Fluid interlayer flow monitoring device and method in hydrate and shallow gas combined exploitation
By designing flow monitoring devices for thermostatic reactors and pipeline components, the problem of difficult monitoring of interlayer fluid exchange in the joint exploitation of natural gas hydrates and shallow gas was solved, enabling accurate monitoring of gas flow and fluid exchange within the wellbore, optimizing the exploitation process and ensuring safe production.
Patent Information
- Application Number
- CN202511236055.7
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-09-01
- Publication Date
- 2025-11-14
AI Technical Summary
Existing technologies are insufficient to accurately monitor the flow and exchange of fluids between layers during the combined extraction of natural gas hydrates and shallow gas, leading to resource waste and wellbore stability issues during extraction.
Design a flow monitoring device comprising a thermo-autoclave, a non-obstructed pipeline assembly, an obstructed porous media channel assembly, a temperature regulation system, and a control system, to monitor airflow and interlayer fluid exchange within the wellbore using flow meters and pressure sensors.
It enables precise monitoring of wellbore airflow and interlayer fluid exchange, optimizes the joint mining process in the same well, and ensures safe production.
Smart Images
Figure CN120946288A_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of natural gas extraction technology, and in particular to a device and method for monitoring interlayer fluid flow in the combined extraction of hydrates and shallow gas. Background Technology
[0002] Against the backdrop of accelerated global energy structure transformation, natural gas hydrates, as a clean energy source with abundant reserves, together with shallow gas, constitute an energy combination with great development potential. Joint extraction of natural gas hydrates and shallow gas from the same well can effectively reduce extraction costs and improve resource utilization, becoming a research hotspot in the energy field. However, in actual extraction, the extraction conditions for natural gas hydrates and shallow gas differ significantly. The pressure required for the decomposition of natural gas hydrates is much lower than the pressure of the lower shallow gas reservoir. When using the same wellbore for joint extraction, the large pressure difference between the two fluid layers may lead to problems such as backflow of shallow gas layer fluid into the hydrate layer.
[0003] The dynamic changes in airflow within the wellbore and the exchange of fluids between different reservoirs have a decisive impact on mining efficiency, safety, and resource recovery rate.
[0004] Currently, traditional physical model experiments do not consider issues such as interlayer fluid backflow under the above circumstances. The extended physical model experimental techniques are also difficult to accurately capture the real-time parameters of interlayer airflow in complex wellbore environments. They cannot effectively track and quantify the flow and exchange process of interlayer fluids, resulting in unclear theoretical research on issues such as resource waste, wellbore stability, and environmental risks during the mining process.
[0005] Therefore, there is an urgent need to develop a monitoring device for interlayer fluid flow in the combined exploitation of hydrates and shallow gas. Summary of the Invention
[0006] This invention provides, on one hand, a fluid interlayer flow monitoring device for the joint exploitation of hydrates and shallow gas, enabling precise monitoring of wellbore gas flow and interlayer fluid exchange, providing technical support for optimizing the joint exploitation process and ensuring safe production. On the other hand, this invention provides a method for monitoring fluid interlayer flow in the joint exploitation of hydrates and shallow gas.
[0007] The first aspect of the present invention provides a fluid interlayer flow monitoring device for the joint exploitation of hydrates and shallow gas, comprising a first thermo-pressure vessel, a second thermo-pressure vessel, a first unobstructed pipeline assembly, a second unobstructed pipeline assembly, an obstructed porous medium channel assembly, a temperature regulation system, a temperature detection module, a pressure regulation system, and a control system; The first thermostatic reactor and the second thermostatic reactor are connected through the first unobstructed pipeline assembly, the second unobstructed pipeline assembly and the obstructed porous media channel assembly, so that the first unobstructed pipeline assembly is used to monitor the gas flow rate from the first thermostatic reactor to the second thermostatic reactor, the second unobstructed pipeline assembly is used to monitor the gas flow rate from the second thermostatic reactor to the first thermostatic reactor, and the obstructed porous media channel assembly is used to simulate different permeability septa, so as to realize the test of fluid flow under different permeability septa conditions; The first and second thermo-pressure vessels are respectively equipped with the temperature control system on their exteriors, and the first and second thermo-pressure vessels are respectively equipped with the temperature detection module inside their interiors; The pressure regulating system includes a gas injection system, a pressure monitoring module, and a connecting pipeline. The gas injection system is connected to the first thermostatic reactor and the second thermostatic reactor through the connecting pipeline to inject gas into the interior of the first thermostatic reactor and the interior of the second thermostatic reactor, respectively. The connecting pipeline is connected in series with the first unobstructed pipeline assembly and the second unobstructed pipeline assembly, respectively. The pressure monitoring module is installed at the inlet of the first thermostatic reactor and the inlet of the second thermostatic reactor. The temperature regulation system, the temperature detection module, and the pressure sensor are respectively connected to the control system.
[0008] In the fluid interlayer flow monitoring device for the combined exploitation of hydrates and shallow gas, preferably, the gas injection system includes a first gas source and a second gas source; the pressure monitoring module includes a first pressure sensor and a second pressure sensor; the connecting pipeline includes a first pipeline, a second pipeline, a third pipeline, and a valve assembly; the first pipeline, the second pipeline, the third pipeline, the first unobstructed pipeline assembly, and the second unobstructed pipeline assembly are connected in series to connect the first gas source to the first thermostatic reactor, the second gas source to the second thermostatic reactor, and the third pipeline to the control system. Along the fluid flow direction in the pipeline, the third pipeline is sequentially equipped with a first flow meter and a first drying system; the valve assembly is respectively installed on the first pipeline, the second pipeline, and the third pipeline; the first pressure sensor is installed at the inlet of the first thermostatic reactor, and the second pressure sensor is installed at the inlet of the second thermostatic reactor.
[0009] The fluid interlayer flow monitoring device in the combined exploitation of hydrates and shallow gas, preferably, includes a first unobstructed pipeline assembly comprising a first connecting pipeline, a first unobstructed pipeline, a second connecting pipeline, a first four-way valve, a third shut-off valve, a second three-way valve, a fifth shut-off valve, a second drying system, a second flow meter, a fourth three-way valve, an eleventh shut-off valve, and a second four-way valve. The first connecting pipeline, the third pipeline, and the first pressure sensor are respectively connected to the first thermo-autoclave via the first four-way valve. The second connecting pipeline is connected to the second thermo-autoclave, the second pressure sensor, and the obstructed porous media channel assembly via the second four-way valve. The first connecting pipeline is connected to the first unobstructed pipeline via the second three-way valve, and the first unobstructed pipeline is connected to the second connecting pipeline via the fourth three-way valve. Along the flow direction of the fluid from the first thermo-autoclave to the second thermo-autoclave, the first connecting pipeline is equipped with the third shut-off valve, the first unobstructed pipeline is sequentially equipped with the fifth shut-off valve, the second drying system, and the second flow meter, and the second connecting pipeline is equipped with the eleventh shut-off valve.
[0010] The fluid interlayer flow monitoring device in the combined exploitation of hydrates and shallow gas, preferably, includes a second unobstructed pipeline assembly comprising a first connecting pipeline, a second connecting pipeline, a second unobstructed pipeline, a tenth shut-off valve, a third three-way valve, a sixth shut-off valve, a third drying system, a third flow meter, a first three-way valve, and a second shut-off valve. The first connecting pipeline is connected to the second unobstructed pipeline via the second three-way valve, and the second connecting pipeline is connected to the second unobstructed pipeline via the third three-way valve. Along the flow direction of the fluid from the second thermostatic reactor to the first thermostatic reactor, the sixth shut-off valve, the third drying system, and the third flow meter are sequentially arranged on the second unobstructed pipeline. The third three-way valve is connected to the first gas source via the first pipeline, and the first three-way valve is connected to the second gas source via the second pipeline.
[0011] In the aforementioned fluid interlayer flow monitoring device for the combined exploitation of hydrates and shallow gas, preferably, the temperature regulation system includes a first jacket, a second jacket, and a condensation mechanism. The temperature detection module includes a first temperature sensor and a second temperature sensor. The condensation mechanism is respectively provided on the first jacket and the second jacket. The first jacket wraps around the outer periphery of the first thermo-pressure vessel, and the second jacket wraps around the outer periphery of the second thermo-pressure vessel. The condensation mechanism is connected to the control system. The control system causes the coolant in the condensation mechanism to circulate at a set temperature to regulate the internal temperature of the first thermo-pressure vessel and / or the internal temperature of the second thermo-pressure vessel. The first temperature sensor is installed inside the first thermo-pressure vessel, and the second temperature sensor is installed inside the second thermo-pressure vessel. The first temperature sensor and the second temperature sensor are respectively connected to the control system.
[0012] In the aforementioned fluid interlayer flow monitoring device for the combined exploitation of hydrates and shallow gas, preferably, the obstructed porous media channel assembly includes a seventh shut-off valve, an obstructed porous media channel, and an eighth shut-off valve. The seventh shut-off valve and the eighth shut-off valve are respectively provided at both ends of the obstructed porous media channel. The eighth shut-off valve is connected to the second four-way valve. The obstructed porous media channel is filled with porous media contents.
[0013] The fluid interlayer flow monitoring device for the combined exploitation of hydrates and shallow gas is preferably provided in a valve assembly comprising a first shut-off valve, a fourth shut-off valve, and a ninth shut-off valve, wherein the first shut-off valve is provided on the first pipeline, the ninth shut-off valve is provided on the second pipeline, and the fourth shut-off valve is provided on the third pipeline.
[0014] A second aspect of the present invention provides a method for monitoring inter-layer fluid flow in the combined exploitation of hydrates and shallow gas, comprising the aforementioned monitoring device for inter-layer fluid flow in the combined exploitation of hydrates and shallow gas, specifically including the following steps: The first and second thermo-autoclaves are filled with sediment, all shut-off valves between the first and second thermo-autoclaves are closed, and the temperature and pressure of the first and second thermo-autoclaves are controlled by the control system. A hydrate-gas-water phase and free gas are formed in the pores of the first and second thermo-autoclaves. After the fluid phase is formed and stabilized, the pressure in the first and second thermostatic reactors is adjusted so that the pressure in the second thermostatic reactor is much higher than that in the first thermostatic reactor. Shut down the gas injection system and the obstructed porous medium channel assembly, open the first unobstructed pipeline assembly, and after confirming that there is no fluid flow, shut down the first unobstructed pipeline assembly. Open the second unobstructed pipeline assembly and monitor the readings of the third flow meter on the second unobstructed pipeline assembly and the first flow meter on the pressure regulating system; A third aspect of the present invention provides a method for monitoring inter-layer fluid flow in the combined exploitation of hydrates and shallow gas, comprising the aforementioned monitoring device for inter-layer fluid flow in the combined exploitation of hydrates and shallow gas, specifically including the following steps: The first and second thermo-autoclaves are filled with sediment, all shut-off valves between the first and second thermo-autoclaves are closed, and the temperature and pressure of the first and second thermo-autoclaves are controlled by the control system. A hydrate-gas-water phase and free gas are formed in the pores of the first and second thermo-autoclaves. After the fluid phase is formed and stabilized, the pressure in the first and second thermostatic reactors is adjusted so that the pressure in the second thermostatic reactor is much higher than that in the first thermostatic reactor. Open the obstructed porous medium channel assembly and close the gas injection system. Open the first unobstructed pipeline assembly. After confirming that there is no fluid flow, close the first unobstructed pipeline assembly. Open the second unobstructed pipeline assembly and monitor the readings of the third flow meter on the second unobstructed pipeline assembly and the first flow meter on the pressure regulating system; After the exhaust test is completed, the porous medium material filled in the porous medium channel assembly is replaced, and the exhaust test is repeated multiple times to monitor the readings of the third flow meter on the second unobstructed pipeline assembly and the first flow meter on the pressure regulating system.
[0015] The beneficial effects are: The present invention sets up an unobstructed channel and a flow meter between the two thermo-pressure reactors to monitor the interlayer gas flow phenomenon in the wellbore under the scenarios of high bottom hole pressure for mining underlying gas and low bottom hole pressure for mining hydrate layer. It can explore the interlayer interference phenomenon caused by pressure communication in the wellbore during the co-production of the two gases.
[0016] The present invention provides a barrier channel filled with porous media between the two thermo-pressure reactors. The porous media in the channel can be flexibly replaced. It can be used to monitor the interlayer gas flow phenomenon in the wellbore under different interlayer permeability between the hydrate layer and the underlying gas. It can also be used to explore the interlayer interference law caused by pressure communication in the wellbore during the two-gas co-production process under different interlayer permeability.
[0017] This invention enables precise monitoring of wellbore airflow and interlayer fluid exchange, providing technical support for optimizing joint well mining processes and ensuring safe production. Attached Figure Description
[0018] Figure 1 This is a schematic diagram of the structure of the present invention.
[0019] In the picture: 11. First gas source; 12. Second gas source; 21. First thermostatic flask; 22. Second thermostatic flask; 31. First jacket; 32. Second jacket; 41. First drying system; 42. Second drying system; 43. Third drying system; 51. First flow meter; 52. Second flow meter; 53. Third flow meter; 6. Obstructed porous media channels; 7. Control system; 91. First shut-off valve; 92. Second shut-off valve; 93. Third shut-off valve; 94. Fourth shut-off valve; 95. Fifth shut-off valve; 96. Sixth shut-off valve; 97. Seventh shut-off valve; 98. Eighth shut-off valve; 99. Ninth shut-off valve; 910. Tenth shut-off valve; 911. Eleventh shut-off valve; 101. First three-way valve; 102. Second three-way valve; 103. Third three-way valve; 104. Fourth three-way valve; 111. First four-way valve; 112. Second four-way valve; 121. First pressure sensor; 122. Second pressure sensor; 131. First temperature sensor; 132. Second temperature sensor; 141. First pipeline; 142. Second pipeline; 143. Third pipeline; 151. First connecting pipe; 152. Second connecting pipe; 161. First unobstructed pipeline; 162. Second unobstructed pipeline. Detailed Implementation
[0020] To make the objectives, technical solutions, and advantages of this invention clearer, the technical solutions of this invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of this invention. All other embodiments obtained by those skilled in the art based on the embodiments of this invention without creative effort are within the scope of protection of this invention.
[0021] In the description of this invention, it should be noted that the terms "upper," "lower," etc., indicating the orientation or positional relationship are based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing the invention and simplifying the description, and do not indicate or imply that the system or component referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the invention. Furthermore, the use of terms such as "first," "eleventh," etc., to define components is merely for the convenience of distinguishing the aforementioned components; unless otherwise stated, these terms have no special meaning and should not be construed as indicating or implying relative importance.
[0022] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "setting," and "connection" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.
[0023] This invention provides a fluid interlayer flow monitoring device for the combined exploitation of hydrates and shallow gas, comprising a first thermo-autoclave, a second thermo-autoclave, a first unobstructed pipeline assembly, a second unobstructed pipeline assembly, a blocked porous media channel assembly, a temperature control system, a temperature detection module, a pressure regulating system, and a control system. The first and second thermo-autoclaves are connected via the first unobstructed pipeline assembly, the second unobstructed pipeline assembly, and the blocked porous media channel assembly. The first unobstructed pipeline assembly monitors the gas flow rate from the first thermo-autoclave to the second thermo-autoclave, and the second unobstructed pipeline assembly monitors the gas flow rate from the second thermo-autoclave to the first thermo-autoclave. The blocked porous media channel assembly simulates interlayers with different permeability to test flow under different permeability interlayer conditions. The invention relates to a system for controlling gas flow in wellbore. The first and second thermo-pressure vessels are externally equipped with temperature control systems, and internally equipped with temperature detection modules. The pressure control system includes a gas injection system, a pressure monitoring module, and connecting pipelines. The gas injection system is connected to the first and second thermo-pressure vessels via the connecting pipelines to inject gas into the interiors of the first and second thermo-pressure vessels, respectively. The connecting pipelines are connected in series with the first and second unobstructed pipeline assemblies. Pressure monitoring modules are installed at the inlets of both the first and second thermo-pressure vessels. The temperature control system, the temperature detection module, and the pressure sensor are connected to the control system. This invention enables precise monitoring of wellbore gas flow and inter-layer fluid exchange, providing technical support for optimizing joint well mining processes and ensuring safe production.
[0024] The following section uses a fluid interlayer flow monitoring device in the combined exploitation of hydrates and shallow gas as an example to illustrate the entire technical process in detail.
[0025] Example 1 like Figure 1As shown, a fluid interlayer flow monitoring device for the joint exploitation of hydrates and shallow gas includes a first thermo-pressure vessel 21, a second thermo-pressure vessel 22, a first unobstructed pipeline assembly, a second unobstructed pipeline assembly, an obstructed porous medium channel assembly, a temperature regulation system, a temperature detection module, a pressure regulation system, and a control system 7; wherein, the control system 7 is a computer; The first thermo-autoclave 21 and the second thermo-autoclave 22 are connected by a first unobstructed pipeline assembly, a second unobstructed pipeline assembly, and a blocked porous media channel assembly. The first unobstructed pipeline assembly is used to monitor the gas flow rate from the first thermo-autoclave 21 to the second thermo-autoclave 22, the second unobstructed pipeline assembly is used to monitor the gas flow rate from the second thermo-autoclave 22 to the first thermo-autoclave 21, and the blocked porous media channel assembly is used to simulate different permeability septa to test fluid flow under different permeability septa conditions. The first thermo-pressure vessel 21 and the second thermo-pressure vessel 22 are respectively equipped with a temperature regulation system on their exteriors, and the first thermo-pressure vessel 21 and the second thermo-pressure vessel 22 are respectively equipped with a temperature detection module inside their interiors; The pressure regulating system includes a gas injection system, a pressure monitoring module, and a connecting pipeline. The gas injection system is connected to the first thermo-pressure vessel 21 and the second thermo-pressure vessel 22 through the connecting pipeline to inject gas into the interior of the first thermo-pressure vessel 21 and the interior of the second thermo-pressure vessel 22, respectively. The connecting pipeline is connected in series with the first unobstructed pipeline assembly and the second unobstructed pipeline assembly, respectively. Pressure monitoring modules are installed at the inlet of the first thermo-pressure vessel 21 and the inlet of the second thermo-pressure vessel 22. The temperature control system, temperature detection module, and pressure sensor are connected to the control system 7.
[0026] The gas injection system includes a first gas source 11 and a second gas source 12. The pressure monitoring module includes a first pressure sensor 121 and a second pressure sensor 122. The connecting pipeline includes a first pipeline 141, a second pipeline 142, a third pipeline 143, and a valve assembly. The first pipeline 141, the second pipeline 142, the third pipeline 143, the first unobstructed pipeline assembly, and the second unobstructed pipeline assembly are connected in series to connect the first gas source 11 to the first thermo-pressure vessel 21, the second gas source 12 to the second thermo-pressure vessel 22, and the third pipeline 143 to the control system 7. Along the fluid flow direction in the pipeline, the third pipeline 143 is sequentially equipped with a first flow meter 51 and a first drying system 41. The first pipeline 141, the second pipeline 142, and the third pipeline 143 are respectively equipped with valve assemblies. The first pressure sensor 121 is located at the inlet of the first thermo-pressure vessel 21, and the second pressure sensor 122 is located at the inlet of the second thermo-pressure vessel 22.
[0027] The valve assembly includes a first shut-off valve 91, a fourth shut-off valve 94, and a ninth shut-off valve 99. The first shut-off valve 91 is provided on the first pipeline 141, the ninth shut-off valve 99 is provided on the second pipeline 142, and the fourth shut-off valve 94 is provided on the third pipeline 143.
[0028] The first unobstructed pipeline assembly includes a first connecting pipeline 151, a first unobstructed pipeline 161, a second connecting pipeline 152, a first four-way valve 111, a third shut-off valve 93, a second three-way valve 102, a fifth shut-off valve 95, a second drying system 42, a second flow meter 52, a fourth three-way valve 104, an eleventh shut-off valve 911, and a second four-way valve 112. The first connecting pipeline 151, the third pipeline 143, and the first pressure sensor 121 are respectively connected to the first thermostatic reactor 21 through the first four-way valve 111, and the second connecting pipeline 152 is connected to the second thermostatic reactor through the second four-way valve 112. 22. The second pressure sensor 122 and the obstructed porous medium channel assembly are connected. The first connecting pipe 151 is connected to the first unobstructed pipe 161 through the second three-way valve 102. The first unobstructed pipe 161 is connected to the second connecting pipe 152 through the fourth three-way valve 104. Following the flow direction of the fluid from the first thermo-pressure vessel 21 to the second thermo-pressure vessel 22, the first connecting pipe 151 is provided with a third shut-off valve 93. The first unobstructed pipe 161 is sequentially provided with a fifth shut-off valve 95, a second drying system 42 and a second flow meter 52. The second connecting pipe 152 is provided with an eleventh shut-off valve 911.
[0029] The second unobstructed pipeline assembly includes a first connecting pipeline 151, a second connecting pipeline 152, a second unobstructed pipeline 162, a tenth shut-off valve 910, a third three-way valve 103, a sixth shut-off valve 96, a third drying system 43, a third flow meter 53, a first three-way valve 101, and a second shut-off valve 92. The first connecting pipeline 151 is connected to the second unobstructed pipeline 162 through the second three-way valve 102, and the second connecting pipeline 152 is connected to the second unobstructed pipeline 162 through the third three-way valve 103. Following the flow direction of the fluid from the second thermo-pressure vessel 22 to the first thermo-pressure vessel 21, the second unobstructed pipeline 162 is sequentially equipped with the sixth shut-off valve 96, the third drying system 43, and the third flow meter 53. The third three-way valve 103 is connected to the first gas source 11 through the first pipeline 141, and the first three-way valve 101 is connected to the second gas source 12 through the second pipeline 142.
[0030] The temperature control system includes a first jacket 31, a second jacket 32, and a condensation mechanism. The temperature detection module includes a first temperature sensor 131 and a second temperature sensor 132. The condensation mechanism is respectively provided on the first jacket 31 and the second jacket 32. The first jacket 31 wraps around the outer periphery of the first thermo-pressure vessel 21, and the second jacket 32 wraps around the outer periphery of the second thermo-pressure vessel 22. The condensation mechanism is connected to the control system 7. The control system 7 causes the coolant in the condensation mechanism to circulate at a set temperature to regulate the internal temperature of the first thermo-pressure vessel 21 and / or the internal temperature of the second thermo-pressure vessel 22. The first temperature sensor 131 is installed in the first thermo-pressure vessel 21, and the second temperature sensor 132 is installed in the second thermo-pressure vessel 22. The first temperature sensor 131 and the second temperature sensor 132 are respectively connected to the control system 7.
[0031] The condensation mechanism includes a condensation pump and a condensation tube. The condensation tube is disposed in a first jacket 31 and a second jacket 32. The condensation tube is connected to the condensation pump, and the condensation pump is connected to the control system 7.
[0032] The obstructed porous medium channel assembly includes a seventh shut-off valve 97, an obstructed porous medium channel 6, and an eighth shut-off valve 98. The obstructed porous medium channel 6 is equipped with a seventh shut-off valve 97 and an eighth shut-off valve 98 at its two ends, respectively. The eighth shut-off valve 98 is connected to the second four-way valve 112. The obstructed porous medium channel 6 is filled with porous medium contents.
[0033] The porous medium contains a mixture of mud and sand.
[0034] Example 2 This embodiment simulates the situation where there is no permeable interlayer between natural gas hydrate and shallow gas.
[0035] A method for monitoring interlayer fluid flow in the combined exploitation of hydrates and shallow gas includes a fluid interlayer flow monitoring device as described in Example 1, specifically comprising the following steps: S1: Fill the first thermo-pressure vessel 21 and the second thermo-pressure vessel 22 with sediment, close all shut-off valves between the first thermo-pressure vessel 21 and the second thermo-pressure vessel 22, and control the temperature and pressure of the first thermo-pressure vessel 21 and the second thermo-pressure vessel 22 through the control system 7. The first thermo-pressure vessel 21 and the second thermo-pressure vessel 22 form a hydrate-gas-water phase and free gas in the pores.
[0036] Specifically, "closing all shut-off valves between the first thermo-pressure vessel 21 and the second thermo-pressure vessel 22" refers to the fifth shut-off valve 95, the sixth shut-off valve 96, the seventh shut-off valve 97, and the eighth shut-off valve 98.
[0037] "Controlling the temperature and pressure of the first thermo-pressure vessel 21 and the second thermo-pressure vessel 22 through the control system 7" means that the control system 7 regulates the internal temperature of the first thermo-pressure vessel 21 and / or the internal temperature of the second thermo-pressure vessel 22 by controlling the circulation of coolant in the condensation mechanism according to a set temperature. The control system 7 regulates the gas supply pressure by opening the first gas source 11 and the second gas source 12.
[0038] S2: After the fluid phase is formed and stabilized, adjust the pressure in the first thermo-pressure vessel 21 and the second thermo-pressure vessel 22 so that the pressure in the second thermo-pressure vessel 22 is much higher than that in the first thermo-pressure vessel 21.
[0039] Specifically, "adjusting the pressure inside the first thermo-pressure vessel 21 and the second thermo-pressure vessel 22" refers to the control system 7 adjusting the pressure by opening the first gas source 11 and the second gas source 12.
[0040] S3: Close the gas injection system and the obstructed porous medium channel assembly, open the first unobstructed pipeline assembly, and close the first unobstructed pipeline assembly after confirming that there is no fluid flow.
[0041] Specifically, "confirming no fluid flow" means that the second flow meter 52 has no indication.
[0042] S4: Open the second unobstructed pipeline assembly and monitor the readings of the third flow meter 53 on the second unobstructed pipeline assembly and the first flow meter 51 on the pressure regulating system.
[0043] When the reading of the first flow meter 51 is greater than the reading of the third flow meter 53, it means that the gas in the first thermo-pressure vessel 21 and the second thermo-pressure vessel 22 is being extracted simultaneously. When the reading of the first flow meter 51 is equal to the reading of the third flow meter 53, it indicates that the gas inside the second thermostatic reactor 22 is being extracted. When the reading of the first flow meter 51 is less than the reading of the third flow meter 53, it means that the gas in the second thermo-pressure vessel 22 flows into the gas in the first thermo-pressure vessel 21.
[0044] Example 3 This embodiment simulates a situation where there is a permeable interlayer between natural gas hydrate and shallow gas.
[0045] A method for monitoring interlayer fluid flow in the combined exploitation of hydrates and shallow gas includes a fluid interlayer flow monitoring device as described in Example 1, specifically comprising the following steps: S1: Fill the first thermo-pressure vessel 21 and the second thermo-pressure vessel 22 with sediment, close all shut-off valves between the first thermo-pressure vessel 21 and the second thermo-pressure vessel 22, and control the temperature and pressure of the first thermo-pressure vessel 21 and the second thermo-pressure vessel 22 through the control system. The first thermo-pressure vessel 21 and the second thermo-pressure vessel 22 form a hydrate-gas-water phase and free gas in the pores.
[0046] Specifically, "closing all shut-off valves between the first thermo-pressure vessel 21 and the second thermo-pressure vessel 22" refers to the fifth shut-off valve 95, the sixth shut-off valve 96, the seventh shut-off valve 97, and the eighth shut-off valve 98.
[0047] "Controlling the temperature and pressure of the first thermo-pressure vessel 21 and the second thermo-pressure vessel 22 through the control system 7" means that the control system 7 regulates the internal temperature of the first thermo-pressure vessel 21 and / or the internal temperature of the second thermo-pressure vessel 22 by controlling the circulation of coolant in the condensation mechanism according to a set temperature. The control system 7 regulates the gas supply pressure by opening the first gas source 11 and the second gas source 12.
[0048] S2: After the fluid phase is formed and stabilized, adjust the pressure in the first thermo-pressure vessel 21 and the second thermo-pressure vessel 22 so that the pressure in the second thermo-pressure vessel 22 is much higher than that in the first thermo-pressure vessel 21.
[0049] Specifically, "adjusting the pressure inside the first thermo-pressure vessel 21 and the second thermo-pressure vessel 22" refers to the control system 7 adjusting the pressure by opening the first gas source 11 and the second gas source 12.
[0050] S3: Open the obstructed porous medium channel assembly and close the gas injection system. Open the first unobstructed pipeline assembly. After confirming that there is no fluid flow, close the first unobstructed pipeline assembly.
[0051] Specifically, "confirming no fluid flow" means that the second flow meter 52 has no indication.
[0052] S4: Open the second unobstructed pipeline assembly and monitor the readings of the third flow meter 53 on the second unobstructed pipeline assembly and the first flow meter 51 on the pressure regulating system.
[0053] S5: After the exhaust test is completed, replace the porous medium material filled in the porous medium channel assembly, and repeat steps S1 to S4 to conduct multiple exhaust tests, monitoring the readings of the third flow meter 53 on the second unobstructed pipeline assembly and the first flow meter 51 on the pressure regulating system.
[0054] In step S5, the method for "determining the completion of the exhaust test" is as follows: determine whether the values of the first flow meter 51 and the third flow meter 53 change within a set time. If they do not change, then the exhaust test is determined to be complete.
[0055] In steps S4 and S5, when the reading of the first flow meter 51 is greater than the reading of the third flow meter 53, it means that the gas in the first thermo-pressure vessel 21 and the second thermo-pressure vessel 22 is being extracted simultaneously. When the reading of the first flow meter 51 is equal to the reading of the third flow meter 53, it indicates that the gas inside the second thermostatic reactor 22 is being extracted. When the reading of the first flow meter 51 is less than the reading of the third flow meter 53, it means that the gas in the second thermo-pressure vessel 22 flows into the gas in the first thermo-pressure vessel 21.
[0056] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.
Claims
1. A device for monitoring interlayer fluid flow in the combined exploitation of hydrates and shallow gas, characterized in that, It includes a first thermostatic flask, a second thermostatic flask, a first unobstructed pipeline assembly, a second unobstructed pipeline assembly, an obstructed porous media channel assembly, a temperature regulation system, a temperature detection module, a pressure regulating system, and a control system; The first thermostatic reactor and the second thermostatic reactor are connected through the first unobstructed pipeline assembly, the second unobstructed pipeline assembly and the obstructed porous media channel assembly, so that the first unobstructed pipeline assembly is used to monitor the gas flow rate from the first thermostatic reactor to the second thermostatic reactor, the second unobstructed pipeline assembly is used to monitor the gas flow rate from the second thermostatic reactor to the first thermostatic reactor, and the obstructed porous media channel assembly is used to simulate different permeability septa, so as to realize the test of fluid flow under different permeability septa conditions; The first and second thermo-pressure vessels are respectively equipped with the temperature control system on their exteriors, and the first and second thermo-pressure vessels are respectively equipped with the temperature detection module inside their interiors; The pressure regulating system includes a gas injection system, a pressure monitoring module, and a connecting pipeline. The gas injection system is connected to the first thermostatic reactor and the second thermostatic reactor through the connecting pipeline to inject gas into the interior of the first thermostatic reactor and the interior of the second thermostatic reactor, respectively. The connecting pipeline is connected in series with the first unobstructed pipeline assembly and the second unobstructed pipeline assembly, respectively. The pressure monitoring module is installed at the inlet of the first thermostatic reactor and the inlet of the second thermostatic reactor. The temperature regulation system, the temperature detection module, and the pressure sensor are respectively connected to the control system.
2. The fluid interlayer flow monitoring device for the combined exploitation of hydrates and shallow gas as described in claim 1, characterized in that, The gas injection system includes a first gas source and a second gas source. The pressure monitoring module includes a first pressure sensor and a second pressure sensor. The connecting pipeline includes a first pipeline, a second pipeline, a third pipeline, and a valve assembly. The first pipeline, the second pipeline, the third pipeline, the first unobstructed pipeline assembly, and the second unobstructed pipeline assembly are connected in series to connect the first gas source to the first thermostatic reactor, the second gas source to the second thermostatic reactor, and the third pipeline to the control system. Along the fluid flow direction in the pipeline, the third pipeline is sequentially equipped with a first flow meter and a first drying system. The valve assembly is installed on the first pipeline, the second pipeline, and the third pipeline respectively. The first pressure sensor is installed at the inlet of the first thermostatic reactor, and the second pressure sensor is installed at the inlet of the second thermostatic reactor.
3. The fluid interlayer flow monitoring device for the combined exploitation of hydrates and shallow gas as described in claim 2, characterized in that, The first unobstructed pipeline assembly includes a first connecting pipeline, a first unobstructed pipeline, a second connecting pipeline, a first four-way valve, a third shut-off valve, a second three-way valve, a fifth shut-off valve, a second drying system, a second flow meter, a fourth three-way valve, an eleventh shut-off valve, and a second four-way valve. The first connecting pipeline, the third pipeline, and the first pressure sensor are respectively connected to the first thermo-autoclave via the first four-way valve. The second connecting pipeline is connected to the second thermo-autoclave, the second pressure sensor, and the obstructed porous media channel assembly via the second four-way valve. The first connecting pipeline is connected to the first unobstructed pipeline via the second three-way valve, and the first unobstructed pipeline is connected to the second connecting pipeline via the fourth three-way valve. Following the flow direction of the fluid from the first thermo-autoclave to the second thermo-autoclave, the first connecting pipeline is equipped with the third shut-off valve, the first unobstructed pipeline is sequentially equipped with the fifth shut-off valve, the second drying system, and the second flow meter, and the second connecting pipeline is equipped with the eleventh shut-off valve.
4. The fluid interlayer flow monitoring device for the combined exploitation of hydrates and shallow gas as described in claim 3, characterized in that, The second unobstructed pipeline assembly includes a first connecting pipeline, a second connecting pipeline, a second unobstructed pipeline, a tenth shut-off valve, a third three-way valve, a sixth shut-off valve, a third drying system, a third flow meter, a first three-way valve, and a second shut-off valve. The first connecting pipeline is connected to the second unobstructed pipeline through the second three-way valve, and the second connecting pipeline is connected to the second unobstructed pipeline through the third three-way valve. Following the flow direction of the fluid from the second thermostatic reactor to the first thermostatic reactor, the sixth shut-off valve, the third drying system, and the third flow meter are sequentially arranged on the second unobstructed pipeline. The third three-way valve is connected to the first gas source through the first pipeline, and the first three-way valve is connected to the second gas source through the second pipeline.
5. The fluid interlayer flow monitoring device for the combined exploitation of hydrates and shallow gas as described in claim 4, characterized in that, The temperature control system includes a first jacket, a second jacket, and a condensation mechanism. The temperature detection module includes a first temperature sensor and a second temperature sensor. The condensation mechanism is respectively provided on the first jacket and the second jacket. The first jacket wraps around the outer periphery of the first thermostatic vessel, and the second jacket wraps around the outer periphery of the second thermostatic vessel. The condensation mechanism is connected to the control system. The control system causes the coolant in the condensation mechanism to circulate at a set temperature to regulate the internal temperature of the first thermostatic vessel and / or the internal temperature of the second thermostatic vessel. The first temperature sensor is installed in the first thermostatic vessel, and the second temperature sensor is installed in the second thermostatic vessel. The first temperature sensor and the second temperature sensor are respectively connected to the control system.
6. The fluid interlayer flow monitoring device for the combined exploitation of hydrates and shallow gas as described in claim 5, characterized in that, The obstructed porous media channel assembly includes a seventh shut-off valve, an obstructed porous media channel, and an eighth shut-off valve. The seventh shut-off valve and the eighth shut-off valve are respectively provided at both ends of the obstructed porous media channel. The eighth shut-off valve is connected to the second four-way valve. The obstructed porous media channel is filled with porous media contents.
7. The fluid interlayer flow monitoring device for the combined exploitation of hydrates and shallow gas according to any one of claims 1 to 6, characterized in that, The valve assembly includes a first shut-off valve, a fourth shut-off valve, and a ninth shut-off valve. The first shut-off valve is provided on the first pipeline, the ninth shut-off valve is provided on the second pipeline, and the fourth shut-off valve is provided on the third pipeline.
8. A method for monitoring interlayer fluid flow in the combined exploitation of hydrates and shallow gas, characterized in that, The device for monitoring interlayer fluid flow in the combined exploitation of hydrates and shallow gas as described in any one of claims 1 to 7 specifically includes the following steps: The first and second thermo-autoclaves are filled with sediment, all shut-off valves between the first and second thermo-autoclaves are closed, and the temperature and pressure of the first and second thermo-autoclaves are controlled by the control system. A hydrate-gas-water phase and free gas are formed in the pores of the first and second thermo-autoclaves. After the fluid phase is formed and stabilized, the pressure in the first and second thermostatic reactors is adjusted so that the pressure in the second thermostatic reactor is much higher than that in the first thermostatic reactor. Shut down the gas injection system and the obstructed porous medium channel assembly, open the first unobstructed pipeline assembly, and after confirming that there is no fluid flow, shut down the first unobstructed pipeline assembly. Open the second unobstructed pipeline assembly and monitor the readings of the third flow meter on the second unobstructed pipeline assembly and the first flow meter on the pressure regulating system.
9. A method for monitoring interlayer fluid flow in the combined exploitation of hydrates and shallow gas, characterized in that, The device for monitoring interlayer fluid flow in the combined exploitation of hydrates and shallow gas as described in any one of claims 1 to 7 specifically includes the following steps: The first and second thermo-autoclaves are filled with sediment, all shut-off valves between the first and second thermo-autoclaves are closed, and the temperature and pressure of the first and second thermo-autoclaves are controlled by the control system. A hydrate-gas-water phase and free gas are formed in the pores of the first and second thermo-autoclaves. After the fluid phase is formed and stabilized, the pressure in the first and second thermostatic reactors is adjusted so that the pressure in the second thermostatic reactor is much higher than that in the first thermostatic reactor. Open the obstructed porous medium channel assembly and close the gas injection system. Open the first unobstructed pipeline assembly. After confirming that there is no fluid flow, close the first unobstructed pipeline assembly. Open the second unobstructed pipeline assembly and monitor the readings of the third flow meter on the second unobstructed pipeline assembly and the first flow meter on the pressure regulating system; After the exhaust test is completed, the porous medium material filled in the porous medium channel assembly is replaced, and the exhaust test is repeated multiple times to monitor the readings of the third flow meter on the second unobstructed pipeline assembly and the first flow meter on the pressure regulating system.