Detachable combined type natural gas hydrate sand production and sand prevention experimental device and method

Abstract

The invention belongs to the technical field of natural gas hydrate exploitation sand control process experiments, and discloses a detachable combined type natural gas hydrate sand production and sand control experimental device and method.The device comprises a supply unit, a reaction unit and a monitoring unit, and the supply unit is used for supplying gas, liquid and solid-phase sand grains; the reaction unit is connected to the output end of the supply unit, the reaction unit comprises a reservoir simulation cylinder, a well completion sand filling cylinder and a multi-stage sand prevention cylinder which are detachably connected in sequence, and the reservoir simulation cylinder is filled with wetting sand grains to form a natural gas hydrate reservoir; the well completion sand filling cylinder is filled with sand prevention sand grains and is used for simulating a sand filling well wall of a natural gas hydrate reservoir; and a sand prevention assembly and a sand prevention sleeve for simulating natural gas hydrate exploitation are arranged in the multi-stage sand prevention cylinder. A supply mode of the supply unit can be independently selected according to requirements so as to simulate sand production and sand prevention conditions under different working conditions; moreover, the reaction units are detachably connected, so that the reaction units are convenient to disassemble and assemble, and the experiment efficiency is favorably improved.

Description

Technical Field

[0001] The present invention relates to the technical field of natural gas hydrate production and sand control process experiments, and in particular to a detachable combined natural gas hydrate sand production and sand control experimental device and method. Background Art

[0002] Natural gas hydrates, due to their large reserves, high energy density, and widespread distribution, are a promising potential alternative energy source for the new century. Marine natural gas hydrate deposits are primarily found on the seabed of continental shelves and enclosed waters. Sand production during extraction has become a key constraint to the effective and safe development of natural gas hydrates. Given the difficulty and high cost of field research, laboratory studies of optimal sand control strategies for different reservoirs are a proven approach.

[0003] Existing experimental equipment can only conduct sand production and control experiments under a few operating conditions, which is a significant limitation. Furthermore, the experimental equipment is complex and the installation and operation are cumbersome. Furthermore, no sand control experimental equipment can simulate the operating conditions of natural gas hydrate extraction, such as the muddy silt-sand formation with poor cementation strength and the coupled gas, liquid, and solid three-phase flow under high pressure during extraction. Summary of the Invention

[0004] The object of the present invention is to provide a detachable combined natural gas hydrate sand production and control experimental device and method, which can carry out sand production and control experiments under various working conditions and is easy to assemble and disassemble.

[0005] To achieve this object, the present invention adopts the following technical solutions:

[0006] On the one hand, a detachable combined natural gas hydrate sand production and sand control experimental device is provided, comprising:

[0007] A supply unit, used for supplying gas, liquid and solid sand particles;

[0008] A reaction unit is connected to the output end of the supply unit, and the reaction unit includes a reservoir simulation cylinder, a completion sand filling cylinder, and a multi-stage sand control cylinder that are detachably connected in sequence. The reservoir simulation cylinder is filled with wet sand particles to form a natural gas hydrate reservoir; the completion sand filling cylinder is filled with sand control sand particles for simulating the sand filling well wall of the natural gas hydrate reservoir; and the multi-stage sand control cylinder is provided with a sand control assembly for simulating the sand control casing for natural gas hydrate extraction.

[0009] The monitoring unit is used to monitor the injection volume and outflow volume of the reaction unit in real time.

[0010] As an optional solution for the detachable combined natural gas hydrate sand production and sand control experimental device, the supply unit includes:

[0011] A liquid supply module, used for providing liquid;

[0012] A sand supply module, used for providing sand particles;

[0013] A gas supply module, used for providing gas;

[0014] A solid-liquid mixing module is connected to the output end of the liquid supply module and the output end of the sand supply module;

[0015] The solid-liquid-gas mixing module is connected to the output end of the solid-liquid mixing module and the output end of the gas supply module.

[0016] As an optional solution for the detachable combined natural gas hydrate sand production and sand control experimental device, the solid-liquid mixing module includes:

[0017] a sand mixer, connected to the output end of the liquid supply module and the output end of the sand supply module, for mixing liquid and sand particles;

[0018] The first bypass pipeline is connected to the output end of the liquid supply module and the solid-liquid-gas mixing module.

[0019] As an optional solution for the detachable combined natural gas hydrate sand production and sand control experimental device, the solid-liquid-gas mixing module includes:

[0020] A solid-liquid-gas mixer connected to the output end of the sand mixer and the output end of the gas supply module;

[0021] The second bypass pipeline is connected between the output end of the solid-liquid mixing module and the reaction unit.

[0022] As an optional solution of the detachable combined natural gas hydrate sand production and sand control experimental device, it also includes a gas-liquid-solid three-phase separation unit, which is connected to the output end of the reaction unit.

[0023] As an optional solution for the detachable combined natural gas hydrate sand production and sand control experimental device, the gas-liquid-solid three-phase separation unit includes:

[0024] a solid-liquid separator connected to the output end of the reaction unit and used for separating sand particles;

[0025] The gas-liquid separator is connected to the output end of the solid-liquid separator and is used to separate gas and liquid.

[0026] As an optional solution for the detachable combined natural gas hydrate sand production and sand control experimental device, the gas-liquid-solid three-phase separation unit also includes:

[0027] a first gas filter, wherein the output end of the gas-liquid separator is connected to a gas pipeline, and the first gas filter is arranged on the gas pipeline;

[0028] A decompression valve is provided on the gas transmission pipe and is connected to the output end of the first gas filter.

[0029] As an optional solution for the detachable combined natural gas hydrate sand production and sand control experimental device, the connection between the reservoir simulation cylinder and the completion sand filling cylinder, and the connection between the completion sand filling cylinder and the multi-stage sand control cylinder are both provided with sealing components.

[0030] As an optional solution for the detachable combined natural gas hydrate sand production and sand control experimental device, the length of the reservoir simulation cylinder is more than three times the sum of the lengths of the completion sand filling cylinder and the multi-stage sand control cylinder.

[0031] On the other hand, a natural gas hydrate sand production and control experimental method is provided, which is applied to the above-mentioned detachable combined natural gas hydrate sand production and control experimental device, comprising the following steps:

[0032] S1: Assemble the supply unit and select the supply mode of the supply unit according to the experimental purpose;

[0033] S2: Assemble the reaction unit, load the wetted sand into the reservoir simulation cylinder, load the sand control sand into the completion sand filling cylinder, load the sand control assembly into the multi-stage sand control cylinder, and then connect the reservoir simulation cylinder, completion sand filling cylinder and multi-stage sand control cylinder in sequence;

[0034] S3: Connect the supply unit and the reaction unit, and set up the monitoring unit to check the airtightness of the experimental device;

[0035] S4: methane gas is injected into the reservoir simulation tube. When the preset temperature and pressure are reached, natural gas hydrates may be formed in the reservoir simulation tube.

[0036] S5: The supply unit supplies into the reaction unit to conduct a sand production and sand control experiment, and the monitoring unit monitors the injection volume and outflow volume of the reaction unit in real time.

[0037] Beneficial effects of the present invention:

[0038] The present invention provides a detachable and modular natural gas hydrate sand production and control experimental device and method. This experimental device allows for the autonomous selection of supply modes for the supply unit based on the experimental objectives to simulate and test sand production and control under various operating conditions. Sand production during natural gas hydrate decomposition and sand transport during reservoir gas-liquid flow can be studied under various parameters, including pressure differential, pressure drop gradient, sand-control gravel specifications, gravel thickness, and gravel uniformity coefficient. Furthermore, the reaction unit utilizes a detachable connection for easy disassembly and assembly, improving experimental efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] Figure 1It is a structural schematic diagram of a detachable combined natural gas hydrate sand production and sand control experimental device provided in an embodiment of the present invention;

[0040] Figure 2 It is a structural schematic diagram of a supply unit provided in a specific embodiment of the present invention, omitting some structures;

[0041] Figure 3 Schematic diagram of the structure of the reaction unit provided in the embodiment of the present invention;

[0042] Figure 4 It is a structural schematic diagram of a gas-liquid-solid three-phase separation unit provided in an embodiment of the present invention.

[0043] In the picture:

[0044] 1. Supply unit;

[0045] 11. Liquid supply module; 111. Liquid storage tank; 112. Liquid delivery mechanism; 113. One-way valve; 114. First valve; 115. First flow meter; 116. First pressure gauge;

[0046] 12. Gas supply module; 121. Gas storage tank; 122. Pressure relief valve; 123. Second gas filter; 124. First gas supply pipe; 1241. Second valve; 1242. Second flow meter; 1243. Second pressure gauge; 125. Second gas supply pipe; 1251. Third valve; 1252. Third flow meter;

[0047] 13. Solid-liquid mixing module;

[0048] 131. Sand mixer; 1311. Fourth valve;

[0049] 132. First bypass line; 1321. Fifth valve;

[0050] 14. Solid-liquid-gas mixing module;

[0051] 141. solid-liquid-gas mixer; 1411. sixth valve;

[0052] 142. Second bypass line; 1421. Seventh valve;

[0053] 15. Input valve; 16. Third pressure gauge; 17. Fourth pressure gauge;

[0054] 2. Reaction unit;

[0055] 21. Reservoir simulation cylinder; 22. Completion sand filling cylinder; 23. Multi-stage sand control cylinder; 231. Sand control assembly; 24. Sealing assembly; 25. Output valve; 26. Fifth pressure gauge; 27. First connecting section; 28. Second connecting section;

[0056] 3. Gas-liquid-solid three-phase separation unit;

[0057] 31. Solid-liquid separator; 32. Gas-liquid separator; 33. First gas filter; 34. Gas pipeline; 35. Pressure relief valve; 36. Gas cylinder; 37. Fourth flow meter. DETAILED DESCRIPTION

[0058] The present invention will be further described in detail below with reference to the accompanying drawings and examples. It will be understood that the specific embodiments described herein are intended only to illustrate the present invention and are not intended to limit the present invention. It should also be noted that, for ease of description, the accompanying drawings only illustrate portions relevant to the present invention, not all structures.

[0059] In the description of the present invention, unless otherwise expressly specified or limited, the terms "connected," "connected," and "fixed" should be understood in a broad sense. For example, they may refer to fixed connections, detachable connections, or integration; mechanical connections or electrical connections; direct connections or indirect connections through an intermediate medium; and internal communication between two components or interaction between two components. Those skilled in the art will understand the specific meanings of the above terms in the present invention in specific circumstances.

[0060] In the present invention, unless otherwise expressly specified or limited, a first feature being "above" or "below" a second feature may include the first and second features being in direct contact, or may include the first and second features being in contact not directly but through another feature between them. Furthermore, a first feature being "above," "above," and "above" a second feature may include the first feature being directly above or obliquely above the second feature, or may simply mean that the first feature is higher in level than the second feature. A first feature being "below," "below," and "below" a second feature may include the first feature being directly below or obliquely below the second feature, or may simply mean that the first feature is lower in level than the second feature.

[0061] In the description of this embodiment, terms such as "upper," "lower," and "right" are used to refer to positions or locations based on the positions or locations shown in the accompanying drawings. These terms are intended solely to facilitate description and simplify operation, and are not intended to indicate or imply that the devices or components referred to must have, be constructed, or operate in a specific orientation. Therefore, they should not be construed as limitations on the present invention. Furthermore, the terms "first" and "second" are used solely for descriptive purposes and have no special meaning.

[0062] The technical solution of the present invention will be further described below with reference to the accompanying drawings and through specific implementation methods.

[0063] like Figures 1 to 4As shown, this embodiment provides a detachable and modular natural gas hydrate sand production and control experimental device, comprising a supply unit 1, a reaction unit 2, and a monitoring unit. The supply unit 1 is used to supply gas, liquid, and solid sand particles. The reaction unit 2 is connected to the output end of the supply unit 1. The reaction unit 2 comprises a reservoir simulation cylinder 21, a completion sand filling cylinder 22, and a multi-stage sand control cylinder 23, which are detachably connected in sequence. The reservoir simulation cylinder 21 is filled with wet sand particles to form a natural gas hydrate reservoir; the completion sand filling cylinder 22 is filled with sand control sand particles to simulate the sand filling well wall of the natural gas hydrate reservoir; and the multi-stage sand control cylinder 23 is provided with a sand control assembly 231 to simulate the sand control casing used in natural gas hydrate production. The monitoring unit is used to monitor the injection and outflow of the reaction unit 2 in real time to facilitate subsequent analysis of the sand production and sand control situation. The experimental device can independently select the supply mode of the supply unit 1 according to the experimental purpose to simulate and test the sand production and sand prevention conditions under different working conditions; and the reaction unit 2 adopts a detachable connection method, which is easy to disassemble and assemble, and is conducive to improving the experimental efficiency.

[0064] Specifically, the monitoring unit is an existing device already disclosed in the prior art. While monitoring the injection and outflow rates of reaction unit 2, the monitoring unit can also monitor data such as the temperature, pressure, and flow rate of reaction unit 2, achieving dynamic monitoring and facilitating subsequent analysis of experimental parameter changes during various stages of sand control in natural gas hydrate production. Under different pressure differentials, pressure drop gradients, sand control gravel specifications, gravel thickness, and gravel uniformity coefficients, the sand production during the natural gas hydrate decomposition process and the sand migration during reservoir gas-liquid flow are studied. For natural gas hydrate reservoirs composed of argillaceous siltstone with poor cementation strength and the high-pressure coupling of gas, liquid, and solid three-phase flow involved in the production process, the sand production and production capacity during the natural gas hydrate production process are closely related to sand control methods and a series of factors, including sand particle size, mud content, clay mineral composition in the mud, fluid viscosity, flow rate, production pressure differential, and the degree of pressure differential change.

[0065] Alternatively, as Figure 2 As shown, the supply unit 1 includes a liquid supply module 11, a sand supply module (not shown), an air supply module 12, a solid-liquid mixing module 13, and a solid-liquid-gas mixing module 14. The liquid supply module 11 is used to provide liquid, the sand supply module is used to provide sand, and the air supply module 12 is used to provide gas; the solid-liquid mixing module 13 is connected to the output end of the liquid supply module 11 and the output end of the sand supply module, and is used to mix liquid and solid-phase sand; the solid-liquid-gas mixing module 14 is connected to the output end of the solid-liquid mixing module 13 and the output end of the air supply module 12, and is used to mix liquid, solid-phase sand, and gas. Experimenters can selectively open the liquid supply module 11, the sand supply module, and the air supply module 12 according to the purpose of the experiment to simulate different experimental conditions, making it more flexible to use.

[0066] Specifically, continue to refer to Figure 2 The liquid supply module 11 includes a liquid storage tank 111, a liquid delivery mechanism 112, a one-way valve 113, a first valve 114, a first flow meter 115, and a first pressure gauge 116. The liquid storage tank 111 stores liquid. The liquid delivery mechanism 112 has a suction end connected to the liquid storage tank 111 and a suction end connected to the solid-liquid mixing module 13. Under the suction action of the liquid delivery mechanism 112, the liquid can be delivered into the solid-liquid mixing module 13. A one-way valve 113, a first valve 114, a first flow meter 115, and a first pressure gauge 116 are provided on the connection pipeline between the suction end of the liquid delivery mechanism 112 and the solid-liquid mixing module 13. The one-way valve 113 can prevent the liquid from flowing back, ensuring that the liquid always flows in the direction toward the solid-liquid mixing module 13; the first valve 114 can be selectively opened and closed. When it is not necessary to supply liquid to the reaction unit 2, the first valve 114 can be closed, otherwise the first valve 114 can be opened; the first flow meter 115 is used to monitor the flow rate of the delivered liquid, and the first pressure gauge 116 is used to monitor the pressure of the delivered liquid. Exemplarily, the liquid delivery mechanism 112 is an existing constant speed and constant pressure horizontal flow pump, and the first valve 114, the first flow meter 115, and the first pressure gauge 116 are all existing structures.

[0067] The gas supply module 12 includes a main gas supply pipe, a gas storage tank 121, a pressure relief valve 122, a second gas filter 123, a first gas supply pipe 124, and a second gas supply pipe 125. The gas storage tank 121 stores gas. The main gas supply pipe is connected to the output end of the gas storage tank 121. The input ends of the first gas supply pipe 124 and the second gas supply pipe 125 are both connected to the output end of the main gas supply pipe. The output end of the first gas supply pipe 124 is connected to the solid-liquid-gas mixing module 14, and the output end of the second gas supply pipe 125 is connected to the reservoir simulation cylinder 21 of the reaction unit 2. The pressure relief valve 122 and the second gas filter 123 are both located on the main gas supply pipe. The pressure relief valve 122 is used to reduce the pressure of the gas flowing out of the gas storage tank 121, and the second gas filter 123 is used to filter impurities in the gas.

[0068] The first gas pipeline 34 is provided with a second valve 1241, a second flow meter 1242, and a second pressure gauge 1243. The second valve 1241 is selectively openable and closable; when gas is not required to be supplied to the reaction unit 2, the second valve 1241 is closed; otherwise, the second valve 1241 is opened. The second flow meter 1242 is used to monitor the gas flow rate within the first gas pipeline 34, and the second pressure gauge 1243 is used to monitor the gas pressure within the first gas pipeline 34.

[0069] The second gas pipeline 34 is provided with a third valve 1251 and a third flowmeter 1252. The third valve 1251 is selectively openable and closable. When gas is not required to be supplied to the reservoir simulation cylinder 21, the third valve 1251 can be closed, and otherwise opened. The third flowmeter 1252 is used to monitor the gas flow in the second gas pipeline 34.

[0070] Illustratively, the pressure relief valve 122 , the second gas filter 123 , the second valve 1241 , the second flow meter 1242 , the second pressure gauge 1243 , the third valve 1251 , the third flow meter 1252 , etc. are all existing structures.

[0071] Further, refer to Figure 2 The solid-liquid mixing module 13 includes a sand mixer 131 and a first bypass line 132. The sand mixer 131 is connected to the output end of the liquid supply module 11 and the output end of the sand supply module to mix liquid and sand. The first bypass line 132 is connected to the output end of the liquid supply module 11 and the solid-liquid-gas mixing module. When liquid and solid-phase sand need to be supplied to the reaction unit 2 simultaneously, the liquid supply unit supplies liquid to the sand mixer 131, and the sand supply unit supplies solid-phase sand to the sand mixer 131. After the liquid and solid-phase sand are mixed in the sand mixer 131, they are sent to the solid-liquid-gas mixing module 14 or directly to the reaction unit 2. If solid-phase sand is not needed to be supplied to the reaction unit 2, the liquid provided by the liquid supply unit is sent to the solid-liquid-gas mixing module 14 or directly to the reaction unit 2 via the first bypass line 132. With the above configuration, the experimenter can flexibly choose whether to supply solid-phase sand to the reaction unit 2 according to experimental requirements.

[0072] Specifically, a fourth valve 1311 is provided at both the input and output ends of the sand mixer 131, and a fifth valve 1321 is provided on the first bypass line 132. When liquid is required but solid sand particles are not, the fourth valve 1311 at the input end of the sand mixer 131 is closed and the fifth valve 1321 is opened, allowing liquid to flow through the first bypass line 132 to the solid-liquid-gas mixing module 14. When both liquid and solid sand particles are required, the fourth valves 1311 at the input and output ends of the sand mixer 131 are opened and the fifth valve 1321 is closed.

[0073] Exemplarily, the sand mixer 131 includes a fully enclosed cylindrical sand storage barrel with a piston installed in the top cover. The bottom inner cavity of the sand storage barrel is equipped with a stirring auger driven by a stirring motor. The required solid-liquid ratio is obtained by adjusting the auger speed and the liquid supply flow of the liquid supply module 11.

[0074] Further, continue to refer to Figure 2The solid-liquid-gas mixing module 14 includes a solid-liquid-gas mixer 141 and a second bypass line 142. The solid-liquid-gas mixer 141 is connected to the output end of the sand mixer 131 and the output end of the gas supply module 12. The second bypass line 142 is connected between the output end of the solid-liquid mixing module 13 and the reaction unit 2. When liquid, gas, and solid sand particles need to be supplied to the reaction unit 2 simultaneously, the solid-liquid two-phase flow mixed in the sand mixer 131 is delivered to the solid-liquid-gas mixer 141, and the gas supply module 12 supplies gas to the solid-liquid-gas mixer 141. Under the stirring action of the solid-liquid-gas mixer 141, a solid-liquid-gas three-phase flow is formed and delivered to the reaction unit 2. If gas is not needed to be supplied to the reaction unit 2, the solid-liquid two-phase flow mixed in the sand mixer 131 or the liquid supplied through the first bypass line 132 is delivered to the reaction unit 2 via the second bypass line 142. That is, with the above settings, the experimenter can flexibly choose whether to supply gas to the reaction unit 2 according to the experimental requirements.

[0075] Specifically, a sixth valve 1411 is provided at both the input and output ends of the solid-liquid-gas mixer 141, and a seventh valve 1421 is provided on the second bypass line 142. When liquid, gas, and solid sand particles, liquid and gas, or solid sand particles and gas are required to be supplied simultaneously, both sixth valves 1411 are opened. To supply only gas, only the sixth valve 1411 at the output end of the solid-liquid-gas mixer 141 is opened. When gas supply is not required, both sixth valves 1411 are closed, and the seventh valve 1421 is opened.

[0076] Alternatively, as Figure 1 As shown, the supply unit 1 further includes an input valve 15, a third pressure gauge 16, and a fourth pressure gauge 17. The input valve 15 and the fourth pressure gauge 17 are both disposed on the pipeline connecting the solid-liquid-gas mixing module 14 and the reaction unit 2. The third pressure gauge 16 is disposed on the pipeline connecting the solid-liquid mixing module 13 and the solid-liquid-gas mixing module 14. Specifically, the input valve 15 is an existing common valve, and the third pressure gauge 16 and the fourth pressure gauge 17 are both existing structures.

[0077] Optionally, the reservoir simulation cylinder 21 and the completion sand filling cylinder 22, as well as the completion sand filling cylinder 22 and the multi-stage sand control cylinder 23 are all connected by threads, which is simple and convenient to operate and helps to improve the assembly efficiency of the experimental device.

[0078] Specifically, refer to Figure 3The reaction unit 2 also includes a first connecting section 27 and a second connecting section 28. The first connecting section 27 is connected to the inlet of the reservoir simulation tube 21 and has a trumpet-shaped flared channel inside to achieve uniform flow. The second connecting section 28 is connected to the outlet of the multi-stage sand control tube 23 and has a tapered channel inside to increase flow rate and reduce static pressure. For example, the first connecting section 27 is threadedly connected to the reservoir simulation tube 21, and the second connecting section 28 is threadedly connected to the multi-stage sand control tube 23.

[0079] Optionally, continue with reference to Figure 3 The connection between the reservoir simulation cylinder 21 and the completion sand filling cylinder 22, and the connection between the completion sand filling cylinder 22 and the multi-stage sand control cylinder 23 are both sleeved with sealing components 24 to achieve sealed connection and ensure the sealing of the reaction unit 2.

[0080] Specifically, the sealing assembly 4 includes a sealing ring and a sealing sleeve. The sealing sleeve is sleeved on the connection part, and the sealing ring is arranged between the connection part and the sealing sleeve.

[0081] Optionally, the length of the reservoir simulation tube 21 is at least three times the combined length of the completion sand packing tube 22 and the multi-stage sand control tube 23 to minimize the size effect of the one-dimensional natural gas hydrate reservoir production simulation. Specifically, in this embodiment, the length of both the completion sand packing tube 22 and the multi-stage sand control tube 23 does not exceed 5 cm.

[0082] Optionally, the sand control component 231 can select the first-stage sand control screen cylinder, the second-stage sand control screen cylinder, the third-stage sand control screen cylinder according to needs, or select suitable sand control media or sand control material fillings, such as metal wool, metal screen, metal woven mesh, etc.

[0083] Specifically, wet sand particles of different particle sizes are loaded into the reservoir simulation cylinder 21 and fully compacted and fixed to simulate the natural gas hydrate reservoir; sand-proof gravel of different particle sizes and thicknesses are loaded into the completion sand filling cylinder 22 and fully compacted and fixed to simulate the sand filling well wall of the natural gas hydrate reservoir.

[0084] Alternatively, as Figure 1 As shown, the detachable combined natural gas hydrate sand production and sand control experimental device also includes a gas-liquid-solid three-phase separation unit 3, which is connected to the output end of the reaction unit 2 and is used to separate the multiphase fluid flowing out of the reaction unit 2 to achieve the recycling of gas, liquid and solid sand particles.

[0085] Specifically, an output valve 25 and a fifth pressure gauge 26 are provided between the reaction unit 2 and the gas-liquid-solid three-phase separation unit 3 , and the fifth pressure gauge 26 is also an existing structure.

[0086] Further, refer to Figure 4The gas-liquid-solid three-phase separation unit 3 includes a solid-liquid separator 31 and a gas-liquid separator 32. The solid-liquid separator 31 is connected to the output end of the reaction unit 2, and the gas-liquid separator 32 is connected to the output end of the solid-liquid separator 31. The solid-liquid separator 31 is used to separate the solid-phase sand particles. The separated solid-phase sand particles are stored in the solid-liquid separator 31, while the separated gas-liquid two-phase flow flows through the output end of the solid-liquid separator 31 to the gas-liquid separator 32. The liquid separated by the gas-liquid separator 32 is temporarily stored in the collection cylinder of the gas-liquid separator 32, and the separated gas can be sent to the gas storage cylinder 36.

[0087] Specifically, the solid-liquid separator 31 and the gas-liquid separator 32 are both existing devices, and their specific structures and working principles are all based on the existing technology and will not be described in detail here.

[0088] Further, continue to refer to Figure 4 The gas-liquid-solid three-phase separation unit 3 further includes a gas filter 33 and a pressure relief valve 35. The output end of the gas-liquid separator 32 is connected to a gas supply pipe 34. The gas filter 33 is disposed on the gas supply pipe 34 and is used to filter the gas. The pressure relief valve 35 is also disposed on the gas supply pipe 34 and is connected to the output end of the gas filter 33. The gas filtered by the gas filter 33 flows through the pressure relief valve 35 and is delivered to the gas cylinder 36. This reduces the gas pressure to a pressure range that the gas cylinder 36 can withstand, preventing the gas cylinder 36 from exploding or being damaged due to overpressure, while ensuring the safety of the experiment.

[0089] Specifically, the gas-liquid-solid three-phase separation unit 3 further includes a fourth flow meter 37 , which is provided on the gas delivery pipe 34 to monitor the flow of gas delivered to the gas storage cylinder 36 .

[0090] For example, the gas filter 33, the pressure relief valve 35 and the fourth flow meter 37 are all existing devices disclosed in the prior art. Their specific structures and working principles refer to the prior art and are not described in detail here.

[0091] Specifically, the experimental device's supply unit 1 has six supply modes: gas injection, liquid injection, gas-liquid, liquid-solid, gas-liquid, and no external supply. In the no external supply mode, the inlet valve 15 at the reaction unit entrance is closed, and the supply unit 1 does not supply liquid, gas, or solid sand particles to the reaction unit 2. The experiment relies on the decomposition of natural gas hydrates within the reservoir simulation cylinder 21.

[0092] In addition, this embodiment also provides a natural gas hydrate sand production and control experimental method, which is applied to the above-mentioned detachable combined natural gas hydrate sand production and control experimental device, and includes the following steps:

[0093] S1: Assemble the supply unit 1 and select the supply mode of the supply unit 1 according to the experimental purpose;

[0094] S2: Assemble the reaction unit 2, load the wetted sand into the reservoir simulation cylinder 21, load the sand control sand into the completion sand filling cylinder 22, load the sand control assembly 231 into the multi-stage sand control cylinder 23, and then connect the reservoir simulation cylinder 21, the completion sand filling cylinder 22 and the multi-stage sand control cylinder 23 in sequence;

[0095] S3: Connect the supply unit 1 and the reaction unit 2, and set up a monitoring unit to detect the airtightness of the experimental device;

[0096] The above steps, specifically in this embodiment, connect the supply unit 1 and the reaction unit 2 and set up a monitoring unit. Then test the air tightness of the experimental device. Close the input valve 15 at the entrance of the reaction unit 2 and the output valve 25 at the outlet. Then, inject a certain amount of gas into the reaction unit 2 through the second gas supply pipe 125 of the gas supply module 12. Then, close the third valve 1251 and let it stand for two hours to test the air tightness of the reaction unit 2. After completing the air tightness test, methane gas is introduced into the reaction unit 2 for exhaust treatment.

[0097] S4: injecting methane gas into the reservoir simulation tube 21. When the preset temperature and pressure are reached, natural gas hydrates may be formed in the reservoir simulation tube 21.

[0098] Specifically, in this embodiment, sufficient methane gas is injected into the reservoir simulation cylinder 21 through the second gas supply pipe 125 of the gas supply module 12. Under certain temperature and pressure conditions, the methane gas in the reservoir simulation cylinder 21 forms natural gas hydrates. Specifically, the experimental device can be placed in an air bath to meet preset temperature and pressure conditions.

[0099] S5: The supply unit 1 supplies to the reaction unit 2 to perform a sand production and sand control experiment, and the monitoring unit monitors the injection volume and outflow volume of the reaction unit 2 in real time.

[0100] In the above steps, specifically in this embodiment, the supply unit 1 supplies the reaction unit 2 according to the selected supply mode to perform the sand production and sand control experiment. At the same time, the monitoring unit monitors the injection and outflow of the reaction unit 2 in real time.

[0101] Obviously, the above embodiments of the present invention are merely examples for the purpose of clearly illustrating the present invention and are not intended to limit the embodiments of the present invention. A person skilled in the art would be able to make various obvious changes, readjustments, and substitutions without departing from the scope of protection of the present invention. It is not necessary and impossible to enumerate all embodiments here. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention shall be included within the scope of protection of the claims of the present invention.

Claims

1. A detachable combined natural gas hydrate sand production and sand control experimental device, characterized in that: include: A supply unit (1) for supplying gas, liquid and solid sand particles; A reaction unit (2) is connected to the output end of the supply unit (1), and the reaction unit (2) comprises a reservoir simulation cylinder (21), a completion sand filling cylinder (22), and a multi-stage sand control cylinder (23) which are sequentially detachably connected. The reservoir simulation cylinder (21) is filled with wet sand particles to form a natural gas hydrate reservoir; the completion sand filling cylinder (22) is filled with sand control sand particles for simulating the sand filling well wall of the natural gas hydrate reservoir; and the multi-stage sand control cylinder (23) is provided with a sand control assembly (231) for simulating the sand control casing for natural gas hydrate extraction. The monitoring unit is used to monitor the injection volume and outflow volume of the reaction unit (2) in real time.

2. The detachable combined natural gas hydrate sand production and sand control experimental device according to claim 1 is characterized in that: The supply unit (1) comprises: A liquid supply module (11), configured to supply liquid; A sand supply module, used for providing sand particles; A gas supply module (12), used for providing gas; A solid-liquid mixing module (13) is connected to the output end of the liquid supply module (11) and the output end of the sand supply module; The solid-liquid-gas mixing module (14) is connected to the output end of the solid-liquid mixing module (13) and the output end of the gas supply module (12).

3. The detachable combined natural gas hydrate sand production and sand control experimental device according to claim 2 is characterized in that: The solid-liquid mixing module (13) comprises: A sand mixer (131), connected to the output end of the liquid supply module (11) and the output end of the sand supply module, for mixing liquid and sand particles; The first bypass pipeline (132) is connected to the output end of the liquid supply module (11) and the solid-liquid-gas mixing module (14).

4. The detachable combined natural gas hydrate sand production and sand control experimental device according to claim 3 is characterized in that: The solid-liquid-gas mixing module (14) comprises: a solid-liquid-gas mixer (141), connected to the output end of the sand mixer (131) and the output end of the gas supply module (12); The second bypass pipeline (142) is connected between the output end of the solid-liquid mixing module (13) and the reaction unit (2).

5. The detachable combined natural gas hydrate sand production and sand control experimental device according to claim 1 is characterized in that: It also includes a gas-liquid-solid three-phase separation unit (3), which is connected to the output end of the reaction unit (2).

6. The detachable combined natural gas hydrate sand production and sand control experimental device according to claim 5 is characterized in that: The gas-liquid-solid three-phase separation unit (3) comprises: a solid-liquid separator (31), connected to the output end of the reaction unit (2), for separating sand particles; The gas-liquid separator (32) is connected to the output end of the solid-liquid separator (31) and is used to separate gas and liquid.

7. The detachable combined natural gas hydrate sand production and sand control experimental device according to claim 6 is characterized in that: The gas-liquid-solid three-phase separation unit (3) further comprises: a first gas filter (33), wherein the output end of the gas-liquid separator (32) is connected to a gas pipe (34), and the first gas filter (33) is arranged on the gas pipe (34); A decompression valve (35) is provided on the gas delivery pipe (34) and is connected to the output end of the first gas filter (33).

8. The detachable combined natural gas hydrate sand production and sand control experimental device according to any one of claims 1 to 7, characterized in that: The connection between the reservoir simulation cylinder (21) and the well completion sand filling cylinder (22), and the connection between the well completion sand filling cylinder (22) and the multi-stage sand control cylinder (23) are both sleeved with sealing components (24).

9. The detachable combined natural gas hydrate sand production and sand control experimental device according to any one of claims 1 to 7, characterized in that: The length of the reservoir simulation cylinder (21) is more than three times the sum of the lengths of the well completion sand filling cylinder (22) and the multi-stage sand control cylinder (23).

10. A natural gas hydrate sand production and control experimental method, applied to the detachable combined natural gas hydrate sand production and control experimental device according to any one of claims 1 to 9, characterized in that: The steps include: S1: Assemble the supply unit (1) and select the supply mode of the supply unit (1) according to the experimental purpose; S2: Assemble the reaction unit (2), load the wetted sand into the reservoir simulation cylinder (21), load the sand control sand into the completion sand filling cylinder (22), load the sand control assembly (231) into the multi-stage sand control cylinder (23), and then connect the reservoir simulation cylinder (21), the completion sand filling cylinder (22) and the multi-stage sand control cylinder (23) in sequence; S3: Connect the supply unit (1) and the reaction unit (2), and set up a monitoring unit to check the airtightness of the experimental device; S4: injecting methane gas into the reservoir simulation tube (21), and when the preset temperature and the preset pressure are reached, natural gas hydrates may be formed in the reservoir simulation tube (21); S5: The supply unit (1) supplies to the reaction unit (2) to perform a sand production and sand control experiment, and the monitoring unit monitors the injection volume and outflow volume of the reaction unit (2) in real time.

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