An experimental system for elutriating hydrogen sulfide gas and an experimental method thereof

Abstract

The present invention discloses an experimental system and an experimental method for elutriating hydrogen sulfide gas, which includes: a gripper, one end of the gripper is connected to a third pipeline through a first pipeline, and the other end is connected to a fourth pipeline through a second pipeline; both ends of the third pipeline and the fourth pipeline are respectively connected to a sulfur-containing gas delivery pipeline and a purified gas delivery pipeline, the pipeline between the first pipeline and a third control valve and a fourth control valve is connected, and the pipeline between the second pipeline and a fifth control valve and a sixth control valve is connected; a sampling pipeline is connected to the first pipeline, and a sampling control valve, a pressure regulating valve, a flowmeter, a sampler device and a discharge control valve are connected in series on the sampling pipeline. The experimental system of the present invention can complete hydrogen sulfide production experiments under different injection-production conditions, can reveal the hydrogen sulfide elutriation characteristics and influencing factors of reservoir rocks under multiple cycles, lays an experimental foundation for the reconstruction of sulfur-containing gas reservoirs into gas storage reservoirs, and ensures the consistency between the simulated experimental conditions and the actual conditions of the gas storage reservoir.

Description

Technical Field

[0001] The present invention relates to the technical field of natural gas storage, and particularly to an experimental system for eluting hydrogen sulfide gas and an experimental method thereof. Background Art

[0002] A gas storage reservoir is a gas storage site formed by injecting purified gas (sulfur-free natural gas) into underground traps or artificial caves. It has multiple functions such as seasonal peak shaving, emergency gas supply in case of accidents, and national energy strategic reserve. However, the vast majority of underground natural gas storage reservoirs contain toxic hydrogen sulfide substances and cannot be directly used as storage sites for purified gas. Therefore, it is necessary to elute the hydrogen sulfide in the sulfur-containing gas storage reservoir to reduce the sulfur content of the natural gas in the gas storage reservoir, ensure the mining safety of the gas storage reservoir, and install different desulfurization devices at different wellheads to reduce the cost of secondary mining. The elution experiment is carried out with multi-cycle injection and production, so that the sulfur content in the gas storage reservoir meets the national use standards, ensuring that the sulfur-containing gas storage reservoir becomes a sulfur-free gas storage reservoir and achieving the purpose of reusable.

[0003] Currently, for the existing experimental system for eluting hydrogen sulfide in natural gas for gas storage reservoirs, the system includes an intermediate container, a core holder, a vacuum pump, and a methane storage tank. The intermediate container is used to mix methane and hydrogen sulfide; the core holder is used to hold the core sample; the vacuum pump can make the intermediate container in a vacuum state; the methane storage tank inputs methane into the core holder. The intermediate container inputs methane and hydrogen sulfide for mixing in a vacuum state to form a mixed gas of methane and hydrogen sulfide. After the mixed gas enters the core holder and makes the core sample reach a saturated state, the methane storage tank inputs methane into the core holder to elute the hydrogen sulfide in the core sample. However, this system can only perform simple elution of hydrogen sulfide, cannot control the flow rate and pressure at the sampler outlet, cannot simulate the gas production rate during the mining of the gas storage reservoir, nor can it simulate different injection and production conditions, failing to meet the requirements of simulating on-site conditions in the laboratory; at the same time, due to its own design defects, this system cannot effectively ensure that the physical property parameters of the experimental core are the same as those of the gas storage reservoir. Summary of the Invention

[0004] The invention purpose of the present invention is: aiming at the above problems, to provide an experimental system for eluting hydrogen sulfide gas and an experimental method thereof. The experimental system of the present invention can complete hydrogen sulfide production experiments under different injection and production conditions (simultaneous injection and production, one injection and one production), reveal the characteristics of hydrogen sulfide elution in reservoir rocks under multi-cycles and its influencing factors, and lay an experimental foundation for the reconstruction of sulfur-containing gas reservoirs into gas storage reservoirs, overcoming the deficiencies of the existing hydrogen sulfide elution experimental system.

[0005] The technical solution adopted by the present invention is as follows: An experimental system for eluting hydrogen sulfide gas, which includes:

[0006] A gripper, which is a core gripper with a circular diameter, is used to grip rock samples in a gas storage reservoir. One end of the gripper is connected to a third pipeline through a first pipeline, and the other end is connected to a fourth pipeline through a second pipeline;

[0007] The first pipeline is used to transport sulfur-containing gas, purified gas, and a mixture of the two. A first control valve and an inlet pressure gauge for detecting pipeline pressure are provided on the first pipeline. The two ends of the third pipeline are respectively connected to a sulfur-containing gas transmission pipeline and a purified gas transmission pipeline. A third control valve and a fourth control valve are provided on the third pipeline, and the pipeline between the first pipeline and the third control valve and the fourth control valve is connected;

[0008] The second pipeline is used to transport purified gas and sulfur-containing gas. A second control valve and an outlet pressure gauge for detecting pipeline pressure are provided on the second pipeline. The two ends of the fourth pipeline are respectively connected to a sulfur-containing gas transmission pipeline and a purified gas transmission pipeline. A fifth control valve and a sixth control valve are provided on the fourth pipeline, and the pipeline between the second pipeline and the fifth control valve and the sixth control valve is connected;

[0009] The first pipeline is connected to a sampling pipeline. Along the direction of gas flow in the pipeline, a sampling control valve, a pressure regulating valve, a flowmeter, a sampler device, and a discharge control valve are successively connected in series on the sampling pipeline to sample the mixed gas in the gripper through the sampling pipeline. At the same time, different production times can be simulated through the sampling pipeline to better create an actual production site. Moreover, the sampling device can also collect all the sulfur-containing gas (the volume of the sampler is generally larger than the void volume of the rock in the gripper). The sulfur-containing gas in the system pipeline does not need to be directly discharged, and it will not pollute the surrounding environment.

[0010] Furthermore, the fourth pipeline is connected to a vacuum pump through a vacuum pipeline, and a vacuum control valve is provided on the vacuum pipeline to evacuate the system pipeline through the vacuum pump.

[0011] Furthermore, a pressurization pipeline is respectively connected to the sulfur-containing gas transmission pipeline and the purified gas transmission pipeline. An air compressor, a pressurization control valve, a gas injection pump, and an opening and closing valve are successively connected in series on the pressurization pipeline. The pressurization pipeline respectively pressurizes the air pressure in the sulfur-containing gas transmission pipeline and the purified gas transmission pipeline through the air compressor to supplement the air pressure required for the test.

[0012] Furthermore, the pressurization pipeline is connected to a pressure relief water tank through a pressure relief pipeline, and a pressure relief control valve is provided on the pressure relief pipeline to relieve the pressure of the system pipeline through the pressure relief pipeline. At the same time, harmful gases (i.e., the discharged sulfur-containing gas) can also be absorbed through the pressure relief pipeline, thereby protecting the surrounding environment.

[0013] Further, differential pressure pipelines are also connected to both ends of the gripper. The two ends of the differential pressure pipeline are respectively connected to the first pipeline and the second pipeline. A differential pressure control valve A, a differential pressure control valve B, and a differential pressure control valve C are successively connected in series on the differential pressure pipeline. A differential pressure gauge is also arranged on the differential pressure pipeline. The two ends of the differential pressure gauge are respectively connected to the pipelines at both ends of the differential pressure control valve B.

[0014] Further, the gripper is connected to a confining pressure pump through a confining pressure pipeline. The confining pressure pump applies confining pressure to the gripper to simulate the overlying rock pressure of the reservoir.

[0015] Further, the fourth pipeline is connected to a venting water tank through a venting pipeline (the venting water tank also has the function of absorbing harmful gases, thus protecting the surrounding environment). A venting valve is arranged on the venting pipeline. The system pipeline is depressurized through the venting pipeline.

[0016] Further, one end of the sulfur-containing gas delivery pipeline is connected to a sulfur-containing gas storage device through a first intake valve, and one end of the purified gas delivery pipeline is connected to a purified gas storage device through a second intake valve.

[0017] Further, the present invention also includes an experimental method for an experimental system for elutriating hydrogen sulfide gas. When performing a one-injection-one-production elutriation experiment, the following steps are included:

[0018] A. Place the experimental rock sample into the gripper and load the confining pressure to a set pressure value through the confining pressure pipeline;

[0019] B. Close the first intake valve, the second intake valve, the venting valve, the sixth control valve, the fourth control valve, and the sampling control valve, and open the third control valve, the first control valve, the second control valve, the fifth control valve, the differential pressure control valve A, the differential pressure control valve B, and the differential pressure control valve C;

[0020] C. Open the vacuum control valve of the vacuum pump and evacuate the system pipeline with the vacuum pump;

[0021] D. After the evacuation is completed, close the vacuum control valve and open the first intake valve to allow sulfur-containing natural gas to enter the system. Record the values of the inlet pressure gauge, the differential pressure gauge, and the outlet pressure gauge until the system pressure reaches the set initial pressure; when it is necessary to increase the pressure of the system pipeline, pressurize the system through the pressurization pipeline;

[0022] E. Close the differential pressure control valve B, the first intake valve, the third control valve, the pressure relief control valve, and the fifth control valve. Open the second intake valve and the sixth control valve, and let the purified gas in the purified gas delivery pipeline enter the system pipeline at the designed injection speed. At the same time, detect the change of the pressure readings of the inlet pressure gauge and the outlet pressure gauge over time until the values of the inlet pressure gauge and the outlet pressure gauge reach the set values. Then close the sixth control valve, and let the pressure of the entire system pipeline stabilize for a period of time. When it is necessary to increase the pressure of the system pipeline, pressurize the system through the pressurization pipeline.

[0023] F. Open the sampling control valve and the pressure regulating valve, simulate the production process at the set gas sampling speed. At the same time, at the set cut-off period, sample and analyze by opening the discharge control valve until the system pressure reaches the set pressure value, and record the values of the inlet pressure gauge, the outlet pressure gauge, and the differential pressure gauge at both ends of the gripper during the gas sampling process.

[0024] G. After the experiment is completed, open the differential pressure control valve B, the third control valve, the fifth control valve, and the vent valve, unload the pore pressure and handle the remaining sulfur-containing natural gas in the core system. Close the confining pressure pump and unload the confining pressure.

[0025] H. Repeat the above experimental process, design a comparative experiment using the single variable method, so as to obtain the corresponding experimental results.

[0026] Furthermore, when conducting the simultaneous production and injection elutriation experiment, it includes the following steps:

[0027] S1. Place the experimental rock sample in the gripper and load the confining pressure to the set pressure value through the confining pressure pipeline.

[0028] S2. Close the first intake valve, the second intake valve, the vent valve, the sixth control valve, the fourth control valve, and the sampling control valve. Open the first control valve, the second control valve, the fifth control valve, the differential pressure control valve A, the differential pressure control valve B, and the differential pressure control valve C.

[0029] S3. Open the vacuum control valve of the vacuum pump and evacuate the system pipeline with the vacuum pump.

[0030] S4. After the evacuation is completed, close the vacuum control valve and open the first intake valve to let the sulfur-containing natural gas enter the system. Record the values of the inlet pressure gauge, the differential pressure gauge, and the outlet pressure gauge until the system pressure reaches the set initial pressure. When it is necessary to increase the pressure of the system pipeline, pressurize the system through the pressurization pipeline.

[0031] S5. Close the first intake valve, the third control valve, the pressure relief control valve, the fifth control valve, the sixth control valve, and the differential pressure control valve B. Open the second intake valve and the fourth control valve, and let the purified gas in the purified gas delivery pipeline enter the system pipeline at the designed injection speed. At the same time, detect the change of the pressure readings of the inlet pressure gauge and the outlet pressure gauge over time until the values of the inlet pressure gauge and the outlet pressure gauge reach the set values. Then close the fourth control valve, and let the pressure of the entire system pipeline stabilize for a period of time. Among them, when delivering purified gas, when it is necessary to increase the pressure of the system pipeline, the system is pressurized through the pressurization pipeline.

[0032] S6. Open the sampling control valve and the pressure regulating valve, simulate the production process at the set gas sampling speed. At the same time, at the set cut-off period, sample and analyze by opening the discharge control valve until the system pressure reaches the set pressure value, and record the values of the inlet pressure gauge, the outlet pressure gauge, and the differential pressure gauge at both ends of the gripper during the gas sampling process.

[0033] S7. After the experiment is over, open the differential pressure control valve B, the third control valve, the fifth control valve, and the vent valve, unload the pore pressure and process the remaining sulfur-containing natural gas in the core system. Close the confining pressure pump and remove the confining pressure.

[0034] S8. Repeat the above experimental process, design a comparative experiment using the single variable method, so as to obtain the corresponding experimental results.

[0035] In summary, due to the adoption of the above technical solutions, the beneficial effects of the present invention are as follows:

[0036] 1. The present invention replaces the conventional core gripper with a full-diameter core gripper, ensuring that the physical properties of the experimental core are basically the same as those of the reservoir formation of the gas storage reservoir. At the same time, the present invention designs a pressure regulating valve and a flow meter in the front section of the sampler device, ensuring that after the gas sampling flow rate in the laboratory is calculated by the similarity criterion, it is the same as the actual gas sampling flow rate of the gas storage reservoir, so that the experiment will not cause errors due to different flow rates, and can effectively reduce experimental errors.

[0037] 2. Through continuous injection and production experiments on rock samples by the experimental system of the present invention, the hydrogen sulfide in the gas storage reservoir can be fully washed out. It can not only predict the content of hydrogen sulfide in the gas when the gas storage reservoir is producing gas again, but also install different desulfurization devices at different gas production ports. For gas storage reservoirs that meet the standards, desulfurization devices may not even be installed, thus achieving the purpose of maximizing economic benefits.

[0038] 3. The experimental system of the present invention can complete the hydrogen sulfide production experiments under different injection-production conditions (same injection and production, one injection and one production), which can reveal the hydrogen sulfide washing characteristics and their influencing factors of reservoir rocks in multiple cycles, laying an experimental foundation for the reconstruction of sulfur-containing gas reservoirs into gas storage reservoirs. At the same time, the entire system can be carried out in an incubator, which can fully solve the problem of how to simulate the temperature of the gas storage reservoir, ensuring the consistency between the simulated experimental conditions and the actual conditions of the gas storage reservoir, and solving the problem that the existing hydrogen sulfide washing experimental system has poor simulation of gas storage reservoir conditions. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] Figure 1 It is a schematic structural diagram of the process of an experimental system for washing hydrogen sulfide gas according to the present invention. In the figure, the markings are as follows: 1 is a clamp, 2 is a first pipeline, 3 is a third pipeline, 4 is a second pipeline, 5 is a fourth pipeline, 6 is an annulus pressure pipeline, 7 is an annulus pressure pump, 8 is a first control valve, 9 is an inlet pressure gauge, 10 is a second control valve, 11 is an outlet pressure gauge, 12 is a sulfur-containing gas transmission pipeline, 13 is a purified gas transmission pipeline, 14 is a third control valve, 15 is a fourth control valve, 16 is a fifth control valve, 17 is a sixth control valve, 18 is a first intake valve, 19 is a sulfur-containing gas storage device, 20 is a second intake valve, 21 is a purified gas storage device, 22 is a vent pipeline, 23 is a vent water tank, 24 is a sampler, 25 is a vent valve, 26 is a vacuum pipeline, 27 is a vacuum pump, 28 is a vacuum control valve, 29 is a sampling pipeline, 30 is a sampling control valve, 31 is a pressure regulating valve, 32 is a flowmeter, 33 is a discharge control valve, 34 is a differential pressure pipeline, 35 is a differential pressure control valve A, 36 is a differential pressure control valve B, 37 is a differential pressure control valve C, 38 is a differential pressure gauge, 39 is a pressurization pipeline, 40 is an air compressor, 41 is a pressurization control valve, 42 is a gas injection pump, 43 is a pressure relief pipeline, 44 is a pressure relief water tank, 45 is a pressure relief control valve, 46 is an opening and closing valve. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0040] The present invention will be described in detail below with reference to the accompanying drawings.

[0041] In order to make the objectives, technical solutions and advantages of the present invention clearer, the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0042] As Figure 1As shown in the figure, an experimental system for washing hydrogen sulfide gas in a gas storage reservoir includes a gripper 1. One end of the gripper 1 is connected to a third pipeline 3 through a first pipeline 2, and the other end is connected to a fourth pipeline 5 through a second pipeline 4. The gripper 1 is connected to a confining pressure pump 7 through a confining pressure pipeline 6. The confining pressure pump 7 applies confining pressure to the gripper 1 to simulate the overlying rock pressure of the reservoir. A first control valve 8 and an inlet pressure gauge 9 are provided on the first pipeline 2 to control the opening and closing of the first pipeline 2 through the first control valve 8. The inlet pressure gauge 9 is used to detect the pressure in the first pipeline 2, and then detect the end pressure of the gripper 1. A second control valve 10 and an outlet pressure gauge 11 are provided on the second pipeline 4 to control the opening and closing of the second pipeline 4 through the second control valve 10. The outlet pressure gauge 10 is used to detect the pressure in the second pipeline 4, and then detect the pressure at the other end of the gripper 1. Both ends of the third pipeline 3 are respectively connected to a sulfur-containing gas transmission pipeline 12 and a purified gas transmission pipeline 13. A third control valve 14 and a fourth control valve 15 are provided on the third pipeline 3, and the pipeline between the first pipeline 2 and the third control valve 14 and the fourth control valve 15 is connected. Both ends of the fourth pipeline 5 are respectively connected to a sulfur-containing gas transmission pipeline 12 and a purified gas transmission pipeline 13. A fifth control valve 16 and a sixth control valve 17 are provided on the fourth pipeline 5, and the pipeline between the second pipeline 4 and the fifth control valve 16 and the sixth control valve 17 is connected.

[0043] Further, the first pipeline 2 is also connected to a sampling pipeline 29. Along the direction of gas flow in the pipeline, a sampling control valve 30, a pressure regulating valve 31, a flow meter 32, a sampler device, and a discharge control valve 33 are successively connected in series on the sampling pipeline 29. The mixed gas in the gripper 1 is sampled through the sampling pipeline 29, and at the same time, different-time production is simulated through the sampling pipeline to better create an actual production site. Moreover, the sampling device can also collect all the sulfur-containing gas (the volume of the sampler is generally larger than the void volume of the rock in the gripper). The sulfur-containing gas in the system pipeline does not need to be directly discharged, and it will not cause pollution to the surrounding environment.

[0044] Further, multiple samplers 24 can be connected in parallel to the sampler device, as Figure 1 shown. Three samplers 24 can be connected in parallel. A control valve (not shown, an existing manual control valve can be used) is configured for each pipeline where the sampler is located. Then, the gas in the gripper can be sampled at different time periods. For example, if a gas sample after 1 hour needs to be collected, the first sampler 24 connected in parallel can be opened. If a gas sample after 2 hours needs to be collected, the second sampler 24 connected in parallel can be opened, and so on.

[0045] Further, differential pressure pipelines 34 are also connected to both ends of the gripper 1. The two ends of the differential pressure pipeline 34 are respectively connected to the first pipeline 2 and the second pipeline 4. A differential pressure control valve A 35, a differential pressure control valve B 36, and a differential pressure control valve C 37 are successively connected in series on the differential pressure pipeline 34. A differential pressure gauge 38 is also provided on the differential pressure pipeline 34. The two ends of the differential pressure gauge 38 are respectively connected to the pipelines at both ends of the differential pressure control valve B 36. The differential pressure gauge 38 is used to detect the differential pressure at both ends of the gripper 1. When the differential pressure value at both ends of the gripper 1 is small, it is detected by the differential pressure gauge 38 to make up for the deficiency that the inlet pressure gauge 9 and the outlet pressure gauge 11 are difficult to accurately detect small differential pressures.

[0046] Further, as Figure 1 shown, the sulfur-containing gas transmission pipeline 12 and the purified gas transmission pipeline 13 are respectively connected to the third pipeline 3 through a booster pipeline 39. An air compressor 40, a booster control valve 41, a gas injection pump 42, and an opening and closing valve 46 are successively connected in series on the booster pipeline 39. The booster pipeline 39 respectively boosts the air pressures in the sulfur-containing gas transmission pipeline 12 and the purified gas transmission pipeline 13 through the air compressor 40 to supplement the air pressures required for the test. Further, the booster pipeline 39 is also connected to a pressure relief water tank 44 through a pressure relief pipeline 43. A pressure relief control valve 45 is provided on the pressure relief pipeline 43 to relieve the pressure of the booster pipeline 39 through the pressure relief pipeline 43.

[0047] Further, as Figure 1 shown, one end of the sulfur-containing gas transmission pipeline 12 is connected to a sulfur-containing gas storage device 19 (which can be a sulfur-containing gas cylinder) through a first intake valve 18, and the other end is respectively connected to the third pipeline 3 and the fourth pipeline 5 through the booster pipeline 39. One end of the purified gas transmission pipeline 13 is connected to a purified gas storage device 21 (which can be a purified gas cylinder) through a second intake valve 20, and the other end is respectively connected to the third pipeline 3 and the fourth pipeline 5 through the booster pipeline 39.

[0048] Further, the fourth pipeline 5 is connected to a vent water tank 23 through a vent pipeline 22. A vent valve 25 is provided on the vent pipeline 22 to relieve the pressure of the system pipeline through the vent pipeline 22.

[0049] Further, the fourth pipeline 5 is connected to a vacuum pump 27 through a vacuum pipeline 26. A vacuum control valve 28 is provided on the vacuum pipeline 26 to evacuate the system pipeline through the vacuum pump 27.

[0050] In the hydrogen sulfide gas elutriation experiment system of the present invention, the holder 1 is a full-diameter core holder, which is used to hold the core samples in the gas storage reservoir. Replacing the conventional core holder with a full-diameter core holder ensures that the physical properties of the experimental core are basically the same as those of the reservoir formation in the gas storage reservoir. Further, since natural gas is prone to explosion caused by electricity, all the electric control valves involved in the present invention are replaced with manual control valves.

[0051] To better implement the present invention, the above hydrogen sulfide gas elutriation experiment system is adopted, and the following experiments are carried out:

[0052] I. One-injection and one-production elutriation experiment

[0053] Adopt Figure 1 The elutriation experiment system to carry out the one-injection and one-production elutriation experiment, including the following steps:

[0054] S1. Measure the basic physical property parameters such as the porosity and permeability of the experimental core sample, establish the irreducible water saturation, and place the prepared experimental core sample into the holder 1, and load the confining pressure to the set pressure value through the confining pressure pump 7 and the confining pressure pipeline 6;

[0055] S2. Close the first intake valve 18, the second intake valve 20, the vent valve 25, the sixth control valve 17, the fourth control valve 15, and the sampling control valve 30, and open the third control valve 14, the first control valve 8, the second control valve 10, the fifth control valve 16, the differential pressure control valve A 35, the differential pressure control valve B 36, and the differential pressure control valve C 37;

[0056] S3. Open the vacuum control valve 28 of the vacuum pump 27, and use the vacuum pump 27 to evacuate the pipeline. Under a vacuum degree of -0.1 MPa, evacuate for at least 4 hours;

[0057] S4. After the evacuation is completed, close the vacuum control valve 28, open the first intake valve 18 and the booster pipeline 39 on the sulfur-containing gas delivery pipeline 12, and let the sulfur-containing natural gas enter the system (after the holder 1 is evacuated, its intake speed is very fast, and the sulfur-containing gas enters from both ends of the holder 1 at the same time, which can further accelerate the intake time of the holder 1. Of course, the sulfur-containing gas can also enter from one end of the holder 1. When only one end of the holder 1 needs to intake gas, the third control valve 14 can be not opened. If the system pipeline is not evacuated, both ends of the holder 1 need to intake gas to shorten the intake time), record the values of the inlet pressure gauge 9 and the outlet pressure gauge 11 (i.e., the system pressure value), until the pressure in the system reaches the set initial pressure (such as the current pressure of 0.45 MPa in the sulfur-containing gas reservoir);

[0058] S5. Close the differential pressure control valve B 36, the first intake valve 18, the third control valve 14, the pressure relief control valve 45, and the fifth control valve 16. Open the second intake valve 20, the booster line 39 on the purified gas delivery line 13, and the sixth control valve 17. Let the purified gas enter the system line at the designed injection rate. At the same time, detect the change of the pressure readings of the inlet pressure gauge 9 and the outlet pressure gauge 11 over time until the values of the inlet pressure gauge 9 and the outlet pressure gauge 11 reach the set values (such as the set value of 14 MPa in the gas storage reservoir). Then close the sixth control valve 17, and then let the entire core system balance for the set time (such as 5 minutes).

[0059] S6. Open the sampling control valve 30 and the pressure regulating valve 31 to ensure that the pressure entering the flowmeter 32 during gas production is less than 10 MPa. Simulate the production process at the set gas production rate. At the same time, take samples for gas sample analysis (discharge the gas sample through the discharge control valve 33) at the set cut-off times (such as 1 h, 2 h, etc.) until the system pressure reaches the set pressure value, and record the values of the inlet pressure gauge 9, the outlet pressure gauge 11, and the differential pressure gauge 38 at both ends of the core during gas production.

[0060] S7. After the experiment is over, open the differential pressure control valve B 36, the third control valve 14, the fifth control valve 16, and the vent valve 25 to unload the pore pressure and handle the remaining sour gas in the core system. Close the confining pressure pump 7 to remove the confining pressure.

[0061] S8. Repeat the above experimental process, design a comparative experiment using the single variable method to explore the effects of gas initial flow rate, initial pressure, production time, and injection-production mode on sulfur elutriation, so as to reveal the mechanism of multi-cycle injection-production hydrogen sulfide component elutriation, and judge whether the mechanism between hydrogen sulfide and purified gas is diffusion or mixing, or both coexist.

[0062] In the above experiment, generally, the gas coming out of the sour gas storage device 19 and the purified gas storage device 21 has a pressure not exceeding 12 MPa (the pressure of the gas cylinder). If the experiment requires the system pressure to exceed 12 MPa, for example, 20 MPa, the system pressure can be increased through the booster line 39. When the booster line is no longer needed for boosting, the pressure on the booster line can be relieved through the pressure relief line 43.

[0063] II. Co-injection and co-production elutriation experiment

[0064] Use the Figure 1 elutriation experiment system to conduct the co-injection and co-production elutriation experiment, including the following steps:

[0065] S1. Measure the basic physical property parameters such as the porosity and permeability of the experimental rock sample, establish the irreducible water saturation, and place the prepared experimental rock sample into the holder 1, and load the confining pressure to the set pressure value through the confining pressure pump 7 and the confining pressure line 6.

[0066] S2. Close the first intake valve 18, the second intake valve 20, the vent valve 25, the sixth control valve 17, the fourth control valve 15, and the sampling control valve 30, and open the third control valve 14, the first control valve 8, the second control valve 10, the fifth control valve 16, the differential pressure control valve A 35, the differential pressure control valve C 37, and the differential pressure control valve B 36;

[0067] S3. Open the vacuum control valve 28 of the vacuum pump 27, and use the vacuum pump 27 to evacuate the pipeline. At a vacuum degree of -0.1 MPa, evacuate for at least 4 hours;

[0068] S4. After the evacuation is completed, close the vacuum control valve 28, open the first intake valve 18 and the booster pipeline 39 on the sulfur-containing gas transmission pipeline 12, and let the sulfur-containing natural gas enter the system. Record the values of the inlet pressure gauge 9 and the outlet pressure gauge 11 (i.e., the system pressure value) until the pressure in the system reaches the set initial pressure (such as the current pressure of 0.45 MPa in the sulfur-containing gas reservoir);

[0069] S5. Close the first intake valve 18, the third control valve 14, the pressure relief control valve 45, the fifth control valve 16, and the differential pressure control valve C 37, and open the second intake valve 20, the booster pipeline 39 on the purified gas transmission pipeline 13, and the fourth control valve 15, and let the purified gas enter the core system at the designed injection speed. At the same time, detect the change of the pressure readings of the inlet pressure gauge 9 and the outlet pressure gauge 11 over time until the values of the inlet pressure gauge 9 and the outlet pressure gauge 11 reach the set values (such as the set value of 14 MPa in the gas storage reservoir). Then close the fourth control valve 15, and then let the entire core system balance for the set time (such as 5 min);

[0070] S6. Open the sampling control valve 30 and the pressure regulating valve 31 to ensure that the pressure entering the flowmeter 32 during the gas production process is less than 10 MPa. Simulate the production process at the set gas production speed. At the same time, take samples for gas sample analysis at the set cut-off points (discharge the gas sample through the discharge control valve 33) until the system pressure reaches the set pressure value, and record the values of the inlet pressure gauge 9, the outlet pressure gauge 11, and the differential pressure gauge 38 at both ends of the core during the gas production process;

[0071] S7. After the experiment is completed, open the differential pressure control valve B 36, the third control valve 14, the fifth control valve 16, and the vent valve 25 to unload the pore pressure and process the remaining sulfur-containing natural gas in the core system; close the confining pressure pump 7 to remove the confining pressure;

[0072] S8. Repeat the above experimental process, design a comparative experiment using the single-variable method, explore the effects of the initial gas flow rate, initial pressure, production time, and injection-production method on sulfur elutriation, so as to reveal the mechanism of multi-cycle injection-production hydrogen sulfide component elutriation, and determine whether the mechanism between hydrogen sulfide and purified gas is diffusion, mixing, or the coexistence of both.

[0073] In the above experiment, generally, the gas coming out of the sulfur-containing gas storage device 19 and the purified gas storage device 21 has a pressure not exceeding 12 MPa (the pressure of the gas storage cylinder). If the experimental requirement for the system pressure exceeds 12 MPa, for example, 20 MPa is required, the system pipeline can be pressurized by the pressurization pipeline 39. When the pressurization of the pressurization pipeline is no longer needed, the pressure on the pressurization pipeline can be released through the pressure relief pipeline 43.

[0074] The above are only the preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent replacements, and improvements made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. An experimental system for elutriating hydrogen sulfide gas, characterized in that, it includes: A holder (1), the holder is a full-diameter core holder, used to hold the rock sample in the gas storage reservoir. One end of the holder (1) is connected to the third pipeline (3) through the first pipeline (2), and the other end is connected to the fourth pipeline (5) through the second pipeline (4); Differential pressure pipelines (34) are also connected to both ends of the holder (1). The two ends of the differential pressure pipeline (34) are respectively connected to the first pipeline (2) and the second pipeline (4). A differential pressure control valve A (35), a differential pressure control valve B (36) and a differential pressure control valve C (37) are successively connected in series on the differential pressure pipeline (34). A differential pressure gauge (38) is also arranged on the differential pressure pipeline (34). The two ends of the differential pressure gauge (38) are respectively connected to the pipelines at both ends of the differential pressure control valve B (36); The first pipeline (2) is used to transport sulfur-containing gas, purified gas and the mixed gas of the two. A first control valve (8) and an inlet pressure gauge (9) for detecting the pipeline pressure are arranged on the first pipeline (2). The two ends of the third pipeline (3) are respectively connected to the sulfur-containing gas transmission pipeline (12) and the purified gas transmission pipeline (13). A third control valve (14) and a fourth control valve (15) are arranged on the third pipeline (3). The pipeline between the first pipeline (2) and the third control valve (14) and the fourth control valve (15) is connected; The second pipeline (4) is used to transport purified gas and sulfur-containing gas. A second control valve (10) and an outlet pressure gauge (11) for detecting the pipeline pressure are arranged on the second pipeline (4). The two ends of the fourth pipeline (5) are respectively connected to the sulfur-containing gas transmission pipeline (12) and the purified gas transmission pipeline (13). A fifth control valve (16) and a sixth control valve (17) are arranged on the fourth pipeline (5). The pipeline between the second pipeline (4) and the fifth control valve (16) and the sixth control valve (17) is connected; The first pipeline (2) is connected to a sampling pipeline (29). Along the direction of gas flow in the pipeline, a sampling control valve (30), a pressure regulating valve (31), a flowmeter (32), a sampler device and a discharge control valve (33) are successively connected in series on the sampling pipeline (29) to sample the mixed gas in the holder (1) through the sampling pipeline (29).

2. The experimental system for elutriating hydrogen sulfide gas according to claim 1, characterized in that, The fourth pipeline (5) is connected to a vacuum pump (27) through a vacuum pipeline (26). A vacuum control valve (28) is arranged on the vacuum pipeline (26) to evacuate the system pipeline through the vacuum pump (27).

3. The experimental system for elutriating hydrogen sulfide gas according to claim 2, characterized in that, The sulfur-containing gas transmission pipeline (12) and the purified gas transmission pipeline (13) are respectively connected with a pressurization pipeline (39). An air compressor (40), a pressurization control valve (41), a gas injection pump (42), and an opening and closing valve (46) are successively connected in series on the pressurization pipeline (39). The pressurization pipeline (39) pressurizes the air pressures in the sulfur-containing gas transmission pipeline (12) and the purified gas transmission pipeline (13) respectively through the air compressor (40) to supplement the air pressure required for the experiment.

4. The experimental system for elutriating hydrogen sulfide gas as described in claim 3, characterized in that, the pressurization pipeline (39) is connected to a pressure relief water tank (44) through a pressure relief pipeline (43). A pressure relief control valve (45) is provided on the pressure relief pipeline (43) to relieve the pressure of the system pipeline through the pressure relief pipeline (43).

5. The experimental system for elutriating hydrogen sulfide gas as described in claim 4, characterized in that, the holder (1) is connected to an annular pressure pump (7) through an annular pressure pipeline (6). The annular pressure pump (7) applies an overburden pressure to the holder (1) to simulate the overlying rock pressure of the reservoir.

6. The experimental system for elutriating hydrogen sulfide gas as described in claim 5, characterized in that, the fourth pipeline (5) is connected to a vent water tank (23) through a vent pipeline (22). A vent valve (25) is provided on the vent pipeline 22 to relieve the pressure of the system pipeline through the vent pipeline (22).

7. The experimental system for elutriating hydrogen sulfide gas as described in claim 6, characterized in that, one end of the sulfur-containing gas transmission pipeline (12) is connected to a sulfur-containing gas storage device (19) through a first intake valve (18), and one end of the purified gas transmission pipeline (13) is connected to a purified gas storage device (21) through a second intake valve (20).

8. The experimental method of the experimental system for elutriating hydrogen sulfide gas as described in claim 7, characterized in that, when performing a one-production and one-injection elutriation experiment, it includes the following steps: A. Place the experimental rock sample into the holder (1), and load the overburden pressure to a set pressure value through the annular pressure pipeline (6); B. Close the first intake valve (18), the second intake valve (20), the vent valve (25), the sixth control valve (17), the fourth control valve (15), and the sampling control valve (30), and open the third control valve (14), the first control valve (8), the second control valve (10), the fifth control valve (16), the differential pressure control valve A (35), the differential pressure control valve B (36), and the differential pressure control valve C (37); C. Open the vacuum control valve (28) of the vacuum pump (27), and use the vacuum pump (27) to evacuate the system pipeline; D. After the evacuation is completed, close the vacuum control valve (28), open the first intake valve (18), and let the sulfur-containing natural gas enter the system. Record the values of the inlet pressure gauge (9), the differential pressure gauge (38), and the outlet pressure gauge (11) until the system pressure reaches the set initial pressure; when it is necessary to increase the pressure of the system pipeline, pressurize the system through the pressurization pipeline (39); E. Close the differential pressure control valve B (36), the first intake valve (18), the third control valve (14), the pressure relief control valve (45), and the fifth control valve (16). Open the second intake valve (20) and the sixth control valve (17) to allow the purified gas in the purified gas delivery pipeline (13) to enter the system pipeline at the designed injection rate. At the same time, detect the change of the pressure readings of the inlet pressure gauge (9) and the outlet pressure gauge (11) over time until the values of the inlet pressure gauge (9) and the outlet pressure gauge (11) reach the set values. Then close the sixth control valve (17), and let the pressure of the entire system pipeline stabilize for a period of time. When it is necessary to increase the pressure of the system pipeline, pressurize the system through the pressurization pipeline (39). F. Open the sampling control valve (30) and the pressure regulating valve (31), simulate the production process at the set gas sampling rate. At the same time, at the set cut-off time period, sample and analyze by opening the discharge control valve (33) until the system pressure reaches the set pressure value, and record the values of the inlet pressure gauge (9), the outlet pressure gauge (11), and the differential pressure gauge (38) at both ends of the holder (1) during the gas sampling process. G. After the experiment is completed, open the differential pressure control valve B (36), the third control valve (14), the fifth control valve (16), and the vent valve (25) to unload the pore pressure and process the remaining sulfur-containing natural gas in the core system. Close the confining pressure pump (7) to remove the confining pressure. H. Repeat the above experimental process, design a comparative experiment using the single variable method to obtain the corresponding experimental results.

9. The experimental method of the experimental system for scrubbing hydrogen sulfide gas as described in claim 7, characterized in that when conducting the co-production and co-injection scrubbing experiment, it includes the following steps: S1. Place the experimental rock sample into the holder (1), and load the confining pressure to the set pressure value through the confining pressure pipeline (6). S2. Close the first intake valve (18), the second intake valve (20), the vent valve (25), the sixth control valve (17), the fourth control valve (15), and the sampling control valve (30). Open the third control valve (14), the first control valve (8), the second control valve (10), the fifth control valve (16), the differential pressure control valve A (35), the differential pressure control valve B (36), and the differential pressure control valve C (37). S3. Open the vacuum control valve (28) of the vacuum pump (27), and use the vacuum pump (27) to evacuate the system pipeline. S4. After the evacuation is completed, close the vacuum control valve (28), open the first intake valve (18), and let the sulfur-containing natural gas enter the system. Record the values of the inlet pressure gauge (9), the differential pressure gauge (38), and the outlet pressure gauge (11) until the system pressure reaches the set initial pressure. When it is necessary to increase the pressure of the system pipeline, pressurize the system through the pressurization pipeline (39). S5. Close the first intake valve (18), the third control valve (14), the pressure relief control valve (45), the fifth control valve (16), the sixth control valve (17), and the differential pressure control valve B (36). Open the second intake valve (20) and the fourth control valve (15). Let the purified gas in the purified gas delivery pipeline (13) enter the system pipeline at the designed injection rate. At the same time, detect the change of the pressure readings of the inlet pressure gauge (9) and the outlet pressure gauge (11) over time until the values of the inlet pressure gauge (9) and the outlet pressure gauge (11) reach the set values. Then close the fourth control valve (15), and let the pressure of the entire system pipeline stabilize for a period of time. Among them, when delivering purified gas, when it is necessary to increase the pressure of the system pipeline, the system is pressurized through the pressurization pipeline (39). S6. Open the sampling control valve (30) and the pressure regulating valve (31). Simulate the production process at the set gas sampling rate. At the same time, at the set cut-off point period, sample and analyze by opening the discharge control valve (33) until the system pressure reaches the set pressure value, and record the values of the inlet pressure gauge (9), the outlet pressure gauge (11), and the differential pressure gauge (38) at both ends of the gripper (1) during the gas sampling process. S7. After the experiment is completed, open the differential pressure control valve B (36), the third control valve (14), the fifth control valve (16), and the vent valve (25) to unload the pore pressure and process the remaining sulfur-containing natural gas in the core system. Close the confining pressure pump (7) to remove the confining pressure. S8. Repeat the above experimental process, design a comparative experiment using the single variable method to obtain the corresponding experimental results.

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