A multiphase flow switching system and method based on online nuclear magnetic detection

Abstract

The application discloses a multiphase flow switching system and method based on online nuclear magnetic detection, relates to the field of geological rock and soil medium detection, and the system is used for detecting the permeability of a sampling core in gas measurement, liquid measurement, acidification and liquid measurement after acidification without replacing experimental devices, reduces experimental errors caused by pipeline replacement, and reduces time spent on replacing experimental devices. Meanwhile, the online real-time nuclear magnetic detection system can observe the pore formation process of the sampling core in the acidification process in real time, more directly and accurately determines relevant experimental data, and increases the permeability of the sampling core.

Description

Technical Field

[0001] This invention relates to the field of detection of geological and soil media, specifically to a multiphase flow switching system and switching method based on online nuclear magnetic resonance detection. Background Technology

[0002] Reservoir rocks are porous media, and their permeability is a reservoir characteristic of great interest to engineers. Permeability specifically refers to the ability of sandstone to allow fluids to pass through under a certain pressure differential, and it is generally expressed as permeability rate. The permeability of the rock directly affects the production of oil and gas wells.

[0003] Currently, gas chromatography, liquid chromatography, and acidizing experiments in the laboratory are mostly conducted independently. Furthermore, the physical properties of the sampled cores are primarily obtained by comparing CT scans before and after acidizing—that is, a CT scan is performed before acidizing and again afterward, and the scan structures are then compared. However, this method cannot observe the porosity formed in the core under the influence of acid during acidizing in real time. The independent operation of gas chromatography and liquid chromatography increases the difficulty of controlling variables and is more likely to introduce errors.

[0004] Furthermore, if liquid or gas analysis is performed on the sampled core after the acidification experiment, the corresponding system device needs to be replaced, and the final test results will also be affected by the device replacement. Summary of the Invention

[0005] To address the problems existing in the prior art, this invention proposes a multiphase flow switching system and method based on online NMR detection. This system allows for the detection of permeability in sampled rock cores through gas chromatography, liquid chromatography, acidification, and post-acidification liquid chromatography without replacing the experimental system. This reduces experimental errors caused by pipeline replacement and also reduces the time spent on replacing experimental equipment. Furthermore, the online real-time NMR detection system allows for real-time observation of the pore formation process in the sampled rock core during acidification, providing a more intuitive and accurate determination of relevant experimental data and improving the accuracy of permeability detection in the sampled rock cores.

[0006] Specifically, the detailed technical solution provided by this invention is as follows:

[0007] A multiphase flow switching system based on online NMR detection, including

[0008] A gas supply cylinder, which supplies gas medium to the entire system through a gas medium channel;

[0009] A base liquid medium flow channel is connected to the gas supply bottle, and the base liquid medium in the base liquid medium flow channel flows to the system under the action of the gas supply bottle;

[0010] An acid medium flow channel is connected to the gas supply cylinder, and the acid medium in the acid medium flow channel flows into the system under the action of the gas supply cylinder.

[0011] The gas medium channel, base liquid medium channel, and acid liquid medium channel are merged and connected at the tail end to form a main pipeline. A core fixing assembly is connected in the main pipeline, and the core fixing assembly is surrounded and monitored by a nuclear magnetic resonance analysis and imaging system. An exhaust monitoring mechanism and a liquid discharge monitoring mechanism are respectively connected at the tail end of the main pipeline. The exhaust monitoring mechanism is configured to monitor the gas medium discharged from the system. The liquid discharge monitoring mechanism is configured to monitor the base liquid or acid liquid discharged from the system.

[0012] Furthermore, the core fixing assembly includes a clamp and a ring clamp. After the core is placed in the clamp, it is tightened by the ring clamp. The clamp is connected to the main pipeline, so that gas, base liquid or acid liquid through the main pipeline can be injected into the core.

[0013] Furthermore, an inlet pressure gauge is installed at the inlet of the core fixing assembly; an outlet pressure gauge is installed at the outlet of the core fixing assembly.

[0014] Furthermore, the gas supply cylinder is connected to the gas medium channel, the base liquid medium channel, and the acid liquid medium channel respectively via a four-way valve;

[0015] A first electrically controlled valve is provided in the gas medium channel;

[0016] A second electric control valve is provided in the base liquid medium flow channel;

[0017] A third electric control valve is provided in the acid medium flow channel;

[0018] The first, second, and third electric control valves are controlled by a computer operating system.

[0019] Furthermore, a base liquid container is also provided in the base liquid medium flow channel; the base liquid container is filled with base liquid, and the gas supply bottle injects gas into the base liquid container, so that the base liquid flows in the direction of the main pipeline.

[0020] Furthermore, an acid container is also provided in the acid medium flow channel; the acid container is filled with acid, and the gas supply bottle injects gas into the acid container, so that the acid flows towards the main pipeline.

[0021] Furthermore, the acid medium flow channel and the base liquid medium flow channel are connected by a drainage pipe; an intermediate container is also provided in the acid medium flow channel, and a stirrer is built into the intermediate container.

[0022] The base liquid enters the acid medium flow channel through the drainage pipe and mixes with the acid liquid in a sealed intermediate container equipped with a stirrer.

[0023] Furthermore, the main pipeline is also equipped with a first drain pipe, which is connected to the front of the inlet pressure gauge via a first three-way controller, and the first drain pipe is externally connected to a first solution receiver.

[0024] Furthermore, the drainage monitoring mechanism includes a second drainage pipe and a second solution receiver, the second drainage pipe being connected to the main pipeline via a second three-way controller; the exhaust monitoring mechanism includes a U-shaped pipe and liquid injected into the U-shaped pipe.

[0025] In response to the above switching system, a multiphase flow switching method based on online NMR detection is also proposed. The specific steps include:

[0026] Step 1: Before the test begins, check the sealing of each pipeline. The pipeline is made of Hastelloy material. Check the connection of the pipeline joints. Check the airflow control of the gas cylinder. Turn on the computer operating system.

[0027] Step 2: Perform online detection of physical parameters of the sampled rock core in the nuclear magnetic resonance analysis and imaging system, and record the initial detection results R1;

[0028] Step 3: Close all valves, place the sampled core into the holder, fix the sampled core in the holder using the ring clamp, connect all pipelines according to the design drawing, and set the temperature in the nuclear magnetic resonance analysis and imaging system to the required value;

[0029] Step 4: Open the gas valve of the gas cylinder to allow the gas to be output stably at a certain pressure and flow rate. Control the opening of the first electric control valve, the closing of the second and third electric control valves, the opening of the connection between the first three-way controller and the inlet pressure gauge, and the opening of the second three-way controller connected to the U-tube through the computer operating system.

[0030] Step 5: First, perform gas analysis on the sampled core. The computer operating system controls the first electric control valve to set the flow rate to 400 ml / min. Observe the values ​​of the inlet pressure gauge and the outlet pressure gauge. When a stable flow of gas is released in the U-tube 20, record the gas flow data F1. F1 is the gas analysis result.

[0031] Step Six: After the gas measurement is completed, the sampled core is subjected to liquid measurement. The computer operating system closes the first electric control valve and opens the second electric control valve. The second electric control valve is set to a fixed value to smoothly push the liquid injected in the base liquid container into the holder. The values ​​of the inlet pressure gauge and the outlet pressure gauge are observed. When the values ​​of the inlet pressure gauge and the outlet pressure gauge change, and the outlet flow rate at the second solution receiver is consistent with the inlet flow rate, the data F2 of the inlet pressure gauge and the outlet pressure gauge is recorded. F2 is the liquid measurement result.

[0032] Step 7: The computer operating system closes the second electric control valve, opens the first electric control valve, opens the switch connecting the first three-way controller to the solution receiver pipeline, sets the value to control the first electric control valve to smoothly push the gas into the pipeline, and allows the residual liquid in the pipeline to flow into the first solution receiver;

[0033] Step 8: After the liquid test is completed, an acidification test is performed. The computer operating system opens the second and third electric control valves and sets the flow rates of the second and third electric control valves respectively. The liquid injected into the base liquid container is smoothly mixed with the acid injected into the acid container through the drainage pipe and flows into the intermediate container with a stirrer. The two solutions are mixed evenly through the intermediate container with a stirrer and smoothly pushed into the clamp. The values ​​of the inlet pressure gauge and the outlet pressure gauge are observed. When the values ​​of the inlet pressure gauge and the outlet pressure gauge change and the outlet flow rate obtained at the second solution receiver is consistent with the inlet flow rate, the data F3 of the inlet pressure gauge and the outlet pressure gauge is recorded. F3 is the acid test result.

[0034] Then, the second and third electric control valves are closed, and the physical parameters of the sampled rock core are detected online in the nuclear magnetic resonance analysis and imaging system. The detection results R2 are recorded.

[0035] Retain the liquid in the second solution receiver for subsequent titration experiments;

[0036] Step 9: The computer operating system closes the second and third electric control valves, opens the first electric control valve, opens the switch connecting the first three-way controller to the solution receiver pipeline, sets the value to control the first electric control valve to smoothly push the gas into the pipeline, and allows the residual liquid in the pipeline to flow into the first solution receiver;

[0037] Step 10: After the acidification experiment, the sampled core is rinsed and subjected to secondary liquid analysis. The computer operating system closes the first electric control valve and opens the second electric control valve. The second electric control valve is set to a fixed value to smoothly advance the liquid injected in the base liquid container into the holder. The values ​​of the inlet pressure gauge and the outlet pressure gauge are observed. When the values ​​of the inlet pressure gauge and the outlet pressure gauge change, and the outlet flow rate obtained at the second solution receiver is consistent with the inlet flow rate, the data of the inlet pressure gauge and the outlet pressure gauge F3 are recorded. The sampled core is subjected to online detection of physical parameters in the nuclear magnetic resonance analysis and imaging system, and the detection results R3 are recorded.

[0038] Step 11: Close the gas supply cylinder, close the first electric control valve, the second electric control valve and the third electric control valve, close the ring pressure device, close the nuclear magnetic resonance analysis and imaging system, and take out the sample core from the holder;

[0039] Step 12: Analyze and process the gas, liquid, and acid test data F1, F2, and F3. Analyze the R1, R2, and R3 data and images obtained from the nuclear magnetic resonance analysis and imaging system. Analyze and compare the data with relevant data from the untreated well-steaming experiment to obtain the physical properties and structural changes of the core.

[0040] The beneficial effects achieved by adopting this technical solution are as follows:

[0041] This system, through its rational structural layout, enables rapid multiphase fluid switching flow experiments on rock cores. It allows for core monitoring at various stages of liquid testing and acidizing experiments, facilitating more convenient and rapid permeability measurements and acidizing operations. Furthermore, the use of online nuclear magnetic resonance imaging (NMR) technology allows for more comprehensive and accurate observation of the rock core's physical properties and structural changes. Specifically,

[0042] 1. Computer-controlled multiphase flow velocity. A computer operating system controls the first, second, and third electrically operated control valves separately, intelligently achieving rapid switching of multiphase fluids and more precise control of multiphase flow rates. No manual adjustment is required, and relevant data can be recorded online in real time.

[0043] 2. Enables flow experiments with rapid switching of multiphase fluids. A four-way control valve connects three pipelines to the gas supply cylinder, allowing for integrated gas measurement, liquid measurement, acidification, and subsequent liquid measurement after acidification, eliminating the need for frequent pipeline replacements. The three-way control valve at the inlet of the clamp can completely drain residual liquid from the preceding pipeline, reducing the impact of residual liquid on the core and increasing the accuracy of the experiment.

[0044] 3. Dynamically monitor changes in core physical properties using NMR (low-field nuclear magnetic resonance) technology. Since NMR systems allow real-time observation of core physical properties during acidizing experiments, and by varying the time and acid concentration, the physical properties of the same sampled core at any given time point can be obtained. Analyzing and processing the data allows for the determination of the impact of acidizing experiments on the sampled core, and whether it can increase oil and gas production. Attached Figure Description

[0045] Figure 1 This is the schematic diagram of the system.

[0046] The components include: 100 gas supply cylinder, 101 computer operating system, 110 gas medium channel, 111 first electric control valve, 120 base liquid medium flow channel, 121 second electric control valve, 122 base liquid container, 130 acid medium flow channel, 131 third electric control valve, 132 acid container, 140 drainage pipe, 141 intermediate container, 200 main pipeline, 201 inlet pressure gauge, 202 outlet pressure gauge, 203 first drain pipe, 204 first three-way controller, 205 first solution receiver, 206 second drain pipe, 207 second solution receiver, 208 second three-way controller, 209 U-tube, 300 nuclear magnetic resonance analysis and imaging system, 301 clamp, and 302 ring pressure device. Detailed Implementation

[0047] The principles and features of the present invention are described below with reference to the accompanying drawings. The examples given are only for explaining the present invention and are not intended to limit the scope of the present invention.

[0048] This embodiment provides a multiphase flow switching system based on online NMR detection. By adopting the switching system provided in this solution, the rapid switching of multiphase fluids can be intelligently realized, the flow rate of multiphase fluids can be controlled more accurately, no manual debugging is required, and relevant data can be recorded online in real time.

[0049] Specifically, the switching system comprises a gas supply cylinder 100 and a gas medium channel 110, a base liquid medium channel 120, and an acid medium channel 130, all connected to the gas supply cylinder 100. The gas supply cylinder 100 supplies gas to the entire system through the gas medium channel 110; the base liquid medium channel 120 is connected to the gas supply cylinder 100, allowing the base liquid medium in the channel to flow into the system under the influence of the gas supply cylinder 100; similarly, the acid medium channel 130 is connected to the gas supply cylinder 100, allowing the acid medium in the channel to flow into the system under the influence of the gas supply cylinder 100.

[0050] The gas medium channel 110, the base liquid medium channel 120, and the acid liquid medium channel 130 are merged and connected at the tail end to form a main pipeline 200. A core fixing assembly is connected in the main pipeline 200, and the core fixing assembly is surrounded and monitored by the nuclear magnetic resonance analysis and imaging system 300. An exhaust monitoring mechanism and a liquid discharge monitoring mechanism are respectively connected at the tail end of the main pipeline 200. The exhaust monitoring mechanism is configured to monitor the gas medium discharged from the system. The liquid discharge monitoring mechanism is configured to monitor the base liquid or acid liquid discharged from the system.

[0051] To facilitate a full understanding of this system, the specific components of the system will be described in detail below.

[0052] Specifically, the gas cylinder 100 is connected to the gas medium channel 110, the base liquid medium channel 120, and the acid medium channel 130 respectively via a four-way valve; wherein, a first electric control valve 111 is provided in the gas medium channel 110; a second electric control valve 121 is provided in the base liquid medium channel 120; and a third electric control valve 131 is provided in the acid medium channel 130; and the first electric control valve 111, the second electric control valve 121, and the third electric control valve 131 are controlled by a computer operating system 101.

[0053] Meanwhile, a base liquid container 122 is also provided in the base liquid medium flow channel 120; the base liquid container 122 is filled with base liquid, and the gas supply cylinder 100 injects gas into the base liquid container 122, which will cause the base liquid to flow in the direction of the main pipeline 200.

[0054] Meanwhile, an acid container 132 is also provided in the acid medium flow channel 130; the acid container 132 is filled with acid, and the gas supply cylinder 100 injects gas into the acid container 132, which will cause the acid to flow in the direction of the main pipeline 200.

[0055] In a specific embodiment of this solution, the acid medium channel 130 and the base medium channel 120 are connected by a drainage pipe 140; an intermediate container 141 is also provided in the acid medium channel 130, and a stirrer is built into the intermediate container 141; the base liquid enters the acid medium channel 130 through the drainage pipe 140 and mixes with the acid liquid in the sealed intermediate container 141 with the stirrer.

[0056] An inlet pressure gauge 201 is installed at the inlet of the core fixing assembly; an outlet pressure gauge 202 is installed at the outlet of the core fixing assembly; a first drain pipe 203 is also provided in the main pipeline 200, the first drain pipe 203 is connected to the inlet pressure gauge 201 through a first three-way controller 204, and the first drain pipe 203 is externally connected to a first solution receiver 205.

[0057] The core fixing assembly includes a clamp 301 and a ring clamp 302. After the core is placed in the clamp 301, it is tightened by the ring clamp 302. The clamp 301 is connected to the main pipeline 200, so that gas, base liquid or acid liquid through the main pipeline 200 can be injected into the core.

[0058] Meanwhile, the drainage monitoring mechanism includes a second drainage pipe 206 and a second solution receiver 207. The second drainage pipe 206 is connected to the main pipeline 200 through a second three-way controller 208. The exhaust monitoring mechanism includes a U-shaped pipe 209 and liquid injected into the U-shaped pipe 209.

[0059] The above describes the specific structure of this system. The following section uses the system provided in the above solution to introduce the specific usage steps. The specific steps include:

[0060] Step 1: Before the test begins, check the sealing of each pipeline. The pipeline is made of Hastelloy material. Check the connection of the pipeline joints. Check the airflow control of the gas cylinder 100. Turn on the computer operating system 101.

[0061] Step 2: Perform online detection of physical parameters on the sampled rock core using the nuclear magnetic resonance analysis and imaging system 300, and record the initial detection results R1;

[0062] Step 3: Close all valves, place the sampled core into the holder 301, fix the sampled core in the holder 301 using the ring clamp 302, connect all pipelines according to the design drawing, and set the temperature in the nuclear magnetic resonance analysis and imaging system 300 to the required value.

[0063] Step 4: Open the gas valve of the gas supply cylinder 100 to allow the gas to be output stably at a certain pressure and flow rate. Control the opening of the first electric control valve 111, the closing of the second electric control valve 121 and the third electric control valve 131 by setting the computer operating system 101, opening the connection between the first three-way controller 204 and the inlet pressure gauge 201, and opening the second three-way controller 208 connected to the U-tube 209.

[0064] Step 5: First, perform gas analysis on the sampled core. The computer operating system 101 controls the first electric control valve 111 to set the flow rate to 400 ml / min. Observe the values ​​of the inlet pressure gauge 201 and the outlet pressure gauge 202. When a stable flow of gas is released in the U-tube 209, record the gas flow data F1. F1 is the gas analysis result.

[0065] Step Six: After the gas measurement is completed, the sampled core is subjected to liquid measurement. The computer operating system 101 closes the first electric control valve 111 and opens the second electric control valve 121. The second electric control valve 121 is set to smoothly push the liquid in the base liquid container 122 into the clamp 301 at a fixed value. The values ​​of the inlet pressure gauge 201 and the outlet pressure gauge 202 are observed. When the values ​​of the inlet pressure gauge 201 and the outlet pressure gauge 202 change, and the outlet flow rate at the second solution receiver 207 is consistent with the inlet flow rate, the data F2 of the inlet pressure gauge 201 and the outlet pressure gauge 202 is recorded. F2 is the liquid measurement result.

[0066] Step 7: The computer operating system 101 closes the second electric control valve 121, opens the first electric control valve 111, opens the switch of the first three-way controller 204 connecting to the solution receiver pipeline, sets the value to control the first electric control valve 111 to smoothly push the gas into the pipeline, and lets the residual liquid in the pipeline flow into the first solution receiver 205.

[0067] Step 8: After the liquid test is completed, an acidification test is performed. The computer operating system 101 opens the second electric control valve 121 and the third electric control valve 131, and sets the flow rate values ​​of the second electric control valve 121 and the third electric control valve 131 respectively. The liquid injected into the base liquid container 122 is smoothly mixed with the acid injected into the acid liquid container 132 through the drainage pipe 140 and flows into the intermediate container 141 with a stirrer. The two solutions are mixed evenly through the intermediate container 141 with a stirrer and smoothly pushed into the clamp 301. The values ​​of the inlet pressure gauge 201 and the outlet pressure gauge 202 are observed. When the values ​​of the inlet pressure gauge 201 and the outlet pressure gauge 202 change, and the outlet flow rate obtained at the second solution receiver 207 is consistent with the inlet flow rate, the data F3 of the inlet pressure gauge 201 and the outlet pressure gauge 202 is recorded. F3 is the acid test result.

[0068] Then, the second electric control valve 121 and the third electric control valve 131 are closed, and the physical parameters of the sampled rock core are detected online in the nuclear magnetic resonance analysis and imaging system 300. The detection results R2 are recorded.

[0069] The liquid in the second solution receiver 207 is retained for subsequent titration experiments;

[0070] Step 9: The computer operating system 101 closes the second electric control valve 121 and the third electric control valve 131, opens the first electric control valve 111, opens the switch of the first three-way controller 204 connecting to the solution receiver pipeline, sets the value to control the first electric control valve 111 to smoothly push the gas into the pipeline, and lets the residual liquid in the pipeline flow into the first solution receiver 205.

[0071] Step 10: After the acidification experiment, the sampled core is rinsed and subjected to secondary liquid analysis. The computer operating system 101 closes the first electric control valve 111 and opens the second electric control valve 121. The second electric control valve 121 is set to smoothly advance the liquid injected in the base liquid container 122 into the clamp 301 at a fixed value. The values ​​of the inlet pressure gauge 201 and the outlet pressure gauge 202 are observed. When the values ​​of the inlet pressure gauge 201 and the outlet pressure gauge 202 change, and the outlet flow rate obtained at the second solution receiver 207 is consistent with the inlet flow rate, the data F3 of the inlet pressure gauge 201 and the outlet pressure gauge 202 is recorded. The physical parameters of the sampled core are detected online in the nuclear magnetic resonance analysis and imaging system 300, and the detection results R3 are recorded.

[0072] Step 11: Close the gas supply cylinder 100, close the first electric control valve 111, the second electric control valve 121 and the third electric control valve 131, close the ring compressor 302, close the nuclear magnetic resonance analysis and imaging system 300, and take out the sample core from the holder 301.

[0073] Step 12: Analyze and process the gas, liquid, and acid test data F1, F2, and F3. Analyze the R1, R2, and R3 data and images obtained from the nuclear magnetic resonance analysis and imaging system 300. Analyze and compare the data with relevant data from the untreated well-steaming experiment to obtain the physical properties and structural changes of the core.

[0074] This technical solution, through a rational structural layout, allows for rapid multiphase fluid switching flow experiments on rock cores. It also enables core analysis at various points in the liquid measurement and acidizing experiments, facilitating more convenient and rapid permeability measurement and acidizing experiments. Furthermore, the use of online nuclear magnetic resonance imaging technology allows for more comprehensive and accurate observation of the rock core's physical properties and structural changes. Specifically,

[0075] 1. Computer-controlled multiphase flow velocity. A computer operating system controls the first, second, and third electrically operated control valves separately, intelligently achieving rapid switching of multiphase fluids and more precise control of multiphase flow rates. No manual adjustment is required, and relevant data can be recorded online in real time.

[0076] 2. Enables flow experiments with rapid switching of multiphase fluids. A four-way control valve connects three pipelines to the gas supply cylinder, allowing for integrated gas measurement, liquid measurement, acidification, and subsequent liquid measurement after acidification, eliminating the need for frequent pipeline replacements. The three-way control valve at the inlet of the clamp can completely drain residual liquid from the preceding pipeline, reducing the impact of residual liquid on the core and increasing the accuracy of the experiment.

[0077] 3. Dynamically monitor changes in core physical properties using NMR (low-field nuclear magnetic resonance) technology. Since NMR systems allow real-time observation of core physical properties during acidizing experiments, and by varying the time and acid concentration, the physical properties of the same sampled core at any given time point can be obtained. Analyzing and processing the data allows for the determination of the impact of acidizing experiments on the sampled core, and whether it can increase oil and gas production.

[0078] It should be noted that similar labels and letters in the following figures indicate similar items. Therefore, once an item is defined in one figure, it does not need to be further defined and explained in subsequent figures.

[0079] It should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, or the orientation or positional relationship commonly used when the technical product is in use. They are used only for the convenience of describing the technology and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the technology. Furthermore, "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined with "first" or "second" may explicitly or implicitly include one or more of that feature. Therefore, the terms "first," "second," "third," etc., are used only for distinguishing descriptions and should not be construed as indicating or implying relative importance. In the description of this invention, unless otherwise stated, "a plurality of" means two or more.

[0080] Furthermore, terms such as "horizontal," "vertical," and "sag" do not imply that components must be absolutely horizontal or suspended, but rather that they can be slightly tilted. For example, "horizontal" simply means that its direction is more horizontal relative to "vertical," and does not mean that the structure must be completely horizontal, but can be slightly tilted.

[0081] In the description of this technology, it should also be noted that, unless otherwise explicitly specified and limited, the terms "set up," "install," "connect," and "link" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this technology based on the specific circumstances.

[0082] The above are merely preferred embodiments of this technology. It should be noted that, due to the limitations of written expression and the existence of an infinite number of specific structures, those skilled in the art can make several improvements, modifications, or changes without departing from the principles of this technology, and can also combine the above-mentioned technical features in an appropriate manner. These improvements, modifications, changes, or combinations, or the direct application of the technical concept and solution to other situations without modification, should all be considered within the scope of protection of this technology.

Claims

1. A multiphase flow switching method based on online nuclear magnetic detection, characterized in that, A kind of multi-phase flow switching system based on online nuclear magnetic detection is used for switching, and the multi-phase flow switching system based on online nuclear magnetic detection includes: A gas supply bottle (100) provides gas medium to the whole system through a gas medium channel (110); A base fluid medium flow channel (120) is communicated with the gas supply bottle (100), and under the action of the gas supply bottle (100), the base fluid medium in the base fluid medium flow channel (120) flows to the system; An acid liquid medium flow channel (130) is communicated with the gas supply bottle (100), and under the action of the gas supply bottle (100), the acid liquid medium in the acid liquid medium flow channel (130) flows to the system; The gas medium channel (110), base fluid medium flow channel (120) and acid liquid medium flow channel (130) are connected into a total pipeline (200) at the tail end, a core fixing assembly is connected in the total pipeline (200), and the core fixing assembly is surrounded and monitored by a nuclear magnetic resonance analysis and imaging system (300); The tail end of the total pipeline (200) is respectively connected with an exhaust monitoring mechanism and a liquid discharge monitoring mechanism; The exhaust monitoring mechanism is configured to monitor the gas medium discharged from the system; The liquid discharge monitoring mechanism is configured to monitor the base fluid or acid liquid discharged from the system; The core fixing assembly includes a clamp (301) and a ring pressure device (302), and the core is placed in the clamp (301) and then fastened and pressed by the ring pressure device (302); The clamp (301) is connected with the total pipeline (200), so that the gas, base fluid or acid liquid passing through the total pipeline (200) can be injected into the core; An inlet pressure gauge (201) is installed at the inlet of the core fixing assembly; An outlet pressure gauge (202) is installed at the outlet of the core fixing assembly; The gas supply bottle (100) is communicated with the gas medium channel (110), base fluid medium flow channel (120) and acid liquid medium flow channel (130) through a four-way valve respectively; A first electric control valve (111) is arranged in the gas medium channel (110); A second electric control valve (121) is arranged in the base fluid medium flow channel (120); A third electric control valve (131) is arranged in the acid liquid medium flow channel (130); The first electric control valve (111), second electric control valve (121) and third electric control valve (131) are controlled by a computer operating system (101); A base fluid container (122) is further arranged in the base fluid medium flow channel (120); The base fluid container (122) contains base fluid, and the gas supply bottle (100) injects gas into the base fluid container (122), so that the base fluid flows in the direction of the total pipeline (200). The acid liquid medium flow channel (130) is further provided with an acid liquid container (132); the acid liquid container (132) contains acid liquid, and the gas supply bottle (100) injects gas into the acid liquid container (132), so that the acid liquid flows towards the direction of the main pipeline (200); The acid liquid medium flow channel (130) and the base liquid medium flow channel (120) are further communicated through a flow guide pipe (140); the acid liquid medium flow channel (130) is further provided with an intermediate container (141), and the intermediate container (141) is internally provided with a stirrer; The base liquid enters the acid liquid medium flow channel (130) through the flow guide pipe (140) and is mixed with the acid liquid in the sealed intermediate container (141) with the stirrer; The main pipeline (200) is further provided with a first liquid discharge pipe (203), the first liquid discharge pipe (203) is connected in front of the inlet pressure gauge (201) through a first three-way controller (204), and the first liquid discharge pipe (203) is externally connected with a first solution receiver (205); The liquid discharge monitoring mechanism comprises a second liquid discharge pipe (206) and a second solution receiver (207), the second liquid discharge pipe (206) is communicated with the main pipeline (200) through a second three-way controller (208); the gas discharge monitoring mechanism comprises a U-shaped pipe (209) and a liquid injected into the U-shaped pipe (209); Specific steps include: step one: before detection, detect the sealing performance of each pipeline, the pipeline is made of hastelloy material, detect the connection of the pipeline connection, detect the gas flow control of the gas supply bottle (100), and open the computer operating system (101); Step two: the sampled core is subjected to online detection of physical parameters in the nuclear magnetic resonance analysis and imaging system (300), and the initial detection result R1 is recorded; Step three: close all valves, put the sampled core into the clamp (301), fix the sampled core in the clamp (301) through the ring pressure device (302), connect all pipelines according to the design drawing, and set the temperature in the nuclear magnetic resonance analysis and imaging system (300) to the required value; Step four: open the gas valve of the gas supply bottle (100) to make the gas output stably at a certain pressure and flow rate, control the opening of the first electric control valve (111) through the setting of the computer operating system (101), close the second electric control valve (121) and the third electric control valve (131), open the connection between the first three-way controller (204) and the inlet pressure gauge (201), and open the second three-way controller (208) connected with the U-shaped pipe (209); Step five: first, gas measurement is performed on the sampled core, the computer operating system (101) controls the first electric control valve (111) to set the flow rate to 400 ml / min, the values of the inlet pressure gauge (201) and the outlet pressure gauge (202) are observed, when the U-shaped pipe (209) 20 has a stable flow rate of gas, the gas flow data F1 is recorded, and F1 is the gas measurement detection result; Step six: after the end of gas measurement, liquid measurement is performed on the sampling core, the computer operating system (101) closes the first electric control valve (111), opens the second electric control valve (121), sets the second electric control valve (121) to a fixed value to smoothly push the liquid in the base liquid container (122) into the holder (301), observes the values of the inlet pressure gauge (201) and the outlet pressure gauge (202), when the values of the inlet pressure gauge (201) and the outlet pressure gauge (202) change and the outlet flow rate at the second solution receiver (207) is consistent with the inlet flow rate, records the data F2 of the inlet pressure gauge (201) and the outlet pressure gauge (202), F2 is the liquid measurement detection result; Step seven: the computer operating system (101) closes the second electric control valve (121), opens the first electric control valve (111), opens the first three-way controller (204) connected to the solution receiver pipeline switch, sets the value to control the first electric control valve (111) to smoothly push the gas into the pipeline, and flow the residual liquid in the pipeline into the first solution receiver (205); Step eight: after the end of liquid measurement, acidification test is performed, the computer operating system (101) opens the second electric control valve (121) and the third electric control valve (131), respectively sets the flow rate value of the second electric control valve (121) and the flow rate value of the third electric control valve (131), smoothly mixes the liquid in the base liquid container (122) with the acid liquid in the acid liquid container (132) through the drainage pipeline (140), flows into the intermediate container (141) with a stirrer, mixes the two solutions uniformly through the intermediate container (141) with a stirrer, and smoothly pushes into the holder (301), observes the values of the inlet pressure gauge (201) and the outlet pressure gauge (202), when the values of the inlet pressure gauge (201) and the outlet pressure gauge (202) change and the outlet flow rate obtained at the second solution receiver (207) is consistent with the inlet flow rate, records the data F3 of the inlet pressure gauge (201) and the outlet pressure gauge (202), F3 is the acid measurement detection result; Then, the second electric control valve (121) and the third electric control valve (131) are closed, the sampling core is subjected to online detection of physical parameters in the nuclear magnetic resonance analysis and imaging system (300), and the detection result R2 is recorded, the liquid in the second solution receiver (207) is reserved for subsequent titration test; Step nine: the computer operating system (101) closes the second electric control valve (121) and the third electric control valve (131), opens the first electric control valve (111), opens the first three-way controller (204) connected to the solution receiver pipeline switch, sets the value to control the first electric control valve (111) to smoothly push the gas into the pipeline, and flow the residual liquid in the pipeline into the first solution receiver (205); Step ten: after the acidizing experiment, the sampling core is flushed and liquid measurement is performed for the second time, the computer operating system (101) closes the first electric control valve (111), opens the second electric control valve (121), sets the second electric control valve (121) to steadily push the liquid in the base fluid container (122) into the holder (301) at a fixed value, observes the values of the inlet pressure gauge (201) and the outlet pressure gauge (202), when the values of the inlet pressure gauge (201) and the outlet pressure gauge (202) change and the outlet flow rate and the inlet flow rate obtained at the second solution receiver (207) are consistent, the data F3 of the inlet pressure gauge (201) and the outlet pressure gauge (202) are recorded, the sampling core is subjected to online detection of physical parameters in the nuclear magnetic resonance analysis and imaging system (300), and the detection result R3 is recorded; Step eleven: the gas supply cylinder (100) is closed, the first electric control valve (111), the second electric control valve (121) and the third electric control valve (131) are closed, the ring pressure device (302) is closed, the nuclear magnetic resonance analysis and imaging system (300) is closed, and the sampling core in the holder (301) is taken out; Step twelve: the data F1, F2 and F3 obtained by gas measurement, liquid measurement and acid measurement are analyzed and processed, the data and images R1, R2 and R3 obtained by the nuclear magnetic resonance analysis and imaging system (300) are analyzed, and the data and related data obtained without the acidizing soak experiment are compared, so that the physical properties and structural changes of the core are obtained.

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