Dynamic gelling evaluation device and method for simulating stratum seepage characteristics

Abstract

The invention discloses a dynamic gelling evaluation device and method for simulating stratum seepage characteristics, the dynamic gelling evaluation device comprises an injection pump, an intermediate container, a vacuumizing bottle and a saturation container, the injection pump is sequentially connected with the intermediate container, a valve and a core holder, the saturation container and the vacuumizing bottle are respectively connected with the core holder through the valve, and the vacuumizing bottle is connected with the vacuumizing pump and a pressure gauge. A pressure monitoring device is arranged on the core holder, and the core holder is respectively connected with the back pressure pump, the collecting container and the output fluid weighing device through valves. The output fluid weighing device is connected with one end of the circulating pump, the other end of the circulating pump is connected with the injection pipeline, and the whole device is arranged in a drying oven. According to the method, the gel forming state of the gel is observed in real time, cyclic utilization of the gel is achieved, meanwhile, different oil reservoir parameter conditions are set according to requirements, the seepage characteristics and dynamic gel forming characteristics of the gel system under the conditions of oil reservoir temperature, pressure and oil-water distribution are simulated, and online monitoring and evaluation of the strength of the gel system at different stages are achieved.

Description

Technical Field

[0001] The invention belongs to the technical field of oil extraction, and in particular relates to a dynamic gelation evaluation device and method for simulating formation seepage characteristics. Background Art

[0002] As water-flooded oilfields enter the high-water-cut stage, oil production continues to decline while water content continues to rise. This leads to increasingly strong reservoir heterogeneity, seriously impacting development effectiveness. By injecting a gel system into the formation, a cross-linking reaction occurs over time, transforming it into a very strong gel state that seals the large pores in the formation.

[0003] The gel system is generally composed of polymers, cross-linking agents, water and coagulants in a certain proportion. After configuration, the gel system gradually becomes viscous and gradually becomes a gel after a period of time at a certain temperature.

[0004] Currently, gelation performance is mostly evaluated indoors using static and dynamic methods. The static method involves preparing a gel system at a certain concentration, placing it in an oven set to reservoir temperature, and observing and measuring the gel system at regular intervals. The dynamic method involves injecting a prepared gel system into the core, closing the inlet and outlet, and waiting for a period of time. The change in resistance coefficient before and after the gelation is measured to determine the gelation time and strength.

[0005] Field applications have shown significant differences between the gelation patterns of gel systems in reservoirs and the performance patterns of gels evaluated in laboratory experiments. This is because, in actual field applications, the gel system injected into the subsurface is in a state of continuous flow, rather than remaining stationary upon injection into the formation. This discrepancy between laboratory experiments and actual field conditions affects performance optimization and dosage selection of the gel system, thereby reducing the effectiveness of field profile control. Therefore, it is essential to design a device and method that can simulate the formation environment and evaluate the dynamic gelation performance of the gel.

[0006] Currently, there are few dynamic gelation evaluation devices and methods that simulate formation seepage characteristics. Indoor dynamic and static evaluation methods are generally used. These methods cannot simulate the impact of formation fluids beneath oil formations on gel systems; cannot simulate the seepage characteristics of gel systems under formation conditions; cannot simulate the dynamic gelation performance of gel systems under formation conditions; and cannot simulate the strength measurement of gel systems at different stages under formation conditions. Summary of the Invention

[0007] The problem to be solved by the present invention is to provide a dynamic gelation evaluation device and method that simulates the seepage characteristics of the formation. The device and method can simulate the influence of the formation fluid on the gel system under formation conditions; can simulate the seepage characteristics of the gel system under formation conditions; can simulate the dynamic gelation performance of the gel system under formation conditions; and can simulate the strength measurement of the gel system at different stages under formation conditions.

[0008] In order to solve the above technical problems, the technical solution adopted by the present invention is: a dynamic gelation evaluation device for simulating formation seepage characteristics, including an injection system, a model system, a measurement system and a collection circulation system.

[0009] The injection system includes an injection pump, an intermediate container, a vacuum bottle and a saturation container. The injection pump is connected to the intermediate container and then connected to the first end of the model system through a first valve. The saturation container is connected to the second end of the model system through a second valve. The vacuum bottle is connected to the third end of the model system through a third valve. The vacuum bottle is connected to the vacuum pump and a pressure gauge.

[0010] The model system includes a core holder and a back pressure pump, the core holder is provided with a pressure monitoring device, the fourth end of the model system is connected to the back pressure pump via a fourth valve, the fifth end of the model system is connected to the measurement system via a fifth valve, and the sixth end of the model system is connected to the collection circulation system via a sixth valve;

[0011] The measuring system includes a collection container, a collection probe is provided in the collection container, and the collection probe is connected to a digital display meter;

[0012] The collection circulation system includes an output fluid weigher, the output fluid weigher is connected to one end of a circulation pump, and the other end of the circulation pump is connected to the injection system;

[0013] The injection system, the model system, the measurement system and the collection circulation system are all placed in an oven.

[0014] Furthermore, the intermediate container includes a formation water intermediate container, a simulated oil intermediate container and a gel system intermediate container connected in parallel. The formation water intermediate container is connected to the core clamp through a seventh valve, the simulated oil intermediate container is connected to the core clamp through an eighth valve, and the gel system intermediate container is connected to the core clamp through a ninth valve.

[0015] Furthermore, the present invention also provides a dynamic gelation evaluation method for simulating formation seepage characteristics, using the above-mentioned dynamic gelation evaluation device for simulating formation seepage characteristics, comprising the following steps:

[0016] S1: Establishing the negative pressure vacuum state of the model system;

[0017] S2: Complete the core saturation work;

[0018] S3: Simulate and establish the oil and water distribution pattern under formation conditions;

[0019] S4: establish the cycle of the gel system;

[0020] S5: Make the subsequent system flow to the collection circulation system.

[0021] Furthermore, the S1 includes the following steps:

[0022] S11: Open the third valve and start the vacuum pump to make the pressure gauge display a negative pressure state;

[0023] S12: The model system is set up in a negative pressure vacuum state by pumping the vacuum bottle and working under negative pressure for 8 hours.

[0024] Furthermore, the S2 includes the following steps:

[0025] S21: closing the third valve, closing the vacuum pump, and opening the second valve to allow the saturated container to self-absorb into the model system;

[0026] S22: After the liquid level in the saturated container stabilizes, close the second valve;

[0027] S23: opening the seventh valve and the first valve, starting the injection pump, and displacing the water in the formation water intermediate container into the model system;

[0028] S23: Open the sixth valve, wait for the outlet liquid to flow to the output fluid weigher and stabilize, then weigh the core holder to complete the core saturation work.

[0029] Furthermore, the S3 includes the following steps:

[0030] S31: closing the seventh valve, opening the eighth valve, and starting the injection pump to displace the oil in the simulated oil intermediate container into the model system;

[0031] S32: After the outlet liquid flows to the output fluid weigher and stabilizes, the saturated oil volume is calculated;

[0032] S32: Close the eighth valve, open the seventh valve, start the injection pump, displace the water in the formation water intermediate container into the model system, and stop the experiment after the outlet liquid flows to the output fluid weigher through the core clamp and reaches the formation water content condition.

[0033] Furthermore, the S4 includes the following steps:

[0034] S41: placing the gel system to be used into the gel system intermediate container;

[0035] S42: Open the ninth valve, start the injection pump, and displace the gel system in the intermediate container into the core holder;

[0036] S43: Open the fourth valve, simulate the formation pressure through the back pressure pump, and after the outlet fluid shows a stable gel system output, stop the injection pump and close the ninth valve;

[0037] S44: Start the circulation pump to displace the gel system in the produced fluid weigher into the core holder to achieve the oil-water distribution pattern under formation conditions.

[0038] Furthermore, the S5 includes the following steps:

[0039] S51: closing the sixth valve, opening the fifth valve, and allowing the gel system to flow into the collection container;

[0040] S52: The data is transmitted to the digital display through the acquisition probe to monitor the strength of the gel system in real time;

[0041] S53: After the monitoring is completed, the fifth valve is closed and the sixth valve is opened to allow the subsequent system to flow into the collection circulation system.

[0042] The advantages and positive effects of the present invention are:

[0043] 1. The present invention simulates the impact of oil-water distribution in the formation on the gel system, solving the problem of large differences between on-site gelation and indoor evaluation. It simulates the seepage characteristics of the gel system under formation conditions, solving the problem that traditional evaluation methods are unable to monitor its seepage characteristics during the gelation process. It simulates the dynamic gelation performance evaluation under reservoir conditions, solving the problem that traditional evaluation methods are unable to achieve dynamic gelation performance evaluation. It simulates the strength measurement of the gel system at different stages under formation conditions, monitors and evaluates the gel strength system in real time, solving the problem that traditional methods are unable to achieve dynamic gelation performance measurement. According to the experimental plan and experimental requirements, different reservoir parameter conditions are set, and the gelation of the gel system during deep migration in the formation is simulated through the circulation acquisition system, and the gelation time in the real formation is predicted, solving the problem that traditional methods cannot simulate the field.

[0044] 2. The present invention realizes the recycling of gel, avoids the use of a large amount of gel system, and also avoids tedious operations such as replacing intermediate containers, without the need to disassemble and assemble the model multiple times; there is no need to replace the intermediate container; it can simulate the dynamic gelation performance evaluation under reservoir conditions; it can monitor and evaluate the gel strength system in real time; through the test of the strength of the gel system at different stages, it can infer the actual formation gelation time, gelation distance, sealing performance after gelation, and seepage capacity, providing technical support for the subsequent adjustment of the plan. BRIEF DESCRIPTION OF THE DRAWINGS

[0045] Figure 1 It is a schematic diagram of the overall structure of an embodiment of the device of the present invention.

[0046] Figure 2 It is an overall flow chart of an embodiment of the method of the present invention.

[0047] In the picture:

[0048] 1. Injection pump; 2. Seventh valve; 3. Eighth valve;

[0049] 4. The ninth valve; 5. Formation water intermediate container; 6. Simulated oil intermediate container;

[0050] 7. Gel system intermediate container; 8. First valve; 9. Second valve;

[0051] 10. Third valve; 11. Oven; 12. Vacuum bottle;

[0052] 13. Vacuum pump; 14. Pressure gauge; 15. Saturation container;

[0053] 16. Core holder; 17. Pressure monitoring; 18. Fourth valve;

[0054] 19. Back pressure pump; 20. Fifth valve; 21. Collection probe;

[0055] 22. Collection container; 23. Digital display; 24. Sixth valve;

[0056] 25. Output fluid weigher; 26. Circulation pump; 27. Injection system;

[0057] 28. Model system; 29. Measurement system; 30. Acquisition circulation system. DETAILED DESCRIPTION

[0058] The technical solution of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the embodiments described are only some embodiments of the present invention, not all embodiments. All other embodiments obtained by ordinary technicians in this field based on the embodiments of the present invention without making any creative efforts shall fall within the scope of protection of the present invention.

[0059] In the description of the present invention, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicating orientations or positional relationships, are based on the orientations or positional relationships shown in the accompanying drawings and are intended solely to facilitate and simplify the description of the present invention. They are not intended to indicate or imply that the devices or components referred to must have, be constructed, or operate in a specific orientation, and therefore should not be construed as limitations on the present invention. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0060] In the description of the present invention, it should be noted that, unless otherwise expressly specified or limited, the terms "mounted," "connected," and "connected" should be understood in a broad sense. For example, they may refer to fixed, detachable, or integral connections; mechanical or electrical connections; direct or indirect connections through an intermediate medium; and internal communication between two components. Those skilled in the art will understand the specific meanings of the above terms in the present invention based on the specific circumstances.

[0061] The embodiments of the present invention are further described below with reference to the accompanying drawings:

[0062] like Figure 1 As shown, a dynamic gelation evaluation device for simulating formation seepage characteristics includes an injection system 27, a model system 28, a measurement system 29 and a collection circulation system 30.

[0063] Among them, the injection system 27 includes an injection pump 1, an intermediate container, a vacuum bottle 12 and a saturation container 15. After the injection pump 1 is connected to the intermediate container, it is connected to the first end of the model system through the first valve 8. The saturation container 15 is connected to the second end of the model system through the second valve 9. The vacuum bottle 12 is connected to the third end of the model system through the third valve 10. The vacuum bottle 12 is connected to the vacuum pump 13 and the pressure gauge 14.

[0064] Preferably, the intermediate container includes a formation water intermediate container 5, a simulated oil intermediate container 6 and a gel system intermediate container 7 connected in parallel, the formation water intermediate container 5 is connected to the core clamp 16 through the seventh valve 2, the simulated oil intermediate container 6 is connected to the core clamp 16 through the eighth valve 3, and the gel system intermediate container 7 is connected to the core clamp 16 through the ninth valve 4.

[0065] The model system 28 includes a core holder 16 and a back pressure pump 19. The core holder 16 is provided with a pressure monitoring device 17. The fourth end of the model system is connected to the back pressure pump 19 through a fourth valve 18. The fifth end of the model system is connected to the measurement system 29 through a fifth valve 20. The sixth end of the model system is connected to the collection circulation system 30 through a sixth valve 24.

[0066] The measuring system 29 includes a collection container 22 , in which a collection probe 21 is provided. The collection probe 21 is connected to a digital display meter 23 .

[0067] The collection circulation system 30 includes a production fluid weigher 25 , which is connected to one end of a circulation pump 26 , and the other end of the circulation pump 26 is connected to an injection system 27 .

[0068] The injection system 27 , the model system 28 , the measurement system 29 and the collection circulation system 30 are all placed in the oven 11 .

[0069] The device of the present invention can simulate the seepage characteristics and dynamic gelation characteristics of the gel system under the conditions of reservoir temperature, pressure, and oil-water distribution, and can also conduct online monitoring and evaluation of the strength of the gel system at different stages. By testing the strength of the gel system at different stages, the gelation time, gelation distance, sealing performance after gelation, and seepage capacity of the actual formation gel can be calculated, providing technical support for subsequent program adjustments.

[0070] like Figure 2 As shown, the present invention also provides a dynamic gelation evaluation method for simulating formation seepage characteristics, using the above-mentioned dynamic gelation evaluation device for simulating formation seepage characteristics, including the following steps:

[0071] S1: Open the third valve 10, start the vacuum pump 13 to make the pressure gauge 14 display a negative pressure state, and work under negative pressure conditions for 8 hours by vacuuming the vacuum bottle 12 to establish a negative pressure vacuum state in the model system 28.

[0072] S2: Close the third valve 10, turn off the vacuum pump 13, open the second valve 9, and allow the saturation container 15 to self-prime to the model system 28. After the liquid level in the saturation container 15 stabilizes, close the second valve 9, open the seventh valve 2 and the first valve 8, start the injection pump 1, and displace the water in the formation water intermediate container 5 to the model system 28. Open the sixth valve 24, and after the outlet liquid flows to the output fluid weigher 25 and stabilizes, weigh its core clamp 16 to complete the core water saturation work.

[0073] S3: Close the seventh valve 2, open the eighth valve 3, start the injection pump 1, and displace the oil in the simulated oil intermediate container 6 into the model system 28. After the outlet liquid flows to the produced fluid weighing device 25 and stabilizes, calculate the saturated oil volume. Close the eighth valve 3, open the seventh valve 2, start the injection pump 1, and displace the water in the formation water intermediate container 5 into the model system 28. After the outlet liquid flows to the produced fluid weighing device 25 through the core holder and reaches the formation water content, the experiment is terminated to simulate the oil-water distribution pattern under formation conditions.

[0074] S4: The gel system to be used is loaded into the gel system intermediate container 7; the ninth valve 4 is opened, the injection pump 1 is started, and the gel system intermediate container 7 is displaced to the core clamp 16; the fourth valve 18 is opened, and the formation pressure is simulated by the back pressure pump 19. After the outlet fluid shows a stable gel system output, the injection pump 1 is stopped and the ninth valve 4 is closed; the circulation pump 26 is started to displace the gel system in the output fluid weigher 25 to the core clamp 16, so as to realize the oil-water distribution pattern under the formation conditions and establish the circulation of the gel system.

[0075] S5: Close the sixth valve 24, open the fifth valve 20, and let the gel system flow to the collection container 22; transmit the data to the digital display 23 through the collection probe 21 to monitor the strength of the gel system in real time; after the monitoring is completed, close the fifth valve 20, open the sixth valve 24, and let the subsequent system flow to the collection circulation system 30.

[0076] The advantages and positive effects of the present invention are:

[0077] 1. The present invention simulates the impact of oil-water distribution in the formation on the gel system, solving the problem of large differences between on-site gelation and indoor evaluation. It simulates the seepage characteristics of the gel system under formation conditions, solving the problem that traditional evaluation methods are unable to monitor its seepage characteristics during the gelation process. It simulates the dynamic gelation performance evaluation under reservoir conditions, solving the problem that traditional evaluation methods are unable to achieve dynamic gelation performance evaluation. It simulates the strength measurement of the gel system at different stages under formation conditions, monitors and evaluates the gel strength system in real time, solving the problem that traditional methods are unable to achieve dynamic gelation performance measurement. According to the experimental plan and experimental requirements, different reservoir parameter conditions are set, and the gelation of the gel system during deep migration in the formation is simulated through the circulation acquisition system, and the gelation time in the real formation is predicted, solving the problem that traditional methods cannot simulate the field.

[0078] 2. The present invention realizes the recycling of gel, avoids the use of a large amount of gel system, and also avoids tedious operations such as replacing intermediate containers, without the need to disassemble and assemble the model multiple times; there is no need to replace the intermediate container; it can simulate the dynamic gelation performance evaluation under reservoir conditions; it can monitor and evaluate the gel strength system in real time; through the test of the strength of the gel system at different stages, it can infer the actual formation gelation time, gelation distance, sealing performance after gelation, and seepage capacity, providing technical support for the subsequent adjustment of the plan.

[0079] The above is a detailed description of an embodiment of the present invention. However, the content described is only a preferred embodiment of the present invention and should not be considered to limit the scope of the present invention. All equivalent changes and improvements made within the scope of the present invention should still fall within the scope of the patent coverage of the present invention.

Claims

1. A dynamic gelation evaluation device simulating formation seepage characteristics, characterized by: Including injection system, model system, measurement system and collection circulation system, The injection system includes an injection pump, an intermediate container, a vacuum bottle and a saturation container. The injection pump is connected to the intermediate container and then connected to the first end of the model system through a first valve. The saturation container is connected to the second end of the model system through a second valve. The vacuum bottle is connected to the third end of the model system through a third valve. The vacuum bottle is connected to the vacuum pump and a pressure gauge. The model system includes a core holder and a back pressure pump, the core holder is provided with a pressure monitoring device, the fourth end of the model system is connected to the back pressure pump via a fourth valve, the fifth end of the model system is connected to the measurement system via a fifth valve, and the sixth end of the model system is connected to the collection circulation system via a sixth valve; The measuring system includes a collection container, a collection probe is provided in the collection container, and the collection probe is connected to a digital display meter; The collection circulation system includes an output fluid weigher, the output fluid weigher is connected to one end of a circulation pump, and the other end of the circulation pump is connected to the injection system; The injection system, the model system, the measurement system and the collection circulation system are all placed in an oven.

2. A dynamic gelation evaluation device for simulating formation seepage characteristics according to claim 1, characterized in that: The intermediate container includes a formation water intermediate container, a simulated oil intermediate container and a gel system intermediate container connected in parallel. The formation water intermediate container is connected to the core clamp through a seventh valve, the simulated oil intermediate container is connected to the core clamp through an eighth valve, and the gel system intermediate container is connected to the core clamp through a ninth valve.

3. A dynamic gelation evaluation method for simulating formation seepage characteristics, using the dynamic gelation evaluation device for simulating formation seepage characteristics according to claim 1 or 2, characterized in that: The following steps are included: S1: Establishing the negative pressure vacuum state of the model system; S2: Complete the core saturation work; S3: Simulate and establish the oil and water distribution pattern under formation conditions; S4: establish the cycle of the gel system; S5: Make the subsequent system flow to the collection circulation system.

4. A dynamic gelation evaluation method for simulating formation seepage characteristics according to claim 3, characterized in that: Said S1 comprises the following steps, S11: Open the third valve and start the vacuum pump to make the pressure gauge display a negative pressure state; S12: The model system is set up in a negative pressure vacuum state by pumping the vacuum bottle and working under negative pressure for 8 hours.

5. A dynamic gelation evaluation method for simulating formation seepage characteristics according to claim 3 or 4, characterized in that: Said S2 comprises the following steps, S21: closing the third valve, closing the vacuum pump, and opening the second valve to allow the saturated container to self-absorb into the model system; S22: After the liquid level in the saturated container stabilizes, close the second valve; S23: opening the seventh valve and the first valve, starting the injection pump, and displacing the water in the formation water intermediate container into the model system; S23: Open the sixth valve, wait for the outlet liquid to flow to the output fluid weigher and stabilize, then weigh the core holder to complete the core saturation work.

6. A dynamic gelation evaluation method for simulating formation seepage characteristics according to claim 3 or 4, characterized in that: Said S3 comprises the following steps, S31: closing the seventh valve, opening the eighth valve, and starting the injection pump to displace the oil in the simulated oil intermediate container into the model system; S32: After the outlet liquid flows to the output fluid weigher and stabilizes, the saturated oil volume is calculated; S32: Close the eighth valve, open the seventh valve, start the injection pump, displace the water in the formation water intermediate container into the model system, and stop the experiment after the outlet liquid flows to the output fluid weigher through the core clamp and reaches the formation water content condition.

7. A dynamic gelation evaluation method for simulating formation seepage characteristics according to claim 3 or 4, characterized in that: Said S4 comprises the following steps, S41: placing the gel system to be used into the gel system intermediate container; S42: Open the ninth valve, start the injection pump, and displace the gel system in the intermediate container into the core holder; S43: Open the fourth valve, simulate the formation pressure through the back pressure pump, and after the outlet fluid shows a stable gel system output, stop the injection pump and close the ninth valve; S44: Start the circulation pump to displace the gel system in the produced fluid weigher into the core holder to achieve the oil-water distribution pattern under formation conditions.

8. A dynamic gelation evaluation method for simulating formation seepage characteristics according to claim 3 or 4, characterized in that: Said S5 comprises the following steps, S51: closing the sixth valve, opening the fifth valve, and allowing the gel system to flow into the collection container; S52: The data is transmitted to the digital display through the acquisition probe to monitor the strength of the gel system in real time; S53: After the monitoring is completed, the fifth valve is closed and the sixth valve is opened to allow the subsequent system to flow into the collection circulation system.

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