Normal temperature and pressure short core displacement experimental device

Abstract

The present application belongs to the technical field of short core material experiment detection, in particular to a normal temperature and pressure short core displacement experiment device, which comprises a base, an experiment table and a stand column arranged between the base and the experiment table, further comprising: a fluorescent displacement liquid preparation tank arranged on the upper surface of the experiment table, a bracket fixedly arranged between the bottom of the fluorescent displacement liquid preparation tank and the upper surface of the experiment table, and a feeding pipe fixedly arranged on the top of the fluorescent displacement liquid preparation tank. The present application uses fluorescent displacement liquid and is matched with a fluorescence spectrum analysis mechanism, can intuitively distinguish oil and displacement liquid, accurately deduces the remaining oil condition inside the core, can accurately control the injection amount, pressure and speed, avoids abnormal pressure, ensures that the experimental data truly reflects the original characteristics of the core, and can obtain spectrum data from multiple directions and improve accuracy.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of short core material experiment detection, and particularly relates to a normal-temperature and normal-pressure short core displacement experiment device. BACKGROUND

[0002] The core displacement experiment is an important means for studying the flow law of reservoir fluid in rock pores, evaluating the recovery ratio and optimizing the mining scheme, and the normal-temperature and normal-pressure short core displacement experiment device is widely used in basic research and preliminary experiment stage due to relatively simple operation, low cost and the ability to simulate certain actual working conditions. For example, the normal-temperature and normal-pressure short core displacement experiment device is disclosed in the announcement No. CN208076355U.

[0003] In the current normal-temperature and normal-pressure short core displacement experiment, water is often selected as the displacement fluid. However, due to the lack of intuitive and effective distinguishing method when oil and water flow in the core, the distribution of remaining oil cannot be accurately monitored, which affects the simulation and analysis of reservoir dynamics based on experimental data. In addition, the accurate control of the injection speed of the displacement fluid is crucial. Although the constant pressure pump is currently used to control the injection process, due to the mechanical structure of the constant pressure pump itself, the pulse characteristics of the fluid and the complex resistance changes in the system, etc., the displacement fluid pressure fluctuates. When the injection speed is too fast, the internal pressure of the core will rise rapidly, and the excessively high pressure may exceed the bearing limit of the core, causing the original pore structure of the core to be damaged, resulting in changes in the key physical parameters such as the permeability and porosity of the core. When the injection speed is too slow, the displacement fluid may not fully enter all the pores of the core, resulting in incomplete displacement and inaccurate simulation of the displacement of the displacement fluid and oil in the actual reservoir mining process. In this way, the data obtained from the experiment cannot truly reflect the original characteristics of the core.

[0004] Therefore, the normal-temperature and normal-pressure short core displacement experiment device is proposed. SUMMARY

[0005] The purpose of the application is to provide a normal-temperature and normal-pressure short core displacement experiment device to solve the above problems.

[0006] To achieve the above purpose, the following technical scheme is adopted: a normal-temperature and normal-pressure short core displacement experiment device, comprising a base, an experiment table and a stand column arranged between the base and the experiment table, further comprising:

[0007] A fluorescent displacement fluid preparation tank is arranged on the upper surface of the experiment table, and a bracket is fixedly arranged between the bottom of the fluorescent displacement fluid preparation tank and the upper surface of the experiment table. A feed pipe is fixedly arranged at the top of the fluorescent displacement fluid preparation tank, and a first injection pipe is fixedly arranged at the bottom of one side of the fluorescent displacement fluid preparation tank, and a liquid metering valve is arranged on the pipe wall of the first injection pipe.

[0008] stirring mechanism, arranged in the interior of the fluorescent displacement fluid preparation tank;

[0009] an injection pump, fixedly arranged on the upper surface of the experimental table, and having one end of the injection pump fixedly connected with one end of the first injection pipe, and the other end of the injection pump fixedly provided with a second injection pipe;

[0010] a core holder, fixedly arranged on the upper surface of the experimental table, and having one end of the core holder fixedly connected with one end of the second injection pipe, and the other end of the core holder fixedly provided with a discharge pipe, and a collecting barrel fixedly arranged on the top of the base and below the discharge pipe;

[0011] a liquid pressure sensor, fixedly arranged on the pipe wall of the second injection pipe;

[0012] an impurity filter, fixedly arranged on the pipe wall of the discharge pipe;

[0013] a fluorescence spectrum analysis mechanism, fixedly arranged on the upper surface of the experimental table and above the collecting barrel;

[0014] a PLC controller, fixedly arranged on one side of the upper surface of the experimental table, and electrically connected with the liquid metering valve, the stirring mechanism, the injection pump, the liquid pressure sensor, the impurity filter and the fluorescence spectrum analysis mechanism.

[0015] Preferably, the stirring mechanism comprises a stirrer arranged in the interior of the fluorescent displacement fluid preparation tank, the top of the fluorescent displacement fluid preparation tank is fixedly provided with a first motor, the output end of the first motor is fixedly connected with the upper end of the stirrer, and the side wall of the fluorescent displacement fluid preparation tank is fixedly provided with a viscosity detector, and the detection end of the viscosity detector extends into the interior of the fluorescent displacement fluid preparation tank.

[0016] Preferably, the core holder comprises a cylindrical shell fixedly arranged on the upper surface of the experimental table, both ends of the cylindrical shell are threadedly provided with clamping heads, a short core body is clamped between the two clamping heads, and the side walls of the two clamping heads are respectively fixedly connected with one end of the second injection pipe and one end of the discharge pipe.

[0017] Preferably, the impurity filter comprises a filter cartridge fixedly arranged on the discharge pipe, a polytetrafluoroethylene filter membrane is vertically fixedly arranged in the interior of the filter cartridge, and the filter cartridge is composed of two half-cylindrical bodies threadedly connected with each other.

[0018] Preferably, the outer wall of the filter cartridge is fixedly provided with a protective cover, the top corner and the bottom corner of the protective cover are fixedly provided with inclined plates, the surfaces of the two inclined plates are respectively fixedly provided with an infrared spectrometer and a spectrum detector, and the inner wall of the filter cartridge is fixedly provided with a quartz glass protective sheet corresponding to the positions of the infrared spectrometer and the spectrum detector.

[0019] Preferably, the fluorescence spectrum analysis mechanism comprises a support fixedly arranged on the upper surface of the experiment table, a sliding groove is arranged in the horizontal part of the support, a sliding block is arranged in the sliding groove, a screw rod is arranged in the sliding groove and rotates laterally, the rod wall of the screw rod is threadedly connected with the middle part of the sliding block, a second motor is fixedly arranged at one end of the horizontal part of the support, the output end of the second motor is fixedly connected with one end of the screw rod, and the bottom of the sliding block is fixedly provided with a fluorescence spectrometer.

[0020] Preferably, the top opening of the collecting barrel is fixedly provided with a flexible rubber mask, the lower end of the fluorescence spectrometer and one end of the discharge pipe are arranged to extend into the interior of the collecting barrel through the interior of the flexible rubber mask.

[0021] Preferably, the bottom of the side wall of the collecting barrel is fixedly provided with a layered recovery pipe, the pipe wall of the layered recovery pipe is provided with an on-off valve, and the side wall of the collecting barrel is provided with a transparent observation window in the vertical direction.

[0022] Compared with the prior art, the present application has the following beneficial effects:

[0023] 1. The fluorescence displacement liquid preparation tank provides storage space for the mixing of fluorescent substances and water; at the same time, the fluorescence spectrum analysis mechanism is used to detect the mixed body after displacement, which can intuitively distinguish oil and displacement liquid, accurately monitor the remaining oil distribution, provide reliable data for oil reservoir dynamic simulation and analysis, and solve the problem that the remaining oil distribution cannot be intuitively monitored in traditional experiments; in addition, the stirring mechanism can uniformly disperse the fluorescent substances in the water body, effectively avoid the uneven concentration of the fluorescent displacement liquid, and can detect the viscosity of the fluorescent displacement liquid in real time; as a key parameter of the displacement liquid, the viscosity is kept within a suitable range to ensure that the displacement liquid flows in the best state in the core pore, avoid large pressure fluctuations due to viscosity problems, protect the core pore structure from being damaged, and thus ensure that the experimental data truly reflect the original characteristics of the core.

[0024] 2、Through the liquid metering valve, injection pump and liquid pressure sensor arranged and the cooperation of the PLC controller, the injection pump power can be automatically adjusted according to the real-time pressure data, the injection amount, injection pressure and speed of the fluorescent displacement fluid are accurately controlled, the situation that the core pore structure is damaged due to too fast injection speed or the displacement is not thorough due to too slow injection speed is avoided, and it is ensured that the experimental data can truly reflect the original characteristics of the core.

[0025] 3、Through the impurity filter arranged, the polytetrafluoroethylene filter membrane is used to filter the impurities in the oil and fluorescent displacement fluid mixture, the accuracy of the fluorescent analysis is prevented from being affected by the impurities, meanwhile, the saturation degree of the filter membrane is monitored in real time through the infrared spectrometer and the spectrum detector, the filter membrane can be replaced in time, the filtering effect is ensured, and the detection precision is further improved. BRIEF DESCRIPTION OF DRAWINGS

[0026] Figure 1 It is a perspective view of a normal temperature and pressure short core displacement experiment device provided by the application;

[0027] Figure 2 It is a partial cutaway perspective view of a fluorescent displacement fluid preparation tank of a normal temperature and pressure short core displacement experiment device provided by the application;

[0028] Figure 3 It is a partial cutaway perspective view of a core holder of a normal temperature and pressure short core displacement experiment device provided by the application;

[0029] Figure 4 It is a structural schematic view of an impurity filter of a normal temperature and pressure short core displacement experiment device provided by the application;

[0030] Figure 5 It is a perspective view of a fluorescent spectrum analysis mechanism of a normal temperature and pressure short core displacement experiment device provided by the application;

[0031] Figure 6 It is a partial cutaway perspective view of a collection barrel of a normal temperature and pressure short core displacement experiment device provided by the application.

[0032] In the diagram: 1. Base, 2. Experimental table, 3. Column, 4. Fluorescent displacement solution mixing tank, 5. Bracket, 6. Feed pipe, 7. First injection pipe, 8. Liquid metering valve, 9. Stirring mechanism, 91. Stirrer, 92. First motor, 93. Viscometer, 10. Injection pump, 11. Second injection pipe, 12. Core holder, 121. Cylindrical shell, 122. Clamping head, 123. Short core body, 13. Discharge pipe, 14. Collection bucket, 15. Liquid pressure sensor, 16. Impurity filter, 161. Filter cylinder, 162. PTFE filter membrane, 163. Protective cover, 164. Inclined plate, 165. Infrared spectrometer, 166. Spectrometer detector, 167. Quartz glass protective sheet, 17. Fluorescence spectroscopy analysis mechanism, 171. Support, 172. Slide, 173. Slider, 174. Screw, 175. Second motor, 176. Fluorescence spectrometer, 18. PLC controller, 19. Flexible rubber mask, 20. Layered recovery pipe, 21. Switch valve, 22. Transparent observation window. Detailed Implementation

[0033] The technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments.

[0034] like Figures 1-6 As shown, a short core displacement experimental device under ambient temperature and pressure includes a base 1, an experimental platform 2, and a column 3 disposed between the base 1 and the experimental platform 2, and further includes:

[0035] A fluorescent displacing solution preparation tank 4 is set on the upper surface of the experimental platform 2, and a bracket 5 is fixed between the bottom of the fluorescent displacing solution preparation tank 4 and the upper surface of the experimental platform 2. A feed pipe 6 is fixed on the top of the fluorescent displacing solution preparation tank 4, and a first injection pipe 7 is fixed on the bottom of one side of the fluorescent displacing solution preparation tank 4. A liquid metering valve 8 is provided on the wall of the first injection pipe 7.

[0036] A stirring mechanism 9 is installed inside the fluorescent displacing liquid preparation tank 4. The stirring mechanism 9 includes a stirrer 91 installed inside the fluorescent displacing liquid preparation tank 4. A first motor 92 is fixedly installed on the top of the fluorescent displacing liquid preparation tank 4. The output end of the first motor 92 is fixedly connected to the upper end of the stirrer 91. A viscosity meter 93 is fixedly installed on the side wall of the fluorescent displacing liquid preparation tank 4, and the detection end of the viscosity meter 93 extends into the interior of the fluorescent displacing liquid preparation tank 4. The operation of the first motor 92 can drive the stirrer 91 to rotate. The stirrer 91 can mix the fluorescent material and water inside the fluorescent displacing liquid preparation tank 4, so that the fluorescent material can be evenly dispersed in the water. During the stirring and mixing process, the viscosity meter 93 can detect the viscosity of the fluorescent displacing liquid in real time.

[0037] The injection pump 10 is fixedly arranged on the upper surface of the experiment table 2, and the input end of the injection pump 10 is fixedly connected with one end of the first injection pipe 7, and the output end of the injection pump 10 is fixedly provided with the second injection pipe 11; the liquid pressure sensor 15 is fixedly arranged on the pipe wall of the second injection pipe 11.

[0038] The core holder 12 is fixedly arranged on the upper surface of the experiment table 2, one end of the core holder 12 is fixedly connected with one end of the second injection pipe 11, and the other end of the core holder 12 is fixedly provided with the discharge pipe 13, the core holder 12 comprises a cylindrical shell 121 fixedly arranged on the upper surface of the experiment table 2, both ends of the cylindrical shell 121 are threadedly provided with clamping heads 122, a short core body 123 is clamped between the two clamping heads 122, and the side walls of the two clamping heads 122 are respectively fixedly connected with one end of the second injection pipe 11 and one end of the discharge pipe 13; the second injection pipe 11 and the discharge pipe 13 are both soft pipes, so that the two clamping heads 122 are not affected when rotating, and the two clamping heads 122 can be disassembled from both ends of the cylindrical shell 121, so that the short core body 123 can be installed.

[0039] The impurity filter 16 is fixedly arranged on the pipe wall of the discharge pipe 13, and the impurity filter 16 comprises a filter cylinder 161 fixedly arranged on the discharge pipe 13, a polytetrafluoroethylene filter membrane 162 is vertically fixedly arranged in the inside of the filter cylinder 161, and the filter cylinder 161 is composed of two half cylinders which are threadedly connected with each other; when the polytetrafluoroethylene filter membrane 162 needs to be disassembled and replaced, the two half cylinders are rotated in opposite directions, so that the filter cylinder 161 is disassembled and the polytetrafluoroethylene filter membrane 162 is exposed; a protective cover 163 is fixedly arranged on the outer wall of the filter cylinder 161, inclined plates 164 are fixedly arranged at the top corner and the bottom corner of the protective cover 163, an infrared spectrometer 165 and a spectrum detector 166 are respectively fixedly arranged on the surfaces of the two inclined plates 164, the infrared spectrometer 165 and the spectrum detector 166 are arranged in a 90° distribution, and quartz glass protective sheets 167 are fixedly arranged on the inner wall of the filter cylinder 161 and correspond to the positions of the infrared spectrometer 165 and the spectrum detector 166; the infrared spectrometer 165 emits infrared light of a specific wavelength range, the spectrum detector 166 is used for receiving infrared light which is transmitted through or reflected by the polytetrafluoroethylene filter membrane 162, and the quartz glass protective sheets 167 can protect the infrared spectrometer 165 and the spectrum detector 166; in addition, the quartz glass has low adhesion, which reduces the possibility of oil and fluorescent displacement fluid adhering to the surface.

[0040] The fluorescence spectrum analysis mechanism 17 is fixedly arranged on the upper surface of the experiment table 2, and the fluorescence spectrum analysis mechanism 17 is located above the collecting barrel 14. The fluorescence spectrum analysis mechanism 17 comprises a support 171 fixedly arranged on the upper surface of the experiment table 2. A horizontal part of the support 171 is provided with a sliding groove 172. The sliding groove 172 is internally provided with a sliding block 173. The sliding groove 172 is internally and transversely rotatably provided with a screw rod 174. The rod wall of the screw rod 174 is threadedly connected with the middle part of the sliding block 173. A horizontal part of the support 171 is fixedly provided with a second motor 175 at one end. The output end of the second motor 175 is fixedly connected with one end of the screw rod 174. The bottom of the sliding block 173 is fixedly provided with a fluorescence spectrometer 176. The second motor 175 can drive the screw rod 174 to rotate. The screw rod 174 can drive the sliding block 173 to move horizontally in the sliding groove 172, so that the horizontal position of the fluorescence spectrometer 176 can be moved. The fluorescence spectrometer 176 can emit light of a specific wavelength to irradiate the oil and fluorescent displacement liquid mixture in multiple directions.

[0041] The top opening of the collecting barrel 14 is fixedly provided with a flexible rubber mask 19. The lower end of the fluorescence spectrometer 176 and one end of the discharge pipe 13 all pass through the inside of the flexible rubber mask 19 and extend into the inside of the collecting barrel 14. The flexible rubber mask 19 can play a role in isolation and protection, so that the oil and fluorescent displacement liquid mixture in the inside of the collecting barrel 14 is not polluted. At the same time, the flexible rubber mask 19 is made of flexible material, so that the flexible rubber mask 19 will not hinder the movement of the fluorescence spectrometer 176. The top of the base 1 and below the discharge pipe 13 are fixedly provided with the collecting barrel 14. The sidewall of the collecting barrel 14 is fixedly provided with a layered recovery pipe 20 at the bottom. The pipe wall of the layered recovery pipe 20 is provided with an on-off valve 21. The sidewall of the collecting barrel 14 is provided with a transparent observation window 22 in the vertical direction. In the process of standing, the experimenter can observe the layering condition in the inside of the collecting barrel 14 through the transparent observation window 22. Then, the oil phase and the fluorescent displacement liquid phase are layered and discharged and recovered in sequence through the layered recovery pipe 20 by opening the on-off valve 21.

[0042] The PLC controller 18 is fixedly arranged on one side of the upper surface of the experiment table 2. The liquid metering valve 8, the stirring mechanism 9, the injection pump 10, the liquid pressure sensor 15, the impurity filter 16 and the fluorescence spectrum analysis mechanism 17 are all electrically connected with the PLC controller 18.

[0043] The operation principle of the present application is described as follows: first, the experimental device is placed in a laboratory at normal temperature and pressure, then the experimental personnel select a length of short core body 123, then the clamping head 122 at one end of the cylindrical shell 121 is taken out from the end of the cylindrical shell 121, at this time, the short core body 123 is inserted into the inside of the cylindrical shell 121, and the two ends of the short core body 123 are clamped and fixed by the clamping heads 122 on both sides, then the concentration of the fluorescent substance in the required fluorescent displacement fluid and the total volume of the fluorescent displacement fluid to be configured are determined, the amount of fluorescent substance and water is calculated, for example, 50 milliliters of fluorescent substance is required for 1000 milliliters of fluorescent displacement fluid, and the volume of water is 950 milliliters, then the fluorescent substance and water are added together through the feeding pipe 6 into the inside of the fluorescent displacement fluid preparation tank 4 through the metering tool, after adding, the opening of the feeding pipe 6 is plugged, the experimental personnel operate the PLC controller 18 with hands, so that the PLC controller 18 starts the first motor 92, the first motor 92 can drive the stirrer 91 to rotate, the stirrer 91 can mix the fluorescent substance and water in the inside of the fluorescent displacement fluid preparation tank 4, so that the fluorescent substance can be uniformly dispersed in the water body, in the process of stirring and mixing, the viscosity detector 93 can detect the viscosity of the fluorescent displacement fluid in real time, if the viscosity is abnormal, it may cause the displacement fluid to break through too early or cannot be completely displaced, which affects the recovery rate, and moreover, if the viscosity increases, the fluorescent displacement fluid will flow difficultly in the core pore, the injection pressure will instantaneously increase, on the contrary, if the viscosity decreases, the injection pressure may suddenly decrease, so as to avoid that the fluorescent displacement fluid generates larger pressure fluctuation when being injected, then the viscosity of the fluorescent displacement fluid is adjusted according to the detected value and in a reasonable range, so as to ensure that the fluorescent displacement fluid uniformly advances in the porous medium such as oil reservoir, and effectively displaces the oil liquid;

[0044] When the fluorescent displacement fluid is prepared, the experimenter manually operates the PLC controller 18 to start the liquid metering valve 8, the injection pump 10, the liquid pressure sensor 15 and the impurity filter 16 in turn, and the injection pump 10 can suck out the fluorescent displacement fluid in the fluorescent displacement fluid preparation tank 4 and inject it into the inside of the core holder 12, so that the fluorescent displacement fluid can displace the oil in the short core body 123. During the process of fluorescent displacement, due to the extremely complex pore structure of the short core body 123, the sizes of the pores and the throats are uneven, when the fluorescent displacement fluid is injected, the water-soluble part of the fluorescent displacement fluid will flow into the small pores of the rock due to the interaction between the surface tension and the rock surface, driven by the capillary force (the surface tension will act along the tangent direction of the liquid surface, at the concave liquid surface, the resultant force of these forces points to the inside of the liquid, forming an additional pressure), it is this capillary force that promotes the gradual advancement of the fluorescent displacement fluid in the pores, continuously expelling the oil originally occupying the pore space, so that it moves towards the center of the pore or the larger pore channel, then, due to the difference in viscosity, the oil with low viscosity is more likely to flow under the push of the high-viscosity displacement fluid, the fluorescent displacement fluid forms a continuous flow phase in the pores, continuously pushing the oil droplets to move towards the outlet direction of the core, so as to realize the displacement of the oil from the short core body 123.

[0045] When the fluorescent displacement fluid is injected into the inside of the cylindrical shell 121, the liquid metering valve 8 can accurately control the injection amount of the fluorescent displacement fluid, at the same time, when the fluorescent displacement fluid passes through the inside of the second injection pipe 11, the liquid pressure sensor 15 can detect the pressure of the fluorescent displacement fluid injected into the inside of the cylindrical shell 121 in real time, and the liquid pressure sensor 15 sends the detected pressure value to the PLC controller 18, when the actual pressure value is lower than the threshold value set in the PLC controller 18, the PLC controller 18 will automatically increase the power of the injection pump 10 to increase the injection speed, so that the injection pressure rises, avoiding too high pressure, which causes the original pore structure of the core to be damaged, resulting in the change of the key physical parameters such as the permeability and porosity of the core, when the actual pressure value is higher than the threshold value set in the PLC controller 18, the PLC controller 18 will reduce the power of the injection pump 10 to reduce the injection speed, so that the injection pressure decreases, which can realize the accurate adjustment of the injection pressure, so that it always remains near the set value, avoiding the phenomenon that the displacement is not thorough and the original characteristics of the core cannot be truly reflected;

[0046] The oil and fluorescent displacement fluid mixture driven out from the short core body 123 will be discharged outwardly through the discharge pipe 13. In the process of discharge, the oil and fluorescent displacement fluid mixture passes through the inside of the filter cartridge 161, and the impurities (rock debris, mineral particles and colloidal substances) in the oil and fluorescent displacement fluid mixture are filtered out by the polytetrafluoroethylene filter membrane 162, ensuring the accuracy of the later fluorescence analysis (the polytetrafluoroethylene filter membrane 162 has excellent chemical stability and can resist the erosion of oil and various fluorescent substances and will not chemically react with the components of the oil and fluorescent displacement fluid mixture);

[0047] In the process of filtration, as the surface impurities of the polytetrafluoroethylene filter membrane 162 increase, the filtering effect of the polytetrafluoroethylene filter membrane 162 gradually decreases. At this time, the infrared spectrometer 165 and the spectrum detector 166 can detect the saturation of the polytetrafluoroethylene filter membrane 162 in real time. The infrared spectrometer 165 emits infrared light of a specific wavelength range. When the infrared light irradiates the polytetrafluoroethylene filter membrane 162, different substances have different absorption characteristics of infrared light. The polytetrafluoroethylene itself has a specific infrared absorption spectrum, and the impurities adsorbed on its surface also have their own unique infrared absorption peaks (it needs to be emphasized that the main detection target of the infrared spectrometer 165 is the impurities on the polytetrafluoroethylene filter membrane 162, not the oil and fluorescent displacement fluid mixture itself. The absorption peaks of the polytetrafluoroethylene and the impurities of the specific wavelength infrared light are different from the absorption peaks of the oil and fluorescent displacement fluid. As long as the absorption peak change related to the impurities can be clearly distinguished, the influence of a small amount of infrared light passing through the mixture can be weakened). As the impurities accumulate on the surface of the polytetrafluoroethylene filter membrane 162, the overall absorption of the polytetrafluoroethylene filter membrane 162 to the infrared light will change. At this time, the spectrum detector 166 is used to receive the infrared light that passes through or is reflected by the polytetrafluoroethylene filter membrane 162, and convert the light signal into an electric signal, and then send the electric signal to the PLC controller 18. The PLC controller 18 can infer the change of the content of the impurities on the surface of the polytetrafluoroethylene filter membrane 162 by analyzing the intensity and position change of each absorption peak in the infrared spectrum, so as to judge the saturation of the polytetrafluoroethylene filter membrane 162. If the saturation of the polytetrafluoroethylene filter membrane 162 reaches a certain value, it means that the filtering effect of the polytetrafluoroethylene filter membrane 162 reaches the minimum. At this time, the polytetrafluoroethylene filter membrane 162 needs to be disassembled and replaced;

[0048] The filtered oil and the fluorescent displacement fluid mixture can flow slowly into the inside of the collection barrel 14 through the discharge pipe 13 until reaching a suitable liquid level, and the experimenter operates the PLC controller 18 to start the fluorescence spectrometer 176. The fluorescence spectrometer 176 has an excitation light source that emits light of a specific wavelength, usually ultraviolet or visible light, which is irradiated on the oil and fluorescent displacement fluid mixture. After the interaction of the oil and fluorescent displacement fluid mixture, the oil and fluorescent displacement fluid mixture will be excited under the specific excitation light. When the fluorescent substance in the fluorescent displacement fluid mixture is excited, it will emit fluorescence of different wavelengths. The optical system in the fluorescence spectrometer 176 is responsible for collecting these fluorescence signals. The optical system generally includes lenses, filters and other components. The lenses are used to focus the fluorescence signals so that they accurately enter the detection unit of the fluorescence spectrometer 176. The filters are used to filter out the excitation light and other stray light, allowing only the fluorescence to pass through to avoid interfering with the collection of the fluorescence signal. After being processed by the optical system, the fluorescence signal enters the built-in detector of the fluorescence spectrometer 176, which is usually a photomultiplier tube or a charge-coupled device, which converts the fluorescence signal into an electrical signal. The intensity of the electrical signal is proportional to the intensity of the fluorescence. These electrical signals are amplified and analog-to-digital converted to digital signals. After receiving the digital signals, the control system of the fluorescence spectrometer 176 processes the data according to the built-in algorithm. The processing process includes removing background noise, correcting wavelength and other operations to improve the accuracy and reliability of the spectrum. Finally, the processed data is presented in the form of a spectrum on the computer, with the horizontal axis representing the wavelength of the fluorescence and the vertical axis representing the intensity of the fluorescence. The experimenter can analyze the characteristics of the spectrum, such as the position and intensity of the peaks, to obtain information related to the oil in the fluid and infer the remaining oil in the core.

[0049] During the fluorescence spectrum analysis process, the experimenter operates the PLC controller 18 to turn on the second motor 175, which can drive the screw 174 to rotate. The screw 174 can drive the sliding block 173 to move horizontally inside the sliding groove 172, thereby moving the fluorescence spectrometer 176 horizontally. This allows the fluorescence spectrometer 176 to emit light of a specific wavelength in multiple directions to irradiate on the oil and fluorescent displacement fluid mixture, which can improve data accuracy, eliminate sample unevenness and measurement errors, and enhance experimental flexibility and efficiency while adapting to different needs, saving time and manpower.

[0050] After the fluorescence spectrum analysis is completed, the oil and fluorescent displacement fluid mixture is allowed to stand for a period of time (1-2 hours) to allow the oil and fluorescent displacement fluid mixture to separate into two layers, with the upper layer being the oil phase and the lower layer being the fluorescent displacement fluid phase. Finally, the oil phase and the fluorescent displacement fluid phase are discharged and recovered in sequence by opening the switch valve 21.

[0051] The above merely describes preferred embodiments of the present application, and is not used to limit the present application, and any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A normal temperature and pressure short core displacement experiment device, comprising a base (1), an experiment table (2) and a stand (3) arranged between the base (1) and the experiment table (2), characterized in that, Also include: The fluorescent displacement liquid preparation tank (4) is arranged on the upper surface of the experiment table (2), and a bracket (5) is fixed between the bottom of the fluorescent displacement liquid preparation tank (4) and the upper surface of the experiment table (2). The top of the fluorescent displacement liquid preparation tank (4) is fixedly provided with a feeding pipe (6), and the bottom of one side of the fluorescent displacement liquid preparation tank (4) is fixedly provided with a first injection pipe (7), and the pipe wall of the first injection pipe (7) is provided with a liquid metering valve (8). The stirring mechanism (9) is arranged in the interior of the fluorescent displacement liquid preparation tank (4). The injection pump (10) is fixedly arranged on the upper surface of the experiment table (2), and the input end of the injection pump (10) is fixedly connected with one end of the first injection pipe (7). The output end of the injection pump (10) is fixedly provided with a second injection pipe (11). The core holder (12) is fixedly arranged on the upper surface of the experiment table (2), one end of the core holder (12) is fixedly connected with one end of the second injection pipe (11), and the other end of the core holder (12) is fixedly provided with a discharge pipe (13). The top of the base (1) and below the discharge pipe (13) are fixedly provided with a collecting barrel (14). The liquid pressure sensor (15) is fixedly arranged on the pipe wall of the second injection pipe (11). The impurity filter (16) is fixedly arranged on the pipe wall of the discharge pipe (13). The fluorescence spectrum analysis mechanism (17) is fixedly arranged on the upper surface of the experiment table (2), and the fluorescence spectrum analysis mechanism (17) is located above the collecting barrel (14). The PLC controller (18) is fixedly arranged on one side of the upper surface of the experiment table (2), and the liquid metering valve (8), the stirring mechanism (9), the injection pump (10), the liquid pressure sensor (15), the impurity filter (16) and the fluorescence spectrum analysis mechanism (17) are electrically connected with the PLC controller (18).

2. The normal temperature and pressure short core displacement experiment device according to claim 1, characterized in that, The stirring mechanism (9) includes a stirrer (91) arranged in the interior of the fluorescent displacement liquid preparation tank (4). The top of the fluorescent displacement liquid preparation tank (4) is fixedly provided with a first motor (92), the output end of the first motor (92) is fixedly connected with the upper end of the stirrer (91), and the sidewall of the fluorescent displacement liquid preparation tank (4) is fixedly provided with a viscosity detector (93), and the detection end of the viscosity detector (93) extends into the interior of the fluorescent displacement liquid preparation tank (4).

3. The short core displacement experiment device at normal temperature and pressure according to claim 1, characterized in that, The core holder (12) includes a cylindrical shell (121) fixedly arranged on the upper surface of the experiment table (2). The two ends of the cylindrical shell (121) are threadedly provided with clamping heads (122), and a short core body (123) is clamped between the two clamping heads (122). The sidewalls of the two clamping heads (122) are respectively fixedly connected with one end of the second injection pipe (11) and one end of the discharge pipe (13).

4. The short core displacement experiment device at normal temperature and pressure according to claim 1, characterized in that, The impurity filter (16) comprises a filter cylinder (161) fixedly arranged on the discharge pipe (13), the inside of the filter cylinder (161) is vertically fixedly provided with a polytetrafluoroethylene filter membrane (162), and the filter cylinder (161) is composed of two half cylinders which are threadedly connected with each other.

5. The ambient temperature and pressure short core displacement experiment device according to claim 4, characterized in that, The outer wall of the filter cylinder (161) is fixedly provided with a protective cover (163), the top corner and the bottom corner of the protective cover (163) are fixedly provided with inclined plates (164), the surfaces of the two inclined plates (164) are respectively fixedly provided with an infrared spectrometer (165) and a spectrum detector (166), and the inner wall of the filter cylinder (161) is fixedly provided with quartz glass protective sheets (167) corresponding to the positions of the infrared spectrometer (165) and the spectrum detector (166).

6. The ambient temperature and pressure short core displacement experiment device according to claim 1, characterized in that, The fluorescence spectrum analysis mechanism (17) comprises a support (171) fixedly arranged on the upper surface of the experiment table (2), the horizontal portion of the support (171) is provided with a sliding groove (172), the inside of the sliding groove (172) is provided with a sliding block (173), the inside of the sliding groove (172) is laterally rotatably provided with a screw rod (174), the rod wall of the screw rod (174) is threadedly connected with the middle portion of the sliding block (173), one end of the horizontal portion of the support (171) is fixedly provided with a second motor (175), the output end of the second motor (175) is fixedly connected with one end of the screw rod (174), and the bottom of the sliding block (173) is fixedly provided with a fluorescence spectrometer (176).

7. The ambient temperature and pressure short core displacement experiment device according to claim 6, characterized in that, The top opening of the collecting barrel (14) is fixedly provided with a flexible rubber mask (19), and the lower end of the fluorescence spectrometer (176) and one end of the discharge pipe (13) both pass through the inside of the flexible rubber mask (19) and extend into the inside of the collecting barrel (14).

8. The ambient temperature and pressure short core displacement experiment device according to claim 1, characterized in that, The bottom of the side wall of the collecting barrel (14) is fixedly provided with a layered recovery pipe (20), the pipe wall of the layered recovery pipe (20) is provided with an on-off valve (21), and the side wall of the collecting barrel (14) is provided with a transparent observation window (22) in the vertical direction.

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