Visual device and method for simulating spatio-temporal evolution law of microbial cement in oil reservoir environment

Abstract

The invention belongs to the technical field of experimental equipment, and relates to a visual device and method for simulating the spatio-temporal evolution law of microbial cement in an oil reservoir environment, and the device comprises a simulation cylinder, a rock plate sample, an upper chamber, a lower chamber, an observation window, a first pressurized liquid injection assembly, a second pressurized liquid injection assembly, a temperature control assembly, and a shooting assembly. The device can inject a pressurized nutrient solution and a microorganism bacterium solution into the upper chamber through the first pressurized liquid injection assembly, so that microorganisms perform microorganism cement bonding on a rock plate sample, and a pressurized simulated formation fluid is injected into the lower chamber through the second pressurized liquid injection assembly to be matched with the rock plate sample to simulate an actual formation structure. The internal temperature of the simulation cylinder is adjusted through the temperature control assembly, the formation temperature is simulated, and the spatial and temporal distribution rule of microbial cement cement is deduced according to microbial cement bonding images in different time periods, so that more effective mechanism research is provided for microbial cement bonding.

Description

Technical Field

[0001] The invention belongs to the technical field of experimental equipment and relates to a device and method for visualizing the spatiotemporal evolution law of microbial cement in a simulated oil reservoir environment. Background Art

[0002] As an important biomimetic material, microbial cement has attracted wide attention from all walks of life. It is mainly produced through the microbial induced calcium carbonate precipitation (MICP) process, which can realize the in-situ utilization of calcium and magnesium ions. In the 1990s, researchers realized that biomineralization could be used to plug oil layer cracks and improve oil recovery, and microbial cement produced by biomineralization began to attract people's attention.

[0003] At present, the research on microbial cement bonding at home and abroad mainly consists of microbial physical and chemical experiments and model experiments, which have their own focuses and complement each other. Microbial physical and chemical experiments are mainly carried out in solutions, focusing on the dynamics of the physical and chemical parameters of the solution, while model experiments are mainly used for reinforcement methods, focusing on the study of pore blockage and cemented soil. However, there is a lack of relevant research on the observation of the spatiotemporal distribution law of microbial cement bonding in actual situations, especially the lack of indoor simulation experimental devices that simulate the real formation environment visualization. Summary of the invention

[0004] The purpose of the present invention is to provide a device and method for visualizing the spatiotemporal evolution of microbial cement in a simulated reservoir environment, which can effectively simulate and observe the spatiotemporal distribution of microbial cement bonding under actual formations, thereby providing a more effective mechanism study on microbial cement bonding.

[0005] To achieve the above purpose, the present invention provides a device and method for visualizing the spatiotemporal evolution of microbial cement in a simulated reservoir environment. The specific technical solution is as follows:

[0006] A device for visualizing the spatiotemporal evolution of microbial cement in a simulated oil reservoir environment, comprising:

[0007] The simulation tube has closed structures at both ends. A rock plate sample is horizontally arranged inside the simulation tube. The rock plate sample divides the interior of the simulation tube into a sealed upper chamber and a sealed lower chamber from top to bottom. An observation window is opened on the top of the simulation tube;

[0008] The first pressurized liquid injection component is connected to the upper chamber and is used to inject the pressurized nutrient solution and microbial liquid into the upper chamber so that the microorganisms perform microbial cement bonding on the rock plate sample;

[0009] The second pressurized liquid injection assembly is connected to the lower chamber and is used to inject pressurized simulated formation fluid into the lower chamber to simulate the actual formation structure in combination with the rock plate sample;

[0010] A temperature control component, used to adjust the temperature inside the simulation tube, thereby simulating the formation temperature;

[0011] The shooting component is arranged on the observation window and is used for shooting the microbial cement bonding images under the simulation of the actual stratum structure in real time. According to the microbial cement bonding images in different time periods, the temporal and spatial distribution law of the microbial cement mud is deduced.

[0012] The present invention is also characterized in that:

[0013] The first pressurized liquid injection component includes:

[0014] The first piston-type intermediate container and the second piston-type intermediate container are arranged at one end of the simulation cylinder, the first piston-type intermediate container and the second piston-type intermediate container are respectively connected to the upper chamber through the first liquid inlet pipe, the first piston-type intermediate container stores nutrient solution, and the second piston-type intermediate container stores microbial liquid;

[0015] The first horizontal flow pump has an output end which is connected to the first piston type intermediate container and the second piston type intermediate container respectively, and is used for pressurizing the interior of the first piston type intermediate container and the interior of the second piston type intermediate container respectively.

[0016] The second pressurized liquid injection component includes:

[0017] A third piston-type intermediate container is arranged at the other end of the simulation cylinder, the third piston-type intermediate container is connected with the lower chamber through the second liquid inlet pipe, and simulated formation fluid is stored in the third piston-type intermediate container;

[0018] The second horizontal flow pump has an output end connected to the interior of the third piston type intermediate container and is used to pressurize the interior of the third piston type intermediate container.

[0019] The temperature control components include:

[0020] The thermostatic box, the simulation cylinder, the first piston type intermediate container, the second piston type intermediate container and the third piston type intermediate container are all arranged in the thermostatic box.

[0021] The shooting components include:

[0022] At least one high-definition endoscope, disposed on the observation window, for taking images of microbial cement bonding in real time;

[0023] The display terminal is electrically connected to the high-definition endoscope and is used to receive the image of microbial cement bonding sent by the high-definition endoscope and display the image of microbial cement bonding in real time.

[0024] The rock plate sample is connected to the inner wall of the simulation cylinder through a confining pressure sealing structure, and the confining pressure sealing structure includes:

[0025] Two confining pressure sleeves are made of plate-shaped rubber material, and the two confining pressure sleeves are relatively vertically arranged at the two ends of the rock plate sample and are in contact with the two ends of the rock plate sample respectively. First grooves are respectively opened at positions near the two ends of the rock plate sample in the simulation cylinder, and the two confining pressure sleeves are respectively arranged in the two first grooves, and the edge of each confining pressure sleeve is connected to the inner wall of the corresponding first groove;

[0026] Two connecting sleeves are made of strip-shaped rubber material. The two connecting sleeves are relatively horizontally arranged between the two confining pressure sleeves and are respectively located on both sides of the rock plate sample. Each connecting sleeve is connected to the inner wall of the simulation cylinder at the side away from the rock plate sample. Each connecting sleeve is horizontally provided with a second groove at a position close to the rock plate sample. The two sides of the rock plate sample are respectively located in the corresponding second grooves. The two ends of each connecting sleeve pass through the two connecting sleeves and are respectively fixedly connected to the connecting sleeves. The interior of each connecting sleeve is hollow and both ends are open structures.

[0027] The output end of the third advection pump is connected to the first groove close to the first liquid inlet pipe through the third liquid inlet pipe, and the third advection pump is used to transport the confining pressure liquid into the corresponding first groove.

[0028] A method for visualizing the spatiotemporal evolution of microbial cement in a simulated reservoir environment comprises the following steps:

[0029] Select rock samples, measure the size, initial porosity and permeability of the rock samples, obtain rock samples that meet the requirements, perform CT scanning on the rock samples, install the rock samples in the simulation cylinder and seal them through the confining pressure sealing structure, and adjust the internal temperature of the simulation cylinder to the simulated formation temperature through the temperature control component;

[0030] Injecting microbial liquid into the upper chamber through the first pressurized liquid injection component, and after a period of time, injecting nutrients into the upper chamber through the first pressurized liquid injection component, and injecting simulated formation fluid into the lower chamber through the second pressurized liquid injection component;

[0031] By taking real-time images of microbial cement bonding in simulated actual stratum structures, the temporal and spatial distribution of microbial cement sludge is deduced based on the images of microbial cement bonding in different time periods. When the experimental period is reached, the simulation experiment ends.

[0032] The rock slab samples after the simulation experiment were CT scanned, and the microbial cement on them was collected and its microscopic morphology was observed by scanning electron microscopy. Then, the porosity and permeability of the rock slab samples after the simulation experiment were measured, and the porosity and permeability of the rock slab samples before and after the simulation experiment were compared with the CT scanning results.

[0033] The nutrient substance is one of urea medium, LB medium and beef extract peptone medium, the microbial liquid is one of urease-producing bacteria, carbonic anhydrase-producing bacteria and urease-producing and carbonic anhydrase-producing bacteria, the simulated formation fluid is one of CaCl2 solution, configured formation water solution and water, and the confining pressure fluid is water.

[0034] The interval between injecting the microbial liquid into the upper chamber through the first pressurized liquid injection component and injecting the nutrients into the upper chamber through the first pressurized liquid injection component is 6 hours to 12 hours, the experimental period is 30 days to 90 days, and the simulated formation temperature is 30°C to 70°C.

[0035] During the process of observing and recording the microbial cement bonding process and the temporal and spatial distribution of the microbial cement bonding, the microbial liquid is injected into the upper chamber 3 to 9 times and the nutrients are injected 3 to 9 times through the first pressurized liquid injection component.

[0036] The device and method for visualizing the spatiotemporal evolution of microbial cement in a simulated reservoir environment of the present invention have the following advantages:

[0037] First, through the cooperation of the simulation tube, the rock plate sample, the observation window, the first pressurized liquid injection component, the second pressurized liquid injection component, the temperature control component and the shooting component, the pressurized nutrient solution and microbial liquid can be injected into the upper chamber through the first pressurized liquid injection component, so that the microorganisms can perform microbial cement bonding on the rock plate sample, and the pressurized simulated formation fluid is injected into the lower chamber through the second pressurized liquid injection component to cooperate with the rock plate sample to simulate the actual formation structure, the internal temperature of the simulation tube is adjusted through the temperature control component to simulate the formation temperature, and the microbial cement bonding image under the simulated actual formation structure is captured in real time through the shooting component. According to the microbial cement bonding images in different time periods, the spatiotemporal distribution law of microbial cement mud is deduced, thereby providing a more effective mechanism study on microbial cement bonding.

[0038] Second, through the cooperation of two confining pressure sleeves, two connecting sleeves and the rock plate sample, the two confining pressure sleeves and two connecting sleeves can be in close contact with the rock plate sample under the action of force, thereby ensuring the sealing of the contact part between the rock plate sample and the fluid and ensuring the accuracy of the experiment.

[0039] Third, through the setting of high-definition endoscope, the changes in the morphology of microbial cement bonding on the rock slab samples can be monitored in real time during the entire experiment, and the spatiotemporal evolution process of microbial cement bonding can be recorded, providing visual research data for the study of the spatiotemporal evolution of microbial cement bonding.

[0040] Fourth, the present invention can be used not only to study the temporal and spatial evolution of microbial cement bonding, but also to other fields, such as microbial cement crack repair, biocemented sand column, etc.

[0041] Fifth, the experimental device of the present invention has a simple structure, reasonable design, and easy operation, and can simulate a temperature of 30 to 70° C. and a pressure of 0 MPa to 20 MPa. BRIEF DESCRIPTION OF THE DRAWINGS

[0042] Figure 1 It is a schematic diagram of the main structure of the present invention;

[0043] Figure 2 It is a right side structural schematic diagram of one of the confining pressure sleeves of the present invention;

[0044] Figure 3 It is a right side structural schematic diagram of another confining pressure sleeve of the present invention.

[0045] Reference numerals:

[0046] 1. Simulation tube; 2. Upper chamber; 3. Lower chamber; 4. First liquid inlet; 5. Second liquid inlet; 6. Third liquid inlet; 7. First liquid outlet; 8. Second liquid outlet; 9. Third liquid outlet; 10. First liquid inlet pipe; 11. Second liquid inlet pipe; 12. Third liquid inlet pipe; 13. First liquid outlet pipe; 14. Second liquid outlet pipe; 15. Third liquid outlet pipe; 16. Confining pressure sleeve; 17. Connecting sleeve; 18. First valve; 19. Second valve Door; 20. Observation port; 21. Glass plate; 22. High-definition endoscope; 23. First piston-type intermediate container; 24. Second piston-type intermediate container; 25. Third piston-type intermediate container; 26. First horizontal flow pump; 27. Second horizontal flow pump; 28. Third horizontal flow pump; 29. ​​Information processor; 30. Pressure sensor; 31. Constant temperature box; 32. Rock plate sample; 33. First groove; 34. Display terminal; 35. Second groove. DETAILED DESCRIPTION

[0047] The technical solution in the present application will be described clearly and in detail below in conjunction with the accompanying drawings. Among them, in the description of the embodiments of the present application, unless otherwise specified, " / " means or, for example, A / B can mean A or B: "and / or" in the text is only a description of the association relationship of associated objects, indicating that there can be three relationships, such as A and / or B, which can mean: A exists alone, A and B exist at the same time, and B exists alone. In addition, in the description of the embodiments of the present application, "multiple" refers to two or more than two. The following terms "first" and "second" are used for descriptive purposes only and cannot be understood as implying or suggesting relative importance or implicitly indicating the number of technical features indicated. Therefore, the features defined as "first" and "second" may explicitly or implicitly include one or more of the features.

[0048] like Figure 1As shown, the present invention provides a visualization device for the spatiotemporal evolution law of microbial cement in a simulated reservoir environment, comprising a simulation tube 1, a first pressurized liquid injection component, a second pressurized liquid injection component, a temperature control component and a shooting component. The simulation tube 1 is horizontally arranged, and both ends of the simulation tube 1 are closed structures. A rock plate sample 32 is horizontally arranged inside the simulation tube 1. The rock plate sample 32 divides the interior of the simulation tube 1 from top to bottom into a sealed upper chamber 2 and a sealed lower chamber 3, so that the upper chamber 2 and the lower chamber 3 are independent of each other and are respectively in a closed state. An observation window is opened on the upper part of the simulation tube 1, and the first pressurized liquid injection component is connected to the upper chamber 2. The first pressurized liquid injection component is used to inject pressurized nutrient solution and microbial bacterial solution into the upper chamber 2, so that the microorganisms perform microbial cement bonding on the rock plate sample 32. The second pressurized liquid injection component is connected to the The lower chamber 3 is connected, and the second pressurized liquid injection component is used to inject the pressurized simulated formation fluid into the lower chamber 3 to cooperate with the rock plate sample 32 to simulate the actual formation structure. The temperature control component is used to adjust the internal temperature of the simulation tube 1 to simulate the formation temperature. The shooting component is set on the observation window. The shooting component is used to take real-time images of microbial cement bonding under the simulated actual formation structure. According to the microbial cement bonding images in different time periods, the spatiotemporal distribution law of microbial cement mud is deduced. Therefore, through the cooperation of the simulation tube 1, the rock plate sample 32, the observation window, the first pressurized liquid injection component, the second pressurized liquid injection component, the temperature control component and the shooting component, the spatiotemporal distribution law of microbial cement bonding under the actual formation can be effectively simulated and observed, thereby providing a more effective mechanism study on microbial cement bonding.

[0049] like Figure 1 As shown, the observation window includes an observation port 20 and a glass plate 21. The observation port 20 is opened at the upper part of the simulation tube 1. The glass plate 21 is horizontally arranged at the observation port 20. The observation port 20 is connected to the upper chamber 2. The glass plate 21 is horizontally arranged in the observation port 20. The edge of the glass plate 21 is fixed and sealed to the inner wall of the observation port 20.

[0050] like Figure 1As shown, the first pressurized liquid injection component includes a first piston-type intermediate container 23, a second piston-type intermediate container 24 and a first horizontal flow pump 26. The first piston-type intermediate container 23 and the second piston-type intermediate container 24 are arranged at one end of the simulation cylinder 1. The first piston-type intermediate container 23 and the second piston-type intermediate container 24 are respectively connected to the upper chamber 2 through the first liquid inlet pipe 10. The first piston-type intermediate container 23 stores nutrient solution, and the second piston-type intermediate container 24 stores microbial liquid. The output end of the first horizontal flow pump 26 is respectively connected to the first piston-type intermediate container 23 and the second piston-type intermediate container 24. The first horizontal flow pump 26 is used to pressurize the inside of the first piston-type intermediate container 23 and the inside of the second piston-type intermediate container 24, so that the nutrient solution in the first piston-type intermediate container 23 and the microbial liquid in the second piston-type intermediate container 24 can be respectively injected into the upper chamber 2, and the nutrient solution and the microbial liquid are kept at a certain pressure in the upper chamber 2.

[0051] like Figure 1 As shown, the second pressurized liquid injection assembly includes a third piston-type intermediate container 25 and a second horizontal flow pump 27. The third piston-type intermediate container 25 is arranged at the other end of the simulation cylinder 1. The third piston-type intermediate container 25 is connected to the lower chamber 3 through the second liquid inlet pipe 11. The third piston-type intermediate container 25 stores simulated formation fluid. The output end of the second horizontal flow pump 27 is connected to the interior of the third piston-type intermediate container 25. The second horizontal flow pump 27 is used to pressurize the interior of the third piston-type intermediate container 25, so that the simulated formation fluid in the third piston-type intermediate container 25 is injected into the lower chamber 3, and the simulated formation fluid maintains a certain pressure in the lower chamber 3.

[0052] like Figure 1 As shown, the temperature control component includes a constant temperature box 31, and the simulation cylinder 1, the first piston type intermediate container 23, the second piston type intermediate container 24 and the third piston type intermediate container 25 are all arranged in the constant temperature box 31, and the temperature inside the simulation cylinder 1 is adjusted by the constant temperature box 31.

[0053] like Figure 1 , Figure 2 , Figure 3 As shown, the shooting component includes two high-definition endoscopes 22, each with a resolution of 20 million pixels. The two high-definition endoscopes 22 are arranged on the glass plate 21 and are located close to the two ends of the glass plate 21. The two high-definition endoscopes 22 are used to capture images of microbial cement bonding in real time. The display terminal 34 is electrically connected to the two high-definition endoscopes 22. The display terminal 34 is used to receive the images of microbial cement bonding sent by the two high-definition endoscopes 22, and display the images of microbial cement bonding in real time, so as to facilitate the observation and recording of the spatiotemporal distribution of microbial cement bonding under the simulation of the actual stratum structure.

[0054] like Figure 1 , Figure 2 , Figure 3 As shown, the rock plate sample 32 is connected to the inner wall of the simulation cylinder 1 through a confining pressure sealing structure, and the confining pressure sealing structure includes two confining pressure sleeves 16, two connecting sleeves 17 and a third horizontal flow pump 28. The two confining pressure sleeves 16 are made of plate-like rubber material. Preferably, each confining pressure sleeve 16 is elliptical. The two confining pressure sleeves 16 are relatively vertically arranged at the two ends of the rock plate sample 32 and are respectively in contact with the two ends of the rock plate sample 32. The simulation cylinder 1 is provided with first grooves 33 near the two ends of the rock plate sample 32. The first grooves 33 are elliptical. The sleeves 16 are respectively arranged in the two first grooves 33, and the edge of each confining pressure sleeve 16 is connected to the inner wall of the corresponding first groove 33, so that a confining pressure cavity is formed between each confining pressure sleeve 16 and the bottom of the corresponding first groove 33, and the confining pressure cavity is a sealing structure. The two connecting sleeves 17 are made of strip rubber material. The two connecting sleeves 17 are relatively horizontally arranged between the two confining pressure sleeves 16 and are respectively located on both sides of the rock plate sample 32. Each connecting sleeve 17 is connected to the inner wall of the simulation tube 1 away from the side of the rock plate sample 32, and each connecting sleeve 17 is close to the rock plate sample 32. A second groove 35 is horizontally provided at the position of the rock plate sample 32, and the two sides of the rock plate sample 32 are respectively located in the corresponding second grooves 35. The two ends of each connecting sleeve 17 pass through the two connecting sleeves 17 and are respectively fixedly connected to the connecting sleeves 17. The interior of each connecting sleeve 17 is hollow and both ends are open structures, so that the two confining pressure chambers are connected through the two connecting sleeves 17. The output end of the third horizontal flow pump 28 is connected to the first groove 33 close to the first liquid inlet pipe 10 through the third liquid inlet pipe 12. The third horizontal flow pump 28 is used to transport the confining pressure liquid into into the corresponding first groove 33, so that the confining pressure fluid flows from one confining pressure chamber through the two connecting sleeves 17 into the other confining pressure chamber at one time, and the pressure generated by the confining pressure fluid makes the two confining pressure sleeves 16 and the two connecting sleeves 17 closely contact with the rock plate sample 32, and fix the rock plate sample 32, thereby separating the upper chamber 2 from the lower chamber 3, making the upper chamber 2 and the lower chamber 3 relatively independent, thereby avoiding the nutrient solution and microbial liquid in the upper chamber 2 and the simulated formation fluid in the lower chamber 3 during the simulation experiment, thereby affecting the simulation experiment.

[0055] like Figure 1As shown, the first liquid inlet 4 and the first liquid outlet 7 are respectively provided at the positions near the upper chamber 2 at both ends of the simulation cylinder 1, one end of the first liquid inlet pipe 10 is connected to the first liquid inlet 4, and the other end of the first liquid inlet pipe 10 is connected to the first piston type intermediate container 23 and the second piston type intermediate container 24 through a three-way pipe, and the first liquid outlet 7 is connected to the first liquid outlet pipe 13, and the second liquid inlet 5 and the second liquid outlet 8 are respectively provided at the positions near the lower chamber 3 at both ends of the simulation cylinder 1, one end of the second liquid inlet pipe 11 is connected to the second liquid inlet 5, and the other end of the second liquid inlet pipe 11 is connected to the third piston type intermediate container 25, and the second liquid outlet 8 is connected to the second liquid outlet pipe 14, and the third liquid inlet 6 and the third liquid outlet 9 are respectively provided at the positions near the two first grooves 33 at both ends of the simulation cylinder 1, one end of the third liquid inlet pipe 12 is connected to the third liquid inlet 6, and the other end of the third liquid inlet pipe 12 is connected to the output end of the third horizontal flow pump 28, and the third liquid outlet The port 9 is connected to the third liquid outlet pipe 15. The first liquid inlet pipe 10, the second liquid inlet pipe 11 and the third liquid inlet pipe 12 are respectively provided with a first valve 18, the first liquid outlet pipe 13, the second liquid outlet pipe 14 and the third liquid outlet pipe 15 are respectively provided with a second valve 19, the first liquid outlet pipe 13, the second liquid outlet pipe 14 and the third liquid outlet pipe 15 are respectively provided with a pressure sensor 30, the three pressure sensors 30 are electrically connected to the information processor 29, the information processor 29 is electrically connected to the display terminal 34, the three pressure sensors 30 are used to respectively detect the pressure in the first liquid outlet pipe 13, the second liquid outlet pipe 14 and the third liquid outlet pipe 15, and feed back the detected pressure information to the information processor 29. After receiving the three pressure information, the information processor 29 converts it into a pressure value, and then sends it to the display terminal 34 for real-time display, so as to monitor the pressure in the first liquid outlet pipe 13, the second liquid outlet pipe 14 and the third liquid outlet pipe 15 in real time.

[0056] The pressure applied by the first advection pump 26, the second advection pump 27, and the third advection pump 28 is in the range of 0 MPa to 20 MPa, so that the simulated pressure of the entire device is 0 MPa to 20 MPa.

[0057] like Figure 1 , Figure 2 , Figure 3 As shown, the present invention also provides a method for visualizing the spatiotemporal evolution law of microbial cement in a simulated reservoir environment, comprising the following steps:

[0058] Select a rock plate sample 32, measure the size, initial porosity and permeability of the rock plate sample 32, obtain a rock plate sample 32 that meets the requirements, perform a CT scan on the rock plate sample 32, then install the rock plate sample 32 in the simulation tube 1 and seal it through the confining pressure sealing structure, and adjust the internal temperature of the simulation tube 1 to the simulated formation temperature through the temperature control component;

[0059] The microbial liquid is injected into the upper chamber 2 through the first pressurized liquid injection component. After a period of time, the nutrients are injected into the upper chamber 2 through the first pressurized liquid injection component, and the simulated formation fluid is injected into the lower chamber 3 through the second pressurized liquid injection component.

[0060] By taking real-time images of microbial cement bonding in simulated actual stratum structures, the temporal and spatial distribution of microbial cement sludge is deduced based on the images of microbial cement bonding in different time periods. When the experimental period is reached, the simulation experiment ends.

[0061] After the simulation experiment, the rock plate sample 32 was CT scanned, and the microbial cement on it was collected to observe its microscopic morphology by scanning electron microscopy. Then, the porosity and permeability of the rock plate sample 32 after the simulation experiment were measured, and the porosity and permeability of the rock plate sample 32 before and after the simulation experiment were compared with the CT scanning results.

[0062] Among them, the nutrient substance is one of urea medium, LB medium and beef extract peptone medium, LB medium is the abbreviation of Luria-Bertani medium, and its full Chinese name is Luria-Bertani medium, the microbial culture liquid is one of urease-producing bacteria, carbonic anhydrase-producing bacteria and urease-producing carbonic anhydrase-producing bacteria, the simulated formation fluid is one of CaCl2 solution, formation water solution and water, and the confining pressure fluid is water. The injection fluid in the present invention can be adjusted according to demand, including formation fluids with different mineralization, different fungi, different bacterial concentrations and different nutrients, etc., which has important research value for studying microbial cement bonding.

[0063] Among them, the interval between injecting the microbial liquid into the upper chamber 2 through the first pressurized liquid injection component and injecting the nutrients into the upper chamber 2 through the first pressurized liquid injection component is 6 hours to 12 hours, the experimental period is 30 days to 90 days, and the simulated formation temperature is 30°C to 70°C.

[0064] In the process of observing and recording the microbial cement bonding process and the temporal and spatial distribution of the microbial cement bonding process, the microbial liquid is injected into the upper chamber 2 3 to 9 times and the nutrients are injected 3 to 9 times through the first pressurized liquid injection component.

[0065] Among them, the simulation experiment is carried out under corresponding aerobic or anaerobic conditions according to the type of microorganism.

[0066] When conducting simulation experiments:

[0067] A rock sample 32 is selected, and the size, initial porosity and permeability of the rock sample 32 are measured to obtain a rock sample 32 that meets the requirements. The rock sample 32 is CT scanned, and then the rock sample 32 is installed in two confining pressure sleeves 16 and two connecting sleeves 17. The temperature of the constant temperature box 31 is adjusted to the simulated formation temperature, so that the simulated formation is maintained at 30°C to 70°C.

[0068] Open the first valve 18 on the third liquid inlet pipe 12, the second valve 19 on the third liquid outlet pipe 15, and the third horizontal flow pump 18, and inject water into the two first grooves 33 and the two connecting sleeves 17. The pressure of the confining pressure liquid makes the two confining pressure sleeves 16 and the two connecting sleeves 17 closely contact with the rock plate sample 32. When water appears in the third liquid outlet pipe 15, close the second valve 19 on the third liquid outlet pipe 15, and keep the water at sufficient pressure through the third horizontal flow pump 18.

[0069] Inject one of urea culture medium, LB culture medium and beef extract peptone culture medium as nutrients into the first piston-type intermediate container 23, inject one of urease-producing bacteria, carbonic anhydrase-producing bacteria and urease-producing carbonic anhydrase-producing bacteria as microbial liquid into the second piston-type intermediate container 24, inject CaCl2 solution, one of the prepared formation water solution and water as simulated formation fluid into the third piston-type intermediate container 25, open the first valve 18 on the first liquid inlet pipe 10, the second valve 19 on the first liquid outlet pipe 13, the second piston-type intermediate container 24 and the first horizontal flow pump 26, pressurize the microbial liquid in the second piston-type intermediate container 24 and inject it into the upper chamber 2, and after the microbial liquid appears in the first liquid outlet pipe 13, close the first liquid outlet pipe 13. 13 and the first horizontal flow pump 26, after an interval of 12 hours, open the first valve 18 on the first liquid inlet pipe 10, the second valve 19 on the first liquid outlet pipe 13, the first valve 18 on the second liquid inlet pipe 11, the second valve 19 on the second liquid outlet pipe 14, the first piston-type intermediate container 23, the third piston-type intermediate container 25, the first horizontal flow pump 26 and the second horizontal flow pump 28, and inject nutrients into the upper chamber 2 and simulated formation fluid into the lower chamber 3. After nutrients appear in the first liquid outlet pipe 13 and simulated formation fluid appears in the second liquid outlet pipe 14, close the second valve 19 on the first liquid outlet pipe 13, the second valve 19 on the second liquid outlet pipe 14, the first horizontal flow pump 26 and the second horizontal flow pump 28.

[0070] The images of microbial growth metabolism and microbial cement bonding process are captured in real time by a high-definition endoscope 22 and transmitted to a display terminal 34 for real-time display. The microbial cement bonding process is observed and recorded. The spatiotemporal distribution of the microbial cement slurry is deduced based on the microbial cement bonding images in different time periods. The process lasts for 30 to 90 days. During this process, microbial liquid is injected into the upper chamber 2 3 to 9 times and nutrients are injected 3 to 9 times through the first horizontal flow pump 26 and the first piston-type intermediate container 23. When the experimental date is reached, the simulation experiment ends.

[0071] After the simulation experiment, the rock plate sample 32 was CT scanned, and the microbial cement on it was collected to observe its microscopic morphology by scanning electron microscopy. Then, the porosity and permeability of the rock plate sample 32 after the simulation experiment were measured, and the porosity and permeability of the rock plate sample 32 before and after the simulation experiment were compared with the CT scanning results.

[0072] It is to be understood that the present invention is described by some embodiments, and it is known to those skilled in the art that various changes or equivalent substitutions may be made to these features and embodiments without departing from the spirit and scope of the present invention. In addition, under the teachings of the present invention, these features and embodiments may be modified to adapt to specific circumstances and materials without departing from the spirit and scope of the present invention. Therefore, the present invention is not limited by the specific embodiments disclosed herein, and all embodiments falling within the scope of the claims of this application are within the scope of protection of the present invention.

Claims

1. A device for visualizing the spatiotemporal evolution of microbial cement in a simulated oil reservoir environment, characterized in that: include: The simulation tube (1) has closed structures at both ends. A rock plate sample (32) is horizontally arranged inside the simulation tube (1). The rock plate sample (32) divides the interior of the simulation tube (1) from top to bottom into a sealed upper chamber (2) and a sealed lower chamber (3). An observation window is provided at the top of the simulation tube (1); A first pressurized liquid injection component is connected to the upper chamber (2) and is used to inject pressurized nutrient solution and microbial liquid into the upper chamber (2), so that the microorganisms perform microbial cement bonding on the rock plate sample (32); A second pressurized liquid injection assembly is connected to the lower chamber (3) and is used to inject pressurized simulated formation fluid into the lower chamber (3) to simulate the actual formation structure in combination with the rock plate sample (32); A temperature control component, used to adjust the internal temperature of the simulation tube (1) so as to simulate the formation temperature; The shooting component is arranged on the observation window and is used for shooting the microbial cement bonding images under the simulation of the actual stratum structure in real time. According to the microbial cement bonding images in different time periods, the temporal and spatial distribution law of the microbial cement mud is deduced.

2. The device for visualizing the spatiotemporal evolution of microbial cement in a simulated reservoir environment according to claim 1, characterized in that: The first pressurized liquid injection component comprises: A first piston-type intermediate container (23) and a second piston-type intermediate container (24) are arranged at one end of the simulation cylinder (1); the first piston-type intermediate container (23) and the second piston-type intermediate container (24) are respectively connected to the upper chamber (2) through a first liquid inlet pipe (10); a nutrient solution is stored in the first piston-type intermediate container (23), and a microbial liquid is stored in the second piston-type intermediate container (24); The first horizontal flow pump (26) has an output end which is respectively connected to the first piston type intermediate container (23) and the second piston type intermediate container (24) and is used to pressurize the interior of the first piston type intermediate container (23) and the interior of the second piston type intermediate container (24).

3. The device for visualizing the spatiotemporal evolution of microbial cement in a simulated reservoir environment according to claim 1, characterized in that: The second pressurized liquid injection component comprises: A third piston-type intermediate container (25) is arranged at the other end of the simulation cylinder (1), the third piston-type intermediate container (25) is connected to the lower chamber (3) via a second liquid inlet pipe (11), and the third piston-type intermediate container (25) stores simulated formation fluid; The second horizontal flow pump (27) has an output end connected to the interior of the third piston type intermediate container (25) and is used to pressurize the interior of the third piston type intermediate container (25).

4. The device for visualizing the spatiotemporal evolution of microbial cement in a simulated reservoir environment according to claim 1, characterized in that: The temperature control assembly comprises: A thermostatic box (31), wherein the simulation cylinder (1), the first piston-type intermediate container (23), the second piston-type intermediate container (24) and the third piston-type intermediate container (25) are all arranged in the thermostatic box (31).

5. The device for visualizing the spatiotemporal evolution of microbial cement in a simulated reservoir environment according to claim 1, characterized in that: The shooting component comprises: At least one high-definition endoscope (22), arranged in the observation window, for taking images of microbial cement bonding in real time; The display terminal (34) is electrically connected to the high-definition endoscope (22) and is used to receive the image of the microbial cement cementation sent by the high-definition endoscope (22) and display the image of the microbial cement cementation in real time.

6. The device for visualizing the spatiotemporal evolution of microbial cement in a simulated reservoir environment according to claim 1, characterized in that: The rock plate sample (32) is connected to the inner wall of the simulation cylinder (1) via a confining pressure sealing structure, and the confining pressure sealing structure comprises: Two confining pressure sleeves (16) are made of plate-shaped rubber material. The two confining pressure sleeves (16) are relatively vertically arranged at the two ends of the rock plate sample (32) and are respectively in contact with the two ends of the rock plate sample (32). First grooves (33) are respectively opened in the simulation cylinder (1) near the two ends of the rock plate sample (32). The two confining pressure sleeves (16) are respectively arranged in the two first grooves (33), and the edge of each confining pressure sleeve (16) is connected to the inner wall of the corresponding first groove (33); Two connecting sleeves (17) are made of strip-shaped rubber material. The two connecting sleeves (17) are relatively horizontally arranged between the two confining pressure sleeves (16) and are respectively located on both sides of the rock plate sample (32). The side of each connecting sleeve (17) away from the rock plate sample (32) is connected to the inner wall of the simulation cylinder (1). A second groove (35) is horizontally opened at a position of each connecting sleeve (17) close to the rock plate sample (32). The two side surfaces of the rock plate sample (32) are respectively located in the corresponding second grooves (35). The two ends of each connecting sleeve (17) respectively pass through the two connecting sleeves (17) and are respectively fixedly connected to the connecting sleeves (17). The interior of each connecting sleeve (17) is hollow and both ends are open structures. The output end of the third horizontal flow pump (28) is connected to the first groove (33) close to the first liquid inlet pipe (10) through the third liquid inlet pipe (12), and the third horizontal flow pump (28) is used to transport the confining pressure liquid into the corresponding first groove (33).

7. A method for visualizing the spatiotemporal evolution of microbial cement in a simulated reservoir environment, characterized in that: The device for visualizing the spatiotemporal evolution of microbial cement in a simulated reservoir environment as claimed in claim 1 comprises the following steps: Selecting a rock plate sample (32), measuring the size, initial porosity and permeability of the rock plate sample (32), obtaining a rock plate sample (32) that meets the requirements, performing a CT scan on the rock plate sample (32), installing the rock plate sample (32) in a simulation tube (1) and sealing it through a confining pressure sealing structure, and adjusting the internal temperature of the simulation tube (1) to a simulated formation temperature through a temperature control component; Injecting microbial liquid into the upper chamber (2) through a first pressurized liquid injection component, and after a period of time, injecting nutrients into the upper chamber (2) through the first pressurized liquid injection component, and injecting simulated formation fluid into the lower chamber (3) through a second pressurized liquid injection component; By taking real-time images of microbial cement bonding in simulated actual stratum structures, the temporal and spatial distribution of microbial cement sludge is deduced based on the images of microbial cement bonding in different time periods. When the experimental period is reached, the simulation experiment ends. The rock plate sample (32) after the simulation experiment was completed was subjected to a CT scan, and the microbial cement on it was collected and its microscopic morphology was observed by scanning electron microscopy. The porosity and permeability of the rock plate sample (32) after the simulation experiment were measured, and the porosity and permeability of the rock plate sample (32) before and after the simulation experiment were compared with the CT scanning results.

8. The method for visualizing the spatiotemporal evolution of microbial cement in a simulated reservoir environment according to claim 7, characterized in that: The nutrient substance is one of urea culture medium, LB culture medium and beef extract peptone culture medium, the microbial culture liquid is one of urease-producing bacteria, carbonic anhydrase-producing bacteria and urease-producing and carbonic anhydrase-producing bacteria, the simulated formation fluid is one of CaCl2 solution, configured formation water solution and water, and the confining pressure fluid is water.

9. The method for visualizing the spatiotemporal evolution of microbial cement in a simulated reservoir environment according to claim 7, characterized in that: The interval between injecting the microbial liquid into the upper chamber (2) through the first pressurized liquid injection component and injecting the nutrients into the upper chamber (2) through the first pressurized liquid injection component is 6 hours to 12 hours, the experimental period is 30 days to 90 days, and the simulated formation temperature is 30° C. to 70° C.

10. The method for visualizing the spatiotemporal evolution of microbial cement in a simulated reservoir environment according to claim 7, characterized in that: During the process of observing and recording the microbial cement bonding process and the temporal and spatial distribution of the microbial cement bonding, the microbial liquid is injected into the upper chamber (2) 3 to 9 times and the nutrient material is injected 3 to 9 times through the first pressurized liquid injection component.

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