A particle-containing extruded hydrate deposit sample preparation apparatus and method

Abstract

The application discloses a kind of granular expulsive hydrate deposit sample preparation device and method, including synthesis device, gas injection device, exhaust device, vacuum pumping device, hydraulic device, sample preparation device and control module, the synthesis device includes reaction kettle base, reaction kettle base is fixedly installed with reaction kettle bottom plate, the top side of reaction kettle bottom plate is fixedly connected with reaction kettle body, in the present application, the granular expulsive hydrate deposit sample preparation device and method can synthesize different occurrence state granular expulsive hydrate deposit sample according to demand, for hydrate exploration and development technology research, can synthesize the hydrate content hydrate deposit sample required, when the size of hydrate sample after segmentation is small, through the device and method of the application, high saturation degree dispersed hydrate deposit sample can also be synthesized, break through the difficulty of synthesizing high saturation degree dispersed hydrate in conventional method.

Description

Technical Field

[0001] This invention relates to the field of natural gas hydrate sediment sample preparation technology, and in particular to an apparatus and method for preparing particle-displacement type hydrate sediment samples. Background Technology

[0002] Natural gas hydrates are characterized by large reserves, high energy density, and clean combustion, and are considered the most promising clean energy source to replace oil and natural gas in the 21st century. With the rapid growth of global energy demand and increasing emphasis on environmental protection, the development of green and clean new energy sources has become an important direction for energy development. Natural gas hydrates are becoming a strategic high ground in the energy competition among major global powers, and the exploration and development of natural gas hydrates has become a current research hotspot. Obtaining samples of natural gas hydrate reservoirs is the material basis for conducting related research. Marine natural gas hydrates account for more than 90% of the total hydrate resources. Hydrate reservoirs are mostly undiagenetic sediments, which are in a weakly cemented or uncemented state with low mechanical strength, making core sampling difficult and costly. Artificially preparing samples that closely resemble actual reservoirs has become a more feasible alternative.

[0003] Core sampling of marine natural gas hydrates reveals that hydrates mainly occur in sediments in the form of nodules, veins, thick layers, thin layers, and dispersions. Based on the contact relationship between hydrates and sediments, they can be classified into particle-displacement type (including fracture filling, outcrops, veins, masses, nodules, and layers) and pore-infiltrating type (including pore filling, contact cementation, particle encapsulation, skeletal support, local aggregation, and foraminifera filling). Currently, the preparation of artificial hydrate-bearing samples mainly involves mixing sediments, water, and methane, and preparing hydrate-bearing sediment samples under temperature and pressure conditions that can synthesize hydrates. The main difference lies in the timing of adding water and methane, but the synthesized hydrate-bearing samples are mainly of the pore-infiltrating type, while synthesizing particle-displacement type hydrate samples is more difficult. Summary of the Invention

[0004] To address the shortcomings of existing technologies, this invention provides an apparatus and method for preparing particle-displacement hydrate sediment samples, thereby solving the problem that current artificial sample preparation of hydrate-containing sediments mainly focuses on porous infiltrated hydrate samples, while synthesizing particle-displacement hydrate samples is quite difficult.

[0005] To achieve the above objectives, the present invention adopts the following technical solution:

[0006] A sample preparation device for particulate-displacement hydrate sediments includes a synthesis device, a gas injection device, an exhaust device, a vacuum device, a hydraulic device, a sample preparation device, and a control module. The synthesis device includes a reactor base with a reactor bottom plate fixedly mounted on it. A reactor body is fixedly connected to the top side of the reactor bottom plate. The gas injection device includes a gas cylinder, a first pressure gauge, a first valve, a gas booster pump, a second valve, a high-pressure gas tank, a second pressure gauge, a third valve, a gas pressure reducing valve, a third pressure gauge, a first gas flow meter, and a fourth valve. The exhaust device includes a fifth valve, a fourth pressure gauge, a second gas flow meter, a sixth valve, and a gas collector. The vacuum device includes a vacuum pump, a fifth pressure gauge, and a seventh valve. The hydraulic device includes a hydraulic pump, an eighth valve, and a ninth valve. The sample preparation device includes a sample preparation chamber base, a sample preparation chamber bottom plate, a sample preparation chamber enclosure, a sample preparation chamber top plate, a hydraulic pressure head, a sample preparation chamber temperature and pressure sensor, and a sample preparation chamber temperature control box. The control module includes a control device.

[0007] Preferably, a movable piston is movably installed inside the reactor body, and a reactor top plate is fixedly connected to the top side of the reactor body. The movable piston, reactor top plate, and reactor body constitute a sealed reactor. A malleable mesh is placed inside the reactor body, and a reactor temperature control box is installed on the reactor body. The reactor base and reactor bottom plate are provided with the same first hydraulic inlet. The reactor top plate is provided with an injection port, a first exhaust port, and a second exhaust port. The upper part of the reactor temperature control box has a channel for connecting the injection port, the first exhaust port, and the second exhaust port pipelines. Multiple sensors are installed on the inner wall of the reactor body, and the sensors are temperature sensors and pressure sensors.

[0008] Preferably, the first pressure gauge is connected to the gas cylinder, one end of the first valve is connected to the gas cylinder via a pipeline, the other end of the first valve is connected to one end of the gas booster pump via a pipeline, the other end of the gas booster pump is connected to one end of the second valve via a pipeline, the other end of the second valve is connected to one end of the high-pressure gas tank via a pipeline, the other end of the high-pressure gas tank is connected to one end of the second pressure gauge via a pipeline, the other end of the second pressure gauge is connected to one end of the third valve via a pipeline, the other end of the third valve is connected to one end of the gas pressure reducing valve via a pipeline, the other end of the gas pressure reducing valve is connected to one end of the third pressure gauge via a pipeline, the other end of the third pressure gauge is connected to one end of the first gas flow meter via a pipeline, the other end of the first gas flow meter is connected to one end of the fourth valve via a pipeline, and the other end of the fourth valve is connected to the gas injection port via a pipeline.

[0009] Preferably, one end of the fifth valve is connected to the second exhaust port via a pipeline, the other end of the fifth valve is connected to one end of the fourth pressure gauge via a pipeline, the other end of the fourth pressure gauge is connected to one end of the second gas flow meter via a pipeline, the other end of the second gas flow meter is connected to one end of the sixth valve via a pipeline, and the other end of the sixth valve is connected to the gas collector via a pipeline.

[0010] Preferably, one end of the fifth pressure gauge is connected to the vacuum pump via a pipeline, the other end of the fifth pressure gauge is connected to one end of the seventh valve via a pipeline, and the other end of the seventh valve is connected to the first exhaust port via a pipeline.

[0011] Preferably, one end of the hydraulic pump is connected to one end of the eighth valve via a pipeline, the other end of the eighth valve is connected to the first hydraulic inlet via a pipeline, the other end of the hydraulic pump is connected to one end of the ninth valve via a pipeline, and the other end of the ninth valve is connected to the hydraulic head via a pipeline.

[0012] Preferably, the sample preparation chamber bottom plate is fixedly connected to the sample preparation chamber base, the sample preparation chamber surrounding plate is fixedly connected to the sample preparation chamber bottom plate, a sample preparation chamber temperature and pressure sensor is embedded inside the sample preparation chamber surrounding plate, the sample preparation chamber top plate is inside the sample preparation chamber surrounding plate, and a hydraulic pressure head is connected to the sample preparation chamber top plate.

[0013] Preferably, the hydraulic head is connected to a hydraulic pump via a pipeline, and the hydraulic head drives the top plate of the sample preparation chamber to move up and down.

[0014] Preferably, the control device is electrically connected to all sensors, vacuum pump, hydraulic pump, gas booster pump, reactor temperature control box, and sample preparation chamber temperature control box.

[0015] A method for preparing a sample of particulate-displacement hydrate sediment, the method comprising the following steps:

[0016] S1: Determine the material composition and physical properties of the sample to be prepared, prepare the synthesis materials, and complete the equipment preparation;

[0017] Specifically, determine the formation temperature and pressure conditions of the area where the sample to be prepared is located, and use these as the set temperature and pressure conditions for sample preparation; prepare sediment materials based on the composition and grain size distribution of the sediments and the required sample size; add a certain amount of water to the reservoir sediments according to their moisture content, mix them evenly to maintain consistent actual formation moisture, and lower the temperature of the sediments to the set temperature in advance; and determine the required amounts of water and gas based on the hydrate content of the sample to be prepared and the conversion of natural gas hydrate synthesis reactions.

[0018] Specifically, ensure all pipeline connections are correct, keep valves initially closed, use a temperature control box to bring the synthesis and sample preparation devices to the set temperature, and conduct sample preparation in a cold storage room to prevent excessive decomposition of hydrates during the transfer process, while adjusting the cold storage room temperature by 1°C.

[0019] S2: Fill the prepared water into the reactor and place the prepared plastic mesh inside to extract the air from the reactor;

[0020] Specifically, the measured water is added to the reactor, and the morphology and size of the hydrates in the sediment are prepared as needed, while the shape of the plastic mesh in the reactor is controlled.

[0021] Specifically, a vacuum device is used to evacuate the reactor to reduce the interference of air in the reactor on the synthesis reaction.

[0022] S3: Control the temperature control box of the reactor. When the reactor temperature reaches the predetermined temperature, inject sufficient gas required for the reaction to make the pressure inside the reactor reach the set pressure and complete the hydrate synthesis.

[0023] Specifically, hydrate synthesis is carried out by injecting excess gas. When the water in the reactor is completely consumed, the pressure in the reactor is maintained at the set pressure, the gas flow rate displayed by the first gas flow meter in the gas injection line no longer changes, and the temperature in the reactor displayed by the sensor no longer changes, indicating that the synthesis reaction is complete.

[0024] S4: Use a hydraulic device to compress the synthesized hydrate while simultaneously opening the exhaust device to collect excess gas;

[0025] Specifically, a hydraulic device is used to push the movable piston upward to expel excess gas from the reaction. After the hydrate begins to contact the top plate of the reactor, the hydraulic device displays the pressure on the movable piston. The movable piston is pushed upward to reach the preset pressure, compressing the synthesized natural gas hydrate. This pressure is maintained for a certain period of time to allow the compressed hydrate to regain stability.

[0026] Specifically, the actual volume of the hydrate in the reactor can be calculated by the final position of the moving piston. The difference between the gas flow meter data of the gas injection line and the gas discharge line is the amount of gas consumed in the reaction. The volume of the synthesized hydrate can also be calculated based on the synthesis reaction formula.

[0027] S5: The synthesized large hydrate blocks are divided into smaller pieces and mixed with the sediment. The mixture is then added to the sample preparation chamber, and the sediment is compressed to reach the set pressure.

[0028] Specifically, the mesh inside the hydrate forms independent but interconnected small spaces, and by disassembling the mesh, large pieces of hydrate can be quickly divided into the required shapes and sizes.

[0029] Specifically, after rapidly mixing the separated hydrates and sediments according to the required contact relationship, the hydraulic device is activated, and pressure is applied to the top plate of the sample preparation chamber through the hydraulic head to compress the mixture.

[0030] S6: Increase the temperature in the sample preparation chamber to slightly decompose the hydrates, then control the temperature to the set temperature to regenerate the decomposed hydrates, thus preparing a sample containing particle-displacement hydrate sediments.

[0031] Specifically, in actual reservoirs, particle-displacement hydrates and sediments are not simply in contact and completely separated. To better simulate this situation, the pressure in the control chamber is kept constant at the set pressure. The temperature in the sample preparation chamber is slightly increased to cause slight decomposition of the hydrates. Then, the temperature is lowered to the set temperature to cause the decomposed hydrates to regenerate, thereby preparing a sediment sample containing particle-displacement hydrates that is closer to reality.

[0032] Compared with the prior art, the beneficial effects of the present invention are:

[0033] 1. The apparatus and method for preparing particle-containing hydrate sediment samples can synthesize particle-containing hydrate sediment samples in different occurrence states according to requirements, for use in hydrate exploration and development technology research.

[0034] 2. It can synthesize hydrate-containing sediment samples with the required hydrate content.

[0035] 3. When the size of the hydrate sample after segmentation is small, the device and method of this invention can synthesize highly saturated sediment samples containing dispersed hydrates, overcoming the difficulty of synthesizing highly saturated dispersed hydrates by conventional methods. Attached Figure Description

[0036] Figure 1 This is a schematic diagram of the device for preparing particulate-displacement hydrate sediment samples according to the present invention.

[0037] In the diagram: 1. Reactor base; 2. Reactor bottom plate; 3. Reactor body; 4. Movable piston; 5. First hydraulic inlet; 6. Reactor top plate; 7. Gas injection port; 8. First exhaust port; 9. Second exhaust port; 10. Sensor; 11. Shaped mesh; 12. Reactor temperature control box; 13. Gas cylinder; 14. First pressure gauge; 15. First valve; 16. Gas booster pump; 17. Second valve; 18. High-pressure gas tank; 19. Second pressure gauge; 20. Third valve; 21. Gas pressure reducing valve; 22. Third pressure gauge; 23. 24. First gas flow meter; 25. Fourth valve; 26. Fifth valve; 27. Fourth pressure gauge; 28. Second gas flow meter; 29. ​​Sixth valve; 30. Gas collector; 31. Vacuum pump; 32. Fifth pressure gauge; 33. Seventh valve; 34. Hydraulic pump; 35. Eighth valve; 36. Ninth valve; 37. Sample preparation chamber base; 38. Sample preparation chamber bottom plate; 39. Sample preparation chamber surrounding plate; 40. Sample preparation chamber top plate; 41. Hydraulic pressure head; 42. Sample preparation chamber temperature and pressure sensor; 43. Sample preparation chamber temperature control box; 44. Control device. Detailed Implementation

[0038] 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, and 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.

[0039] Example: Refer to Figure 1A sample preparation device for particulate-displacement hydrate sediments includes a synthesis device, a gas injection device, an exhaust device, a vacuum device, a hydraulic device, a sample preparation device, and a control module. The synthesis device includes a reactor base 1, a reactor bottom plate 2 fixedly mounted on the reactor base 1, and a reactor body 3 fixedly connected to the top side of the reactor bottom plate 2. The synthesis device is used to synthesize natural gas hydrates. The gas injection device includes a gas cylinder 13, a first pressure gauge 14, a first valve 15, a gas booster pump 16, a second valve 17, a high-pressure gas tank 18, a second pressure gauge 19, a third valve 20, a gas pressure reducing valve 21, a third pressure gauge 22, a first gas flow meter 23, and a fourth valve 24. The gas injection device is used to inject the gas required for synthesizing natural gas hydrates. The exhaust device includes a fifth valve 25 and a fourth pressure gauge. 26. Second gas flow meter 27. Sixth valve 28 and gas collector 29; vacuum device including vacuum pump 30, fifth pressure gauge 31 and seventh valve 32; exhaust device for discharging residual gas after synthesizing natural gas hydrate; vacuum device for discharging air in the synthesis device before the synthesis reaction; hydraulic device including hydraulic pump 33, eighth valve 34 and ninth valve 35; hydraulic device for providing hydraulic compression power; sample preparation device including sample preparation chamber base 36, sample preparation chamber bottom plate 37, sample preparation chamber surrounding plate 38, sample preparation chamber top plate 39, hydraulic pressure head 40, sample preparation chamber temperature and pressure sensor 41 and sample preparation chamber temperature control box 42; sample preparation device for preparing natural gas hydrate sediment samples; control module including control device 43; control module for collecting system data and controlling system operation.

[0040] As a technical optimization of the present invention, a movable piston 4 is movably installed inside the reactor body 3, and a reactor top plate 6 is fixedly connected to the top side of the reactor body 3. The movable piston 4, the reactor top plate 6, and the reactor body 3 constitute a sealed reactor. A malleable mesh 11 is placed inside the reactor body 3. A reactor temperature control box 12 is installed on the reactor body 3. The reactor temperature control box 12 controls the temperature required for the synthesis reaction. The reactor base 1 and the reactor bottom plate 2 are provided with the same first hydraulic inlet 5. The reactor top plate 6 is provided with a gas injection port 7, a first exhaust port 8, and a second exhaust port 9. The upper part of the reactor temperature control box 12 has a channel for connecting the gas injection port 7, the first exhaust port 8, and the second exhaust port 9. Multiple sensors 10 are installed on the inner wall of the reactor body 3. The sensors 10 are temperature sensors and pressure sensors.

[0041] Furthermore, the malleable mesh 11 is a high-strength fine-pore mesh, which is placed in the reactor to divide the internal space of the reactor. The shape of the divided space is controlled by shaping the mesh. When synthesizing hydrate, the mesh is embedded inside the hydrate. The large hydrate formed can be quickly divided into small pieces of the required shape by tearing the mesh, which effectively reduces the decomposition of hydrate during the hydrate division process.

[0042] As a technical optimization of the present invention, the first pressure gauge 14 is connected to the gas cylinder 13, one end of the first valve 15 is connected to the gas cylinder 13 through a pipeline, the other end of the first valve 15 is connected to one end of the gas booster pump 16 through a pipeline, the other end of the gas booster pump 16 is connected to one end of the second valve 17 through a pipeline, the other end of the second valve 17 is connected to one end of the high-pressure gas tank 18 through a pipeline, the other end of the high-pressure gas tank 18 is connected to one end of the second pressure gauge 19 through a pipeline, the other end of the second pressure gauge 19 is connected to one end of the third valve 20 through a pipeline, the other end of the third valve 20 is connected to one end of the gas pressure reducing valve 21 through a pipeline, the other end of the gas pressure reducing valve 21 is connected to one end of the third pressure gauge 22 through a pipeline, the other end of the third pressure gauge 22 is connected to one end of the first gas flow meter 23 through a pipeline, the other end of the first gas flow meter 23 is connected to one end of the fourth valve 24 through a pipeline, and the other end of the fourth valve 24 is connected to the gas injection port 7 through a pipeline.

[0043] Furthermore, gas cylinder 13 is used to store the gas required for the synthesis reaction of natural gas hydrate, gas booster pump 16 is used to increase the injection pressure, first pressure gauge 14 measures the pressure of gas cylinder 13, high-pressure gas tank 18 is used to temporarily store high-pressure gas, second pressure gauge 19 measures the pressure of high-pressure gas tank 18, gas pressure reducing valve 21 is used to control the gas injection pressure, third pressure gauge 22 measures the pressure of the injected gas, and first gas flow meter 23 is used to calculate the injection volume.

[0044] As a technical optimization of the present invention, one end of the fifth valve 25 is connected to the second exhaust port 9 through a pipeline, the other end of the fifth valve 25 is connected to one end of the fourth pressure gauge 26 through a pipeline, the other end of the fourth pressure gauge 26 is connected to one end of the second gas flow meter 27 through a pipeline, the other end of the second gas flow meter 27 is connected to one end of the sixth valve 28 through a pipeline, and the other end of the sixth valve 28 is connected to the gas collector 29 through a pipeline.

[0045] Furthermore, the gas collector 29 can collect and store the discharged gas, and the gas volume can be measured by the water displacement method.

[0046] As a technical optimization of the present invention, one end of the fifth pressure gauge 31 is connected to the vacuum pump 30 through a pipeline, the other end of the fifth pressure gauge 31 is connected to one end of the seventh valve 32 through a pipeline, and the other end of the seventh valve 32 is connected to the first exhaust port 8 through a pipeline.

[0047] As a technical optimization of the present invention, one end of the hydraulic pump 33 is connected to one end of the eighth valve 34 through a pipeline, the other end of the eighth valve 34 is connected to the first hydraulic inlet 5 through a pipeline, the other end of the hydraulic pump 33 is connected to one end of the ninth valve 35 through a pipeline, and the other end of the ninth valve 35 is connected to the hydraulic head 40 through a pipeline.

[0048] Furthermore, the hydraulic device is connected to the synthesis device and the sample preparation device via two routes respectively. The connection to the synthesis device controls the movable piston 4 to compress hydrates, and the connection to the sample preparation device controls the top plate 39 of the sample preparation chamber to compress hydrate-containing sediments.

[0049] As an optimized technical solution of the present invention, the sample preparation chamber bottom plate 37 is fixedly connected to the sample preparation chamber base 36, the sample preparation chamber surrounding plate 38 is fixedly connected to the sample preparation chamber bottom plate 37, a sample preparation chamber temperature and pressure sensor 41 is embedded inside the sample preparation chamber surrounding plate 38, the sample preparation chamber top plate 39 is inside the sample preparation chamber surrounding plate 38, and a hydraulic pressure head 40 is connected to the sample preparation chamber top plate 39.

[0050] Furthermore, under the action of the hydraulic pressure head 40, it can move up and down, forming a sealed sample preparation chamber with the sample preparation chamber bottom plate 37, sample preparation chamber surrounding plate 38, and sample preparation chamber top plate 39. The sample preparation chamber temperature control box 42 controls the temperature change of the sample preparation chamber.

[0051] As a technical optimization of the present invention, the hydraulic head 40 is connected to the hydraulic pump 33 through a pipeline, and the hydraulic head 40 drives the top plate 39 of the sample preparation chamber to move up and down.

[0052] As a technical optimization of the present invention, the control device 43 is electrically connected to all sensors 10, vacuum pump 30, hydraulic pump 33, gas booster pump 16, reaction vessel temperature control box 12 and sample preparation chamber temperature control box 42.

[0053] A method for preparing a sample of particulate-displacement hydrate sediments, comprising the following steps:

[0054] S1: Determine the material composition and physical properties of the sample to be prepared, prepare the synthesis materials, and complete the equipment preparation;

[0055] Specifically, determine the formation temperature and pressure conditions of the area where the sample to be prepared is located, and use these as the set temperature and pressure conditions for sample preparation; prepare sediment materials according to the composition and grain size distribution of the sediments and the size of the sample to be prepared; add a certain amount of water according to the moisture content of the reservoir sediments and mix them evenly to maintain consistency with the actual formation moisture content; lower the temperature of the sediments to the set temperature in advance; and determine the required amount of water and gas based on the conversion of the natural gas hydrate synthesis reaction, taking into account the hydrate content of the sample to be prepared.

[0056] Specifically, ensure all pipeline connections are correct, keep valves initially closed, use a temperature control box to bring the synthesis and sample preparation devices to the set temperature, and conduct sample preparation in a cold storage room to prevent excessive decomposition of hydrates during the transfer process, while adjusting the cold storage room temperature by 1°C.

[0057] S2: Fill the prepared water into the reactor and place the prepared plastic mesh 11 inside to extract the air from the reactor;

[0058] Specifically, the measured water is added to the reactor, and the morphology and size of the hydrates in the sediment are prepared as needed, while controlling the morphology of the malleable mesh 11 in the reactor.

[0059] Specifically, a vacuum device is used to evacuate the reactor to reduce the interference of air in the reactor on the synthesis reaction.

[0060] S3: Control the temperature control box 12 of the reactor. When the temperature of the reactor reaches the predetermined temperature, inject sufficient gas required for the reaction to make the pressure inside the reactor reach the set pressure and complete the hydrate synthesis.

[0061] Specifically, hydrate synthesis is carried out by injecting excess gas. When the water in the reactor is completely consumed, the pressure in the reactor is maintained at the set pressure, the gas flow rate displayed by the first gas flow meter 23 in the gas injection line no longer changes, and the temperature in the reactor displayed by the sensor 10 in the reactor no longer changes, indicating that the synthesis reaction is complete.

[0062] S4: Use a hydraulic device to compress the synthesized hydrate while simultaneously opening the exhaust device to collect excess gas;

[0063] Specifically, a hydraulic device is used to push the movable piston 4 upward to expel excess gas from the reaction. After the hydrate begins to contact the top plate 6 of the reactor, the hydraulic device displays the pressure on the movable piston 4. The movable piston 4 is pushed upward to reach the preset pressure, compressing the synthesized natural gas hydrate. This pressure is maintained for a certain period of time to allow the compressed hydrate to regain stability.

[0064] Specifically, the actual volume of the hydrate in the reactor can be calculated by determining the final stop position of the moving piston 4. The difference between the gas flow meter data of the gas injection pipeline and the gas discharge pipeline represents the amount of gas consumed in the reaction. The volume of the synthesized hydrate can also be calculated based on the synthesis reaction formula.

[0065] S5: The synthesized large hydrate blocks are divided into smaller pieces and mixed with the sediment. The mixture is then added to the sample preparation chamber, and the sediment is compressed to reach the set pressure.

[0066] Specifically, the mesh inside the hydrate forms independent but interconnected small spaces, and by disassembling the mesh, large pieces of hydrate can be quickly divided into the required shapes and sizes.

[0067] Specifically, after rapidly mixing the separated hydrates and sediments according to the required contact relationship, the hydraulic device is activated, and pressure is applied to the top plate 39 of the sample preparation chamber through the hydraulic head 40 to compress the mixture.

[0068] S6: Increase the temperature in the sample preparation chamber to slightly decompose the hydrates, then control the temperature to the set temperature to regenerate the decomposed hydrates, thus preparing a sample containing particle-displacement hydrate sediments.

[0069] Specifically, in actual reservoirs, particle-displacement hydrates and sediments are not simply in contact and completely separated. To better simulate this situation, the pressure in the control chamber is kept constant at the set pressure. The temperature in the sample preparation chamber is slightly increased to cause slight decomposition of the hydrates. Then, the temperature is lowered to the set temperature to cause the decomposed hydrates to regenerate, thereby preparing a sediment sample containing particle-displacement hydrates that is closer to reality.

[0070] In use: The malleable mesh 11 is a high-strength, fine-pore mesh placed in the reactor. The mesh divides the internal space of the reactor, and its shape can be controlled by shaping the mesh. During hydrate synthesis, the mesh is embedded inside the hydrate. Tearing the mesh allows for rapid division of large hydrate blocks into smaller pieces of the desired shape, effectively reducing hydrate decomposition during the process. Gas cylinder 13 stores the gas required for the natural gas hydrate synthesis reaction. Gas booster pump 16 increases the injection pressure. First pressure gauge 14 measures the pressure in gas cylinder 13. High-pressure gas tank 18 temporarily stores high-pressure gas. Second pressure gauge 19 measures the pressure in high-pressure gas tank 18. Gas pressure reducing valve 21 controls the gas injection pressure. Third pressure gauge 22 measures the injected gas pressure. First gas flow meter 23 calculates the injection volume. Gas collector 29 collects and stores the discharged gas and can... The gas volume is measured by the water displacement method. The hydraulic device is connected to the synthesis device and the sample preparation device through two routes. The connection to the synthesis device controls the movable piston 4 to compress hydrates, and the connection to the sample preparation device controls the top plate 39 of the sample preparation chamber to compress hydrate-containing sediments. Under the action of the hydraulic head 40, it can move up and down. The bottom plate 37, the surrounding plate 38, and the top plate 39 of the sample preparation chamber form a sealed sample preparation chamber. The temperature control box 42 of the sample preparation chamber controls the temperature change of the sample preparation chamber to determine the temperature and pressure conditions of the formation where the sample to be prepared is located, which are used as the set temperature and set pressure conditions for sample preparation. According to the composition and particle size distribution of the sediments and the size of the sample to be prepared, the sediment material is prepared. According to the moisture content of the reservoir sediments, a certain amount of water is added and mixed evenly to keep it consistent with the actual moisture content of the formation. The temperature of the sample preparation sediments is lowered to the set temperature in advance.Based on the required hydrate content of the sample and the conversion of the natural gas hydrate synthesis reaction, the required amounts of water and gas are determined. All pipeline connections are ensured to be correct, and valves are initially kept closed. A temperature control box is used to maintain the set temperatures of the synthesis and sample preparation devices. To prevent excessive hydrate decomposition during transfer, sample preparation is conducted in a cold storage room, with the room temperature adjusted by 1°C. Measured water is added to the reactor. The morphology and size of the hydrates in the prepared sediment are controlled, and the shape of the plastic mesh 11 within the reactor is adjusted accordingly. A vacuum device is used to evacuate the reactor, reducing air interference with the synthesis reaction. Hydrate synthesis is carried out by injecting excess gas. When the water in the reactor is completely consumed and the pressure inside the reactor remains at the set pressure, and the gas flow rate displayed by the first gas flow meter 23 in the gas injection line no longer changes, the synthesis reaction is complete. A hydraulic device is used to push the movable piston 4 upwards, expelling excess gas. After the hydrates begin to contact the top plate 6 of the reactor, the hydraulic device displays the pressure on the movable piston 4. Continue pushing the movable piston 4 upwards to reach the preset pressure, compressing the synthesized natural gas hydrate. The actual volume of the hydrate inside the reactor can be calculated by determining the final stop position of the movable piston 4. The difference between the gas flow meter data from the gas injection pipeline and the gas discharge pipeline represents the amount of gas consumed in the reaction. The volume of the synthesized hydrate can also be calculated based on the synthesis reaction formula. The mesh inside the hydrate forms independent yet interconnected small spaces. By removing the mesh, large hydrate pieces can be quickly divided into the required shapes and sizes. After quickly mixing the divided hydrate with the sediment according to the required contact relationship, the hydraulic device is activated, applying pressure to the top plate 39 of the sample preparation chamber through the hydraulic head 40 to compress the mixture. In actual reservoirs, particle-displacement hydrates and sediments will not be in completely separate, simple contact. To better simulate this situation, the control chamber pressure is kept constant at the set pressure. The temperature inside the sample preparation chamber is slightly increased to cause slight decomposition of the hydrate, and then the temperature is lowered back to the set temperature to allow the decomposed hydrate to regenerate, thus preparing a more realistic sample of sediment containing particle-displacement hydrates.

[0071] It should be noted that, in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such process, method, article, or apparatus.

[0072] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A sample preparation device for particulate-displacement hydrate sediments, comprising a synthesis device, a gas injection device, a gas exhaust device, a vacuum device, a hydraulic device, a sample preparation device, and a control module, characterized in that, The synthesis apparatus includes a reactor base (1), a reactor bottom plate (2) fixedly installed on the reactor base (1), and a reactor body (3) fixedly connected to the top side of the reactor bottom plate (2). The gas injection device includes a gas cylinder (13), a first pressure gauge (14), a first valve (15), a gas booster pump (16), a second valve (17), a high-pressure gas tank (18), a second pressure gauge (19), a third valve (20), a gas pressure reducing valve (21), a third pressure gauge (22), a first gas flow meter (23), and a second pressure gauge (24). The four valves (24), the exhaust device includes a fifth valve (25), a fourth pressure gauge (26), a second gas flow meter (27), a sixth valve (28), and a gas collector (29), the vacuum device includes a vacuum pump (30), a fifth pressure gauge (31), and a seventh valve (32), the hydraulic device includes a hydraulic pump (33), an eighth valve (34), and a ninth valve (35), the sample preparation device includes a sample preparation chamber base (36), a sample preparation chamber bottom plate (37), a sample preparation chamber enclosure plate (38), and a sample preparation chamber top plate (39). 9) Hydraulic pressure head (40), sample preparation chamber temperature and pressure sensor (41), and sample preparation chamber temperature control box (42). The control module includes a control device (43). A movable piston (4) is movably installed inside the reactor body (3). A reactor top plate (6) is fixedly connected to the top side of the reactor body (3). The movable piston (4), reactor top plate (6), and reactor body (3) constitute a sealed reactor. A plastic mesh (11) is placed inside the reactor body (3). A reactor temperature control box is installed on the reactor body (3). (12) The reactor base (1) and the reactor bottom plate (2) are provided with the same first hydraulic inlet (5). The reactor top plate (6) is provided with an air injection port (7), a first exhaust port (8) and a second exhaust port (9). The upper part of the reactor temperature control box (12) is provided with a channel for connecting the air injection port (7), the first exhaust port (8) and the second exhaust port (9). Multiple reactor internal sensors (10) are installed on the inner wall of the reactor body (3). The reactor internal sensors (10) are temperature sensors and pressure sensors.

2. The apparatus for preparing particle-displacement hydrate sediment samples according to claim 1, characterized in that, The first pressure gauge (14) is connected to the gas cylinder (13). One end of the first valve (15) is connected to the gas cylinder (13) via a pipeline. The other end of the first valve (15) is connected to one end of the gas booster pump (16) via a pipeline. The other end of the gas booster pump (16) is connected to one end of the second valve (17) via a pipeline. The other end of the second valve (17) is connected to one end of the high-pressure gas tank (18) via a pipeline. The other end of the high-pressure gas tank (18) is connected to one end of the second pressure gauge (19) via a pipeline. The second pressure gauge (19) The other end is connected to one end of the third valve (20) through a pipeline. The other end of the third valve (20) is connected to one end of the gas pressure reducing valve (21) through a pipeline. The other end of the gas pressure reducing valve (21) is connected to one end of the third pressure gauge (22) through a pipeline. The other end of the third pressure gauge (22) is connected to one end of the first gas flow meter (23) through a pipeline. The other end of the first gas flow meter (23) is connected to one end of the fourth valve (24) through a pipeline. The other end of the fourth valve (24) is connected to the gas injection port (7) through a pipeline.

3. The apparatus for preparing particle-displacement hydrate sediment samples according to claim 1, characterized in that, One end of the fifth valve (25) is connected to the second exhaust port (9) through a pipeline, and the other end of the fifth valve (25) is connected to one end of the fourth pressure gauge (26) through a pipeline. The other end of the fourth pressure gauge (26) is connected to one end of the second gas flow meter (27) through a pipeline. The other end of the second gas flow meter (27) is connected to one end of the sixth valve (28) through a pipeline. The other end of the sixth valve (28) is connected to the gas collector (29) through a pipeline.

4. The apparatus for preparing particle-displacement hydrate sediment samples according to claim 1, characterized in that, One end of the fifth pressure gauge (31) is connected to the vacuum pump (30) through a pipeline, and the other end of the fifth pressure gauge (31) is connected to one end of the seventh valve (32) through a pipeline. The other end of the seventh valve (32) is connected to the first exhaust port (8) through a pipeline.

5. The apparatus for preparing particle-displacement hydrate sediment samples according to claim 1, characterized in that, One end of the hydraulic pump (33) is connected to one end of the eighth valve (34) through a pipeline, the other end of the eighth valve (34) is connected to the first hydraulic inlet (5) through a pipeline, the other end of the hydraulic pump (33) is connected to one end of the ninth valve (35) through a pipeline, and the other end of the ninth valve (35) is connected to the hydraulic head (40) through a pipeline.

6. The apparatus for preparing particle-displacement hydrate sediment samples according to claim 1, characterized in that, The sample preparation chamber bottom plate (37) is fixedly connected to the sample preparation chamber base (36), the sample preparation chamber enclosure plate (38) is fixedly connected to the sample preparation chamber bottom plate (37), a sample preparation chamber temperature and pressure sensor (41) is embedded inside the sample preparation chamber enclosure plate (38), the sample preparation chamber top plate (39) is inside the sample preparation chamber enclosure plate (38), and a hydraulic pressure head (40) is connected to the sample preparation chamber top plate (39).

7. The apparatus for preparing particle-displacement hydrate sediment samples according to claim 1, characterized in that, The hydraulic head (40) is connected to the hydraulic pump (33) through a pipeline, and the hydraulic head (40) drives the top plate (39) of the sample preparation chamber to move up and down.

8. The apparatus for preparing particle-displacement hydrate sediment samples according to claim 1, characterized in that, The control device (43) is electrically connected to all the sensors (10) in the reactor, the vacuum pump (30), the hydraulic pump (33), the gas booster pump (16), the reactor temperature control box (12), and the sample preparation chamber temperature control box (42).

9. A method for preparing a particle-displacement type hydrate sediment sample according to any one of claims 1-8, the method comprising the following steps: S1: Determine the material composition and physical properties of the sample to be prepared, prepare the synthesis materials, and complete the equipment preparation; Specifically, determine the formation temperature and pressure conditions where the sample to be prepared is located, and use these as the set temperature and pressure conditions for sample preparation; prepare sediment materials based on the composition and grain size distribution of the sediments and the required sample size; add a certain amount of water to the reservoir sediments according to their moisture content, mix them evenly to maintain consistency with the actual formation moisture content, and lower the temperature of the sediments to the set temperature in advance; and determine the required amounts of water and gas based on the hydrate content of the sample to be prepared and the conversion of natural gas hydrate synthesis reactions. Specifically, ensure all pipeline connections are correct, keep valves initially closed, use a temperature control box to bring the synthesis and sample preparation devices to the set temperature, and carry out sample preparation in a cold storage room to prevent excessive decomposition of hydrates during the transfer process, while adjusting the cold storage room temperature by 1°C. S2: Fill the prepared water into the reactor and place the prepared plastic mesh (11) inside to extract the air from the reactor; Specifically, the measured water is added to the reactor, and the morphology and size of the hydrates in the sediment are prepared as needed, and the morphology of the plastic mesh (11) in the reactor is controlled. Specifically, a vacuum device is used to evacuate the reactor to reduce the interference of air in the reactor on the synthesis reaction; S3: Control the temperature control box (12) of the reactor. When the temperature of the reactor reaches the predetermined temperature, inject enough gas required for the reaction to make the pressure inside the reactor reach the set pressure and complete the hydrate synthesis. Specifically, hydrate synthesis is carried out by injecting excess gas. When the water in the reactor is completely consumed, the pressure in the reactor is maintained at the set pressure, and the gas flow rate displayed by the first gas flow meter (23) in the gas injection line no longer changes. The temperature in the reactor displayed by the sensor (10) in the reactor no longer changes, indicating that the synthesis reaction is complete. S4: Use a hydraulic device to compress the synthesized hydrate while simultaneously opening the exhaust device to collect excess gas; Specifically, the hydraulic device is used to push the movable piston (4) upward to discharge the excess gas from the reaction. After the hydrate begins to contact the top plate (6) of the reactor, the hydraulic device displays the pressure on the movable piston (4). The movable piston (4) is pushed upward to make the pressure reach the preset pressure, compressing the synthesized natural gas hydrate. The pressure is maintained for a certain period of time to allow the compressed hydrate to regain stability. Specifically, the actual volume of the hydrate in the reactor is calculated by the position where the final moving piston (4) stops, or the difference between the gas flow meter data of the gas injection pipeline and the gas discharge pipeline is the amount of gas consumed in the reaction, and the volume of the synthesized hydrate is calculated according to the synthesis reaction formula; S5: The synthesized large hydrate blocks are divided into smaller pieces and mixed with the sediment. The mixture is then added to the sample preparation chamber, and the sediment is compressed to reach the set pressure. Specifically, the mesh inside the hydrate forms independent but interconnected small spaces, allowing large hydrate pieces to be quickly divided into the required shapes and sizes by disassembling the mesh; Specifically, after rapidly mixing the separated hydrates and sediments according to the required contact relationship, the hydraulic device is turned on, and pressure is applied to the top plate (39) of the sample preparation chamber through the hydraulic head to compress the mixture; S6: Increase the temperature in the sample preparation chamber to slightly decompose the hydrates, then control the temperature to the set temperature to regenerate the decomposed hydrates, thus preparing a sample containing particle-displacement hydrate sediments. Specifically, in actual reservoirs, particle-displacement hydrates and sediments are not simply in contact and completely separated. To better simulate this situation, the pressure in the control chamber is kept constant at the set pressure. The temperature in the sample preparation chamber is slightly increased to cause slight decomposition of the hydrates. Then, the temperature is lowered to the set temperature to cause the decomposed hydrates to regenerate, thereby preparing a sediment sample containing particle-displacement hydrates that is closer to reality.

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