Device and method for testing solubility of elemental sulfur during development of high-sulfur gas reservoirs

Abstract

The application discloses a testing device and method for element sulfur solubility in high-sulfur gas reservoir development process, and the testing device comprises a fluid injection system, a reservoir simulation system, a sulfur solubility metering system and a data tracking and processing system; the fluid injection system is connected with the reservoir simulation system; the reservoir simulation system is connected with the sulfur solubility metering system; the data tracking and processing system is connected with the sulfur solubility metering system; the fluid injection system is used for injecting a sulfur-containing gas sample into the reservoir simulation system and the sulfur solubility metering system; the reservoir simulation system is used for simulating the flow of the sulfur-containing gas sample in a reservoir and a complex interface physicochemical action process; the sulfur solubility metering system is used for metering the sulfur solubility in the sulfur-containing gas sample; and the data tracking and processing system is used for processing data. The testing device in the application comprises two sulfur solubility testing units, so that the testing precision is effectively improved, and the measurement loss and safety risk caused by the flow of the sulfur-containing gas sample in pipelines and valves are reduced.

Description

Technical Field

[0001] This invention belongs to the field of oil and gas exploration and development technology, and specifically relates to a testing device and method for the solubility of elemental sulfur during the development of high-sulfur gas reservoirs. Background Technology

[0002] The proven reserves of high-sulfur gas reservoirs in the Sichuan Basin exceed 900 billion cubic meters, with H2S content reaching as high as 493 g / m³. 3 High-sulfur gas reservoirs are one of the main battlegrounds for natural gas production in my country, and their development potential is enormous. However, the development of high-sulfur gas reservoirs generally faces the problem of sulfur particle deposition and blockage, posing a challenge to their safe and efficient development. Previous studies have shown that in the middle and late stages of high-sulfur gas reservoir development, pressure reduction in the near-wellbore zone leads to the precipitation of large amounts of elemental sulfur particles, which then block the reservoir and affect the gas well's production capacity. Elemental sulfur solubility data within the reservoir is an important reference indicator for evaluating whether sulfur particles precipitate and deposit, and the degree of deposition and blockage. How to accurately obtain sulfur solubility data in gas reservoirs and precisely quantify the sulfur particle precipitation pattern has become one of the key scientific issues in the field of high-sulfur gas reservoir development. Currently, scholars at home and abroad have used various methods to determine the sulfur solubility of sulfur-containing gas samples, obtaining valuable gas reservoir sulfur solubility data.

[0003] For example, Chinese patent document CN106124354A, published on November 16, 2016, discloses an online testing device and method for sulfur solubility in high-sulfur gas reservoirs. It includes a dual-channel sampling system, a CS2 absorption system for elemental sulfur, a high-temperature and high-pressure reaction system simulating the formation environment, a fluorescence sulfur determination system, a data acquisition system, and a cleaning and tail gas treatment system. The testing method includes sulfur-containing gas sample preparation, vacuum preparation, simulation of the high-temperature and high-pressure formation environment, elemental sulfur testing, total sulfur measurement, total sulfur testing after the sulfur dissolution reaction, data acquisition, and cleaning and tail gas treatment. This invention can safely, conveniently, accurately, and efficiently determine the solubility data of elemental sulfur in high-temperature and high-pressure high-sulfur gas reservoirs, laying the foundation for solving the widespread sulfur deposition problem in the development of high-sulfur gas reservoirs and providing scientific data support for formulating reasonable development plans for high-sulfur gas reservoirs.

[0004] For example, Chinese patent document CN109323953A, published on February 12, 2019, discloses a method for determining the solubility of elemental sulfur in sulfur-containing gases. The method includes: collecting sulfur-containing gas from a sulfur-containing gas reservoir and determining the sampling temperature and pressure; transferring the sulfur-containing gas into a sample mixing device, and oscillating the device at a preset temperature and pressure for a preset time; allowing the gas in the sample mixing device to pass through a backpressure valve and have its pressure reduced to the chamber pressure, then flowing into an adsorption tank; passing the gas flowing out of the adsorption tank through a gas flow meter, which measures the volume of the sulfur-containing gas at room temperature and chamber pressure; collecting the carbon disulfide liquid in the adsorption tank and transferring it to a collection tank; heating and then cooling the collection tank, and determining the mass of elemental sulfur in the collection tank; determining the room temperature and chamber pressure; and calculating the solubility of elemental sulfur in the sulfur-containing gas based on the sampling temperature, sampling pressure, room temperature, chamber pressure, mass of elemental sulfur, and volume of the sulfur-containing gas at room temperature and chamber pressure. This invention provides a relatively accurate determination of the solubility of elemental sulfur in sulfur-containing gases.

[0005] However, the prior art, represented by the aforementioned patent documents, still has the following problems:

[0006] (1) High sulfur content well bottom sampling is costly and risky, and the existing experimental methods are mainly aimed at the determination of sulfur solubility at a single point in the sulfur-containing sample under sampling pressure and temperature, which cannot reflect the changes in sulfur solubility under different pressure drops during reservoir development.

[0007] (2) There are more complex interfacial physicochemical interactions between elemental sulfur and the core (such as adsorption, dissolution, precipitation, etc.). When sulfur-containing natural gas flows through the porous media of the core during the pressure reduction development process, the sulfur content of the gas sample will change. However, the current testing methods cannot reflect the sulfur solubility change mechanism of sulfur-containing natural gas during the migration of sulfur-containing natural gas in the porous media of the reservoir core, and there is a lack of corresponding evaluation methods. Summary of the Invention

[0008] To address the aforementioned issues, this invention discloses a testing device for elemental sulfur solubility during the development of high-sulfur gas reservoirs, comprising: a fluid injection system, a reservoir simulation system, a sulfur solubility metering system, and a data tracking and processing system;

[0009] The fluid injection system is connected to the reservoir simulation system;

[0010] The reservoir simulation system is connected to the sulfur solubility metering system;

[0011] The data tracking and processing system is connected to the sulfur solubility metering system;

[0012] The fluid injection system is used to inject sulfur-containing gas samples into the reservoir simulation system and the sulfur solubility metering system;

[0013] The reservoir simulation system is used to simulate the flow of sulfur-containing gas samples in the reservoir and the complex interface physicochemical processes.

[0014] The sulfur solubility metering system is used to measure the sulfur solubility in sulfur-containing gas samples.

[0015] The data tracking and processing system is used to process data.

[0016] Furthermore, the fluid injection system includes: a downhole sulfur-containing gas sample container, a high-pressure intermediate container, a constant-pressure and constant-speed displacement pump, a nitrogen high-pressure cylinder, and a gas booster pump;

[0017] The downhole sulfur-containing gas sample tank is connected to a high-pressure intermediate container via a pipeline.

[0018] The constant pressure and constant speed displacement pump is connected to the high pressure intermediate container via pipeline.

[0019] The nitrogen high-pressure cylinder is connected to a gas booster pump via a pipeline.

[0020] Furthermore, the reservoir simulation system includes: a reservoir core simulation unit, a confining pressure control pump, a pressure detector one, and a pressure detector two;

[0021] The confining pressure control pump is connected to the reservoir core simulation unit via a pipeline;

[0022] The pressure detector is installed at one end of the reservoir core simulation unit;

[0023] The second pressure detector is located at the other end of the reservoir core simulation unit;

[0024] The reservoir core simulation unit is used to simulate the seepage process of sulfur-containing gas samples in the reservoir.

[0025] Furthermore, the reservoir core simulation unit includes: a full-diameter core holder, a rubber sleeve, a reservoir core, core support components, a hydraulic oil annular space, a hydraulic oil inlet, a gas inlet, a gas outlet, a front cover, and a rear cover;

[0026] The reservoir core is surrounded by a rubber sleeve;

[0027] A full-diameter core holder is provided around the rubber sleeve, and a hydraulic oil annular space is provided between the rubber sleeve and the full-diameter core holder.

[0028] The core support component is located within the hydraulic oil annular space and abuts against the rubber sleeve and the full-diameter core holder.

[0029] The front cover is disposed at one end of the full-diameter core holder, and the rear cover is disposed at the other end of the full-diameter core holder;

[0030] The front cover is provided with a gas inlet and a hydraulic oil inlet. The hydraulic oil inlet is connected to the hydraulic oil annular space and is connected to the confining pressure control pump through a pipeline. The gas inlet is connected to the high-pressure intermediate container and the gas booster pump through a pipeline.

[0031] The rear cover is provided with a gas outlet.

[0032] Furthermore, the sulfur solubility measurement system includes: sulfur solubility testing unit one and sulfur solubility testing unit two;

[0033] The sulfur solubility testing unit includes an intermediate container, a displacement pump, a back pressure valve, a back pressure pump, a sulfur element absorption container, and an electronic precision balance.

[0034] The air inlet of intermediate container one is connected to the high-pressure intermediate container and the gas booster pump via a pipeline, and the air outlet of intermediate container one is connected to the back pressure valve one via a pipeline; the liquid inlet of intermediate container one is connected to the displacement pump one via a pipeline.

[0035] The back pressure valve is connected to the back pressure pump and the sulfur element absorption container via pipelines.

[0036] The sulfur element absorption container is mounted on an electronic precision balance.

[0037] The sulfur solubility testing unit 1 is used to test the sulfur solubility of sulfur-containing gas samples under different pressures when they do not flow through the porous media of the core.

[0038] Furthermore, the second sulfur solubility testing unit includes: a second intermediate container, a second displacement pump, a second back pressure valve, a second back pressure pump, a second elemental sulfur absorption container, and a second electronic precision balance;

[0039] The air inlet of the intermediate container two is connected to the gas outlet via a pipeline, and the air outlet of the intermediate container two is connected to the back pressure valve two via a pipeline; the liquid inlet of the intermediate container two is connected to the displacement pump two via a pipeline.

[0040] The second back pressure valve is connected to the second back pressure pump and the second sulfur element absorption container via pipelines.

[0041] The second sulfur element absorption container is mounted on the second electronic precision balance.

[0042] The second sulfur solubility testing unit is used to test the sulfur solubility of sulfur-containing gas samples after they flow through the porous media of the core under different pressures.

[0043] Furthermore, it also includes: a gas component analysis system;

[0044] The gas component analysis system is connected to the sulfur solubility measurement system and the data tracking and processing system.

[0045] The gas component analysis system is an online fully automated gas chromatograph.

[0046] The online fully automated gas chromatograph is connected to back pressure valve two and sulfur elemental absorption container two via pipelines;

[0047] The online fully automated gas chromatograph is used to measure changes in gas components.

[0048] Furthermore, it also includes: exhaust gas treatment systems;

[0049] The exhaust gas treatment system is connected to the sulfur solubility metering system.

[0050] The exhaust gas treatment system includes exhaust gas treatment box one and exhaust gas treatment box two;

[0051] Both exhaust gas treatment box one and exhaust gas treatment box two include an H2S absorption container, exhaust gas combustion treatment equipment, and automatic detection alarm and treatment equipment for sulfur-containing gas samples.

[0052] The exhaust gas treatment box is connected to the sulfur element absorption container via a pipeline.

[0053] The exhaust gas treatment box 2 is connected to an online fully automated gas chromatograph and a sulfur element absorption container 2 via pipelines.

[0054] Furthermore, the data tracking and processing system is a computer.

[0055] A method for testing the solubility of elemental sulfur during the development of high-sulfur gas reservoirs includes the following steps:

[0056] The fluid injection system injects sulfur-containing gas samples into the sulfur solubility metering system and the reservoir simulation system;

[0057] A sulfur solubility metering system was used to determine the sulfur solubility of sulfur-containing gas samples under different pressures.

[0058] A sulfur solubility metering system was used to measure the sulfur solubility of sulfur-containing gas samples under different pressures after they passed through a reservoir simulation system.

[0059] The data tracking and processing system determines the rate of change of sulfur solubility of sulfur-containing gas samples based on the sulfur solubility of the samples and the sulfur solubility of the samples after they flow through the reservoir simulation system.

[0060] Furthermore, the rate of change in sulfur solubility is determined by the following formula:

[0061]

[0062] Among them, S i c is the rate of change in sulfur solubility. ic' represents the sulfur solubility of a sulfur-containing gas sample at iMPa pressure before it flows through the reservoir simulation system. i The value represents the sulfur solubility of a sulfur-containing gas sample at an iMPa pressure after it passes through a reservoir simulation system.

[0063] Furthermore, the sulfur-containing gas sample includes H2S, CO2, and CH4.

[0064] Compared with the prior art, the beneficial effects of the present invention are:

[0065] 1) The sulfur solubility metering system can be used to compare and analyze the changes in sulfur content in sulfur-containing gas samples after sulfur particles are released under different temperature and pressure conditions in real time. It can safely and efficiently obtain sulfur solubility change data under different pressure drops during actual reservoir production and development. The initial pressure system is maintained by high-pressure nitrogen to prevent sulfur particles from being released due to low pressure environment when sulfur-containing gas samples are injected.

[0066] 2) The reservoir conditions were simulated using real reservoir cores. A high-pressure environment was established in the reservoir using pre-positioned high-pressure N2. The original state saturation of the sulfur-containing gas sample was completed by constant-pressure injection of sulfur-containing gas sample combined with online testing using an online fully automated gas chromatograph.

[0067] 3) The provided testing method is mainly aimed at valuable downhole sulfur-containing gas samples. The sulfur solubility data under the abandoned pressure of the gas reservoir is first obtained through the sample transfer process. Then, the sulfur-containing gas sample is pressurized and resampled in a high-pressure intermediate container step by step. The sulfur solubility data of sulfur-containing gas samples under different pressures during the gas reservoir development process is obtained by combining the intermediate container and a precision electronic balance.

[0068] 4) The production process simulation of reservoir depletion development was adopted to obtain sulfur solubility data of sulfur-containing gas samples before and after flowing through the reservoir core. The change rate of sulfur solubility of sulfur-containing gas samples under different pressures in the initial state and after acting in the porous medium of the core was obtained, which provides theoretical support for the analysis and evaluation of the fluid state of high sulfur-containing gas reservoirs.

[0069] 5) The sulfur solubility measurement system includes sulfur solubility testing unit one and sulfur solubility testing unit two. Sulfur solubility testing unit one and sulfur solubility testing unit two are used to determine the sulfur solubility of samples under different conditions. Sulfur solubility testing unit one is used to test the sulfur solubility of sulfur-containing gas samples under different pressures before they flow through the porous media of the core. Sulfur solubility testing unit two is used to test the sulfur solubility of sulfur-containing gas samples under different pressures after they flow through the porous media of the core. The setting of two sulfur solubility testing units improves the accuracy of the test and reduces the measurement loss and safety risks caused by the flow of sulfur-containing gas samples in pipelines and valves.

[0070] Other features and advantages of the invention will be set forth in the description which follows, and will be apparent in part from the description, or may be learned by practicing the invention. The objects and other advantages of the invention may be realized and obtained by means of the structures pointed out in the description, claims and drawings. Attached Figure Description

[0071] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0072] Figure 1 A schematic diagram of the structure of the testing apparatus according to an embodiment of the present invention is shown;

[0073] Figure 2 A schematic diagram of the structure of a reservoir simulation unit according to an embodiment of the present invention is shown.

[0074] Attached reference numerals: 1. Downhole sulfur-containing gas sample container; 2. High-pressure intermediate container; 3. Constant-pressure and constant-speed displacement pump; 4. High-pressure nitrogen cylinder; 5. Gas booster pump; 6. Sulfur solubility branch inlet pipeline; 7. Reservoir simulation branch inlet pipeline; 8. Three-way valve one; 9. Three-way valve two; 10. Temperature-controlled sealed oven; 11. Automatic detection alarm and processing equipment for sulfur-containing gas samples; 12. Intermediate container one; 13. Displacement pump one; 14. Back pressure valve one; 15. Back pressure pump one; 16. Sulfur elemental absorption container one; 17. Electronic precision balance one; 18. Intermediate container two; 19. Displacement pump two; 20. Back pressure valve two; 21. Back pressure pump two; 22. Sulfur element absorption container II; 23. Electronic precision balance II; 24. Three-way valve III; 25. Reservoir core simulation unit; 26. Confining pressure control pump; 27. Pressure detector I; 28. Pressure detector II; 29. ​​Online fully automatic gas chromatograph; 30. Tail gas treatment box I; 31. Tail gas treatment box II; 32. Computer; 251. Full-diameter core holder; 252. Rubber sleeve; 253. Reservoir core; 254. Core support components; 255. Hydraulic oil annular space; 256. Hydraulic oil inlet; 257. Gas inlet; 258. Gas outlet; 259. Front cover; 260. Rear cover. Detailed Implementation

[0075] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0076] like Figure 1 As shown, the device for testing the elemental sulfur solubility during the development of high-sulfur gas reservoirs proposed in this invention includes: a fluid injection system, a reservoir simulation system, a sulfur solubility metering system, and a data tracking and processing system;

[0077] The fluid injection system is connected to the reservoir simulation system;

[0078] The reservoir simulation system is connected to the sulfur solubility metering system;

[0079] The data tracking and processing system is connected to the sulfur solubility metering system;

[0080] The fluid injection system is used to inject sulfur-containing gas samples from downhole sulfur-containing gas sample tank 1 into the reservoir simulation system and the sulfur solubility metering system;

[0081] The reservoir simulation system is used to simulate the flow of sulfur-containing gas samples in real reservoirs and the complex interface physicochemical processes.

[0082] The sulfur solubility metering system is used to measure the sulfur solubility in sulfur-containing gas samples.

[0083] The data tracking and processing system is used to process data.

[0084] Example 1

[0085] The sulfur solubility metering system includes sulfur solubility testing unit one and sulfur solubility testing unit two; sulfur solubility testing unit one includes intermediate container one 12, displacement pump one 13, back pressure valve one 14, back pressure pump one 15, sulfur elemental absorption container one 16 and electronic precision balance one 17.

[0086] The intermediate container 12 is equipped with a dedicated acid gas inlet and outlet port at its top. The inlet port is connected to the sulfur solubility branch inlet line 6 of the fluid injection system via a pipeline. The sulfur solubility branch inlet line 6 is connected to the high-pressure intermediate container 2 and the gas booster pump 5. The outlet port of the intermediate container 12 is connected to the back pressure valve 14 via a pipeline.

[0087] The intermediate container 12 is provided with a liquid inlet at the bottom, and the displacement pump 13 is connected to the liquid inlet at the bottom of the intermediate container 12 through a pipeline.

[0088] Back pressure valve 14 is connected to back pressure pump 15 and sulfur element absorption vessel 16 via pipelines.

[0089] A sulfur absorption container 16 is placed on an electronic precision balance 17. The inlet of the sulfur absorption container 16 is located on the side of the bottom of the container and is equipped with an inlet control valve. The inside of the sulfur absorption container 16 is provided with an inner cavity for storing sulfur solvent. The top of the sulfur absorption container 16 is provided with an outlet, which is connected to the tail gas treatment box 30 of the tail gas treatment system through a pipeline. For example, the sulfur solvent is carbon disulfide.

[0090] The three-way valve 29 of the fluid injection system is connected to the inlet pipeline 7 of the reservoir simulation branch of the reservoir simulation system, and the outlet pipeline of the reservoir simulation system is connected to the inlet interface of the sulfur solubility test unit 2.

[0091] The intermediate container 12 achieves precise control of the gas pressure and volume inside the container through a built-in piston combined with the pressure-transmitting liquid injected by the displacement pump 13, and is used to store gas samples.

[0092] Sulfur solubility test unit one is used to test the sulfur solubility of sulfur-containing gas samples under different pressures when they do not flow through the porous media of the core.

[0093] Displacement pump 13 is used to control the gas pressure inside intermediate container 12;

[0094] Back pressure valve 14 is used to control the gas sample flow rate;

[0095] Back pressure pump 15 is used to control the opening degree of back pressure valve 14;

[0096] Sulfur elemental absorption container 16 is used to store sulfur solvent and absorb elemental sulfur from sulfur-containing gas samples.

[0097] The electronic precision balance-17 is used to measure the amount of elemental sulfur absorbed by sulfur solvents.

[0098] The sulfur solubility testing unit 2 includes an intermediate container 2 18, a displacement pump 2 19, a back pressure valve 20, a back pressure pump 21, a sulfur element absorption container 2 22, and an electronic precision balance 2 23.

[0099] The top of the intermediate container 2 18 is equipped with a dedicated acid gas inlet and outlet port. The inlet port is connected to the outlet pipeline of the reservoir simulation system (or the intermediate container 2 18 is connected to the gas outlet 258 of the reservoir simulation system through a pipeline). The inlet and outlet pipelines are equipped with control valves. The outlet port of the intermediate container 2 18 is connected to the back pressure valve 2 20 through a pipeline.

[0100] The intermediate container 2 18 is provided with a liquid inlet at the bottom, and the displacement pump 2 19 is connected to the liquid inlet at the bottom of the intermediate container 2 18 through a pipeline.

[0101] Back pressure valve 20 is connected to the inlet of back pressure pump 21 and sulfur element absorption container 22 via pipeline;

[0102] The sulfur element absorption container 22 is placed on the electronic precision balance 23. The gas inlet of the sulfur element absorption container 22 is located at the bottom side of the container and is equipped with a control valve. The sulfur element absorption container 22 has an inner cavity for storing sulfur solvent. The top of the sulfur element absorption container 22 is equipped with a gas outlet, which is connected to the tail gas treatment box 21 of the tail gas treatment system through a pipeline.

[0103] Sulfur solubility testing unit two is used to test the sulfur solubility of sulfur-containing gas samples after they flow through the porous media of the core under different pressures.

[0104] The intermediate container 218 achieves precise control of the gas pressure and volume inside the container through the built-in piston combined with the pressure-transmitting fluid injected by the displacement pump 219, and is used to store sulfur-containing gas samples after flowing through the core.

[0105] Displacement pump 219 is used to control the gas sample pressure inside intermediate container 218;

[0106] Back pressure valve 20 is used to control the gas sample flow rate;

[0107] Back pressure pump 21 is used to control the opening degree of back pressure valve 20;

[0108] Sulfur element absorption container 22 is used to store sulfur solvent and absorb elemental sulfur from sulfur-containing gas samples.

[0109] Electronic precision balance 223, used to measure the amount of elemental sulfur absorbed by sulfur solvent;

[0110] The sulfur solubility measurement system includes two sulfur solubility testing units: Unit 1 and Unit 2. Unit 1 is used to determine the sulfur solubility of samples under different conditions. Unit 1 is used to test the sulfur solubility of sulfur-containing gas samples under different pressures before they flow through the porous core medium. Unit 2 is used to test the sulfur solubility of sulfur-containing gas samples under different pressures after they flow through the porous core medium. The two sulfur solubility testing units improve the accuracy of the test and reduce measurement losses and safety risks caused by the flow of sulfur-containing gas samples in pipelines and valves.

[0111] The testing device also includes a gas component analysis system. The gas component analysis system’s inlet is connected to the outlet of the back pressure valve 20 of the sulfur solubility metering system and the inlet of the sulfur elemental absorption container 22 via a pipeline and a three-way valve 24. The gas component analysis system’s outlet is connected to the tail gas treatment box 31 of the tail gas treatment system via a pipeline.

[0112] This embodiment is the most basic one. Except for the sulfur solubility metering system, the other fluid injection system, reservoir simulation system, gas component analysis system, and tail gas treatment system can all utilize existing technologies. Compared to existing technologies, the sulfur solubility metering system allows for real-time comparative analysis of the changes in elemental sulfur content in sulfur-containing gas samples after sulfur particle precipitation under different temperature and pressure conditions. It can safely and efficiently obtain sulfur solubility change data under different pressure drops during actual reservoir production and development. High-pressure nitrogen is used to maintain the initial pressure system during fluid flow simulation, preventing sulfur particle precipitation due to a low-pressure environment during sulfur-containing gas sample injection.

[0113] Example 2

[0114] As another preferred embodiment of the testing apparatus, based on Embodiment 1, a control valve is provided between intermediate container 12 and back pressure valve 14, and between intermediate container 28 and back pressure valve 20. A control valve is provided between displacement pump 13 and intermediate container 12, and between displacement pump 29 and intermediate container 28. Both intermediate containers 12 and 28 are equipped with pressure detection devices to display the pressure of the gas inside the containers in real time. Both intermediate containers 12 and 28 have an up-and-down rotating stirring function and have the largest known internal cavity. A control valve is provided between back pressure pump 15 and back pressure valve 14, and between back pressure pump 21 and back pressure valve 20. A drying absorption jacket is also provided on the top of the sulfur elemental absorption container to absorb the liquid carried out by the filtered gas to improve the accuracy of the test. A control valve is installed between the sulfur elemental absorption container 16 and the tail gas treatment box 30, and a control valve is installed between the sulfur elemental absorption container 22 and the tail gas treatment box 31.

[0115] The reservoir simulation system includes a reservoir core simulation unit 25, a confining pressure control pump 26, a pressure detector 1 27, and a pressure detector 2 28;

[0116] The confining pressure control pump 26 is connected to the reservoir core simulation unit 25 via a pipeline; pressure detector 1 27 is installed at one end of the reservoir core simulation unit 25; pressure detector 28 is installed at the other end of the reservoir core simulation unit 25.

[0117] Reservoir core simulation unit 25 is used to simulate the seepage process of sulfur-containing gas samples in the reservoir;

[0118] Confining pressure control pump 26 is used to simulate the pressure of the overlying rock in the reservoir;

[0119] Pressure detector 27 is used to detect the pressure at the front end of the core sample.

[0120] Pressure detector 28 is used to detect the pressure at the rear end of the core.

[0121] like Figure 2As shown, the reservoir core simulation unit 25 includes a full-diameter core holder 251, a rubber sleeve 252, a reservoir core 253, a core support component 254, a hydraulic oil annular space 255, a hydraulic oil inlet 256, a gas inlet 257, a gas outlet 258, a front cover 259, and a rear cover 260.

[0122] Reservoir core 253 is surrounded by a rubber sheath 252;

[0123] A full-diameter core holder 251 is provided around the rubber sleeve 252, and a hydraulic oil annular space 255 is provided between the rubber sleeve 252 and the full-diameter core holder 251 for filling with hydraulic oil.

[0124] The core support component 254 is located in the hydraulic oil annular space 255 and abuts against the rubber sleeve 252 and the full-diameter core clamp 251.

[0125] The front cover 259 is located at one end of the full-diameter core holder 251 and is embedded in the rubber sleeve 252 and the full-diameter core holder 251. The rear cover 260 is located at the other end of the full-diameter core holder 251 and is embedded in the rubber sleeve 252 and the full-diameter core holder 251.

[0126] The front cover 259 is provided with a gas inlet 257 and a hydraulic oil inlet 256. The hydraulic oil inlet 256 is connected to the hydraulic oil annular space 255. The hydraulic oil inlet 256 is connected to the confining pressure control pump 26 through a pipeline. The gas inlet 257 is connected to the high pressure intermediate container 2 and the gas booster pump 5 through a pipeline.

[0127] The rear cover 260 is provided with a gas outlet 258;

[0128] Full-diameter core holder 251, used to hold reservoir core 253;

[0129] Rubber sleeve 252 is used to separate hydraulic oil and reservoir core 253, and also serves to transmit confining pressure;

[0130] Reservoir core 253 is a representative full-diameter core of the reservoir. After obtaining its porosity and permeability parameters, it is put into the rubber sleeve 252 and then placed into the full-diameter core holder 251.

[0131] Core support component 254 is used to support reservoir core 253 inserted into full-diameter core holder 251;

[0132] The hydraulic oil annular space 255 is used to store hydraulic oil.

[0133] Hydraulic oil inlet 256 is used for hydraulic oil injection;

[0134] Gas inlet 257 is used for the entry of sulfur-containing gas samples;

[0135] Gas outlet 258 is used for the outflow of sulfur-containing gas samples;

[0136] Front cover 259 and rear cover 260 are used for sealing.

[0137] Preferably, the sulfur-containing gas sample inlet pipeline of the full-diameter core holder 251 is equipped with a control valve, the outlet pipeline of the confining pressure control pump 26 is equipped with a control valve, and the outlet pipeline of the full-diameter core holder 251 is equipped with a control valve.

[0138] In this embodiment, apart from the sulfur solubility metering system and the reservoir simulation system, the remaining fluid injection system, gas component analysis system, and tail gas treatment system can all adopt existing technologies. Compared with existing technologies, the actual reservoir core 253 is used to simulate reservoir conditions, a high-pressure reservoir environment is established using pre-pressurized N2, and the sulfur-containing gas sample is saturated in its original state by constant-pressure injection combined with online fully automated gas chromatography 29.

[0139] Example 3

[0140] As the preferred embodiment of the testing device, based on Embodiment 2, such as Figure 1 As shown, the fluid injection system includes a downhole sulfur-containing gas sample tank 1, a high-pressure intermediate container 2, a constant pressure and constant speed displacement pump 3, a nitrogen high-pressure gas cylinder 4, a gas booster pump 5, a sulfur solubility branch gas inlet pipeline 6, a reservoir simulation branch gas inlet pipeline 7, a three-way valve 1 8, and a three-way valve 2 9.

[0141] The downhole sulfur-containing gas sample tank 1 is connected to the inlet of the high-pressure intermediate container 2 via a pipeline; the constant pressure and constant speed displacement pump 3 is connected to the bottom liquid inlet of the high-pressure intermediate container 2 via a pipeline; the outlet of the nitrogen high-pressure cylinder 4 is connected to the inlet of the gas booster pump 5 via a pipeline; the output pipeline of the gas booster pump 5 is connected to the reservoir simulation branch inlet pipeline 7 via a three-way valve 2 9; the three-way valve 1 8 connects the outlet pipeline of the high-pressure intermediate container 2, the sulfur solubility branch inlet pipeline 6, and the reservoir simulation branch inlet pipeline 7.

[0142] The high-pressure intermediate container 2 is equipped with a dedicated acid gas inlet and outlet port at the top and a dedicated pressure-transmitting fluid inlet at the bottom. The high-pressure intermediate container 2 has an up-and-down rotating stirring function. The high-pressure intermediate container 2 achieves precise control of the gas pressure and volume inside the container by using a built-in piston combined with the pressure-transmitting fluid injected by the constant pressure and constant speed displacement pump 3. The high-pressure intermediate container 2 is equipped with a pressure detection device to display the gas pressure inside the container in real time.

[0143] A control valve is installed between the downhole sulfur-containing gas sample tank 1 and the high-pressure intermediate container 2. A control valve is installed between the constant pressure and constant speed displacement pump 3 and the high-pressure intermediate container 2. A control valve is installed on the inlet line of the gas booster pump 5. A control valve is installed on the outlet line of the gas booster pump 5.

[0144] Downhole sulfur-containing gas sample container 1, used to store sulfur-containing gas samples;

[0145] High-pressure intermediate container 2 is used to control the volume of sulfur-containing gas sample inside the container;

[0146] The constant pressure and constant speed displacement pump 3 is used to control the pressure of the sulfur-containing gas sample in the high pressure intermediate container 2;

[0147] Nitrogen high-pressure cylinder 4, used for storing nitrogen;

[0148] Gas booster pump 5 is used to pressurize and inject nitrogen gas into nitrogen high-pressure cylinder 4.

[0149] Sulfur solubility branch inlet line 6 is used for sulfur-containing gas samples to flow into sulfur solubility testing unit 1;

[0150] 7 is a reservoir simulation branch gas inlet pipeline used for sulfur-containing gas samples to flow into sulfur solubility measurement unit 2.

[0151] Three-way valve 8 is used to connect the high-pressure intermediate container 2, the sulfur solubility branch inlet pipeline 6, and the reservoir simulation branch inlet pipeline 7.

[0152] Three-way valve 29 is used to connect gas booster pump 5, reservoir simulation branch air inlet line 7 and three-way valve 18.

[0153] Preferably, the testing device for the solubility of elemental sulfur during the development of high-sulfur gas reservoirs also includes a temperature-controlled sealed oven 10 and an automatic detection alarm and processing device 11 for sulfur-containing gas samples; the automatic detection alarm and processing device 11 for sulfur-containing gas samples is connected to the data tracking and processing system.

[0154] The following components are located inside the downhole sulfur-containing gas sample tank 1, high-pressure intermediate container 2, sulfur solubility branch gas inlet pipeline 6, reservoir simulation branch gas inlet pipeline 7, three-way valve 1 8, three-way valve 2 9, automatic detection alarm and processing equipment for sulfur-containing gas sample 11, intermediate container 1 12, back pressure valve 1 14, sulfur elemental absorption container 1 16, electronic precision balance 1 17, intermediate container 2 18, back pressure valve 2 20, sulfur elemental absorption container 2 22, electronic precision balance 2 23, three-way valve 3 24, reservoir core simulation unit 25, pressure detector 1 27, and pressure detector 2 28 are all located inside the temperature-controlled sealed oven 10; all other components are located outside the temperature-controlled sealed oven 10.

[0155] The automatic detection alarm and processing equipment 11 for sulfur-containing gas samples has the function of detecting trace amounts of H2S gas components, and has H2S alarm function and gas disposal function. After detecting H2S gas, it sends an H2S leak alarm to the technicians in the laboratory through the alarm. At the same time, when H2S gas leak is detected, H2S absorbent can be sprayed into the temperature-controlled sealed oven 10.

[0156] Preferably, the device for testing the solubility of elemental sulfur during the development of high-sulfur gas reservoirs further includes: a gas composition analysis system;

[0157] The gas component analysis system is connected to the sulfur solubility measurement system and the data tracking and processing system;

[0158] The gas component analysis system is an online fully automatic gas chromatograph 29. The gas inlet of the online fully automatic gas chromatograph 29 is connected to the gas outlet of the back pressure valve 20 and the gas inlet of the sulfur element absorption container 22 via pipeline and three-way valve 24. The gas outlet of the online fully automatic gas chromatograph 29 is connected to the tail gas treatment box 21 via pipeline. The online fully automatic gas chromatograph 29 automatically obtains the required test gas volume through the conversion setting of the built-in valve. The remaining gas volume is discharged to the tail gas treatment box 21 via pipeline.

[0159] Preferably, a control valve is installed on the inlet interface line of the online fully automated gas chromatograph 29. A control valve is also installed between the online fully automated gas chromatograph 29 and the exhaust gas treatment box 31.

[0160] The online fully automated gas chromatograph 29 is used to measure changes in gas components and determine whether experimental testing requirements are met.

[0161] The testing equipment for elemental sulfur solubility during the development of high-sulfur gas reservoirs also includes: a tail gas treatment system;

[0162] The exhaust gas treatment system is connected to the sulfur solubility metering system; the exhaust gas treatment system includes exhaust gas treatment box 1 30 and exhaust gas treatment box 2 31, both of which include an H2S absorption container, exhaust gas combustion treatment equipment and automatic detection alarm and treatment equipment 11 for sulfur-containing gas samples.

[0163] The inlet of exhaust gas treatment box 30 is connected to sulfur absorption container 16 via a pipeline. Exhaust gas treatment box 31 contains two inlet pipelines: inlet pipeline 1 is connected to the outlet of online fully automatic gas chromatograph 29, and inlet pipeline 2 is connected to sulfur absorption container 22. The H2S absorption container contains chemical reagents that can absorb H2S components in the gas. The exhaust gas combustion treatment equipment can burn the methane waste gas after H2S absorption, reducing greenhouse gas emissions.

[0164] Preferably, a control valve is installed between the exhaust gas treatment box 30 and the sulfur absorption container 16. Control valves are also installed on both the first and second inlet lines of the exhaust gas treatment box 31.

[0165] The exhaust gas treatment box 30 is used to absorb experimental waste gas.

[0166] Exhaust gas treatment box 231 is used to absorb experimental waste gas;

[0167] H2S absorption container, used to absorb H2S in gas samples;

[0168] Exhaust gas combustion treatment equipment is used to treat CH4 in gas samples;

[0169] Automatic detection alarm and processing equipment 11 for sulfur-containing gas samples, used for detecting H2S and triggering alarms.

[0170] Preferably, the testing device for elemental sulfur solubility during the development of high-sulfur gas reservoirs further includes: a data tracking and processing system, mainly a computer 32 with high-performance data receiving and processing capabilities. The computer 32 is connected to the gas component analysis system, the sulfur solubility metering system, and the automatic detection alarm and processing equipment 11 for sulfur-containing gas samples via data transmission lines. It acquires data from each metering component in real time, generating sulfur solubility curves for sulfur-containing gas samples, sulfur solubility curves after the sulfur-containing gas sample flows through the reservoir simulation system, and gas component change curves. The computer 32 is used for data processing.

[0171] All connecting pipelines use 2mm inner diameter pipes; heating wires are wound around control valves, three-way valves, and back pressure valves to maintain an extra high temperature and minimize the loss of sulfur particles; all pipes, valves, intermediate containers, back pressure valves, and other materials that come into contact with H2S gas are made of corrosion-resistant Hastelloy.

[0172] Based on the aforementioned testing device for elemental sulfur solubility during the development of high-sulfur gas reservoirs, this invention proposes a method for testing elemental sulfur solubility during the development of high-sulfur gas reservoirs, comprising the following steps:

[0173] S1: The fluid injection system injects sulfur-containing gas samples into the sulfur solubility metering system and the reservoir simulation system;

[0174] Open the temperature control system of the temperature-controlled sealed oven 10 and set the temperature to the reservoir temperature of 80℃. Connect the pipeline between the downhole sulfur-containing gas sample tank 1 and the high-pressure intermediate container 2. Use the constant pressure and constant speed displacement pump 3 to place the piston of the high-pressure intermediate container 2 at the top of the container to reduce impurity gas in the container. Open the outlet valve of the downhole sulfur-containing gas sample tank 1 and the inlet valve of the high-pressure intermediate container 2. At the same time, control the constant pressure and constant speed displacement pump 3 to slowly push the built-in piston of the high-pressure intermediate container 2 backward. When the gas pressure in the high-pressure intermediate container 2 drops to the gas reservoir waste pressure of 10MPa, close the outlet valve of the downhole sulfur-containing gas sample tank 1 and the inlet valve of the high-pressure intermediate container 2. Let it stand for 24 hours to allow the sulfur elemental particles precipitated due to pressure changes to fully settle. Inject the sulfur-containing gas sample into the sulfur solubility metering system and the reservoir simulation system.

[0175] Among them, the maximum volume of the high-pressure intermediate container 2 should be at least greater than the volume V0 of the gas in the downhole sulfur-containing gas sample tank 1 under the gas reservoir abandonment pressure. The calculation formula is as follows:

[0176]

[0177] In the formula, V0 is the volume of gas in the downhole sulfur-containing gas sample tank 1 under the gas reservoir abandonment pressure;

[0178] P0—Gas reservoir abandonment pressure;

[0179] Z0—Gas deviation coefficient under abandoned gas reservoir pressure;

[0180] P1—Sampling pressure;

[0181] V1—Volume of downhole sulfur-containing gas sample container 1;

[0182] Z1—Gas deviation coefficient at sampling pressure.

[0183] The sulfur-containing gas sample in the downhole sulfur-containing gas sample container 1 is a downhole sulfur-containing gas sample. The sampling temperature is 80℃ and the sampling pressure is 40MPa.

[0184] The sulfur-containing gas sample had a molar content of 15.6% for H2S, 6.3% for CO2, and 78.1% for CH4.

[0185] Two samples of sulfur-containing gas from the well should be obtained at least at the same time point to further ensure the reliability of the gas volume used in the experiment and the data comparison.

[0186] S2: The sulfur solubility metering system measures the sulfur solubility of sulfur-containing gas samples before they flow through the reservoir simulation system at different pressures;

[0187] Using displacement pump 13, the piston of intermediate container 12 is positioned at the top. The inlet valve of intermediate container 12 is opened, the control valve of sulfur solubility branch inlet line 6 is opened, and the outlet valve of high-pressure intermediate container 2 is opened. Gas from high-pressure intermediate container 2 is injected into intermediate container 12 at a constant pressure of 10 MPa using constant-pressure, constant-speed displacement pump 3. Simultaneously, displacement pump 13 is controlled to slowly retract the piston to the preset maximum position at the bottom of intermediate container 12, filling the maximum inner cavity of the container with gas to prevent sulfur particle precipitation caused by sudden pressure changes. Then, all control valves are closed, and displacement pump 13 is used to maintain the pressure of intermediate container 12. The pressure of the sulfur-containing gas sample in intermediate container 12 is 10 MPa. After rotating and stirring for 2 hours, the trace amounts of sulfur particles that precipitate out are fully dissolved. Then, the control valve of the outlet pipeline of intermediate container 12 is opened, and the sulfur-containing gas sample is slowly injected into the sulfur elemental absorption container 16 through back pressure valve 14 and back pressure pump 15. Simultaneously, the outlet valve of sulfur elemental absorption container 16 is opened, and the sulfur-containing gas sample, after absorption and drying by elemental sulfur, is connected to the tail gas treatment box 30 for desulfurization and combustion treatment to reduce tail gas pollution. The change in the mass of the sulfur solvent before and after the injection of the sulfur-containing gas sample is recorded using an electronic precision balance 17. 10 The sulfur solubility of the sulfur-containing gas sample at that pressure point can then be calculated using the following formula:

[0188]

[0189] In the formula, C 10 —Sulfur solubility in sulfur-containing gas samples at a reservoir pressure of 10 MPa;

[0190] m 10 —Data on the change in mass of sulfur solvent before and after injection of sulfur-containing gas sample;

[0191] V2—The maximum internal volume of the intermediate container 12.

[0192] When the piston of the intermediate container 12 retracts to the bottom preset position, it has a known maximum internal volume V2, which is only 1 / 5 to 1 / 10 of the maximum volume of the high pressure intermediate container 2.

[0193] After obtaining the sulfur solubility data at the first pressure point, i.e. the gas reservoir waste pressure, the gas pressure in the high-pressure intermediate container 2 is increased to 15MPa using a constant pressure and constant speed displacement pump 3. Then, the high-pressure intermediate container 2 is continuously stirred and rotated for 12 hours, so that some of the sulfur particles precipitated at the low pressure of 10MPa are redissolved in the gas at 15MPa. After standing for 24 hours, the sulfur particles that are not dissolved in the gas are redeposited to the bottom of the container.

[0194] The above steps were then repeated to sequentially increase the pressure, obtaining gaseous sulfur solubility data at 20 MPa, 25 MPa, 30 MPa, 35 MPa, and 40 MPa. i Plot the sulfur solubility curves of sulfur-containing gas samples under different pressures:

[0195]

[0196] In the formula, c i —Sulfur solubility in sulfur-containing gas samples at a reservoir pressure of iMPa;

[0197] mi—Data on the change in mass of sulfur solvent before and after injection of sulfur-containing gas sample at a reservoir pressure of iMPa;

[0198] V2—Maximum internal volume of intermediate container 12;

[0199] S3: The sulfur solubility metering system measures the sulfur solubility of sulfur-containing gas samples under different pressures after passing through the reservoir simulation system;

[0200] Simulated reservoir simulation system; Select a representative full-diameter reservoir core 253 with a diameter of 10cm. Multiple full-diameter cores of different lengths can be spliced ​​together to form a 1m combined full-diameter reservoir core 253. After testing the porosity and permeability parameters, put it into the rubber sleeve 252 and place it into the full-diameter core holder 251.

[0201] Establishing the original pressure environment of the reservoir: Open the outlet valve of the nitrogen high-pressure cylinder 4, open the outlet valve of the gas booster pump 5, open the inlet and outlet valves of the full-diameter core holder 251, and open the inlet and outlet valves of the intermediate container 18. Use the displacement pump 19 to retract the piston of the intermediate container 18 to the bottom of the preset maximum inner cavity. Use the gas booster pump 5 to inject nitrogen from the nitrogen high-pressure cylinder 4 into the reservoir core 253 of the full-diameter core holder 251 and into the intermediate container 18, while controlling... Back pressure pump 21 and back pressure valve 20 maintain the pressure of gas in reservoir core 253 and nitrogen in intermediate container 18 in full-diameter core holder 251 at around the original sampling pressure of 40 MPa. During nitrogen filling, the confining pressure control pump 26 is controlled to always keep the confining pressure of full-diameter core holder 251 about 5 MPa greater than the gas pressure inside reservoir core 253. After the original pressure environment of the reservoir is established, the outlet valve of nitrogen high-pressure cylinder 4 and the outlet valve of gas booster pump 5 are closed.

[0202] Open the inlet and outlet valves of the online fully automatic gas chromatograph 29, start the tail gas treatment box 31, and use the constant pressure and constant speed displacement pump 3 to inject the high-pressure sulfur-containing gas sample, which has been stirred in the high-pressure intermediate container 2, into the reservoir core 253 of the full-diameter core holder 251 to displace the nitrogen components in the pores. The pressure of the high-pressure sulfur-containing gas sample is 40 MPa. Control the back pressure pump 21 and back pressure valve 20 to make the gas in the reservoir core 253 flow out steadily at a low rate. When the online fully automatic gas chromatograph 29 shows that the gas composition is close to the original gas composition, that is, the molar content of H2S is 15.6%, the molar content of CO2 is 6.3%, and the molar content of CH4 is 78.1%, it can be considered that the sulfur-containing gas sample in the reservoir core 253 is saturated. After the sulfur-containing gas sample is saturated, close the inlet and outlet valves of the full-diameter core holder 251 and the inlet and outlet valves of the online fully automatic gas chromatograph 29.

[0203] Pressure drop development simulation: Open the inlet and outlet valves of the full-diameter core holder 251, open the inlet valve of the sulfur elemental absorption container 22, open the control valve on the inlet pipeline 2 of the tail gas treatment box 21, and control the back pressure pump 21 and back pressure valve 20 to allow the high-pressure sulfur-containing gas sample in the reservoir core 253 and intermediate container 28 to flow through the sulfur elemental absorption container 22 and finally into the tail gas treatment box 21 at an extremely low gas flow rate;

[0204] During the pressure reduction development process, sulfur solubility testing was conducted. When the pressure detection device showed a pressure of 35 MPa in reservoir core 253 and intermediate container 2 18, the inlet valve of intermediate container 2 18 was closed. The sulfur-containing gas sample in intermediate container 2 18 was then completely driven into sulfur elemental absorption container 2 22 via displacement pump 2 19. The mass change m' after the absorption of elemental sulfur by electronic precision balance 2 23 was recorded. 35 The sulfur solubility of sulfur in a sulfur-bearing gas sample flowing through reservoir core 253 during actual gas reservoir development was obtained as follows:

[0205]

[0206] In the formula, c' 35 —The sulfur solubility of a sulfur-containing gas sample was measured at 35 MPa pressure after passing through reservoir core 253;

[0207] m' 35 —Data on the change in mass of sulfur solvent before and after injection of sulfur-containing gas sample;

[0208] V3—The maximum internal volume of intermediate container II 18;

[0209] Open the inlet valve of intermediate container 218, and continue to simulate the depletion-type pressure drop development using back pressure pump 21 and back pressure valve 20. Repeat the previous step when the pressure detection device displays 30MPa, 25MPa, 20MPa, 15MPa, and 10MPa to obtain the sulfur solubility c' of sulfur-containing gas samples flowing through reservoir core 253 at different pressure stages during actual gas reservoir development. i And plot the sulfur solubility curves under different pressures:

[0210]

[0211] c' i —The sulfur solubility of a sulfur-containing gas sample under iMPa pressure after passing through reservoir core 253;

[0212] m'—Data on the change in mass of sulfur solvent before and after injection of sulfur-containing gas sample;

[0213] V3—The maximum internal volume of intermediate container II 18;

[0214] S4: The data tracking and processing system determines the rate of change in sulfur solubility of sulfur-containing gas samples during reservoir seepage due to complex interface physicochemical effects, based on the sulfur solubility of the sulfur-containing gas samples before and after they flow through the reservoir simulation system.

[0215] Furthermore, the change rate of sulfur solubility in sulfur-containing gas samples under different pressures after initial conditions and within the porous media of the core (sulfur-containing gas samples flowing through reservoir core 253) can be obtained as follows:

[0216]

[0217] Among them, S i c is the rate of change in sulfur solubility. i The solubility of sulfur in a sulfur-containing gas sample at iMPa pressure before it flows through the reservoir simulation system is given.

[0218] The testing method proposed in this invention is primarily aimed at valuable downhole sulfur-containing gas samples. First, initial sulfur solubility data under reservoir abandonment pressure is obtained through a sample transfer process. Then, the sulfur-containing gas sample is resampled by progressively pressurizing it in a high-pressure intermediate container 2. Combined with the intermediate container and a precision electronic balance, sulfur solubility data of the sulfur-containing gas sample under different pressures during reservoir development are obtained. A production process simulation of reservoir depletion development is employed to obtain sulfur solubility data of the sulfur-containing gas sample after flowing through reservoir core 253. The rate of change in sulfur solubility of the sulfur-containing gas sample under different pressures, in its initial state and after acting within the porous media of the core, is obtained, providing theoretical support for the analysis and evaluation of the fluid state of high-sulfur-containing gas reservoirs.

[0219] Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A testing device for the solubility of elemental sulfur during the development of high-sulfur gas reservoirs, characterized in that, include: Fluid injection system, reservoir simulation system, sulfur solubility metering system, and data tracking and processing system; The fluid injection system is connected to the reservoir simulation system; The reservoir simulation system is connected to the sulfur solubility metering system; The data tracking and processing system is connected to the sulfur solubility metering system; The fluid injection system is used to inject sulfur-containing gas samples into the reservoir simulation system and the sulfur solubility metering system; The reservoir simulation system is used to simulate the flow of sulfur-containing gas samples in the reservoir and the complex interface physicochemical processes. The sulfur solubility metering system is used to measure the sulfur solubility in sulfur-containing gas samples. The data tracking and processing system is used to process data; The sulfur solubility measurement system includes: sulfur solubility testing unit one and sulfur solubility testing unit two; The sulfur solubility testing unit includes an intermediate container (12), a displacement pump (13), a back pressure valve (14), a back pressure pump (15), a sulfur element absorption container (16), and an electronic precision balance (17). The air outlet of intermediate container one (12) is connected to back pressure valve one (14) via a pipeline; the liquid inlet of intermediate container one (12) is connected to displacement pump one (13) via a pipeline. The back pressure valve (14) is connected to the back pressure pump (15) and the sulfur element absorption container (16) via pipelines; The sulfur element absorption container (16) is mounted on an electronic precision balance (17); The sulfur solubility testing unit 1 is used to test the sulfur solubility of sulfur-containing gas samples under different pressures when they do not flow through the porous media of the core. The second sulfur solubility testing unit includes: a second intermediate container (18), a second displacement pump (19), a second back pressure valve (20), a second back pressure pump (21), a second sulfur element absorption container (22), and a second electronic precision balance (23). The air outlet of intermediate container two (18) is connected to back pressure valve two (20) via a pipeline; the liquid inlet of intermediate container two (18) is connected to displacement pump two (19) via a pipeline. The second back pressure valve (20) is connected to the second back pressure pump (21) and the second sulfur element absorption container (22) via pipelines; The sulfur element absorption container two (22) is mounted on the electronic precision balance two (23); The second sulfur solubility testing unit is used to test the sulfur solubility of sulfur-containing gas samples after they flow through the porous media of the core under different pressures.

2. The testing device for elemental sulfur solubility during the development of high-sulfur gas reservoirs according to claim 1, characterized in that, The fluid injection system includes: a downhole sulfur-containing gas sample tank (1), a high-pressure intermediate container (2), a constant-pressure and constant-speed displacement pump (3), a nitrogen high-pressure cylinder (4), and a gas booster pump (5). The downhole sulfur-containing gas sample container (1) is connected to the high-pressure intermediate container (2) via a pipeline; The constant pressure and constant speed displacement pump (3) is connected to the high pressure intermediate container (2) through a pipeline; The nitrogen high-pressure cylinder (4) is connected to the gas booster pump (5) via a pipeline.

3. The testing device for elemental sulfur solubility during the development of high-sulfur gas reservoirs according to claim 2, characterized in that, The reservoir simulation system includes: a reservoir core simulation unit (25), a confining pressure control pump (26), a pressure detector one (27), and a pressure detector two (28). The confining pressure control pump (26) is connected to the reservoir core simulation unit (25) via a pipeline; The pressure detector (27) is located at one end of the reservoir core simulation unit (25); The second pressure detector (28) is located at the other end of the reservoir core simulation unit (25); The reservoir core simulation unit (25) is used to simulate the seepage process of sulfur-containing gas samples in the reservoir.

4. The testing device for elemental sulfur solubility during the development of high-sulfur gas reservoirs according to claim 3, characterized in that, The reservoir core simulation unit (25) includes: a full-diameter core holder (251), a rubber sleeve (252), a reservoir core (253), a core support component (254), a hydraulic oil annular space (255), a hydraulic oil inlet (256), a gas inlet (257), a gas outlet (258), a front cover (259), and a rear cover (260); A rubber sleeve (252) is provided around the reservoir core (253); The rubber sleeve (252) is surrounded by a full-diameter core holder (251), and a hydraulic oil annular space (255) is provided between the rubber sleeve (252) and the full-diameter core holder (251). The core support component (254) is disposed within the hydraulic oil annular space (255) and abuts against the rubber sleeve (252) and the full-diameter core clamp (251); The front cover (259) is disposed at one end of the full-diameter core holder (251), and the rear cover (260) is disposed at the other end of the full-diameter core holder (251); The front cover (259) is provided with a gas inlet (257) and a hydraulic oil inlet (256). The hydraulic oil inlet (256) is connected to the hydraulic oil annular space (255). The hydraulic oil inlet (256) is connected to the confining pressure control pump (26) through a pipeline. The gas inlet (257) is connected to the high-pressure intermediate container (2) and the gas booster pump (5) through a pipeline. The rear cover (260) is provided with a gas outlet (258).

5. The testing device for elemental sulfur solubility during the development of high-sulfur gas reservoirs according to claim 4, characterized in that, The air inlet of the intermediate container (12) is connected to the high-pressure intermediate container (2) and the gas booster pump (5) via a pipeline.

6. The testing device for elemental sulfur solubility during the development of high-sulfur gas reservoirs according to claim 5, characterized in that, The air inlet of the intermediate container 2 (18) is connected to the gas outlet (258) via a pipeline.

7. The testing device for elemental sulfur solubility during the development of high-sulfur gas reservoirs according to claim 6, characterized in that, It also includes: gas component analysis system; The gas component analysis system is connected to the sulfur solubility measurement system and the data tracking and processing system. The gas component analysis system is an online fully automated gas chromatograph (29). The online fully automated gas chromatograph (29) is connected to the back pressure valve (20) and the sulfur element absorption container (22) via pipelines; The online fully automated gas chromatograph (29) is used to measure changes in gas components.

8. The testing device for elemental sulfur solubility during the development of high-sulfur gas reservoirs according to claim 7, characterized in that, Also includes: Exhaust gas treatment system; The exhaust gas treatment system is connected to the sulfur solubility metering system. The exhaust gas treatment system includes exhaust gas treatment box one (30) and exhaust gas treatment box two (31); Both the exhaust gas treatment box one (30) and the exhaust gas treatment box two (31) include an H2S absorption container, an exhaust gas combustion treatment device and an automatic detection alarm and treatment device (11) for sulfur-containing gas samples. The exhaust gas treatment box (30) is connected to the sulfur element absorption container (16) via a pipeline; The exhaust gas treatment box 2 (31) is connected to the online fully automatic gas chromatograph (29) and the sulfur element absorption container 2 (22) via pipelines.

9. The apparatus for testing the solubility of elemental sulfur during the development of high-sulfur gas reservoirs according to claim 1 or 8, characterized in that, The data tracking and processing system is a computer (32).

10. A method for testing the elemental sulfur solubility during the development of high-sulfur gas reservoirs, using the testing apparatus for elemental sulfur solubility during the development of high-sulfur gas reservoirs as described in any one of claims 1-9, characterized in that, Includes the following steps: The fluid injection system injects sulfur-containing gas samples into the sulfur solubility metering system and the reservoir simulation system; A sulfur solubility metering system was used to determine the sulfur solubility of sulfur-containing gas samples under different pressures. A sulfur solubility metering system was used to measure the sulfur solubility of sulfur-containing gas samples under different pressures after they passed through a reservoir simulation system. The data tracking and processing system determines the rate of change of sulfur solubility of sulfur-containing gas samples based on the sulfur solubility of the samples and the sulfur solubility of the samples after they flow through the reservoir simulation system.

11. The method for testing the solubility of elemental sulfur during the development of high-sulfur gas reservoirs according to claim 10, characterized in that, The rate of change in sulfur solubility is determined by the following formula: Among them, S i c is the rate of change in sulfur solubility. i The sulfur solubility of a sulfur-containing gas sample at iMPa pressure before it flows through the reservoir simulation system; The value represents the sulfur solubility of a sulfur-containing gas sample at an iMPa pressure after it passes through a reservoir simulation system.

12. The method for testing the solubility of elemental sulfur during the development of high-sulfur gas reservoirs according to claim 10, characterized in that, The sulfur-containing gas sample includes H2S, CO2, and CH4.

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