Experimental device and experimental method for researching elutriation mechanism of hydrogen sulfide in sulfur-containing gas reservoir

Abstract

The invention discloses an experimental device and an experimental method for researching a hydrogen sulfide elutriation mechanism of a sulfur-containing gas reservoir, and the experimental device comprises a three-dimensional artificial rock core model which comprises a sealing layer and an artificial rock core, and the artificial rock core is coated with the sealing layer; the hydrogen sulfide detection mechanism comprises a first hydrogen sulfide detector and a plurality of hydrogen sulfide probes, one ends of the plurality of hydrogen sulfide probes penetrate through the sealing layer and are introduced into the plurality of detection areas in the artificial core, and the other ends of the plurality of hydrogen sulfide probes are electrically connected with the first hydrogen sulfide detector; one end of the injection-production pipe penetrates through the sealing layer and is introduced into the artificial rock core; and the gas injection mechanism is communicated with the other end of the injection-production pipe. According to the invention, the actual hydrogen sulfide elutriation process of the gas reservoir can be simulated, the concentration change of hydrogen sulfide in each detection area can be monitored in real time, and the hydrogen sulfide distribution condition of the artificial rock core can be obtained, so that the hydrogen sulfide elutriation process and mechanism can be researched, and pilot prediction and parameter design are provided for the real gas reservoir hydrogen sulfide elutriation test; and explaining the elutriation result.

Description

Technical Field

[0001] The invention relates to the technical field of natural gas exploitation and storage, and in particular to an experimental device and an experimental method for studying the hydrogen sulfide washing mechanism of sulfur-containing gas reservoirs. Background Art

[0002] Currently, there are many high-sulfur gas reservoirs in the late stages of development. When using these gas reservoirs to build gas storage facilities, hydrogen sulfide washing is required, that is, clean natural gas is injected into the sulfur-containing gas reservoir. After a period of mixing, the sulfur-containing natural gas in the gas reservoir is produced. After several injections of clean gas and production, the hydrogen sulfide content in the gas reservoir is reduced to below the standard content, thereby meeting the requirements for natural gas storage in subsequent gas storage facilities. However, the mechanism of hydrogen sulfide washing is still unclear, and the distribution of hydrogen sulfide during the washing process of sulfur-containing gas reservoirs is also unclear, and the distribution of hydrogen sulfide cannot be observed intuitively.

[0003] Current research on the purification of sour gas reservoirs mostly relies on numerical simulations, because hydrogen sulfide is colorless and cannot be distinguished when mixed with natural gas. The distribution of hydrogen sulfide cannot be observed through experimental testing.

[0004] In the prior art, an experimental device for washing hydrogen sulfide from natural gas used in a gas storage reservoir clamps a rock sample through a core holder, allows a mixture of natural gas and hydrogen sulfide to enter the core holder to saturate the rock sample, and then inputs natural gas into the core holder to wash hydrogen sulfide from the rock sample. Although the hydrogen sulfide in the natural gas in the gas storage reservoir can be fully washed, only the final content of the washed hydrogen sulfide can be obtained, and the distribution and change of hydrogen sulfide inside the core cannot be obtained. Summary of the invention

[0005] The purpose of the present invention is to provide an experimental device and an experimental method for studying the hydrogen sulfide washing mechanism of sour gas reservoirs, so as to solve the technical problem that the current hydrogen sulfide washing experiment can only obtain the final content of the washed hydrogen sulfide, but cannot obtain the distribution and change of hydrogen sulfide inside the core.

[0006] The above-mentioned purpose of the present invention can be achieved by adopting the following technical solutions:

[0007] The present invention provides an experimental device for studying the hydrogen sulfide washing mechanism of sulfur-containing gas reservoirs, comprising: a three-dimensional artificial core model, comprising a sealing layer and an artificial core, wherein the sealing layer is coated on the outside of the artificial core; a hydrogen sulfide detection mechanism, comprising a first hydrogen sulfide detector and a plurality of hydrogen sulfide probes, wherein one end of the plurality of hydrogen sulfide probes penetrates the sealing layer and passes into a plurality of detection areas in the artificial core, and the other end of the plurality of hydrogen sulfide probes is electrically connected to the first hydrogen sulfide detector; at least one injection-production pipe, wherein one end of the injection-production pipe penetrates the sealing layer and passes into the artificial core; and a gas injection mechanism is connected to the other end of the injection-production pipe.

[0008] In an embodiment of the present invention, the artificial core includes a plurality of core layers, the plurality of core layers are stacked and spliced ​​in a vertical direction, and the permeability and / or porosity of each core layer is different.

[0009] In an embodiment of the present invention, the sealing layer is cast and coated on the artificial core by a sealing material.

[0010] In an embodiment of the present invention, there are multiple injection and production pipes, and the multiple injection and production pipes are distributed and arranged close to the edge of the artificial core.

[0011] In an embodiment of the present invention, an injection-production control valve and a pressure monitoring structure are provided on the injection-production pipe.

[0012] In an embodiment of the present invention, the hydrogen sulfide detection mechanism further includes a processing terminal, which is electrically connected to the first hydrogen sulfide detector, and is used to generate a hydrogen sulfide distribution map of the artificial core based on the detection signal analysis and processing of the first hydrogen sulfide detector.

[0013] In an embodiment of the present invention, the gas injection mechanism includes a natural gas pipeline, a natural gas pipeline containing hydrogen sulfide and an injection pump. The natural gas pipeline connects the injection-production pipe with the natural gas supply structure, the natural gas pipeline containing hydrogen sulfide connects the injection-production pipe with the natural gas supply structure containing hydrogen sulfide, and the injection pump is used to provide transportation power for natural gas from the natural gas pipeline to the injection-production pipe and / or hydrogen sulfide from the natural gas pipeline containing hydrogen sulfide to the injection-production pipe.

[0014] In an embodiment of the present invention, a natural gas control valve is provided on the natural gas pipeline, and a hydrogen sulfide-containing natural gas control valve is provided on the hydrogen sulfide-containing natural gas pipeline.

[0015] In an embodiment of the present invention, the experimental device further comprises a gas recovery structure, and the gas recovery structure is connected to the injection and production pipe through a gas production pipeline, and the gas production pipeline is provided with a gas production control valve and a production pump.

[0016] In an embodiment of the present invention, a second hydrogen sulfide detector is also provided on the gas collection pipeline.

[0017] In an embodiment of the present invention, the experimental device further comprises a vacuum pumping structure, and the vacuum pumping structure is used to connect with at least one of the injection and production pipes to vacuum the artificial core.

[0018] In an embodiment of the present invention, the experimental device further comprises a box and a third hydrogen sulfide detector, the three-dimensional artificial core model is placed in the box, and the detection end of the third hydrogen sulfide detector extends into the gap between the box and the three-dimensional artificial core model.

[0019] The present invention also provides an experimental method for studying the hydrogen sulfide washing mechanism of sulfur-containing gas reservoirs, comprising the following steps: S3, injecting hydrogen sulfide-containing natural gas into an artificial core until the pressure in the artificial core reaches a first preset pressure, and then stopping the injection of hydrogen sulfide-containing natural gas; S4, placing the artificial core for a preset time until the internal pressure of the artificial core reaches equilibrium; S5, recording the concentration of hydrogen sulfide in each detection area in the artificial core; S6, injecting natural gas into the artificial core until the pressure in the artificial core reaches a second preset pressure, and then stopping the injection, and monitoring the change of the hydrogen sulfide concentration in each detection area over time in real time; S7, when the hydrogen sulfide concentration in each detection area no longer changes, gas production is carried out, and the change of the hydrogen sulfide concentration in each detection area is also monitored in real time during the gas production process; S8, repeating the steps S6 and S7, and monitoring the change of the hydrogen sulfide concentration in each detection area in real time.

[0020] In an embodiment of the present invention, before step S3, the following steps are also included: S1, detecting the sealing performance of the sealing layer coated on the outer surface of the artificial core to ensure that the sealing performance of the sealing layer meets the requirements; S2, evacuating the artificial core.

[0021] In an embodiment of the present invention, the first preset pressure is 2 MPa; the second preset pressure is 3 MPa.

[0022] In an embodiment of the present invention, step S6 and step S7 are repeated until the concentration of hydrogen sulfide is less than 1 mg / m 3 or the hydrogen sulfide concentration required for the study.

[0023] In an embodiment of the present invention, after step S8, the following steps are also included: S9, interpolating the recorded hydrogen sulfide concentrations of each of the detection areas, and assigning different colors to different hydrogen sulfide concentrations, so as to obtain a hydrogen sulfide distribution map of the artificial core.

[0024] The characteristics and advantages of the present invention are:

[0025] The experimental device and experimental method for studying the hydrogen sulfide washing mechanism of sulfur-containing gas reservoirs of the present invention form a three-dimensional artificial core model by coating an artificial core with a sealing layer, and arrange an injection and production pipe and a plurality of hydrogen sulfide probes that penetrate the sealing layer and pass into the artificial core, so that a mixed gas of natural gas and hydrogen sulfide provided by a gas injection mechanism can first be passed into the artificial core, and then the natural gas provided by the gas injection mechanism is used to wash the hydrogen sulfide in the artificial core, thereby simulating the hydrogen sulfide washing process of an actual gas reservoir, and collecting detection signals of the plurality of hydrogen sulfide probes through a first hydrogen sulfide detector, so that the concentration change of hydrogen sulfide in each detection area can be monitored in real time, and the distribution of hydrogen sulfide in the artificial core during the hydrogen sulfide washing process can be obtained. Therefore, the process and mechanism of hydrogen sulfide washing can be studied by using the present invention, and a leading prediction and parameter design can be provided for a hydrogen sulfide washing test of a real gas reservoir, and the washing result can be explained. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following briefly introduces the drawings required for use in the description of the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0027] Figure 1 It is a schematic diagram of the structure of an experimental device for studying the hydrogen sulfide washing mechanism of a sour gas reservoir in one embodiment of the present invention.

[0028] Figure 2 It is a schematic diagram of the structure of the artificial core in the present invention.

[0029] Figure 3 It is a schematic diagram of the distribution of multiple detection areas of the artificial core in the present invention.

[0030] Figure 4 It is a schematic diagram of the distribution of multiple hydrogen sulfide probes and multiple injection and production pipes on the artificial core in the present invention.

[0031] Figure 5 It is a schematic structural diagram of an experimental device for studying the hydrogen sulfide washing mechanism of sour gas reservoirs in another embodiment of the present invention.

[0032] Figure 6 It is a schematic structural diagram of an experimental device for studying the hydrogen sulfide washing mechanism of a sour gas reservoir in another embodiment of the present invention.

[0033] Figure 7 It is a schematic structural diagram of an experimental device for studying the hydrogen sulfide washing mechanism of a sour gas reservoir in another embodiment of the present invention.

[0034] In the figure:

[0035] 1. Three-dimensional artificial core model; 101. artificial core; 1011. core layer; 1011'. core layer; 1012. detection area; 102. sealing layer;

[0036] 2. Injection and production pipe; 201. Pressure monitoring structure; 202. Injection and production control valve;

[0037] 3. Gas injection mechanism; 301. Natural gas pipeline; 302. Natural gas pipeline containing hydrogen sulfide; 303. Injection pump; 304. Natural gas control valve; 305. Natural gas control valve containing hydrogen sulfide; 306. Natural gas supply structure; 307. Natural gas supply structure containing hydrogen sulfide;

[0038] 4. Hydrogen sulfide detection mechanism; 401. First hydrogen sulfide detector; 402. Hydrogen sulfide probe; 403. Processing terminal;

[0039] 5. Gas recovery structure; 6. Gas production pipeline; 7. Gas production control valve; 8. Production pump; 9. Vacuum structure; 10. Second hydrogen sulfide detector; 11. Box; 12. Third hydrogen sulfide detector; 13. Gas recovery pipeline. DETAILED DESCRIPTION

[0040] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0041] Implementation Method 1

[0042] like Figure 1 As shown, the present invention provides an experimental device for studying the hydrogen sulfide washing mechanism of sulfur-containing gas reservoirs, comprising: a three-dimensional artificial core model 1, comprising a sealing layer 102 and an artificial core 101, wherein the sealing layer 102 is coated on the outside of the artificial core 101; a hydrogen sulfide detection mechanism 4, comprising a first hydrogen sulfide detector 401 and a plurality of hydrogen sulfide probes 402, wherein one end of the plurality of hydrogen sulfide probes 402 penetrates the sealing layer 102 and passes into a plurality of detection areas 1012 in the artificial core 101 (see Figure 3 As shown), the other ends of the multiple hydrogen sulfide probes 402 are electrically connected to the first hydrogen sulfide detector 401; at least one injection and production pipe 2, one end of which passes through the sealing layer 102 and enters the artificial core 101; the gas injection mechanism 3 is connected to the other end of the injection and production pipe 2.

[0043] The experimental device for studying the hydrogen sulfide washing mechanism of sulfur-containing gas reservoirs of the present invention forms a three-dimensional artificial core model 1 by coating an artificial core 101 with a sealing layer 102, and provides an injection and production pipe 2 and a plurality of hydrogen sulfide probes 402 that penetrate the sealing layer 102 and pass into the artificial core 101, so that the hydrogen sulfide-containing natural gas (i.e., a mixture of natural gas and hydrogen sulfide) provided by the gas injection mechanism 3 can be firstly passed into the artificial core 101, and then the natural gas provided by the gas injection mechanism 3 can be used to wash the sulfur in the artificial core 101. The hydrogen sulfide is used for washing, thereby simulating the actual gas reservoir to carry out the hydrogen sulfide washing process, and the detection signals of multiple hydrogen sulfide probes 402 are collected by the first hydrogen sulfide detector 401, so that the concentration change of hydrogen sulfide in each detection area 1012 can be monitored in real time, and the hydrogen sulfide distribution of the artificial core 101 during the hydrogen sulfide washing process can be obtained. Therefore, the present invention can be used to study the process and mechanism of hydrogen sulfide washing, provide leading prediction and parameter design for the hydrogen sulfide washing test of the real gas reservoir, and explain the washing results.

[0044] like Figure 1 As shown, in an embodiment of the present invention, the hydrogen sulfide detection mechanism 4 also includes a processing terminal 403, and the processing terminal 403 is electrically connected to the first hydrogen sulfide detector 401. The processing terminal 403 is used to generate a hydrogen sulfide distribution map of the artificial core 101 according to the detection signal analysis and processing of the first hydrogen sulfide detector 401. Specifically, the processing terminal 403 can be a computer. Among them, the hydrogen sulfide distribution map can be obtained by interpolating the recorded hydrogen sulfide concentrations of each detection area 1012, and assigning different colors to different hydrogen sulfide concentrations, as in some embodiments of the present invention. By representing different hydrogen sulfide concentrations with different colors, the distribution of hydrogen sulfide in the artificial core 101 can be more intuitively reflected.

[0045] like Figure 1 As shown, in an embodiment of the present invention, the gas injection mechanism 3 includes a natural gas pipeline 301, a hydrogen sulfide-containing natural gas pipeline 302 and an injection pump 303. The natural gas pipeline 301 connects the injection-production pipe 2 with the natural gas supply structure 306, the hydrogen sulfide-containing natural gas pipeline 302 connects the injection-production pipe 2 with the hydrogen sulfide-containing natural gas supply structure 307, and the injection pump 303 is used to provide transportation power for natural gas from the natural gas pipeline 301 to the injection-production pipe 2 and / or hydrogen sulfide from the hydrogen sulfide-containing natural gas pipeline 302 to the injection-production pipe 2.

[0046] The hydrogen sulfide-containing natural gas provided by the hydrogen sulfide-containing natural gas supply structure 307 is first injected into the artificial core 101 from the injection and production pipe 2 through the hydrogen sulfide-containing natural gas pipeline 302 by the injection pump 303, and then the natural gas provided by the natural gas supply structure 306 is injected into the artificial core 101 from the injection and production pipe 2 through the natural gas pipeline 301 by the injection pump 303.

[0047] Specifically, a natural gas control valve 304 is provided on the natural gas pipeline 301, and a hydrogen sulfide-containing natural gas control valve 305 is provided on the hydrogen sulfide-containing natural gas pipeline 302. Optionally, the natural gas control valve 304 is provided on the natural gas supply structure 306, and the hydrogen sulfide-containing natural gas control valve 305 is provided on the hydrogen sulfide-containing natural gas supply structure 307.

[0048] like Figure 1 As shown, in the embodiment of the present invention, the experimental device further includes a gas recovery structure 5, which is connected to the injection and production pipe 2 through a gas production pipeline 6, and a gas production control valve 7 and a production pump 8 are provided on the gas production pipeline 6. After the injection of natural gas stops, the gas production control valve 7 can be opened, and the gas in the artificial core 101 can be produced to the gas recovery structure 5 through the gas production pipeline 6 by the production pump 8, so as to achieve the washing of hydrogen sulfide in the artificial core 101 and prevent the gas from being discharged into the environment to pollute the air.

[0049] like Figure 1 As shown, in order to further improve the accuracy of the experiment and avoid the influence of the gas (such as air) in the artificial core 101 on the experiment, in the embodiment of the present invention, the experimental device also includes a vacuum pumping structure 9, which is used to connect at least one injection and production pipe 2 to vacuum the artificial core 101. Before injecting the hydrogen sulfide-containing natural gas, the artificial core 101 is first vacuumed by the vacuum pumping structure 9, so that the subsequent artificial core 101 is only pressurized to a preset pressure by the injected hydrogen sulfide-containing natural gas.

[0050] like Figure 2 As shown, in an embodiment of the present invention, the artificial core 101 includes multiple core layers, and the multiple core layers are stacked and spliced ​​in the vertical direction, and the permeability and / or porosity of each core layer is different. In some embodiments of the present invention, the permeability of multiple core layers gradually decreases from bottom to top. For example, in one embodiment, the number of core layers is two, the permeability of the upper core layer 1011 is 1md, and the permeability of the lower core layer 1011' is 10md. The height H1 of the artificial core 101 is 20cm, the length L1 is 1m, and the width W1 is 1m, wherein the height h of each core layer is 10cm.

[0051] The present invention uses an artificial core 101 to simulate a reservoir, which can achieve large-scale simulation, thereby reducing experimental errors. The artificial core 101 is prepared based on the similarity criterion. On the one hand, it is geometrically similar. The shape and size of the artificial core 101 are similar to the reservoir of the actual gas storage reservoir; on the other hand, it is similar in physical properties. By setting multiple core layers stacked and spliced ​​in the vertical direction and having different porosities and / or permeabilities, the heterogeneity of the reservoir is simulated, and the artificial core 101 is prepared according to the pore structure with the same permeability and porosity as the actual reservoir.

[0052] Combination Figure 3 As shown, one end of the plurality of hydrogen sulfide probes 402 can be pre-buried in the plurality of detection areas 1012 of the artificial core 101 during the manufacturing process of the artificial core 101. The number of the detection areas 1012 may not be specifically limited, and the artificial core 101 may be divided into a plurality of detection areas 1012 as required.

[0053] For example, in some embodiments of the present invention, the artificial core 101 formed by splicing the core layer 1011' and the core layer 1011 has a height H1 of 20 cm, a length L1 of 1 m, and a width W1 of 1 m. The height h of each detection area 1012 is 10 cm, the width W2 is 10 cm, and the length L2 is 10 cm, that is, each detection area 1012 is a cube with a side length of 10 cm, and each core layer is divided into 100 detection areas 1012. Accordingly, 100 hydrogen sulfide probes 402 are set so that the top of the artificial core 101 is buried in the 100 detection areas 1012 of the upper layer and is electrically connected to the first hydrogen sulfide detector 401, and 100 hydrogen sulfide probes 402 are buried in the 100 detection areas 1012 of the lower layer and are electrically connected to the first hydrogen sulfide detector 401. Of course, the artificial core 101 may also be divided into detection areas of other numbers, sizes and / or shapes.

[0054] like Figure 4 As shown, the injection and production pipe 2 is used to simulate the injection and production well. During the production process of the artificial core 101, the hole position for laying the injection and production pipe 2 is reserved, that is, the well position for the reserved injection and production well. The reserved well position is laid out according to the well layout method of the actual reservoir, for example, the nine-point method is used to lay out a quarter of the wells, so that it can be consistent with the injection and production method of the real gas storage, and then the authenticity and accuracy of the hydrogen sulfide washing process simulated in the actual gas reservoir can be further improved. In the embodiment of the present invention, the number of injection and production pipes 2 is multiple, and multiple injection and production pipes 2 are distributed near the edge of the artificial core 101. Multiple injection and production pipes 2 are used to simulate multiple injection and production wells to simulate different injection and production methods of the gas storage, such as simultaneous injection and production, one injection and one production, or multiple injections and multiple productions. In addition, the gas injection structure injects gas from multiple injection and production pipes 2 into the artificial core 101 at the same time, which improves efficiency and makes it easier for the gas to fill the artificial core 101 and reach a more ideal saturation state. Specifically, the injection and production pipe 2 can be a steel pipe. An injection and production control valve 202 is provided on the injection and production pipe 2. The injection and production control valve 202 is provided to control the injection and production pipe 2 to perform gas injection and gas production.

[0055] Combination Figure 1As shown, the sealing layer 102 is cast and coated on the artificial core 101 by the sealing material. Specifically, the sealing material includes but is not limited to epoxy resin. After the artificial core 101 is manufactured (one end of the multiple hydrogen sulfide probes 402 are pre-buried in the multiple detection areas 1012 of the artificial core 101 during the manufacturing process of the artificial core 101), the injection and production pipe 2 is inserted into the reserved hole position of the artificial core 101, and then the sealing material is cast on the artificial core 101 to form a sealing layer 102, which can ensure the sealing between the artificial core 101 and the sealing layer 102, between the sealing layer 102 and the injection and production pipe 2, and between the sealing layer 102 and the hydrogen sulfide probe 402, and avoid leakage of hydrogen sulfide in the artificial core 101, which is conducive to improving the accuracy of the experimental structure. In addition, a pressure monitoring structure 201 is also provided on the injection and production pipe 2 to monitor the injection pressure and the production pressure during the injection and production process.

[0056] In some embodiments of the present invention, the plane shape of the artificial core 101 is a square, and four injection and production pipes 2 are distributed at the four corners of the artificial core 101. The insertion depth of the injection and production pipe 2, that is, the degree of wellbore perforation of the injection and production well simulated by it, may not be specifically limited. For example, it may penetrate the core layer 1011' and the core layer 1011 to simulate a fully perforated wellbore; it may also penetrate only the upper core layer 1011 to simulate a partially perforated wellbore.

[0057] like Figure 5 As shown, in some other embodiments of the present invention, the natural gas control valve 304 and the hydrogen sulfide-containing natural gas control valve 305 can be integrated into a multi-way control valve to control the injection of different gases.

[0058] like Figure 6 As shown, in some other embodiments of the present invention, a second hydrogen sulfide detector 10 is further provided on the gas production pipeline 6. By providing the second hydrogen sulfide detector 10, the concentration of hydrogen sulfide can be monitored during the gas production process.

[0059] like Figure 7As shown, in some other embodiments of the present invention, the experimental device also includes a box 11 and a third hydrogen sulfide detector 12, the three-dimensional artificial core model 1 is placed in the box 11, and the detection end of the third hydrogen sulfide detector 12 extends into the gap between the box 11 and the three-dimensional artificial core model 1. By setting the box 11 and the third hydrogen sulfide detector 12 to detect the concentration of hydrogen sulfide in the gap between the box 11 and the three-dimensional artificial core model 1, it is judged whether the gas in the artificial core 101 leaks from the sealing layer 102 to the gap between the box 11 and the three-dimensional artificial core model 1. On the one hand, it is convenient to monitor whether the sealing layer 402 leaks, and eliminates the factors that cause the simulation effect of the experimental device to be inaccurate due to the leakage of the sealing layer 102; on the other hand, it can prevent gas from leaking into the environment, polluting the air, and avoiding safety accidents caused by gas leakage. Specifically, the material of the box 11 is a high temperature and high pressure resistant material, such as steel, titanium alloy, etc. The wall thickness of the box 11 is 5cm, and of course it can be thicker to ensure that its sealing performance meets the requirements under high temperature and high pressure environments.

[0060] In addition, during the actual use of the box 11 of the present invention, an alarm can be added to the box 11, and the alarm can be controlled and connected to the third hydrogen sulfide detector 12. When the third hydrogen sulfide detector 12 detects hydrogen sulfide gas in the box 11, the alarm will sound, thereby prompting relevant staff to inspect the three-dimensional artificial core model 1 and determine the cause of the fault.

[0061] The box 11 can also be connected to the gas recovery structure 5 through a gas recovery pipeline 13. A recovery control valve is provided on the gas recovery pipeline 13. When gas leakage occurs in the three-dimensional artificial core model 1, the recovery control valve can be opened to discharge the gas in the box 11 through the gas recovery pipeline 13 to the gas recovery structure 5 for centralized treatment.

[0062] Implementation Method 2

[0063] like Figure 1 and Figure 3 As shown, the present invention also provides an experimental method for studying the hydrogen sulfide washing mechanism of sulfur-containing gas reservoirs, which can be implemented using the experimental device in the first embodiment.

[0064] The experimental method of the present invention comprises the following steps:

[0065] Step S1, detecting the sealing performance of the sealing layer 102 coated on the artificial core 101, and ensuring that the sealing performance of the sealing layer 102 meets the requirements.

[0066] Step S2, evacuating the artificial core 101. Specifically, the artificial core 101 is evacuated by starting the evacuation structure 9.

[0067] Step S3, injecting hydrogen sulfide-containing natural gas into the artificial core 101 until the pressure in the artificial core 101 reaches a first preset pressure, and then stopping the injection of hydrogen sulfide-containing natural gas. Specifically, the hydrogen sulfide-containing natural gas control valve 305 is opened, the injection pump 303 is started, and the hydrogen sulfide-containing natural gas in the hydrogen sulfide-containing natural gas pipeline 302 is injected into the artificial core 101 from the injection and production pipe 2 until the pressure in the artificial core 101 reaches the first preset pressure, and then the hydrogen sulfide-containing natural gas control valve 305 and the injection pump 303 are closed to stop injecting hydrogen sulfide-containing natural gas.

[0068] Step S4: place the artificial core 101 for a preset time until the internal pressure of the artificial core 101 reaches equilibrium. Specifically, when the pressure displayed by the pressure monitoring structure 201 does not change or changes very little, it means that the internal pressure of the artificial core 101 reaches equilibrium.

[0069] Step S5, recording the concentration of hydrogen sulfide in each detection area 1012 in the artificial core 101. Specifically, the first hydrogen sulfide detector 404 processes and analyzes the detection signals collected by the multiple hydrogen sulfide probes 402 to generate the concentration of hydrogen sulfide and uploads it to the processing terminal 403 for recording.

[0070] Step S6, inject natural gas into the artificial core 101 until the pressure in the artificial core 101 reaches the second preset pressure, then stop injecting, and monitor in real time the change in the concentration of hydrogen sulfide over time in each detection area 1012. Specifically, open the natural gas control valve 304, start the injection pump 303, inject the hydrogen sulfide-containing natural gas in the natural gas pipeline 301 from the injection and production pipe 2 into the artificial core 101, until the pressure in the artificial core 101 reaches the second preset pressure, then close the natural gas control valve 304 and the injection pump 303, and stop injecting natural gas.

[0071] Step S7: When the concentration of hydrogen sulfide in each detection area 1012 no longer changes, gas production is performed, and the change of the concentration of hydrogen sulfide in each detection area 1012 is also monitored in real time during the gas production process. Specifically, the gas production control valve 7 is opened, and the production pump 8 is started to produce the gas in the artificial core 101 from the injection and production pipe 2 and recover it to the gas recovery structure 5 through the gas production pipeline 6.

[0072] Step S8, repeating step S6 and step S7, and real-time monitoring the change of hydrogen sulfide concentration in each detection area 1012. Specifically, the first hydrogen sulfide detector 404 processes and analyzes the detection signals collected by the multiple hydrogen sulfide probes 402 to generate the concentration of hydrogen sulfide and uploads it to the processing terminal 403 for recording.

[0073] Step S9: interpolate the recorded hydrogen sulfide concentrations of each detection area 1012, and assign different colors to different hydrogen sulfide concentrations, so as to obtain a hydrogen sulfide distribution map of the artificial core 101. Specifically, the processing terminal 403 interpolates the recorded hydrogen sulfide concentrations of each detection area 1012, and assigns different colors to different hydrogen sulfide concentrations, so as to obtain a hydrogen sulfide distribution map of the artificial core 101.

[0074] Among them, in step S3, hydrogen sulfide-containing natural gas is injected into the artificial core 101 to a first preset pressure, thereby simulating a depleted gas reservoir containing hydrogen sulfide natural gas before the reservoir is built. Since the pressure of the depleted gas reservoir itself is relatively low, in the embodiment of the present invention, the upper limit of the pressure resistance of the sealing layer 102 is about 5MPa, and the first preset pressure is set to 2MPa, which can reflect the characteristics of the real gas reservoir. In step S6, natural gas is injected into the artificial core 101 to a second preset pressure to simulate the diffusion of natural gas into the depleted gas reservoir containing hydrogen sulfide natural gas to elutriate hydrogen sulfide. By setting the second preset pressure to 3MPa, the experimental requirements can be met, the process of hydrogen sulfide diffusion and elutriation can be seen, and the safety of the experiment can also be guaranteed, reducing the potential safety hazards caused by hydrogen sulfide leakage due to excessive pressure.

[0075] By repeating steps S6 and S7, the actual production process of the gas storage is simulated as a cycle of injection and production. According to the numerical simulation research, the hydrogen sulfide concentration increases from 20g / m 3 Can be reduced to 1.5g / m 3 After about fifteen cycles of hydrogen sulfide washing, the concentration of hydrogen sulfide changes very little. The injection-production cycle can be reasonably adjusted according to the experimental results, that is, the number of repetitions of step S6 and step S7. If the concentration of hydrogen sulfide is already very low and the concentration of hydrogen sulfide does not change significantly with the injection-production cycle, the washing process can be stopped to obtain the experimental results. In some embodiments of the present invention, the number of repetitions of step S6 and step S7 is set to four to seven times, and the hydrogen sulfide concentration can be washed to less than 1 mg / m 3 In some other embodiments of the present invention, steps S6 and S7 may be repeated until the hydrogen sulfide concentration is lower than the hydrogen sulfide concentration required for the study, for example, 2 mg / m 3 , 1.5mg / m 3 , 0.8mg / m 3 Etc., not specifically limited.

[0076] The above are only several embodiments of the present invention. Those skilled in the art may make various changes or modifications to the embodiments of the present invention based on the contents disclosed in the application documents without departing from the spirit and scope of the present invention.

Claims

1. An experimental device for studying the mechanism of hydrogen sulfide washing in sour gas reservoirs, characterized in that: include: A three-dimensional artificial core model, comprising a sealing layer and an artificial core, wherein the sealing layer is coated on the outside of the artificial core; A hydrogen sulfide detection mechanism, comprising a first hydrogen sulfide detector and a plurality of hydrogen sulfide probes, one end of the plurality of hydrogen sulfide probes passing through the sealing layer into a plurality of detection areas in the artificial core, and the other end of the plurality of hydrogen sulfide probes being electrically connected to the first hydrogen sulfide detector; At least one injection and production pipe, one end of which passes through the sealing layer and enters the artificial core; The gas injection mechanism is connected with the other end of the injection and production pipe.

2. The experimental device according to claim 1, characterized in that: The artificial core comprises a plurality of core layers, the plurality of core layers are stacked and spliced ​​in a vertical direction, and the permeability and / or porosity of each core layer is different.

3. The experimental device according to claim 1, characterized in that: The sealing layer is cast and coated on the artificial rock core by means of sealing material.

4. The experimental device according to claim 1, characterized in that: There are multiple injection and production pipes, and the multiple injection and production pipes are distributed near the edge of the artificial core.

5. The experimental device according to claim 1, characterized in that: The injection-production pipe is provided with an injection-production control valve and a pressure monitoring structure.

6. The experimental device according to claim 1, characterized in that: The hydrogen sulfide detection mechanism also includes a processing terminal, which is electrically connected to the first hydrogen sulfide detector. The processing terminal is used to generate a hydrogen sulfide distribution map of the artificial core according to the detection signal analysis and processing of the first hydrogen sulfide detector.

7. The experimental device according to claim 1, characterized in that: The gas injection mechanism includes a natural gas pipeline, a natural gas pipeline containing hydrogen sulfide and an injection pump. The natural gas pipeline connects the injection-production pipe with the natural gas supply structure. The natural gas pipeline containing hydrogen sulfide connects the injection-production pipe with the natural gas supply structure containing hydrogen sulfide. The injection pump is used to provide transportation power for natural gas from the natural gas pipeline to the injection-production pipe and / or hydrogen sulfide from the natural gas pipeline containing hydrogen sulfide to the injection-production pipe.

8. The experimental device according to claim 7, characterized in that: A natural gas control valve is provided on the natural gas pipeline, and a hydrogen sulfide-containing natural gas control valve is provided on the hydrogen sulfide-containing natural gas pipeline.

9. The experimental device according to claim 1, characterized in that: The experimental device also includes a gas recovery structure, which is connected to the injection and production pipe through a gas production pipeline. A gas production control valve and a production pump are provided on the gas production pipeline.

10. The experimental device according to claim 9, characterized in that: The gas production pipeline is also provided with a second hydrogen sulfide detector.

11. The experimental device according to claim 1, characterized in that: The experimental device also includes a vacuum pumping structure, which is used to connect to at least one of the injection and production pipes to vacuum the artificial core.

12. The experimental device according to claim 1, characterized in that: The experimental device also includes a box and a third hydrogen sulfide detector. The three-dimensional artificial core model is placed in the box, and the detection end of the third hydrogen sulfide detector extends into the gap between the box and the three-dimensional artificial core model.

13. An experimental method for studying the mechanism of hydrogen sulfide washing in sour gas reservoirs, characterized in that: The following steps are involved: S3, injecting hydrogen sulfide-containing natural gas into the artificial core until the pressure in the artificial core reaches a first preset pressure, and then stopping the injection of hydrogen sulfide-containing natural gas; S4, placing the artificial core for a preset time until the internal pressure of the artificial core reaches equilibrium; S5. Record the concentration of hydrogen sulfide in each detection area of ​​the artificial core; S6, injecting natural gas into the artificial core until the pressure in the artificial core reaches a second preset pressure, and stopping the injection, and monitoring the change of the concentration of hydrogen sulfide in each of the detection areas over time in real time; S7, when the concentration of hydrogen sulfide in each detection area no longer changes, gas collection is performed, and changes in the concentration of hydrogen sulfide in each detection area are also monitored in real time during the gas collection process; S8. Repeat step S6 and step S7, and monitor the change of the hydrogen sulfide concentration in each detection area in real time.

14. The experimental method for studying the hydrogen sulfide washing mechanism of sour gas reservoirs according to claim 13, characterized in that: Before step S3, the following steps are also included: S1. Detecting the sealing performance of the sealing layer coated on the artificial core to ensure that the sealing performance of the sealing layer meets the requirements; S2, evacuating the artificial core.

15. The experimental method for studying the hydrogen sulfide washing mechanism of sour gas reservoirs according to claim 13, characterized in that: The first preset pressure is 2 MPa; the second preset pressure is 3 MPa.

16. The experimental method for studying the hydrogen sulfide washing mechanism of sour gas reservoirs according to claim 13, characterized in that: Repeat step S6 and step S7 until the concentration of hydrogen sulfide is less than 1 mg / m 3 or the hydrogen sulfide concentration required for the study.

17. The experimental method for studying the hydrogen sulfide washing mechanism of sour gas reservoirs according to claim 13, characterized in that: After step S8, the method further includes the following steps: S9, performing interpolation calculation on the recorded hydrogen sulfide concentrations of each of the detection areas, and assigning different colors to different hydrogen sulfide concentrations, thereby obtaining a hydrogen sulfide distribution map of the artificial core.

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