A test site and a test method for evaluating carbon dioxide geological storage capacity

Abstract

This invention discloses a test site and method for evaluating the geological storage capacity of carbon dioxide. The test site includes a brine pool and a brine layer and caprock structure located within the pool. The caprock structure is vertically positioned below the brine layer, and a brine reservoir structure is located below it. The brine reservoir structure is connected to a brine storage tank via a simulated extraction well pipe. The brine storage tank is connected to the brine layer via a simulated injection well pipe. Carbon dioxide is injected into the brine reservoir structure via a simulated gas injection well pipe. Pressure sensors installed on the inner wall of the brine pool monitor the pressure within the brine layer and the brine reservoir structure. The carbon dioxide injection rate, brine extraction rate, and brine injection rate are adjusted based on the monitored pressure to achieve pressure balance between the brine layer and the brine reservoir structure. This invention provides a test site for evaluating the geological storage capacity of carbon dioxide under actual site conditions.

Description

Technical Field

[0001] This invention belongs to the field of carbon dioxide geological storage, and in particular relates to a test site and test method for evaluating the capacity of carbon dioxide geological storage. Background Technology

[0002] The geological storage capacity of carbon dioxide is related to many factors, particularly the permeability of the caprock and the porosity of the brine layer. The permeability of the caprock determines whether carbon dioxide can be safely stored in the brine layer, while the porosity of the brine layer determines the amount of carbon dioxide that can be stored. Therefore, numerical software is commonly used to predict the geological storage capacity of carbon dioxide before actual storage.

[0003] For example, the experimental simulation of the feasibility of CO2 geological sequestration is published in (CN111289698A), the CO2 formation sequestration system is published in (CN211847165U), and the CO2 formation sequestration method and system is published in (CN111285374A). These experimental devices mainly predict the migration law of carbon dioxide in the saline layer, but cannot simulate the formation physical properties such as caprock permeability and saline layer porosity under actual site conditions. Therefore, it is difficult to evaluate the carbon dioxide geological sequestration capacity under different caprock permeability and different saline layer porosity conditions.

[0004] Therefore, there is an urgent need to design a test site to evaluate the geological storage capacity of carbon dioxide and solve the problems mentioned above. Summary of the Invention

[0005] The purpose of this invention is to provide a test site for evaluating the geological storage capacity of carbon dioxide, which has the advantage of accurately predicting the geological storage capacity of carbon dioxide under actual site conditions and solves the problems mentioned in the background art.

[0006] To achieve the above objectives, the specific technical solution for the test site for evaluating the geological storage capacity of carbon dioxide according to the present invention is as follows: A test site for evaluating the geological storage capacity of carbon dioxide includes a brine pool and a brine layer and caprock structure disposed inside the brine pool. The caprock structure is located vertically below the brine layer, and a brine reservoir structure is disposed below the caprock structure. The brine reservoir structure is connected to a brine storage tank via a simulated extraction well pipe. The brine storage tank is connected to the brine layer via a simulated injection well pipe. Carbon dioxide is injected into the brine reservoir structure via a simulated gas injection well pipe. The pressure in the brine layer and the brine reservoir structure is monitored by a pressure sensor installed on the inner wall of the brine pool. The carbon dioxide injection rate, brine extraction rate, and brine injection rate are adjusted according to the monitored pressure to balance the pressure in the brine layer and the brine reservoir structure.

[0007] Furthermore, a pumping pump is connected to the simulated pipe of the extraction well, and the pumping pump is connected to the brine storage tank via a high-pressure water pipe.

[0008] Furthermore, a supercritical device is installed on the gas injection well simulation pipe to monitor the amount of carbon dioxide injected.

[0009] Furthermore, the supercritical device is connected to a carbon dioxide gas cylinder via a gas delivery pipe, and a variable gas pump is installed on the gas delivery pipe.

[0010] Furthermore, the extraction well simulation pipe, gas injection well simulation pipe, and water injection well simulation pipe are all connected to the brine pool via fixers.

[0011] Furthermore, the simulated injection well pipe is equipped with a controllable valve to regulate the injection volume of brine.

[0012] Furthermore, the pressure sensor is connected to a display to monitor the pressure value.

[0013] Furthermore, the brine reservoir structure is connected to the controller, and the interconnected spherical particles in the brine reservoir structure are controlled by an external controller.

[0014] A test method for assessing the geological storage capacity of carbon dioxide mainly includes the following steps: S1. Determine and construct the basic test site; S2. Create a heterogeneous brine layer; S3. Manufacturing a capping structure with variable permeability; S4, Inject supercritical carbon dioxide; S5. Open the extraction pump and controllable valve to control the amount of brine in the brine reservoir structure; S6. Record monitoring data.

[0015] Furthermore, keeping the carbon dioxide injection rate and brine extraction rate constant, the permeability of the caprock structure and the porosity of the brine reservoir structure were varied. Experimental steps S1-S6 were repeated to obtain the total carbon dioxide injection amount under different caprock structure permeability and brine reservoir structure porosity, thereby evaluating and analyzing the impact of caprock structure and brine reservoir structure on the geological storage effect of carbon dioxide.

[0016] The test site for evaluating the geological storage capacity of carbon dioxide according to the present invention has the following advantages: By simulating the physical properties of the caprock permeability and saline layer porosity under actual site conditions, this application achieves a carbon dioxide geological sequestration capacity assessment that considers the physical properties of the formation, solving the problem that carbon dioxide sequestration capacity cannot be assessed under actual site conditions. This application utilizes particles of different diameters to fill pore tubes and a filter layer, and controls the change in caprock permeability through the structural design of the pore tubes and switches, thus simulating a variable caprock permeability for carbon dioxide geological sequestration under site conditions. Attached Figure Description

[0017] Figure 1 This is a schematic diagram of the overall structure of the test site used in this invention to evaluate the geological storage capacity of carbon dioxide. Figure 2 This is a top view schematic diagram of the test site used by the present invention to evaluate the geological storage capacity of carbon dioxide; Figure 3 This is a schematic diagram of the structure of the cover module of the present invention; Figure 4 This is a top view of the cover module of the present invention; Figure 5 This is a schematic diagram of the structure of the spherical particles of the present invention; Figure 6 This is a schematic diagram of the structure of Embodiment 1 of the present invention; Figure 7 This is a schematic diagram of the structure of Embodiment 2 of the present invention.

[0018] Explanation of markings in the diagram: 1. Brine layer; 2. Cap layer structure; 201. First pore tube; 202. Second pore tube; 203. Third pore tube; 204. First switch; 205. Second switch; 206. Third switch; 207. Filter layer; 3. Brine reservoir structure; 4. Pumping well simulation pipe; 5. Pumping pump; 6. Fixing device; 7. Brine storage tank; 8. Controllable valve; 9. Carbon dioxide tank; 10. Variable displacement pump; 11. Gas delivery pipe; 12. Supercritical device; 13. Pressure sensor; 14. Display; 15. Controller; 16. Gas injection well simulation pipe; 17. Water injection well simulation pipe; 18. High-pressure water pipe; 19. Spherical particles; 191. Rubber membrane; 192. Telescopic rod; 193. Control core; 20. Brine pool. Detailed Implementation

[0019] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0020] Those skilled in the art will understand that although some embodiments herein include certain features included in other embodiments but not others, combinations of features from different embodiments are intended to be within the scope of the invention and form different embodiments. For example, in the claims, any of the claimed embodiments can be used in any combination.

[0021] The following is a reference to the appendix. Figure 1 To be continued Figure 7The present invention describes a test site for evaluating the geological storage capacity of carbon dioxide.

[0022] like Figure 1 and Figure 2 As shown, the test site for evaluating the geological storage capacity of carbon dioxide in this invention includes a brine pool 20 and a brine layer 1 and a capping structure 2 disposed inside the brine pool 20. The capping structure 2 is located vertically below the brine layer 1, and a brine reservoir structure 3 is disposed below the capping structure 2. The brine reservoir structure 3 is connected to a brine storage tank 7 through a pumping well simulation pipe 4. The brine storage tank 7 is connected to the brine layer 1 through a water injection well simulation pipe 17. Carbon dioxide is injected into the brine reservoir structure 3 through a gas injection well simulation pipe 16. The pressure in the brine layer 1 and the brine reservoir structure 3 is monitored by a pressure sensor 13 disposed on the inner wall of the brine pool 20. The carbon dioxide injection rate, the brine pumping rate, and the brine injection rate are adjusted according to the monitored pressure to balance the pressure in the brine layer 1 and the brine reservoir structure 3.

[0023] Furthermore, such as Figures 1 to 4 As shown, a pumping pump 5 is connected to the pumping well simulation pipe 4, and the pumping pump 5 is connected to the brine storage tank 7 through a high-pressure water pipe 18; a supercritical device 12 is installed on the gas injection well simulation pipe 16 to monitor the amount of carbon dioxide injected; the supercritical device 12 is connected to the carbon dioxide tank 9 through a gas delivery pipe 11, and a variable gas pump 10 is installed on the gas delivery pipe 11.

[0024] As a preferred embodiment, the test site for evaluating the geological storage capacity of carbon dioxide consists of a caprock module, a brine layer module, a carbon dioxide injection module, a brine injection and production module, and a pressure monitoring module.

[0025] The cover module consists of a cover structure 2, a first pore tube 201, a second pore tube 202, a third pore tube 203, a first switch 204, a second switch 205, a third switch 206, a filter layer 207, and a controller 15. The cover structure 2 has five layers, which are arranged from top to bottom as a pore layer, a filter layer 207, a pore layer, a filter layer 207, and a pore layer. The pore layer is uniformly arranged with pore tubes composed of the first pore tube 201, the second pore tube 202, and the third pore tube 203.

[0026] Preferably, the first pore tube 201 is filled with spheres with a diameter of 3-5 mm, the second pore tube 202 is filled with spheres with a diameter of 6-8 mm, and the third pore tube 203 is filled with spheres with a diameter of 9-11 mm, which are responsible for simulating the pores and channels in the rock; the filter layer 207 is filled with spheres with a diameter of 1-2 mm.

[0027] Below the first pore tube 201, the second pore tube 202, and the third pore tube 203, there are corresponding first switches 204, second switches 205, and third switches 206. The switches can be opened or closed by the controller 15 to simulate the permeability of different caprocks.

[0028] A brine layer module is provided below the capping module. The brine layer module consists of a brine reservoir structure 3, spherical particles 19, a rubber membrane 191, a telescopic rod 192, a control core 193, and a controller 15. The brine layer module is filled with brine reservoir structure 3 and is composed of spherical particles 19 of different sizes connected together. The size of the spherical particles 19 is variable. The spherical particles 19 in the brine layer module are interconnected and controlled by an external controller 15.

[0029] Furthermore, such as Figure 1 and Figure 5 As shown, the extraction well simulation pipe 4, the gas injection well simulation pipe 16, and the water injection well simulation pipe 17 are all connected to the brine pool 20 via the fixing device 6; the water injection well simulation pipe 17 is equipped with a controllable valve 8 to adjust the amount of brine injected.

[0030] Meanwhile, the carbon dioxide injection module is located at the top of the brine pool 20. The carbon dioxide injection module consists of a carbon dioxide tank 9, a variable gas pump 10, a gas delivery pipe 11, a supercritical device 12, and a gas injection well simulation pipe 16. The gas injection well simulation pipe 16 is fixed in the brine pool 20 by a fixing device 6, passes through the brine layer 1 and the capping structure 2, and extends into the brine reservoir structure 3. The gas delivery pipe 11 is connected in series with the variable gas pump 10, the carbon dioxide tank 9, and the supercritical device 12, and is responsible for injecting carbon dioxide into the supercritical device 12. The gas injection well simulation pipe 16 is connected to the supercritical device 12, and the supercritical device 12 injects supercritical carbon dioxide into the brine reservoir structure 3 through the gas injection well simulation pipe 16.

[0031] The brine injection and production module is also located at the top of the brine pool 20. The brine injection and production module consists of a extraction well simulation pipe 4, an extraction pump 5, a brine storage tank 7, a controllable valve 8, an injection well simulation pipe 17, and a high-pressure water pipe 18. The extraction well simulation pipe 4 passes through the brine layer 1 and the capping structure 2 and extends into the brine reservoir structure 3. The brine storage tank 7 and the extraction pump 5 are connected in series through the high-pressure water pipe 18, which is responsible for extracting the brine from the brine reservoir into the brine storage tank 7.

[0032] The injection well simulation pipe 17 extends into the brine layer 1, and is connected in series with the extraction pump 5 and the brine storage tank 7 via the high-pressure water pipe 18. The extraction pump 5 can inject the brine in the brine storage tank 7 into the brine layer 1 through the high-pressure water pipe 18 and the injection well simulation pipe 17. A controllable valve 8 is installed at the connection between the high-pressure water pipe 18 and the brine storage tank 7 to control the opening and closing.

[0033] Pressure sensor 13 is connected to display 14 to monitor pressure values; brine reservoir structure 3 is connected to controller 15, and the spherical particles 19 in brine reservoir structure 3 are interconnected and controlled by external controller 15.

[0034] Preferably, the spherical particle 19 is composed of a rubber membrane 191, a telescopic rod 192, and a control core 193. The rubber membrane 191 is located on the outermost side, wrapping the telescopic rod 192 and the control core 193. There are five telescopic rods 192, which connect the rubber membrane 191 and the control core 193. The telescopic rods 192 can be freely extended and retracted by the controller 15, thereby controlling the size change of the spherical particle.

[0035] Furthermore, the pressure monitoring module consists of a pressure sensor 13 and a display 14. Pressure sensors 13 are installed in the brine layer 1 and the brine reservoir structure 3 respectively to monitor the pressure in the brine layer 1 and the brine reservoir structure 3. The display 14 monitors the pressure value and adjusts the carbon dioxide injection rate, brine extraction rate and brine injection rate according to the monitored pressure to balance the pressure in the brine layer and the brine reservoir structure.

[0036] The experimental method for evaluating the geological storage capacity of carbon dioxide in this invention mainly includes the following steps: S1. Determine and construct the basic test site; Among them, a test site of 100m×100m was selected, and a deep pit of 100m×100m×100m was dug down to create a salt water pool 20.

[0037] S2, Creating a heterogeneous brine layer 1; In this process, spherical particles 19 of different sizes are connected to each other and placed at the bottom of the brine pool; the spherical particles 19 are connected to each other, and the internal control core is connected to the controller 15; brine is poured into the bottom of the heterogeneous reservoir until it covers all the spherical particles 19.

[0038] S3. Manufacturing a capping structure with variable permeability; The cover layer of the 100m×100m brine tank 20 is constructed using impermeable wooden boards. The impermeable wooden boards consist of six layers, with pore tubes evenly distributed throughout from top to bottom in layers one through six. These pore tubes are composed of a first pore tube 201, a second pore tube 202, a third pore tube 203, a first switch 204, a second switch 205, and a third switch 206. The interior of each pore tube is filled with particles of varying diameters. Layers two and three, and layers four and five, are filled with particles with a diameter of 1-2 mm. Brine is injected over the cover layer, and then the brine tank 20 is sealed.

[0039] S4, Inject supercritical carbon dioxide; Specifically, the variable gas pump 10 is turned on to pump carbon dioxide from the carbon dioxide tank 9 into the supercritical device 12. The supercritical device 17 processes the carbon dioxide into a supercritical state and then injects it into the brine reservoir structure 3 through the injection well simulation pipe 16.

[0040] S5. Open the extraction pump 5 and the controllable valve 8 to control the amount of brine in the brine reservoir structure 3. Specifically, the extraction pump 5 is turned on to pump the brine in the brine reservoir structure 3 into the brine storage tank 7 through the extraction well simulation pipe 4, and then the brine in the brine storage tank 7 is pumped into the brine layer through the injection well simulation pipe 17 through the extraction pump 5.

[0041] S6. Record monitoring data; The process involves recording the pressure values ​​within brine layer 1 and brine reservoir structure 3 as monitored by pressure sensors, ensuring that the pressure value of brine layer 1 is greater than or equal to the pressure value within brine reservoir structure 3. Carbon dioxide injection is stopped when the pressure value of brine layer 1 equals the pressure value of brine reservoir structure 3. The total amount of carbon dioxide injected is recorded after injection is stopped.

[0042] Finally, a quantitative analysis experiment was conducted: keeping the carbon dioxide injection rate and brine extraction rate constant, the permeability of caprock structure 2 and the porosity of brine reservoir structure 3 were changed, and experimental steps S1-S6 were repeated to obtain the total amount of carbon dioxide injected under different permeabilities of caprock structure 2 and porosities of brine reservoir structure 3. This was used to evaluate and analyze the impact of caprock structure 2 and brine reservoir structure 3 on the geological storage effect of carbon dioxide.

[0043] like Figure 6 As shown, in the preferred embodiment 1, the porosity of the reservoir simulation structure 3 is adjusted by controlling the spherical particles 19 according to S2; different opening and closing combinations of the first switch 204, the second switch 205, and the third switch 206 are controlled according to step 3 to form different permeability simulations of the caprock; a fixed carbon dioxide injection rate of 4 kg / s and a brine extraction rate of 2 kg / s are set according to S4-S5; and the total amount of carbon dioxide injected is recorded according to S6 when the pressure in the brine layer 1 and the brine reservoir structure 3 is equal.

[0044] like Figure 7 As shown, in the preferred embodiment 2, the porosity of the reservoir simulation structure 3 is adjusted by controlling the spherical particles 19 according to S2; different opening and closing combinations of the first switch 204, the second switch 205, and the third switch 206 are controlled according to S3 to form different permeability simulations of the caprock; a fixed carbon dioxide injection rate of 4 kg / s and a brine extraction rate of 2 kg / s are set according to S4-5; and the total amount of carbon dioxide injected is recorded when the pressure in the brine layer 1 and the brine reservoir structure 3 is equal according to S6.

[0045] Based on the test site for evaluating the geological storage capacity of carbon dioxide, this invention uses interconnected spherical particles 19 of different sizes to form the main framework of the reservoir. By adjusting the size of the spherical particles 19 through a controller, the porosity of the saline layer for geological storage of carbon dioxide under site conditions can be simulated.

[0046] Obviously, the above embodiments of the present invention are merely examples for clearly illustrating the present invention, and are not intended to limit the implementation of the present invention. Those skilled in the art can make other variations or modifications based on the above description. It is neither necessary nor possible to exhaustively describe all embodiments here. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the scope of protection of the claims of the present invention.

Claims

1. A test site for evaluating the geological storage capacity of carbon dioxide, characterized in that, The system includes a brine pool and a brine layer and capping structure located inside the brine pool. The capping structure is located vertically below the brine layer, and a brine reservoir structure is located below the capping structure. The brine reservoir structure is connected to a brine storage tank via a simulated extraction well pipe. The brine storage tank is connected to the brine layer via a simulated injection well pipe. Carbon dioxide is injected into the brine reservoir structure via a simulated gas injection well pipe. Pressure sensors installed on the inner wall of the brine pool monitor the pressure in the brine layer and the brine reservoir structure. The carbon dioxide injection rate, brine extraction rate, and brine injection rate are adjusted according to the monitored pressure to balance the pressure in the brine layer and the brine reservoir structure.

2. The test site for evaluating the geological storage capacity of carbon dioxide according to claim 1, characterized in that, A pumping pump is connected to the simulated pipe of the extraction well, and the pumping pump is connected to the brine storage tank via a high-pressure water pipe.

3. The test site for evaluating the geological storage capacity of carbon dioxide according to claim 2, characterized in that, The gas injection well simulation pipe is equipped with a supercritical device to monitor the amount of carbon dioxide injected.

4. The test site for evaluating the geological storage capacity of carbon dioxide according to claim 3, characterized in that, The supercritical unit is connected to a carbon dioxide gas cylinder via a gas delivery pipe, which is equipped with a variable gas pump.

5. The test site for evaluating the geological storage capacity of carbon dioxide according to claim 1, characterized in that, The extraction well simulation pipe, gas injection well simulation pipe, and water injection well simulation pipe are all connected to the brine pool via fixers.

6. The test site for evaluating the geological storage capacity of carbon dioxide according to claim 5, characterized in that, The injection well simulation pipe is equipped with a controllable valve to regulate the injection volume of brine.

7. The test site for evaluating the geological storage capacity of carbon dioxide according to claim 1, characterized in that, The pressure sensor is connected to a display, which monitors the pressure value.

8. The test site for evaluating the geological storage capacity of carbon dioxide according to claim 1, characterized in that, The brine reservoir structure is connected to the controller, and the interconnected spherical particles in the brine reservoir structure are controlled by an external controller.

9. A test method for assessing the geological storage capacity of carbon dioxide, comprising the test site for assessing the geological storage capacity of carbon dioxide as described in any one of claims 1-8, characterized in that, The main steps include: S1. Determine and construct the basic test site; S2. Create a heterogeneous brine layer; S3. Manufacturing a capping structure with variable permeability; S4, Inject supercritical carbon dioxide; S5. Open the extraction pump and controllable valve to control the amount of brine in the brine reservoir structure; S6. Record monitoring data.

10. The test method for evaluating the geological storage capacity of carbon dioxide according to claim 9, characterized in that, Keeping the carbon dioxide injection rate and brine extraction rate constant, the permeability of the caprock structure and the porosity of the brine reservoir structure were varied. Experimental steps S1-S6 were repeated to obtain the total carbon dioxide injection amount under different caprock structure permeability and brine reservoir structure porosity. This was used to evaluate and analyze the impact of caprock structure and brine reservoir structure on the geological storage effect of carbon dioxide.

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