Hydrogen-water-rock geochemical reaction evaluation device for underground hydrogen storage

Abstract

The invention discloses an underground hydrogen storage hydrogen-water-rock geochemical reaction evaluation device which comprises a high-pressure injection unit and a reaction kettle body which are communicated through a connecting pipeline, the high-pressure injection unit is used for injecting high-pressure hydrogen into the reaction kettle body, and a core sample to be reacted is placed in the reaction kettle body; a sealing unit is arranged at the communication position of the reaction kettle body and the high-pressure injection unit, a heating and heat preservation unit is arranged on the periphery of the reaction kettle body, a parameter monitoring unit is arranged on the reaction kettle body, and a safety guarantee unit is arranged outside the reaction kettle body. According to the invention, accurate pressurization control of the pressure of hydrogen introduced into the reaction kettle body is realized through a water pressure piston type pressurization structure of the intermediate container, and underground deep reservoir conditions can be simulated in cooperation with a resistance heating wire; the blank of performing evaluation experiment on hydrogen-water-rock geochemical reaction in a pure hydrogen atmosphere under high-pressure and high-temperature conditions in the prior art is filled up, and the research and development of water-rock reaction of the underground hydrogen storage are promoted.

Description

Technical Field

[0001] The present invention relates to the technical field of underground hydrogen storage, and in particular to a hydrogen-water-rock geochemical reaction evaluation device for an underground hydrogen storage reservoir. Background Art

[0002] Under the background of "carbon peak and carbon neutrality", the hydrogen energy industry has developed rapidly, and hydrogen storage has become a key link in the hydrogen energy industry chain connecting upstream hydrogen production and downstream hydrogen use. Underground hydrogen storage is a technology that uses underground structural space to achieve hydrogen storage, which has the advantages of high safety, low cost, large scale and long cycle. Underground hydrogen storage structures include oil and gas reservoirs, salt caverns and saline aquifers. Evaluating the reaction mechanism of H2 with different types of reservoirs and minerals under the presence of formation water is crucial for the long-term stable storage and efficient extraction of H2. At present, there is a lack of equipment for evaluating the hydrogen-water-rock geochemical reaction in underground hydrogen storage reservoirs. The experimental device reactor in the existing technology mainly conducts experiments under gas atmospheres such as N2, CH4, CO2 and air, and cannot realize reaction evaluation experiments under high pressure and high temperature (70MPa, 150℃) and H2 atmosphere alone. Therefore, a hydrogen-water-rock geochemical reaction evaluation device for underground hydrogen storage reservoirs is developed. Summary of the Invention

[0003] The purpose of the present invention is to provide a hydrogen-water-rock geochemical reaction evaluation device for an underground hydrogen storage reservoir to solve the technical problems mentioned in the above background technology.

[0004] In order to solve the above technical problems, the present invention adopts the following technical solutions:

[0005] The present invention provides a hydrogen-water-rock geochemical reaction evaluation device for an underground hydrogen storage reservoir, comprising a high-pressure injection unit and a reactor body connected by a connecting pipeline, wherein the high-pressure injection unit is used to inject high-pressure hydrogen into the interior of the reactor body, and a core sample to be reacted is placed inside the reactor body; a sealing unit is provided at the connection position between the reactor body and the high-pressure injection unit, a heating and heat preservation unit is provided on the periphery of the reactor body, a parameter monitoring unit is provided on the reactor body, and a safety assurance unit is provided on the outside of the reactor body.

[0006] Furthermore, the high-pressure injection unit includes a hydrogen cylinder, a hydrogen pressure reducing valve and an intermediate container which are sequentially connected through connecting pipelines. The intermediate container is also connected to the reactor body through corresponding connecting pipelines.

[0007] Furthermore, the intermediate container includes a container cavity, a cover body sealed and matched with the container cavity is provided on the upper part of the container cavity, the container cavity is connected to the hydrogen pressure reducing valve and the reactor body respectively through two connecting pipelines passing through the cover body, and a base connected to the bottom of the container cavity is provided, and the base is connected to an external horizontal flow pump through a water supply pipeline, and a piston is slidably provided above the base in the container cavity.

[0008] Furthermore, an internal thread is provided on the inner circumferential wall of the upper open end of the reactor body, and the sealing unit includes a sealing bolt threadedly connected to the upper end of the inner circumferential wall of the reactor body, a rubber sealing ring is provided between the sealing bolt and the inner circumferential wall of the reactor body, and a connecting pipeline connecting the container cavity and the reactor body passes through the sealing bolt.

[0009] Furthermore, a core placement rack for placing core samples is provided inside the reactor body, and the core placement rack includes a cylindrical basket, a plurality of legs are evenly fixedly provided on the bottom of the basket along the circumference, two hanging rings are symmetrically fixedly provided on the upper part of the basket, and a plurality of rows of circular through holes are evenly and densely distributed on the peripheral wall of the basket.

[0010] Furthermore, the heating and heat-insulating unit includes a resistance heating wire arranged on the peripheral wall of the reactor body and a heat-insulating layer sleeved on the outside of the resistance heating wire.

[0011] Furthermore, the reactor body is provided with a gas outlet and a liquid sampling port communicated with the interior thereof, and the gas outlet is used for sampling the gas during the reaction inside the reactor body or for venting the gas before and after the reaction.

[0012] Furthermore, the parameter monitoring unit includes a temperature measuring port and a pressure measuring port provided on the reactor body.

[0013] Furthermore, the safety assurance unit includes an explosion-proof box covered on the outside of the reactor body, and the explosion-proof box is provided with a hydrogen alarm and an exhaust fan.

[0014] The present invention also discloses a method for evaluating hydrogen-water-rock geochemical reactions in underground hydrogen storage reservoirs, which uses the above-mentioned device and includes the following working steps:

[0015] Step 1: Drill natural cores from the target stratum and measure the length, diameter and dry weight of the cores;

[0016] Step 2: Prepare simulated formation water according to the ion composition of the formation water in the target layer;

[0017] Step 3: Add the prepared simulated formation water into the reactor;

[0018] Step 4: Place the drilled natural core into the reactor body, then connect the entire device, keep the connecting pipeline from the high-pressure injection unit to the reactor body unobstructed, close the other outlet valves, and pass nitrogen to test the air tightness of the system;

[0019] Step 5: After checking the air tightness, release the nitrogen through the gas outlet, open the valve on the hydrogen cylinder and the hydrogen pressure reducing valve, and start the horizontal flow pump to pressurize the hydrogen through the intermediate container;

[0020] Step 6: After the hydrogen pressure increases to a predetermined value, the valve on the intermediate container outlet connecting pipeline is opened to allow the pressurized hydrogen to enter the reactor body. The actual hydrogen pressure in the reactor body is measured through the pressure measuring port. After reaching the predetermined value, the valve on the reactor body inlet connecting pipeline is closed;

[0021] Step 7: After hydrogen is introduced, the heating resistance wire is started to heat the reactor to a predetermined temperature and maintain the temperature stable;

[0022] Step 8: Hydrogen will react with the natural rock core at the specified temperature and pressure, and the changes in pressure and temperature over time will be recorded. After the reaction is completed, the composition of the mixed gas, hydrogen concentration, changes in rock mineral composition and other parameters will be tested.

[0023] Compared with the prior art, the present invention has the following beneficial technical effects:

[0024] The present invention achieves precise pressure control of the hydrogen introduced into the reactor body through the hydraulic piston-type boosting structure of the intermediate container. Combined with the resistance heating wire, it can simulate the conditions of deep underground reservoirs. This fills the gap in the existing technology for evaluating hydrogen-water-rock geochemical reactions under high pressure and high temperature conditions in a pure hydrogen atmosphere, and is conducive to promoting the research and development of water-rock reactions in underground hydrogen storage reservoirs. In addition, the safety assurance unit of the present invention forms a three-level protection system through the linkage of an explosion-proof box, a hydrogen alarm, and an exhaust fan, which can effectively avoid hydrogen combustion and explosion accidents during the experiment, further ensuring experimental safety. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] The present invention will be further described below with reference to the accompanying drawings.

[0026] Figure 1 It is a schematic diagram of the overall structure of the present invention;

[0027] Figure 2 This is a schematic diagram of the structure of the intermediate container of the present invention;

[0028] Figure 3 This is a schematic structural diagram of the core placement rack of the present invention;

[0029] Figure 4 This is a schematic structural diagram of the explosion-proof box of the present invention;

[0030] Explanation of the accompanying symbols: 1. Reactor body; 2. Core sample; 3. Hydrogen cylinder; 4. Hydrogen pressure reducing valve; 5. Intermediate container; 5-1. Container cavity; 5-2. Cover; 5-3. Base; 5-4. Piston; 6. Horizontal flow pump; 7. Sealing bolt; 8. Core placement rack; 8-1. Material basket; 8-2. Support leg; 8-3. Lifting ring; 8-4. Circular through hole; 9. Resistance heating wire; 10. Insulation layer; 11. Gas outlet; 12. Liquid sampling port; 13. Temperature measuring port; 14. Pressure measuring port; 15. Explosion-proof box; 16. Hydrogen alarm; 17. Exhaust fan. DETAILED DESCRIPTION

[0031] like Figures 1-4 As shown, an underground hydrogen storage hydrogen-water-rock geochemical reaction evaluation device includes a high-pressure injection unit and a reactor body 1 connected by a connecting pipeline. The high-pressure injection unit is used to inject high-pressure hydrogen into the interior of the reactor body 1, and the reactor body 1 contains a core sample 2 to be reacted. A sealing unit is provided at the connection point between the reactor body 1 and the high-pressure injection unit. A heating and insulation unit is provided on the periphery of the reactor body 1. A parameter monitoring unit is provided on the reactor body 1, and a safety unit is provided on the exterior of the reactor body 1.

[0032] The high-pressure injection unit includes a hydrogen cylinder 3, a hydrogen pressure reducing valve 4 and an intermediate container 5 which are sequentially connected through connecting pipelines. The intermediate container 5 is also connected to the reactor body 1 through corresponding connecting pipelines.

[0033] The intermediate container includes a container cavity 5-1, with a lid 5-2 installed on the upper portion of the container cavity 5-1, which is sealed therewith. The container cavity 5-1 is connected to the hydrogen pressure reducing valve 4 and the reactor body 1 via two connecting pipelines running through the lid 5-2. A base 5-3 is installed at the bottom of the container cavity 5-1, which is connected to the reactor body 1. The base 5-3 is connected to the reactor body 5-1 via a water supply line. A piston 5-4 is slidably installed above the base 5-3 inside the container cavity 5-1. During operation, the hydrogen stored in the hydrogen cylinder 3 is injected into the container cavity 5-1 from the upper portion of the lid 5-2 via the connecting pipeline. The horizontal flow pump 6 is then activated to inject high-pressure water into the lower portion of the container cavity 5-1 through the injection port of the base 5-3, thereby pushing the piston 5-4 upward and compressing the hydrogen inside the container cavity 5-1, increasing the hydrogen pressure.

[0034] An internal thread is provided on the inner circumferential wall of the upper open end of the reactor body 1, and the sealing unit includes a sealing bolt 7 threadedly connected to the upper end of the inner circumferential wall of the reactor body 1. A rubber sealing ring is installed between the sealing bolt 7 and the inner circumferential wall of the reactor body 1 to ensure the sealing performance of the reactor body 1. The connecting pipeline connecting the container cavity 5-1 and the reactor body 1 passes through the sealing bolt 7 and extends to the interior of the reaction cavity.

[0035] The interior of the reactor body 1 is provided with a core rack 8 for placing core samples 2. Specifically, the core rack 8 includes a cylindrical basket 8-1 with a diameter of 6.8 cm and a height of 6.5 cm, which can simultaneously hold four core samples of φ2.5*L5 cm for experiments. The bottom of the basket 8-1 is evenly and fixedly provided with a plurality of vertical legs 8-2 along the circumference, so that the basket 8-1 is supported and placed on the bottom plate of the reactor body 1 by the plurality of legs 8-2. Two hanging rings 8-3 are symmetrically fixed on the upper part of the basket 8-1 to facilitate the placement and removal of the core rack. Multiple rows of circular through holes 8-4 are evenly and densely distributed on the peripheral wall of the basket 8-1. The circular through holes 8-4 are used for full contact between the liquid sample in the reactor body 1 and the core sample 2 in the basket 8-1.

[0036] The heating and insulation unit includes a resistance heating wire 9 installed on the peripheral wall of the reactor body 1 and an insulation layer 10 sleeved on the outside of the resistance heating wire 9. When the resistance heating wire 9 is energized, it heats the reactor body and internal materials, with a maximum heating temperature of 150°C.

[0037] The reactor body 1 is provided with a gas outlet 11 and a liquid sampling port 12 which are connected to the interior thereof. The gas outlet 11 is used for sampling gas during reaction inside the reactor body or for venting gas before and after the reaction. The liquid sampling port 12 is used for sampling liquid samples in the reactor body 1.

[0038] The parameter monitoring unit includes a temperature measuring port 13 and a pressure measuring port 14 installed on the reactor body 1, which are mainly used to monitor the temperature and pressure changes during the reaction process.

[0039] The safety unit includes an explosion-proof housing 15 that is mounted outside the reactor body 1. The explosion-proof housing 15 is a square housing with a length, width, and height of 1m x 0.5m x 0.8m, respectively. It is made of high-strength steel and can withstand the energy generated by the explosion of 10g of TNT explosives and can cover the energy generated by the explosion of the experimental hydrogen, ensuring experimental safety. The explosion-proof housing 15 can accommodate six reactor bodies in two rows, front and back. The explosion-proof housing 15 is equipped with a hydrogen alarm 16 and an exhaust fan 17. The hydrogen alarm 16 has a sensitivity of 50ppm. Once a hydrogen leak occurs and the hydrogen concentration reaches 50ppm, the hydrogen alarm starts to alarm and the exhaust fan 17 is started to exhaust the hydrogen to the outside to reduce the hydrogen concentration, thereby effectively avoiding hydrogen combustion and explosion accidents. This further ensures experimental safety.

[0040] In this embodiment, valves are installed on each connecting pipeline. The reactor body 1, the core rack 8, each connecting pipeline and corresponding components are made of 316L material, which can work for a long time in a hydrogen environment and avoid hydrogen embrittlement.

[0041] In addition, the present invention also discloses a method for evaluating the geochemical reaction of hydrogen-water-rock in an underground hydrogen storage reservoir. According to the above-mentioned device, the reaction evaluation method includes the following working steps:

[0042] Step 1: Drill a natural core from the target stratum and measure its length, diameter, and dry weight. In this step, the core can also be replaced with rock chips or rock powder.

[0043] Step 2: Prepare simulated formation water according to the ion composition of the formation water in the target layer;

[0044] Step 3: Add the prepared simulated formation water into the reactor;

[0045] Step 4: Place the drilled natural rock core (or rock slice or rock powder) into the reactor body 1, then connect the entire device, keep the connecting pipeline from the high-pressure injection unit to the reactor body 1 unobstructed, close the other outlet valves, and pass nitrogen to test the air tightness of the system;

[0046] Step 5: After checking the air tightness, release the nitrogen through the gas outlet 11, open the valve on the hydrogen cylinder 3 and the hydrogen pressure reducing valve 4, and start the horizontal flow pump 6 to pressurize the hydrogen through the intermediate container 5;

[0047] Step 6: After the hydrogen pressure increases to a predetermined value, the valve on the outlet connecting line of the intermediate container 5 is opened, and the pressurized hydrogen is introduced into the reactor body 1. The actual pressure of the hydrogen in the reactor body 1 is measured through the pressure measuring port 14. After reaching the predetermined value, the valve on the inlet connecting line of the reactor body 1 is closed;

[0048] Step 7: After hydrogen is introduced, the heating resistor 9 is started to heat the internal temperature of the reactor body 1 to a predetermined value and maintain the temperature stable;

[0049] Step 8: At the specified temperature and pressure, hydrogen will react with the natural rock core (or rock slice or rock powder), and the changes in pressure and temperature over time will be recorded. After the reaction is completed, the composition of the mixed gas, hydrogen concentration, changes in rock mineral composition and other parameters will be tested.

[0050] The embodiments described above are merely descriptions of preferred embodiments of the present invention and are not intended to limit the scope of the present invention. Without departing from the spirit of the present invention, various modifications and improvements made to the technical solutions of the present invention by ordinary technicians in this field should fall within the scope of protection determined by the claims of the present invention.

Claims

1. An underground hydrogen storage hydrogen-water-rock geochemical reaction evaluation device, characterized by: The invention comprises a high-pressure injection unit and a reactor body connected by a connecting pipeline, wherein the high-pressure injection unit is used to inject high-pressure hydrogen into the interior of the reactor body, and a core sample to be reacted is placed inside the reactor body; a sealing unit is provided at the connection position between the reactor body and the high-pressure injection unit, a heating and heat preservation unit is provided on the periphery of the reactor body, a parameter monitoring unit is provided on the reactor body, and a safety assurance unit is provided on the outside of the reactor body.

2. The underground hydrogen storage hydrogen-water-rock geochemical reaction evaluation device according to claim 1, characterized in that: The high-pressure injection unit includes a hydrogen cylinder, a hydrogen pressure reducing valve and an intermediate container which are sequentially connected through connecting pipelines. The intermediate container is also connected to the reactor body through corresponding connecting pipelines.

3. The underground hydrogen storage hydrogen-water-rock geochemical reaction evaluation device according to claim 2, characterized in that: The intermediate container includes a container cavity, a cover body sealed and matched with the container cavity is provided on the upper part of the container cavity, the container cavity is connected to the hydrogen pressure reducing valve and the reactor body respectively through two connecting pipelines passing through the cover body, and a base connected thereto is provided at the bottom of the container cavity, and the base is connected to an external horizontal flow pump through a water supply pipeline, and a piston is slidably provided above the base in the container cavity.

4. The underground hydrogen storage hydrogen-water-rock geochemical reaction evaluation device according to claim 2, characterized in that: An internal thread is provided on the inner circumferential wall of the upper open end of the reactor body. The sealing unit includes a sealing bolt threadedly connected to the upper end of the inner circumferential wall of the reactor body. A rubber sealing ring is provided between the sealing bolt and the inner circumferential wall of the reactor body. The connecting pipeline connecting the container cavity and the reactor body passes through the sealing bolt.

5. The underground hydrogen storage hydrogen-water-rock geochemical reaction evaluation device according to claim 1, characterized in that: A core placement rack for placing core samples is provided inside the reactor body. The core placement rack includes a cylindrical basket. A plurality of legs are evenly fixedly provided on the bottom of the basket along the circumference. Two hanging rings are symmetrically fixedly provided on the upper part of the basket. A plurality of rows of circular through holes are evenly and densely distributed on the peripheral wall of the basket.

6. The underground hydrogen storage hydrogen-water-rock geochemical reaction evaluation device according to claim 1, characterized in that: The heating and heat-insulating unit comprises a resistance heating wire arranged on the peripheral wall of the reactor body and a heat-insulating layer sleeved on the outside of the resistance heating wire.

7. The underground hydrogen storage hydrogen-water-rock geochemical reaction evaluation device according to claim 1, characterized in that: The reactor body is provided with a gas outlet and a liquid sampling port communicated with the interior thereof. The gas outlet is used for sampling the gas during the reaction inside the reactor body or for venting the gas before and after the reaction.

8. The underground hydrogen storage hydrogen-water-rock geochemical reaction evaluation device according to claim 1, characterized in that: The parameter monitoring unit includes a temperature measuring port and a pressure measuring port arranged on the reactor body.

9. The underground hydrogen storage hydrogen-water-rock geochemical reaction evaluation device according to claim 1, characterized in that: The safety guarantee unit includes an explosion-proof box covered on the outside of the reactor body, and a hydrogen alarm and an exhaust fan are provided on the explosion-proof box.

10. A method for evaluating hydrogen-water-rock geochemical reactions in underground hydrogen storage reservoirs, using the apparatus according to claims 1-9, characterized in that: The following steps are included: Step 1: Drill natural cores from the target stratum and measure the length, diameter and dry weight of the cores; Step 2: Prepare simulated formation water according to the ion composition of the formation water in the target layer; Step 3: Add the prepared simulated formation water into the reactor; Step 4: Place the drilled natural core into the reactor body, then connect the entire device, keep the connecting pipeline from the high-pressure injection unit to the reactor body unobstructed, close the other outlet valves, and pass nitrogen to test the air tightness of the system; Step 5: After checking the air tightness, release the nitrogen through the gas outlet, open the valve on the hydrogen cylinder and the hydrogen pressure reducing valve, and start the horizontal flow pump to pressurize the hydrogen through the intermediate container; Step 6: After the hydrogen pressure increases to a predetermined value, the valve on the intermediate container outlet connecting pipeline is opened to allow the pressurized hydrogen to enter the reactor body. The actual hydrogen pressure in the reactor body is measured through the pressure measuring port. After reaching the predetermined value, the valve on the reactor body inlet connecting pipeline is closed; Step 7: After hydrogen is introduced, the heating resistance wire is started to heat the reactor to a predetermined temperature and maintain the temperature stable; Step 8: Hydrogen will react with the natural rock core at the specified temperature and pressure, and the changes in pressure and temperature over time will be recorded. After the reaction is completed, the composition of the mixed gas, hydrogen concentration, changes in rock mineral composition and other parameters will be tested.

Images