible implementation, the gas supply device includes: a gas storage container connected to the gas inlet, the gas storage container being used to store high-pressure gas; and a gas flow detection device disposed between the gas storage container and the gas inlet, for measuring the gas flow rate.

[0013] In one possible implementation, the simulated wellbore high-temperature and high-pressure foam liquid-carrying evaluation device further includes: an ultrasonic atomizer for atomizing the liquid in the simulated wellbore, the ultrasonic atomizer being disposed above the liquid level detection device; the ultrasonic atomizer being detachably disposed inside the simulated wellbore.

[0014] Secondly, this application provides a method for evaluating the liquid-carrying capacity of high-temperature and high-pressure foam in a simulated wellbore, applicable to any of the above possible implementations of the simulated high-temperature and high-pressure foam liquid-carrying evaluation device, comprising the following steps: controlling a water supply container to supply water to the mixing container; controlling a foaming agent solution production device to supply foaming agent solution to the mixing container and setting a preset ratio for mixing with formation water; determining that the detection value of the liquid level detection device fluctuates within a preset range; controlling a gas supply device to supply gas to the simulated wellbore; determining that the liquid output of the first gas-liquid mixing outlet is stable; controlling the liquid-carrying detection device to open the second gas-liquid mixing outlet and detecting the liquid-carrying rate.

[0015] In one possible implementation, before the control water supply container supplies water to the mixing container, the method further includes: selecting a simulated wellbore of a target size and connecting the simulated wellbore to the mixing container, the air supply device, the liquid level detection device, and the liquid carrying detection device.

[0016] The value of the simulated wellbore high temperature and high pressure foam liquid carrying evaluation device and method provided in this application lies in its ability to directly achieve quantitative evaluation of the liquid carrying "effect" of different foaming agent formulations and optimization verification of the "function" of drainage and gas production processes in a highly simulated and controllable environment.

[0017] First, it enables precise and quantitative evaluation of the "foam liquid carrying effect". Through the liquid carrying detection device, especially the multi-point arranged first back pressure valve and liquid carrying detector, it is possible to directly measure the key performance indicators of different foaming agents under specific working conditions (such as 8MPa pressure, 5000m³ / d gas volume), such as: absolute liquid carrying capacity (the volume of liquid carried out of the wellbore per unit time), liquid carrying efficiency (the ratio of the liquid carried out to the total injected liquid volume), and foam stability (by comparing the differences in liquid carrying capacity at the bottom, middle and top outlets of the simulated wellbore, the attenuation of foam stability during the rise of the simulated wellbore can be quantitatively evaluated).

[0018] Since the experiments in this application are conducted in a stable and controllable simulated environment (such as one guaranteed by a voltage stabilizing device, a heating device, and an angle adjustment mechanism), the evaluation results for different foaming agents and different process parameters (such as gas-liquid ratio) are highly comparable, and the optimal formulation can be accurately screened.

[0019] Furthermore, optimizations were achieved in both "device functions" and "process parameters." The device itself serves as a functional verification platform. For example, by selecting flow guides, it's possible to verify whether the "swirling" function promotes or inhibits the foam's liquid-carrying effect; by turning the ultrasonic atomizer on and off, the contribution of the "ultrasonic atomization" function in co-carrying liquid with foam can be quantified, thus providing direct evidence for the selection of on-site process tools.

[0020] By systematically altering parameters such as gas flow rate, wellbore pressure, and inclination angle, the critical operating point at which a foaming agent can effectively carry liquid (such as the transition point from "stratified flow" to "annular flow") can be precisely defined. This provides crucial experimental data support for determining optimal process parameters and establishing reasonable production regimes (such as minimum gas volume) on-site, enabling accurate prediction.

[0021] Furthermore, it enables the construction of an "effect-operating condition" correlation model. The data generated by this device (such as liquid carrying efficiency, pressure, temperature, angle, gas volume, and formulation) can be used to construct a foam liquid carrying prediction model based on real physical laws. This allows the invention to simulate and optimize the foaming agent injection scheme and process parameters on a computer before actual operation, reducing the cost and risk of on-site testing.

[0022] In summary, the simulated high-temperature and high-pressure foam fluid-carrying evaluation device and method provided in this application solves at least two major bottlenecks in traditional devices, such as 'distorted simulated environment' and 'single evaluation index'. By constructing a highly simulated multi-physics wellbore environment and integrating a multi-point, partial-pressure precision monitoring system, this invention achieves, for the first time in the laboratory, a quantitative and comparable evaluation of the 'effect' of foam fluid-carrying,' as well as the synergistic optimization verification of fluid-carrying 'functions' (such as swirling and atomization). This helps to quickly and accurately screen the optimal foaming agent formulation for specific oil and gas reservoirs, and also provides key data support for defining safe and efficient production process windows and developing new composite fluid-carrying processes, ultimately achieving the goals of improving gas well fluid-carrying efficiency, extending gas well life, and increasing gas production.

[0023] Specifically, by incorporating reusable and removable simulated wellbores, pressure stabilizing devices, and liquid level detection devices, the system can simulate the gas-liquid two-phase flow characteristics of wellbores with different diameters and reproduce the complex operating conditions of real wellbores. The adjustable-angle simulated wellbore allows the evaluation system to adapt to various well types, such as vertical and inclined wells. By adjusting the inclination angle of the simulated wellbore, changes in fluid flow patterns and the interaction between foam and the pipe wall can be simulated, thus realistically reflecting the evolution of foam's liquid-carrying capacity during dynamic flow within the wellbore. Furthermore, through the synergistic action of the liquid level detection device and the liquid-carrying detection device, the evaluation system can simultaneously simulate the real environment and detect dynamic data on foam density and liquid-carrying rate as a function of angle and pressure, thereby improving the accuracy of the measurement data.

[0024] As can be seen, the simulated high-temperature and high-pressure foam liquid-carrying evaluation device and method provided in this application simulates the real working conditions as closely as possible by simulating the high-temperature and high-pressure environment of the wellbore, as well as different well inclinations and gas-liquid ratios; it simulates the fluid dynamics by simulating the multiphase flow inside the wellbore under different gas-liquid ratios; it provides dynamic quantitative data by measuring the change of the dynamic fluid level in the wellbore in real time and detecting and measuring the liquid holdup in the wellbore; and it can ultimately achieve quantitative evaluation of the liquid-carrying efficiency under different gas-liquid ratios and compare the liquid-carrying effect of different foaming agents. In this way, the liquid-carrying effect of different foaming agents can be objectively and comparablely evaluated, providing direct and reliable data support for optimizing foaming agent formulations and production processes. Attached Figure Description

[0025] The accompanying drawings, which are incorporated in and form part of this specification, illustrate embodiments consistent with this application and, together with the description, serve to explain the principles of this application.

[0026] Figure 1 A structural diagram of the simulated wellbore high-temperature and high-pressure foam liquid-carrying evaluation device provided in this application;

[0027] Figure 2 for Figure 1 A schematic diagram of the structure of a medium-sized ultrasonic atomizer.

[0028] Explanation of reference numerals in the attached figures:

[0029] 10-Simulated wellbore; 12-Mixed solution inlet; 13-Gas inlet; 14-First gas-liquid mixture outlet; 15-Second gas-liquid mixture outlet; 16-Ultrasonic atomizer; 161-Air inlet; 162-First-stage acceleration tube; 163-Second-stage acceleration tube; 164-Nozzle; 166-Liquid inlet; 167-Liquid guide tube; 168-Fluid outlet; 17-Rotating support;

[0030] 20 - Mixing container; 22 - Water inlet; 23 - Foaming agent solution inlet;

[0031] 30 - Water supply container;

[0032] 40 - Foaming agent solution production equipment;

[0033] 50 - Gas supply device; 51 - Gas storage container; 52 - Flow detection device;

[0034] 60 - Liquid level detection device;

[0035] 70-Pressure stabilizing device; 71-Second back pressure valve; 72-Second gas-liquid separator; 73-Second exhaust port; 74-Second liquid drain port; 75-Liquid container; 76-Pressure detection device;

[0036] 80-Liquid-carrying detection device; 81-First back pressure valve; 82-First gas-liquid separator; 83-First exhaust port; 84-First liquid discharge port; 85-Liquid-carrying detector;

[0037] 90 - Heating device; 100 - Flow guide.

[0038] The accompanying drawings illustrate specific embodiments of this application, which will be described in more detail below. These drawings and descriptions are not intended to limit the scope of the concept in any way, but rather to illustrate the concept of this application to those skilled in the art through reference to particular embodiments. Detailed Implementation

[0039] Exemplary embodiments will now be described in detail, examples of which are illustrated in the accompanying drawings. When the following description relates to the drawings, unless otherwise indicated, the same numbers in different drawings denote the same or similar elements. The embodiments described in the following exemplary embodiments do not represent all embodiments consistent with this application. Rather, they are merely examples of apparatuses and methods consistent with some aspects of this application as detailed in the appended claims.

[0040] As oil and gas field development expands into deeper and more complex wellbore environments, the need for refined evaluation of the liquid-carrying capacity of gas-liquid two-phase foam is becoming increasingly urgent for processes such as gas well drainage and well washing. Actual wellbore environments are characterized by high temperatures (30-120℃), high pressures (1-12MPa), dynamic changes in inclination angles (0-90°), and complex fluid flow characteristics.

[0041] Existing testing devices mostly employ vertical static reactors to simulate the wellbore environment and conduct gas-liquid mixing experiments within the reactor to measure the liquid-carrying capacity of foam. However, traditional testing devices cannot reproduce the actual wellbore environment, resulting in low accuracy of measurement data.

[0042] In view of this, this application provides a simulated high-temperature and high-pressure foam liquid-carrying evaluation device for wells. By incorporating a reusable and removable simulated wellbore, a pressure stabilizing device, and a liquid level detection device, it can simulate the gas-liquid two-phase flow characteristics of wellbores with different diameters and reproduce the complex working conditions of real wellbores. The angle-adjustable simulated wellbore allows the evaluation system to adapt to various well types, such as vertical and inclined wells. By adjusting the inclination angle of the simulated wellbore, it can simulate changes in fluid flow patterns and the interaction between foam and the pipe wall, thereby realistically reflecting the evolution of foam liquid-carrying performance during dynamic flow in the wellbore. Furthermore, through the synergistic effect of the liquid level detection device and the liquid-carrying detection device, the evaluation system can simultaneously simulate the real environment and detect dynamic data on foam density and liquid-carrying rate as a function of angle and pressure, thereby improving the accuracy of the measurement data.

[0043] The technical solution of this application and how the technical solution of this application solves the above-mentioned technical problems are described in detail below with specific embodiments. These specific embodiments can be combined with each other, and the same or similar concepts or processes may not be described again in some embodiments. The embodiments of this application will now be described with reference to the accompanying drawings:

[0044] refer to Figure 1 This application provides a simulated wellbore high temperature and high pressure foam liquid carrying evaluation device, including a simulated wellbore 10, a mixing container 20, a water supply container 30, a foaming agent solution production device 40, a gas supply device 50, a liquid level detection device 60, a pressure stabilizing device 70, and a liquid carrying detection device 80.

[0045] The simulated wellbore 10 is used to mix gas-liquid two-phase fluids to simulate the drainage and gas production process. As the core simulation unit, it can reproduce the state of a real wellbore. Specifically, the simulated wellbore 10 has a fluid cavity and a mixed solution inlet 12, a gas inlet 13, a first gas-liquid mixing outlet 14, and a second gas-liquid mixing outlet 15. The mixed solution inlet 12, gas inlet 13, first gas-liquid mixing outlet 14, and second gas-liquid mixing outlet 15 are all connected to the fluid cavity. Further, the mixed solution inlet 12 and gas inlet 13 can be located at the bottom of the simulated wellbore 10. Specifically, the mixed solution inlet 12 can be located at the very bottom of the simulated wellbore 10, and the gas inlet 13 can be located at the bottom of the simulated wellbore 10, such as 10 cm above the bottom. The second gas-liquid mixing outlet 15 can be located in the middle of the simulated wellbore 10. The first gas-liquid mixing outlet 14 can be located at the top of the simulated wellbore 10.

[0046] Optionally, the angle of the simulated wellbore 10 relative to the vertical direction is adjustable. The simulated wellbore 10 can be angled via a rotating bracket 17 and an arc-shaped guide rail. Specifically, the simulated wellbore 10 can be connected to the base of the rotating bracket 17 via a rotating shaft. An arc-shaped guide rail is provided on the base, and angle scale markings are provided on the arc-shaped guide rail. The bottom or side of the simulated wellbore 10 can be fixed to the rotating shaft via a hinge mechanism, and the simulated wellbore 10 can slide along the arc-shaped guide rail and be fixed at the target angle position by locking bolts or hydraulic buckles. After driving the simulated wellbore 10 to move along the arc-shaped guide rail to the preset tilt angle, it is fixed at the target position by locking bolts to ensure angle stability during the experiment. Alternatively, a hydraulic push rod or an electric telescopic rod can be installed between the simulated wellbore 10 and the base of the rotating bracket 17, and the extension and retraction length of the push rod can be adjusted by a controller to dynamically change the tilt angle of the simulated wellbore 10.

[0047] In addition, the simulated well shaft 10 can be made of a rigid material such as stainless steel to ensure that the simulated well shaft 10 can withstand sufficient pressure. Of course, the specific material of the simulated well shaft 10 is not limited in this embodiment of the application, and can be reasonably selected according to actual needs, as long as it can meet the pressure bearing requirements of the simulated well shaft 10.

[0048] A mixing container 20 can be positioned below the simulated wellbore 10. The mixing container 20 is used to mix formation water and a concentrated foaming agent solution in situ to form a mixed solution, simulating bottom-hole fluid accumulation. The mixing container 20 has a mixing chamber, an inlet 22, a foaming agent solution inlet 23, and a mixed solution outlet. The inlet 22, foaming agent solution inlet 23, and mixed solution outlet are all connected to the mixing chamber of the mixing container 20. The mixed solution outlet is connected to the mixed solution inlet 12, thus connecting to the simulated wellbore 10. The mixing container 20 can receive water and foaming agent through the inlet 22 and foaming agent solution inlet 23, forming a homogeneous gas-liquid mixture within the mixing chamber, which is then transported to the simulated wellbore 10 through the mixed solution outlet to ensure the consistency of the experimental foam ratio.

[0049] The water supply container 30 can provide a constant flow and pressure of water to the mixing container 20 to simulate the actual operating conditions of well water or injected fluid. The water supply container 30 is connected to the mixing chamber through the inlet 22. The foaming agent solution production device 40 can control the injection volume and concentration of the foaming agent to generate a stable foaming agent solution system. The foaming agent solution production device 40 can be connected to the mixing chamber through the foaming agent solution inlet 23. The gas supply device 50 can inject high-pressure gas (such as nitrogen) through the gas inlet 13 at the bottom of the simulated well 10 to simulate the shearing and mixing effects of the gas-liquid two-phase flow in the well.

[0050] The liquid level detection device 60 can be positioned at a preset liquid level in the fluid cavity to detect the liquid level in the fluid cavity. Optionally, the liquid level detection device 60 can be a capacitive electrode. It should be understood that the capacitive electrode consists of a coaxial bipolar structure, and the electrode surface is coated with a high-temperature and high-pressure resistant insulating layer (such as polytetrafluoroethylene). When the electrode comes into contact with different media (such as foam or liquid), the capacitance value between the electrodes will change due to the difference in dielectric constant. The dielectric constant of foam (gas + liquid film) is significantly lower than that of liquid, and the capacitance value will decrease when the electrode comes into contact with the foam. The liquid level detection device 60 can be fixed at a preset liquid level height in the fluid cavity (such as the expected critical position for foam carrying), and by monitoring the change in capacitance value, it can be determined whether the liquid level in the fluid cavity has reached the preset value.

[0051] The pressure stabilizing device 70 can be located at the first gas-liquid mixing outlet 14. The pressure stabilizing device 70 is used to regulate the pressure within the fluid cavity to keep it within a preset pressure range. It is understood that the foam-liquid carrying process in an actual wellbore is directly affected by formation pressure. High pressure compresses the foam nuclei, thus changing the liquid film thickness and affecting foam stability and liquid carrying efficiency. The pressure stabilizing device 70 dynamically adjusts the fluid cavity pressure to maintain it within a preset pressure range, ensuring that foam generation, flow, and collapse behavior are consistent with actual formation conditions, avoiding the distortion of foam performance caused by low-pressure environments in traditional experiments.

[0052] The liquid-carrying detection device 80 can be connected to the second gas-liquid mixing outlet 15. The liquid-carrying detection device 80 is used to open the second gas-liquid mixing outlet 15 when the pressure inside the fluid chamber reaches a preset pressure, and to detect the liquid-carrying efficiency. The liquid-carrying detection device 80 can be a weighing detection device, a flow metering device, a measuring cylinder, etc.

[0053] Understandably, by setting up an angle-adjustable simulated wellbore 10, a pressure stabilizing device 70, and a liquid level detection device 60, the gas-liquid two-phase flow characteristics under different wellbore inclination states can be simulated, and the complex working conditions of a real wellbore can be reproduced. The angle-adjustable simulated wellbore 10 allows the evaluation system to adapt to various well types, such as vertical and inclined wells. By adjusting the inclination angle of the simulated wellbore 10, changes in fluid flow patterns and the interaction between foam and the pipe wall can be simulated, thereby realistically reflecting the evolution of the liquid-carrying capacity of foam in the dynamic flow of the wellbore. In addition, through the synergistic effect of the liquid level detection device 60 and the liquid-carrying detection device 80, the evaluation system can simultaneously simulate the real environment and detect dynamic data on foam density and liquid-carrying rate as a function of angle and pressure, thereby improving the accuracy of the measurement data.

[0054] In one possible implementation, there are multiple second gas-liquid mixing outlets 15. These multiple second gas-liquid mixing outlets 15 can be spaced apart along the height of the simulated wellbore 10. The pressure stabilizing device 70 includes multiple first back pressure valves 81, each corresponding to one of the second gas-liquid mixing outlets 15. Each first back pressure valve 81 can be located at its corresponding second gas-liquid mixing outlet 15. The first back pressure valve 81 is configured to open when the pressure within the fluid cavity reaches a first opening pressure. Thus, the first back pressure valve 81 at each second gas-liquid mixing outlet 15 is independently controlled, opening only when the fluid cavity pressure reaches the first opening pressure, ensuring that foam flows out only under specific pressure conditions and avoiding pressure cross-interference at different heights.

[0055] The liquid-carrying detection device 80 includes multiple first gas-liquid separators 82 and a liquid-carrying detector 85. Each first gas-liquid separator 82 is connected to multiple first back pressure valves 81. Specifically, the multiple first back pressure valves 81 are located between the simulated wellbore 10 and the first gas-liquid separators 82. Each first gas-liquid separator 82 has a first vent 83 and a first drain 84. The first vent 83 of the first gas-liquid separator 82 is used to discharge the separated gas. The liquid-carrying detector 85 can be connected to the first drain 84 and is used to detect the liquid-carrying rate. The liquid-carrying rate of the foam can be calculated by the volume of liquid discharged from the first drain 84 and the volume of the simulated wellbore 10. Specifically, the liquid-carrying rate is the volume ratio of the liquid discharged from the first drain 84 to the volume of the simulated wellbore 10.

[0056] In one possible implementation, the simulated wellbore high-temperature and high-pressure foam-carrying liquid evaluation device further includes a second gas-liquid separator 72, and the pressure stabilizing device 70 further includes a second back pressure valve 71 and a liquid container 75. The second back pressure valve 71 may be located at the first gas-liquid mixing outlet 14. The second back pressure valve 71 is configured to open when the pressure in the fluid chamber reaches a second opening pressure. The second gas-liquid separator 72 may be connected to the second back pressure valve 71. The second gas-liquid separator 72 has a second vent 73 and a second drain port 74. The second vent 73 is used to discharge the separated gas. The second drain port 74 may be connected to the liquid container 75 to collect the liquid discharged from the top of the simulated wellbore 10.

[0057] In the initial stage of testing, the gas-liquid flow and pressure within the system are unstable. The unstable liquid volume collected in liquid container 75 indicates that the gas-liquid flow, pressure, and foam-liquid interaction within the simulated wellbore 10 have not reached a stable state. If testing begins at this point, the measured liquid-carrying efficiency will be affected by various factors and will not reflect the true situation. Only when the liquid collected in liquid container 75 stabilizes can it be considered that the system has reached dynamic equilibrium, gas-liquid flow rate, pressure, and other conditions are stable, the experimental environment is stable, and subsequent measurement data are reliable.

[0058] In one possible implementation, the pressure stabilizing device 70 further includes a pressure detection device 76. The pressure detection device 76 is located between the second back pressure valve 71 and the first gas-liquid mixing outlet 14, and is used to detect the pressure within the fluid chamber. Optionally, the pressure detection device 76 can be a pressure gauge, pressure sensor, etc.

[0059] Understandably, the pressure detection device 76 can acquire pressure data within the fluid chamber in real time. This helps researchers understand pressure changes within the system at any time, providing crucial information for determining whether the system is operating normally. For example, when abnormal pressure fluctuations occur, researchers can promptly detect them and take appropriate measures to avoid experimental errors or even failures due to pressure issues.

[0060] In one possible implementation, the simulated wellbore high-temperature and high-pressure foam-carrying fluid evaluation device further includes a heating device 90. The heating device 90 can be wound around the outside of the simulated wellbore 10. The heating device 90 is used to heat the simulated wellbore 10. Optionally, the heating device 90 can be a flexible electric heating belt or heating coil, tightly fitted to the outside of the simulated wellbore 10 in a spiral shape to ensure uniform heat conduction along the axial and circumferential directions of the wellbore. The spiral spacing can be adjusted according to the heating power and temperature gradient requirements to avoid local overheating or uneven heat dissipation. Further, nickel-chromium alloy or carbon fiber heating materials can be used, converting electrical energy into heat energy, combined with an insulating layer (such as silicone rubber) to achieve safe heating. The heating device 90 supports continuous adjustment from ambient temperature (25°C) to high temperature (e.g., 150°C, which can be customized according to the actual formation temperature) to meet the simulation needs of different oil and gas reservoir environments (e.g., shallow ambient temperature wells, deep high temperature wells).

[0061] In one possible implementation, the simulated wellbore high-temperature and high-pressure foam-carrying liquid evaluation device further includes a flow guide 100. The flow guide 100 may be spirally arranged inside the fluid cavity to allow the fluid inside the fluid cavity to spiral forward.

[0062] Optionally, the fluid may be at least one of a gas and a liquid. In a first example, the fluid may be a gas; in a second example, the fluid may be a liquid; and in a third example, the fluid may be a gas-liquid mixture.

[0063] Optionally, the flow guide 100 can be made of high-temperature, high-pressure resistant, and corrosion-resistant materials, such as stainless steel, Hastelloy, or polyetheretherketone (PEEK). A low-surface-energy coating can be applied to the surface to reduce foam liquid adhesion and prevent scaling from affecting the flow field. The helix angle and pitch of the flow guide 100 can be adjusted according to the target flow regime. A small pitch and large helix angle can enhance the swirling flow intensity, suitable for simulating foam breakup and regeneration under high-shear environments. A large pitch and small helix angle create a weak swirling flow, used to study the transition flow regime from laminar to turbulent flow. The blade height of the flow guide 100 is typically 1 / 5 to 1 / 3 of the pipe diameter, with a thickness of 0.5 to 2 mm. A tapered blade design (thick at the inlet, thin at the outlet) is used to reduce flow resistance and avoid abnormal pressure drop caused by the structure of the flow guide 100 itself.

[0064] In one possible implementation, the gas supply device 50 includes a gas storage container 51 and a gas flow detection device 52. The gas storage container 51 is used to store high-pressure gas. The gas storage container 51 can be connected to the gas inlet 13, thereby introducing high-pressure gas into the simulated wellbore 10. The gas flow detection device 52 can be located between the gas storage container 51 and the gas inlet 13, and is used to measure the gas flow rate. Optionally, the gas flow detection device 52 can be a rotor flowmeter. In the simulated wellbore high-temperature and high-pressure foam-carrying liquid evaluation device of this application, the gas in the gas supply device 50 can be nitrogen, natural gas, etc. The gas in the gas supply device 50 can be determined according to actual needs, and this application does not impose any restrictions.

[0065] Understandably, real formations contain high pressures. By introducing high-pressure gas into the simulated wellbore 10, a high-pressure environment can be simulated, making the experimental conditions closer to real formation conditions. This allows the experimental results to better reflect the actual liquid-carrying effect of foam in real formations, providing a more reliable reference for actual production. Furthermore, the high-pressure gas flowing within the simulated wellbore 10 carries the liquid. The gas flow propels the liquid upwards, thus achieving the foam liquid-carrying process. By adjusting the gas flow rate and pressure, different operating conditions can be simulated, allowing for the study of the foam liquid-carrying efficiency and effect under various conditions, providing data support for optimizing the foam liquid-carrying process.

[0066] In some embodiments, see Figure 1 and Figure 2 As shown, the simulated wellbore high temperature and high pressure foam liquid carrying evaluation device also includes an ultrasonic atomizer 16, which is used to atomize the liquid in the simulated wellbore 10. The ultrasonic atomizer 16 is located above the liquid level detection device 60.

[0067] Optionally, in some examples, the ultrasonic atomizer 16 may be detachably disposed within the simulated wellbore 10; in other examples, the ultrasonic atomizer 16 may be fixedly disposed within the simulated wellbore 10.

[0068] Specifically, the ultrasonic atomizer 16 can be a fluid-type vibrating ultrasonic atomizer 16, including an air inlet 161, a first-stage accelerating tube 162, a second-stage accelerating tube 163, a nozzle 164, a resonant atomizing chamber, a liquid inlet 166, a liquid guide tube 167, and a fluid outlet 168. The inner diameters of the first-stage accelerating tube 162 and the second-stage accelerating tube 163 decrease progressively. High-speed gas flows through the air inlet 161 and is accelerated sequentially through the first-stage accelerating tube 162 and the second-stage accelerating tube 163, and is then sprayed into the resonant atomizing chamber through the nozzle 164. At the same time, liquid enters the liquid guide tube 167 through the liquid inlet 166. The liquid guide tube 167 is connected to the nozzle 164, and the liquid is sprayed into the resonant atomizing chamber through the nozzle 164. The high-speed gas and liquid resonate in the resonant atomizing chamber to achieve atomization. After atomization, the liquid is discharged through the fluid outlet 168.

[0069] In practical implementation, the liquid accumulated inside the simulated wellbore 10 is torn apart and atomized into small droplets by the ultrasonic atomizer 16. These droplets can be carried out of the simulated wellbore 10 at low gas flow rates. The droplet size can be calculated using the following formula:

[0070]

[0071] Where T is the surface tension coefficient of the liquid. The density of the liquid, For frequency.

[0072] Furthermore, the relationship between gas velocity and droplet diameter can be obtained by simulating the critical liquid-carrying flow rate formula in wellbore 10:

[0073]

[0074] in, The density of the liquid; The density of the gas; The diameter of the droplet; Let be the gas velocity. Therefore, by combining the above two equations, we can obtain the relationship between gas velocity and frequency:

[0075]

[0076] The frequency of sound waves that can be generated by an ultrasonic resonant atomizing cavity is related to the ultrasonic velocity and the size of the atomizing cavity, and the calculation formula is as follows:

[0077]

[0078] Where c is the velocity of the high-speed airflow, r is the well casing end correction factor used to correct the acoustic radiation effect at the well casing opening, and V is the resonant cavity volume.

[0079] By controlling the gas production rate of the production well, the gas flow rate inside the wellbore can be controlled, which in turn controls the ultrasonic frequency. The droplet diameter can be controlled by changing the frequency of the ultrasonic atomizer 16. When the gas-carrying liquid flow rate is constant, the droplet diameter after ultrasonic atomization is smaller than the critical droplet diameter, and the accumulated liquid can be carried out of the simulated wellbore 10, allowing the gas well to produce normally.

[0080] It should be noted that the simulated wellbore high temperature and high pressure foam liquid carrying evaluation device of this application can meet the requirements for evaluating the liquid carrying performance of foaming agent even without the installation of ultrasonic atomizer 16. However, installing ultrasonic atomizer 16 can improve the liquid carrying effect by combining foam and ultrasonic atomization, thereby realizing the synergistic effect of foam liquid carrying and ultrasonic atomization. Therefore, ultrasonic atomizer 16 can be set to be detachably connected to simulated wellbore 10. In specific implementation, it is possible to choose whether to install ultrasonic atomizer 16 according to actual needs.

[0081] Furthermore, this application provides a method for evaluating the liquid-carrying capacity of high-temperature and high-pressure foam in a simulated wellbore, applied to the aforementioned device for evaluating the liquid-carrying capacity of high-temperature and high-pressure foam in a simulated wellbore. The method specifically includes the following steps:

[0082] S1. Select the target specification of the simulated wellbore 10, and connect the simulated wellbore 10 to the mixing container 20, the gas supply device 50, the liquid level detection device 60 and the liquid carrying detection device 80.

[0083] Specifically, the simulated wellbore 10 can be detachably connected to the mixing container 20, the gas supply device 50, the liquid level detection device 60, and the liquid carrying detection device 80. Therefore, simulated wellbores 10 of different diameters can be selected and connected to the simulated wellbore high temperature and high pressure foam liquid carrying evaluation device. The operation is convenient and the liquid carrying efficiency of simulated wellbores 10 of different diameters can be measured according to specific conditions, which is highly flexible.

[0084] S2. Control the water supply container 30 to supply water into the mixing container 20.

[0085] Specifically, the water supply container 30 can be connected to the mixing chamber of the mixing container 20 through the water inlet 22. Its core function is to simulate the actual working conditions of well water or injection fluid, providing the mixing container 20 with a constant flow rate and pressure of water (such as deionized water, simulated well water, etc.). The water supply rate is adjusted by a flow controller (such as a plunger pump or constant flow pump) to ensure a stable water flow into the mixing chamber. A stable water supply is the foundation for subsequent foaming agent mixing and uniform gas-liquid distribution. A stable water supply can avoid instability of the foam system or deviation in liquid carrying efficiency measurement due to water flow fluctuations.

[0086] S3. Control the foaming agent solution production device 40 to supply foaming agent solution into the mixing container 20 and set a preset ratio to mix with the formation water.

[0087] Specifically, the foaming agent solution production device 40 is connected to the mixing chamber via the foaming agent solution inlet 23. Its function is to inject foaming agent (such as anionic surfactants, polymer compound systems, etc.) at a preset concentration. During the experiment, the appropriate type of foaming agent needs to be selected according to the simulated well conditions (such as temperature and salinity), and the injection volume is controlled by a metering pump to ensure that the foaming agent and water are fully mixed in the mixing chamber to form a stable foam precursor liquid. A stirring device can also be installed in the mixing container 20 to assist in uniform mixing and avoid excessively high or low local concentrations of foaming agent, which would affect the subsequent foam generation quality and liquid carrying capacity evaluation. It should be noted that this step is optional, and the foaming agent solution production device 40 can be turned on to supply foaming agent solution according to actual needs.

[0088] S4. Determine that the detection value of the liquid level detection device 60 fluctuates within the preset range.

[0089] Specifically, the liquid level detection device 60 (such as a capacitive electrode) can be fixed at a preset liquid level height in the fluid cavity (such as the expected critical position for foam carrying), and the gas-liquid interface position is determined by detecting the difference in dielectric constant. When foam and liquid dynamically mix in the fluid cavity, the electrode contacting the foam or liquid will cause the capacitance value to fluctuate. When the capacitance value fluctuates within a preset range, it indicates that the gas-liquid interface is stable and in a dynamic equilibrium state, and there is no abnormal situation of liquid submerging the electrode or pure gas passing through, providing stable initial conditions for subsequent gas supply steps.

[0090] S5. Control the gas supply device 50 to supply gas into the fluid cavity.

[0091] Specifically, the gas supply device 50 can inject high-pressure gas (such as nitrogen or natural gas) into the gas inlet 13 at the bottom of the simulated wellbore 10. The high-pressure gas stored in the gas storage container 51 enters the fluid chamber after being metered by the gas flow detection device 52. The gas flow rate is adjustable to simulate the high-pressure environment of the wellbore and the shear effect of gas-liquid two-phase flow. When the gas is injected at high speed from the bottom, it mixes violently with the foam precursor liquid transported in the mixing chamber to form a foam flow, while simultaneously pushing the liquid upward.

[0092] In practical implementation, the supply flow rates of liquid and gas can be adjusted by the water supply container 30 and the gas supply device 50 respectively. In the simulated wellbore 10, a fluid with a preset gas-liquid ratio is injected into the fluid cavity by the water supply container 30 and the gas supply device 50, thereby measuring the liquid carrying efficiency under different gas-liquid ratios. Therefore, the simulated wellbore high temperature and high pressure foam liquid carrying evaluation device of this application embodiment can cover a wide range from low gas-liquid ratio to high gas-liquid ratio, thereby adapting to different application scenarios and helping to expand the application scope of the simulated wellbore high temperature and high pressure foam liquid carrying evaluation device.

[0093] S6. Determine that the liquid output of the first gas-liquid mixing outlet 14 is stable.

[0094] Specifically, the first gas-liquid mixture outlet 14 is located at the top of the simulated wellbore 10 and connected to a pressure stabilizing device 70 (including a second back pressure valve 71 and a second gas-liquid separator 72). When the pressure inside the fluid chamber reaches the second opening valve pressure, the second back pressure valve 71 opens, and the gas-liquid mixture is separated by the second gas-liquid separator 72. The liquid flows into the liquid container 75, and the gas is discharged. In the initial stage of detection, the system experiences fluctuations in the liquid output due to unstable gas-liquid flow. Continuous monitoring is required until the collected volume in the liquid container 75 is basically consistent within a unit time (e.g., flow rate change < 5% within 5 minutes). This indicates that the system has reached dynamic equilibrium. At this point, the pressure, flow rate, and foam-carrying liquid state inside the fluid chamber are all stable, meeting the detection conditions. In other words, a stable liquid output is a key indicator for determining whether the flow pattern meets expectations.

[0095] S7. Control the liquid carrying detection device 80 to open the second gas-liquid mixing outlet 15 and detect the liquid carrying rate.

[0096] Specifically, the second gas-liquid mixing outlets 15 can be distributed at intervals along the height of the simulated wellbore 10 (e.g., one at the bottom, one in the middle, and one at the top). Each second gas-liquid mixing outlet 15 corresponds to a first back pressure valve 81. When the pressure inside the fluid chamber reaches the first opening pressure of a certain second gas-liquid mixing outlet 15, the corresponding first back pressure valve 81 opens, the foam-carrying liquid mixture enters the first gas-liquid separator 82, the gas is discharged, and the liquid flows into the liquid-carrying detector 85 through the first discharge port 84. The liquid carrying rate is calculated as the ratio of the discharged liquid volume to the volume of the simulated wellbore 10, and parameters such as the pressure, gas flow rate, and temperature of each outlet need to be recorded simultaneously. This step, through independent control of multiple outlets, allows for comparison of liquid carrying efficiency at different heights (i.e., different back pressure conditions). Combined with flow regime observation, it analyzes the impact of foam stability and gas-liquid interface characteristics on liquid carrying performance, providing data support for optimizing the actual formation foam liquid carrying process.

[0097] The various embodiments or implementation methods described in this specification are presented in a progressive manner. Each embodiment focuses on the differences from other embodiments, and the same or similar parts between the embodiments can be referred to each other.

[0098] It should be noted that the embodiments referred to in the specification, such as "one embodiment," "embodiment," "exemplary embodiment," and "some embodiments," may include specific features, structures, or characteristics, but not every embodiment necessarily includes that specific feature, structure, or characteristic. Furthermore, such phrases do not necessarily refer to the same embodiment. Moreover, 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, is within the knowledge scope of those skilled in the art.

[0099] Generally speaking, terms should be understood at least in part by their use in context. For example, at least in part by context, the term "one or more" as used in the text can be used to describe any feature, structure, or characteristic of the singular meaning, or a combination of features, structures, or characteristics of the plural meaning. Similarly, at least in part by context, terms such as "a" or "the" can also be understood to convey either singular or plural usage.

[0100] It should be readily understood that the terms “on,” “above,” and “on top of” in this disclosure should be interpreted in the broadest possible sense, such that “on” means not only “directly on something” but also “on something” with an intermediate feature or layer therebetween, and that “above” or “on top of” means not only “on top of something” but also “on top of something” without an intermediate feature or layer therebetween (i.e., directly on something).

[0101] Furthermore, for ease of explanation, spatially relative terms such as "below," "below," "under," "above," and "above" may be used to describe the relationship of one element or feature relative to other elements or features as shown in the figures. Spatially relative terms are intended to encompass different orientations of the device in use or operation other than those shown in the figures. The device may have other orientations (rotated 90 degrees or in other orientations), and the spatially relative descriptive terms used herein may be interpreted accordingly.

[0102] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this application, and are not intended to limit them. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of this application.

Claims

1. A device for evaluating high-temperature, high-pressure foam-carrying liquid in simulated wellbore conditions, characterized in that, include: A simulated wellbore (10) is used to mix gas-liquid two-phase fluids to simulate the drainage and gas production process. The simulated wellbore (10) has a mixed solution inlet (12), a gas inlet (13), a first gas-liquid mixing outlet (14), and a second gas-liquid mixing outlet (15). The mixed solution inlet (12) is located at the bottom of the simulated wellbore (10), and the gas inlet (13) is located at the bottom of the simulated wellbore (10). The angle of the simulated wellbore (10) relative to the vertical direction is adjustable. A mixing container (20) is used to mix formation water and foaming agent solution in situ to form a mixed solution to simulate bottom fluid accumulation. The mixing container (20) is provided with a water inlet (22) and a foaming agent solution inlet (23). The mixing container (20) is connected to the mixed solution inlet (12) and communicates with the simulated wellbore (10) through the mixed solution inlet (12). A water supply container (30) is connected to the water inlet (22); A foaming agent solution production device (40) is connected to the foaming agent solution inlet (23); A gas supply device (50) is connected to the gas inlet (13); A liquid level detection device (60) is installed at a preset liquid level in the simulated wellbore (10) to detect the liquid level in the simulated wellbore (10); A pressure stabilizing device (70) is used to adjust the pressure inside the simulated wellbore (10) so that the pressure inside the simulated wellbore (10) is within a preset pressure range; The liquid carrying detection device (80) is connected to the second gas-liquid mixing outlet (15). The liquid carrying detection device (80) is used to open the second gas-liquid mixing outlet (15) when the pressure in the simulated wellbore (10) reaches the preset pressure, and to detect the liquid carrying efficiency. The second gas-liquid mixing outlet (15) consists of multiple outlets spaced apart along the height direction of the simulated wellbore (10); The voltage regulator (70) includes: The first back pressure valve (81) is one of a kind corresponding to the second gas-liquid mixing outlet (15). The first back pressure valve (81) is provided at the corresponding second gas-liquid mixing outlet (15). The first back pressure valve (81) is configured to open when the pressure in the simulated wellbore (10) reaches the first valve opening pressure. The liquid-carrying detection device (80) includes: The first gas-liquid separator (82) is connected to a plurality of the first back pressure valves (81), and the first gas-liquid separator (82) has a first exhaust port (83) and a first liquid discharge port (84). The liquid carrying detector (85) is connected to the first drain port (84) and is used to detect the liquid carrying rate.

2. The simulated wellbore high-temperature and high-pressure foam liquid-carrying evaluation device according to claim 1, characterized in that, The voltage regulator (70) also includes: A second back pressure valve (71) is provided at the first gas-liquid mixing outlet (14), and the second back pressure valve (71) is configured to open when the pressure inside the simulated wellbore (10) reaches a second opening pressure.

3. The simulated wellbore high-temperature and high-pressure foam liquid-carrying evaluation device according to claim 2, characterized in that, It also includes a second gas-liquid separator (72); The second gas-liquid separator (72) is connected to the second back pressure valve (71), and the second gas-liquid separator (72) has a second exhaust port (73) and a second liquid outlet (74). The voltage regulator (70) also includes: The liquid container (75) is connected to the second drain port (74).

4. The simulated wellbore high-temperature and high-pressure foam liquid-carrying evaluation device according to claim 3, characterized in that, The voltage regulator (70) also includes: A pressure detection device (76) is located between the second back pressure valve (71) and the first gas-liquid mixing outlet (14) for detecting the pressure inside the simulated wellbore (10).

5. The simulated wellbore high-temperature and high-pressure foam liquid-carrying evaluation device according to claim 1, characterized in that, Also includes: A heating device (90) is provided on the outside of the simulated wellbore (10), and the heating device (90) is used to heat the simulated wellbore (10).

6. The simulated wellbore high-temperature and high-pressure foam liquid-carrying evaluation device according to claim 1, characterized in that, Also includes: The flow guide (100) is spirally disposed inside the simulated wellbore (10) to cause the fluid inside the simulated wellbore (10) to spiral forward.

7. The simulated wellbore high-temperature and high-pressure foam liquid-carrying evaluation device according to claim 1, characterized in that, The gas supply device (50) includes: A gas storage container (51) is connected to the gas inlet (13), and the gas storage container (51) is used to store high-pressure gas; A gas flow detection device (52) is located between the gas storage container (51) and the gas inlet (13) for measuring gas flow.

8. The simulated wellbore high-temperature and high-pressure foam liquid-carrying evaluation device according to claim 1, characterized in that, Also includes: An ultrasonic atomizer (16) is used to atomize the liquid in the simulated well barrel (10). The ultrasonic atomizer (16) is located above the liquid level detection device (60). The ultrasonic atomizer (16) is detachably installed inside the simulated well barrel (10).

9. A method for evaluating the liquid-carrying capacity of high-temperature, high-pressure foam in a simulated wellbore, characterized in that, The device applied to the simulated wellbore high-temperature and high-pressure foam-carrying liquid evaluation device as described in any one of claims 1 to 8 includes the following steps: Control the water supply container (30) to supply water into the mixing container (20); The foaming agent solution production device (40) supplies foaming agent solution to the mixing container (20) and sets a preset ratio to mix with formation water; The detection value of the liquid level detection device (60) is determined to fluctuate within a preset range; The gas supply device (50) supplies gas into the simulated wellbore (10); The liquid output of the first gas-liquid mixing outlet (14) is determined to be stable; The liquid carrying detection device (80) opens the second gas-liquid mixing outlet (15) and detects the liquid carrying rate.

10. The method for evaluating high-temperature and high-pressure foam-carrying liquid in simulated wellbores according to claim 9, characterized in that, Before the water supply container (30) supplies water to the mixing container (20), it also includes: Select a simulated wellbore (10) of the target specification and connect the simulated wellbore (10) to the mixing container (20), the gas supply device (50), the liquid level detection device (60) and the liquid carrying detection device (80).

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