Crude oil injection-production-storage system and crude oil injection-production-storage method

Abstract

The application relates to the technical field of underground energy storage and CO2 geological storage, in particular to a crude oil injection-production storage system and a crude oil injection-production storage method. The crude oil injection-production storage system comprises an oil storage library for storing crude oil, a gas storage library for storing CO2, a first pipeline assembly with a first passage to connect the oil storage library and the gas storage library, and the first pipeline assembly is connected to a surface storage facility; a second pipeline assembly with a second passage to connect the oil storage library and the gas storage library, and the second pipeline assembly is connected to the surface storage facility; a valve assembly arranged in the first pipeline assembly and the second pipeline assembly respectively to control the connection state of the first passage and the second passage; wherein the oil storage library and the gas storage library are both salt cavern spaces formed by water-soluble mining of a salt rock stratum. The CO2 displacement does not cause water resource pollution and crude oil waste, effectively improves the salt cavern utilization rate and economic benefits, and realizes efficient utilization of CO2 and CO2 geological storage.

Description

Technical Field

[0001] This application relates to the field of underground energy storage and CO2 geological sequestration technology, and in particular to a crude oil injection-production-storage system and a crude oil injection-production-storage method. Background Technology

[0002] Currently, my country's oil resources are relatively scarce and its dependence on foreign oil is high, making the construction of large-scale strategic oil reserves imperative.

[0003] Due to its low permeability, low porosity, and excellent rheological properties, salt rock is internationally recognized as the optimal medium for strategic petroleum reserves. Currently, underground salt cavern oil storage facilities are typically constructed in salt caverns hundreds to over a thousand meters deep using water-soluble extraction methods. Compared to surface oil storage tanks, underground salt cavern oil storage facilities offer advantages such as ease of storage, high safety, smaller footprint, and lower investment costs.

[0004] Existing salt cavern oil storage systems typically utilize the immiscibility of brine and crude oil, injecting saturated brine or fresh water into the cavity to displace the crude oil and achieve extraction. However, waterflooding technology has many drawbacks. Injecting fresh water or unsaturated brine into the cavity can cause secondary dissolution, affecting its stability. When crude oil is injected, the saturated brine discharged from the bottom of the cavity contains an oil-water mixture, leading to water pollution and significant waste of crude oil resources. High-viscosity heavy oil has poor fluidity, low oil recovery rates, and the risk of tubing blockage.

[0005] The combustion of fossil fuels also produces large amounts of carbon dioxide, contributing to the greenhouse effect and increasing extreme weather events globally. Currently, carbon capture, utilization, and storage (CVC) technology is considered the most effective solution to address climate change. Meanwhile, CO2 has wide applications in chemical engineering, building materials, and fuels. However, traditional large-scale underground CO2 storage for short periods requires large amounts of bottom gas, and long-term storage carries risks such as leakage.

[0006] Therefore, it is necessary to propose a crude oil injection-production-storage system and a CO2 injection-production-storage method to reduce and partially solve the problems existing in the current technology. Summary of the Invention

[0007] The summary section introduces a series of simplified concepts, which will be further explained in detail in the detailed description section. The summary section of this invention is not intended to limit the key features and essential technical features of the claimed technical solution, nor is it intended to determine the scope of protection of the claimed technical solution.

[0008] The present invention aims to solve at least one of the technical problems existing in the prior art or related art.

[0009] Therefore, a first aspect of the present invention provides a crude oil injection-production-storage system.

[0010] A second aspect of the present invention provides a crude oil injection-production-storage method.

[0011] In view of this, a crude oil injection-production-storage system is proposed according to a first aspect of the embodiments of this application, comprising: Oil storage depots are used to store crude oil; Gas storage facility, used to store CO2; The first pipeline assembly forms a first passage to connect the oil storage tank and the gas storage tank, and the first pipeline assembly is connected to the surface storage facility. The second pipeline assembly forms a second passage to connect the oil storage tank and the gas storage tank, and the second pipeline assembly is connected to the surface storage facility. A valve assembly is respectively disposed in the first pipeline assembly and the second pipeline assembly, and is used to control the connection state of the first passage and the second passage; The oil storage facility and the gas storage facility are both salt cavern spaces mined from salt rock strata. The above-mentioned surface storage facilities are used to store saturated brine, crude oil and CO2.

[0012] In one feasible implementation, the first piping assembly includes: The first pipe body is installed inside the aforementioned oil storage tank; The second pipe is installed inside the aforementioned gas storage tank. The third pipe is connected to the first pipe and the second pipe to form the first passage, and both ends of the third pipe are connected to the surface storage facility.

[0013] In one feasible implementation, the second piping assembly includes: The fourth pipe body is installed inside the aforementioned oil storage tank; The fifth pipe is installed inside the aforementioned gas storage tank; The sixth pipe is connected to the fourth and fifth pipes to form the second passage, and both ends of the sixth pipe are connected to the surface storage facility.

[0014] In one feasible implementation, the fourth tube is sleeved on the first tube, and a first annular space is formed between the fourth tube and the first tube. The fifth tube is fitted onto the second tube, and a second annular space is formed between the fifth tube and the second tube.

[0015] In one feasible implementation, a seal is provided at the connection between the valve assembly and the first pipeline assembly and / or at the connection between the valve assembly and the second pipeline assembly.

[0016] In one feasible implementation, the valve assembly includes: The first valve is disposed on the third pipe body and located between the first pipe body and the second pipe body; The second valve is located at one end of the third pipe body near the first pipe body; The third valve is located at one end of the third pipe body near the second pipe body. The fourth valve is installed on the sixth pipe body and is located between the fourth pipe body and the fifth pipe body. The fifth valve is located at one end of the sixth pipe body near the fourth pipe body. The sixth valve is located at one end of the sixth pipe body near the fifth pipe column.

[0017] According to a second aspect of the embodiments of this application, a crude oil injection-production-storage method is provided for use in a crude oil injection-production-storage system as described in any of the above technical solutions, comprising: Acquire the aforementioned oil storage facility and the aforementioned gas storage facility; Control the valve assembly to the first state, inject CO2 into the oil storage tank, so that the saturated brine in the oil storage tank is discharged into the gas storage tank, and the original saturated brine in the gas storage tank is discharged into the surface storage facility. Control the valve assembly to the second state, inject crude oil into the oil storage tank, so that the CO2 in the oil storage tank is discharged into the gas storage tank, and the original saturated brine in the gas storage tank is discharged into the surface storage facility. Saturated brine is injected into the gas storage tank to allow CO2 from the gas storage tank to be discharged into the oil storage tank, and crude oil from the oil storage tank to be discharged into the oil storage tank.

[0018] In one feasible implementation, the above-mentioned crude oil injection-production-storage method further includes: In the case of discharging part of the CO2 in the gas storage tank, the valve assembly is controlled to the third state so that the CO2 in the gas storage tank is discharged to the surface storage facility. After all CO2 in the gas storage tank is discharged, the valve assembly is controlled to the fourth state to inject saturated brine into the gas storage tank so that all CO2 in the gas storage tank is discharged to the surface storage facility.

[0019] In one feasible implementation, the above-mentioned crude oil injection-production-storage method further includes: When the oil storage tank reaches the end of its service life, the valve assembly is controlled to the fifth state, CO2 is injected into the gas storage tank, and the CO2 from the gas storage tank enters the oil storage tank through the second pipeline assembly to discharge the crude oil in the oil storage tank to the surface storage facility until the gas storage tank and the oil storage tank are filled with CO2, and then the gas storage tank and the oil storage tank are sealed.

[0020] In one feasible implementation, the steps of acquiring the aforementioned oil storage tank and gas storage tank include: Fresh water is injected into the target salt rock formation to form two salt cavern spaces, one of which is an oil storage reservoir and the other is a gas storage reservoir.

[0021] Compared to existing technologies, the present invention offers at least the following advantages: The crude oil injection-production-storage system provided in this application includes an oil storage tank, a gas storage tank, a first pipeline assembly, a second pipeline assembly, a valve assembly, and surface storage facilities. The oil storage tank and gas storage tank are salt caverns formed in salt rock strata using saturated brine or fresh water. Crude oil is stored in the oil storage tank, and CO2 is stored in the gas storage tank. The surface storage facilities include surface oil tanks, surface CO2 gas tanks, surface brine pools, and surface freshwater pools. The low permeability, low porosity, and good rheological properties of salt rock enable better storage of crude oil. The first pipeline assembly forms a first passageway, connecting the oil storage tank and the gas storage tank. The first pipeline assembly is also connected to the surface storage facilities, allowing both the gas storage tank and the oil storage tank to store and utilize energy. The second pipeline assembly forms a second passage connecting the oil storage tank and the gas storage tank. This second pipeline assembly is also connected to surface storage facilities, enabling both the gas storage tank and the oil storage tank to store and utilize energy. Valve assemblies are respectively installed on the first and second pipeline assemblies, controlling the state of the first and second passages. Specifically, changing the valve assembly state allows the gas storage tank and the oil storage tank to discharge saturated brine into the surface brine pool and freshwater into the surface freshwater pool; changing the valve assembly state allows the surface CO2 storage tank to inject CO2 into the gas storage tank for CO2 storage, and the surface oil storage tank to inject crude oil into the oil storage tank for crude oil storage; changing the valve assembly state allows the gas storage tank to inject saturated brine into the gas storage tank, enabling the gas storage tank to transfer CO2 to the oil storage tank for crude oil extraction; and changing the valve assembly state allows the gas storage tank to inject saturated brine into the gas storage tank, discharging CO2 from the gas storage tank. After the oil storage tank reaches its service life, CO2 can be injected into the gas storage tank by changing the valve assembly. Once the gas storage tank is full of CO2, it flows into the oil storage tank through a second passage, thereby discharging all the crude oil in the oil storage tank. This process continues until both the oil storage tank and the gas storage tank are full of CO2, sealing them off and completing the long-term geological sequestration of CO2 in the salt cavern. This ensures the stability of the abandoned salt cavern and minimizes long-term leakage. Furthermore, this application utilizes CO2 to displace crude oil for extraction, which, compared to traditional brine displacement, avoids water pollution and crude oil waste, effectively improving the utilization rate and economic benefits of the salt cavern, and achieving carbon capture.

[0022] The crude oil injection-production-storage system and method of the present invention, other advantages, objectives and features of the present invention will be apparent in part from the following description, and in part will be understood by those skilled in the art through study and practice of the present invention. Attached Figure Description

[0023] Various other advantages and benefits will become apparent to those skilled in the art upon reading the following detailed description of preferred embodiments. The accompanying drawings are for illustrative purposes only and are not intended to limit this specification. Furthermore, the same reference numerals denote the same parts throughout the drawings. In the drawings: Figure 1 A schematic structural diagram of a crude oil injection-production-storage system provided in this application embodiment; Figure 2 This is a schematic flowchart illustrating a crude oil injection-production-storage method provided in an embodiment of this application.

[0024] in, Figure 1 The correspondence between the reference numerals and component names in the attached drawings is as follows: 1 Oil storage tank, 2 Gas storage tank, 3 First pipe body, 4 Second pipe body, 5 Third pipe body, 6 Fourth pipe body, 7 Fifth pipe body, 8 Sixth pipe body, 9 First valve, 10 Second valve, 11 Third valve, 12 Fourth valve, 13 Fifth valve, 14 Sixth valve. Detailed Implementation

[0025] To better understand the above technical solutions, the technical solutions of the embodiments of this application will be described in detail below with reference to the accompanying drawings and specific embodiments. It should be understood that the embodiments of this application and the specific features in the embodiments are detailed descriptions of the technical solutions of the embodiments of this application, rather than limitations on the technical solutions of this application. In the absence of conflict, the embodiments of this application and the technical features in the embodiments can be combined with each other.

[0026] like Figure 1 As shown, a crude oil injection-production-storage system according to a first aspect of the present application includes: an oil storage tank 1 for storing crude oil; a gas storage tank 2 for storing CO2; a first pipeline assembly forming a first passage to connect the oil storage tank 1 and the gas storage tank 2, the first pipeline assembly being connected to a surface storage facility; a second pipeline assembly forming a second passage to connect the oil storage tank 1 and the gas storage tank 2, the second pipeline assembly being connected to the surface storage facility; and valve assemblies respectively disposed on the first pipeline assembly and the second pipeline assembly for controlling the connection state of the first passage and the second passage; wherein the oil storage tank 1 and the gas storage tank 2 are both salt cavern spaces mined from salt rock strata, and the surface storage facility is used to store saturated brine, crude oil, and CO2.

[0027] It is understood that the crude oil injection-production-storage system provided in this application embodiment includes an oil storage tank 1, a gas storage tank 2, a first pipeline assembly, a second pipeline assembly, a valve assembly, and surface storage facilities. The oil storage tank 1 and gas storage tank 2 are salt cavern spaces formed in salt rock strata using saturated brine or fresh water. Crude oil is stored in the oil storage tank 1, and CO2 is stored in the gas storage tank 2. The surface storage facilities include surface oil tanks, surface CO2 gas tanks, surface brine pools, and surface freshwater pools. The low permeability, low porosity, and good rheological properties of salt rock enable better storage of crude oil. The first pipeline assembly forms a first passageway, connecting the oil storage tank 1 and the gas storage tank 2. The first pipeline assembly is also connected to the surface storage facilities, allowing both the gas storage tank 2 and the oil storage tank 1 to store and utilize energy. The second pipeline assembly forms a second passage, connecting oil storage tank 1 and gas storage tank 2. This second pipeline assembly is also connected to surface storage facilities, enabling both gas storage tank 2 and oil storage tank 1 to store and utilize energy. Valve assemblies are respectively installed on the first and second pipeline assemblies, controlling the states of the first and second passages. Specifically, changing the valve assembly states allows gas storage tank 2 and oil storage tank 1 to discharge saturated brine into the surface brine pool and freshwater into the surface freshwater pool; changing the valve assembly states allows the surface CO2 storage tank to inject CO2 into gas storage tank 2 for CO2 storage, and the surface oil storage tank to inject crude oil into oil storage tank 1 for crude oil storage; changing the valve assembly states allows saturated brine to be injected into gas storage tank 2, enabling gas storage tank 2 to deliver CO2 to oil storage tank 1 for crude oil extraction; and changing the valve assembly states allows saturated brine to be injected into gas storage tank 2 to discharge CO2 from gas storage tank 2. After the oil storage tank 1 reaches its service life, CO2 can be injected into the gas storage tank 2 by changing the valve assembly. Once the gas storage tank 2 is full of CO2, it will flow back into the oil storage tank 1 through a second passage, thus completely draining the crude oil from the oil storage tank 1. This process continues until both the oil storage tank 1 and the gas storage tank 2 are filled with CO2, sealing both tanks and completing the long-term geological sequestration of CO2 in the salt cavern. This ensures the stability of the abandoned salt cavern and minimizes long-term leakage. Furthermore, this application utilizes CO2 to displace crude oil for extraction, which, compared to traditional brine displacement, avoids water pollution and crude oil waste, effectively improving the utilization rate and economic benefits of the salt cavern, and achieving carbon capture.

[0028] It should be noted that, compared to traditional brine displacement, CO2 is more soluble in crude oil, which can expand the volume of crude oil by 10% to 40%, while reducing the viscosity of crude oil, enhancing its fluidity, and significantly improving the extraction efficiency of crude oil in salt cavern storage 1.

[0029] In some examples, such as Figure 1As shown, the first pipeline assembly includes: a first pipe body 3, which passes through the inner cavity of the oil storage tank 1; a second pipe body 4, which passes through the inner cavity of the gas storage tank 2; and a third pipe body 5, which is connected to the first pipe body 3 and the second pipe body 4 respectively to form the first passage, and the two ends of the third pipe body 5 are respectively connected to the surface storage facility.

[0030] Understandably, the first pipeline assembly includes a first pipe body 3, a second pipe body 4, and a third pipe body 5. The first pipe body 3 passes through the inner cavity of the oil storage tank 1, with one end of the first pipe body 3 near the bottom of the inner cavity of the oil storage tank 1. The second pipe body 4 passes through the inner cavity of the gas storage tank 2, with one end of the second pipe body 4 near the bottom of the inner cavity of the gas storage tank 2. The third pipe body 5 connects to both the first pipe body 3 and the second pipe body 4 to form a first passage, and both ends of the third pipe body 5 are connected to the ground of the surface storage facility. This configuration allows substances to be transported from the third pipe body 5 to the first pipe body 3 and the second pipe body 4.

[0031] In some examples, such as Figure 1 As shown, the second pipeline assembly includes: a fourth pipe body 6, which passes through the inner cavity of the oil storage tank 1; a fifth pipe body 7, which passes through the inner cavity of the gas storage tank 2; and a sixth pipe body 8, which is connected to the fourth pipe body 6 and the fifth pipe body 7 respectively to form the second passage, and the two ends of the sixth pipe body 8 are respectively connected to the surface storage facility.

[0032] Understandably, the second pipeline assembly includes a fourth pipe body 6, a fifth pipe body 7, and a sixth pipe body 8. The fourth pipe body 6 passes through the inner cavity of the oil storage tank 1, with one end of the fourth pipe body 6 near the top of the inner cavity of the oil storage tank 1. The fifth pipe body 7 passes through the inner cavity of the gas storage tank 2, with one end of the fifth pipe body 7 near the top of the inner cavity of the gas storage tank 2. The sixth pipe body 8 connects to both the fourth pipe body 6 and the fifth pipe body 7 to form a second passage, and both ends of the sixth pipe body 8 are connected to surface storage facilities. This configuration allows energy to be transmitted from the sixth pipe body 8 to the fourth pipe body 6 and the fifth pipe body 7.

[0033] It should be noted that, considering the density of saturated brine and fresh water is greater than that of crude oil, and the density of crude oil is greater than that of CO2, water is located at the bottom layer in oil storage tank 1 and gas storage tank 2, crude oil is located in the middle layer, and CO2 is located at the top layer. Therefore, the first pipe 3 is inserted into oil storage tank 1 near the bottom to facilitate the supply of crude oil for storage or the discharge of crude oil stored in oil storage tank 1 to surface storage tanks. The fourth pipe 6 is inserted into oil storage tank 1 near the top to facilitate the supply of CO2 to oil storage tank 1 to discharge saturated brine or crude oil from oil storage tank 1. Similarly, the second pipe 4 and the fifth pipe 7 are also configured in the same way.

[0034] In some examples, such as Figure 1As shown, the fourth tube 6 is sleeved on the first tube 3, and a first annular space is formed between the fourth tube 6 and the first tube 3; the fifth tube 7 is sleeved on the second tube 4, and a second annular space is formed between the fifth tube 7 and the second tube 4.

[0035] Understandably, the fourth pipe 6 is fitted onto the first pipe 3, and a first annular space is formed between the fourth pipe 6 and the first pipe 3. The fourth pipe 6 is closer to the top of the oil storage tank 1 than the first pipe 3. The fifth pipe 7 is fitted onto the second pipe 4, and a second annular space is formed between the fifth pipe 7 and the second pipe 4. The fifth pipe 7 is also closer to the top of the oil storage tank 1 than the second pipe 4. This design is more suitable for the structure of the oil storage tank 1 and the gas storage tank 2, and the installation process is simpler, reducing the number of openings in the oil storage tank 1 and the gas storage tank 2, thus ensuring greater structural stability.

[0036] In some examples, a seal is provided at the connection between the valve assembly and the first pipeline assembly and / or at the connection between the valve assembly and the second pipeline assembly.

[0037] It is understandable that seals can be installed at the connection between the valve assembly and the first pipeline assembly, as well as at the connection between the valve assembly and the second pipeline assembly, to ensure the reliability of valve use and prevent crude oil, CO2, and saturated brine from leaking from the connection.

[0038] In some examples, such as Figure 1 As shown, the valve assembly includes: a first valve 9, disposed on the third pipe body 5, located between the first pipe body 3 and the second pipe body 4; a second valve 10, disposed on the third pipe body 5 near the end of the first pipe body 3; a third valve 11, disposed on the third pipe body 5 near the end of the second pipe body 4; a fourth valve 12, disposed on the sixth pipe body 8, located between the fourth pipe body 6 and the fifth pipe body 7; a fifth valve 13, disposed on the sixth pipe body 8 near the end of the fourth pipe body 6; and a sixth valve 14, disposed on the sixth pipe body 8 near the end of the fourth pipe body 6.

[0039] Understandably, the valve assembly includes valves 9 through 14. Specifically, valve 9 is located on the third pipe body 5, between the first pipe body 3 and the second pipe body 4, to control the flow of materials between the first pipe body 3 and the second pipe body 4. Valve 10 is located at the end of the third pipe body 5 near the first pipe body 3, to control the storage and utilization of energy between the oil storage tank 1 and the surface storage facility. Valve 11 is located at the end of the third pipe body 5 near the second pipe body 4, to control the storage and utilization of energy between the gas storage tank 2 and the surface storage facility. Valve 12 is located on the sixth pipe body 8, between the fourth pipe body 6 and the fifth pipe body 7, to control the flow of materials between the fourth pipe body 6 and the fifth pipe body 7. Valve 13 is located at the end of the sixth pipe body 8 near the fourth pipe body 6, to control the storage and utilization of energy between the oil storage tank 1 and the surface storage facility. Valve 14 is located at the end of the sixth pipe body 8 near the fifth pipe body 7, to control the storage and utilization of energy between the gas storage tank 2 and the surface storage facility.

[0040] It should be noted that the operating state of the crude oil injection-production-storage system is altered by adjusting the states of valves 9 through 14 and the substances supplied to gas storage tank 2 and oil storage tank 1. Specifically, when two salt caverns are formed in the salt rock strata using saturated brine to serve as gas storage tank 2 and oil storage tank 1, both tanks are filled with saturated brine. During the subsequent CO2 injection and brine discharge phase in oil storage tank 1, valves 13, 9, and 14 are opened, while the remaining valves are closed. CO2 is injected into oil storage tank 1 from the surface CO2 storage tank via pipe 6, causing the saturated brine in oil storage tank 1 to enter gas storage tank 2 via pipes 5 and 4. Finally, the brine is discharged into the surface brine pool via pipes 7 and 8.

[0041] During the CO2 and crude oil storage phase, valves 10, 11, and 12 are opened, and the remaining valves are closed. Crude oil is injected into storage tank 1 through pipe 5 and pipe 3. CO2 in storage tank 1 enters gas storage tank 2 through pipe 6 and pipe 7. Saturated brine in gas storage tank 2 is discharged to a surface brine pool through pipe 4 and pipe 5. This phase completes the crude oil storage in storage tank 1 and the CO2 storage in gas storage tank 2.

[0042] During the crude oil extraction stage, the second valve 10, the third valve 11, and the fourth valve 12 are opened, while the remaining valves are closed. Saturated brine is injected into the gas storage tank 2 through the third pipe 5 and the second pipe 4. CO2 in the gas storage tank 2 enters the oil storage tank 1 through the fifth pipe 7 and the fourth pipe 6. Crude oil in the oil storage tank 1 is discharged to the surface oil storage tank through the first pipe 3 and the third pipe 5, completing the crude oil extraction.

[0043] During the CO2 extraction phase, valve 14 is opened and the remaining valves are closed. Under the pressure difference, CO2 is discharged through pipes 7 and 8 to the surface CO2 storage tank. To extract all CO2, valves 11 and 14 are opened and the remaining valves are closed. Saturated brine is injected through pipe 4, and CO2 is discharged through pipes 7 and 8, completing the extraction of all CO2. It should be noted that the CO2 injection phase can be performed using the reverse process, repeating the above steps to complete the CO2 and crude oil injection-production cycle.

[0044] When oil storage tank 1 reaches its service life, open the second valve 10, the third valve 11, and the sixth valve 14, and close the remaining valves. Inject CO2 into gas storage tank 2 through the third pipe 5 and the second pipe 4. Simultaneously, the CO2 enters oil storage tank 1 through the fifth pipe 7, the sixth pipe 8, and the fourth pipe 6. Under the action of CO2, crude oil is discharged from oil storage tank 1 through the first pipe 3 and the third pipe 5 to the surface oil storage tank, so that gas storage tank 2 and oil storage tank 1 are completely filled with CO2, sealing the wellbore tubing of gas storage tank 2 and oil storage tank 1, completing the long-term geological sequestration of CO2 in the salt cavern.

[0045] like Figure 2 As shown, a crude oil injection-production-storage method is proposed according to a first aspect of the embodiments of this application, comprising: S101: Obtain the aforementioned oil storage facility 1 and the aforementioned gas storage facility 2; Step S101 also includes step S1011.

[0046] Step S1011: The steps of obtaining the above-mentioned oil storage tank 1 and gas storage tank 2 include: injecting fresh water into the target salt rock formation to form two salt cavern spaces, one of which is the oil storage tank 1 and the other is the gas storage tank 2.

[0047] It is understandable that oil storage facility 1 and gas storage facility 2 are salt cavern spaces formed by fresh water in salt rock strata. Oil storage facility 1 stores crude oil, and gas storage facility 2 stores CO2. The low permeability, low porosity, and good rheological properties of salt rock enable better storage of crude oil. For example, both gas storage facility 2 and oil storage facility 1 have a capacity of 300,000 cubic meters or more.

[0048] S102: Control the valve assembly to the first state and inject CO2 into the oil storage tank 1 to drain the existing saturated brine in the oil storage tank 1 into the gas storage tank 2. It is understood that after the preparation of gas storage tank 2 and oil storage tank 1, both contain a large amount of saturated brine, requiring CO2 injection into oil storage tank 1 to drain the brine. At this stage, control the valve assembly to the first state, i.e., open the fifth valve 13, the first valve 9, and the sixth valve 14, and close the remaining valves. Inject CO2 from the surface CO2 storage tank into oil storage tank 1 through the fourth pipe 6, allowing the saturated brine in oil storage tank 1 to enter gas storage tank 2 through the third pipe 5 and the second pipe 4. Finally, discharge it into the surface brine pool through the fifth pipe 7 and the sixth pipe 8.

[0049] S103: Control the valve assembly to the second state, inject crude oil into the oil storage tank 1, so that the CO2 in the oil storage tank 1 is discharged into the gas storage tank 2, and the original saturated brine in the gas storage tank 2 is discharged into the surface brine pool. It can be understood that during the crude oil storage stage of the oil storage tank 1, the valve assembly can be controlled to the second state, i.e., opening the second valve 10, the third valve 11, and the fourth valve 12 and closing the remaining valves. Crude oil is injected into the oil storage tank 1 through the third pipe 5 and the first pipe 3. The CO2 in the oil storage tank 1 enters the gas storage tank 2 through the fourth pipe 6 and the fifth pipe 7. The saturated brine in the gas storage tank 2 is discharged into the surface brine pool through the second pipe 4 and the third pipe 5. At this stage, the crude oil storage in the oil storage tank 1 and the CO2 storage in the gas storage tank 2 are completed.

[0050] S104: Saturated brine is injected into the gas storage tank 2 to allow CO2 in the gas storage tank 2 to be discharged into the oil storage tank 1, and the crude oil in the oil storage tank 1 is discharged into the surface oil storage tank. It is understood that during the crude oil extraction stage, the second valve 10, the third valve 11, and the fourth valve 12 can be opened while the remaining valves are closed. Saturated brine is injected into the gas storage tank 2 through the third pipe 5 and the second pipe 4. CO2 in the gas storage tank 2 enters the oil storage tank 1 through the fifth pipe 7 and the fourth pipe 6. The crude oil in the oil storage tank 1 is discharged into the surface oil storage tank through the first pipe 3 and the third pipe 5, completing the crude oil extraction.

[0051] In some examples, the above-mentioned crude oil injection-production-storage method further includes: when some of the CO2 in the gas storage tank 2 is discharged, controlling the valve assembly to a third state so that the CO2 in the gas storage tank 2 is discharged to a surface CO2 storage tank; when all the CO2 in the gas storage tank 2 is discharged, controlling the valve assembly to a fourth state, injecting saturated brine into the gas storage tank 2 so that all the CO2 in the gas storage tank 2 is discharged to a surface CO2 storage tank.

[0052] Understandably, during the CO2 extraction phase, the valve assembly can be controlled to the third state, opening the fifth valve 14 and closing the remaining valves. Under the pressure difference, CO2 is discharged through the fifth pipe 7 and the sixth pipe 8 into the surface CO2 storage tank. To extract all CO2, the valve assembly can be controlled to the fourth state, opening the third valve 11 and the sixth valve 14 and closing the remaining valves. Saturated brine is injected through the second pipe 4, and CO2 is discharged through the fifth pipe 7 and the sixth pipe 8, completing the complete CO2 extraction. It should be noted that the CO2 injection phase can be performed using the reverse process, repeating the above steps to complete the CO2 and crude oil injection-production cycle.

[0053] In some examples, the crude oil injection-production-storage method further includes: when the oil storage tank 1 reaches its service life, controlling the valve assembly to the fifth state, injecting CO2 into the gas storage tank 2, and the CO2 in the gas storage tank 2 enters the oil storage tank 1 along the second pipeline assembly to discharge the crude oil in the oil storage tank 1 to the surface oil storage tank, until the gas storage tank 2 and the oil storage tank 1 are filled with CO2, and then sealing the gas storage tank 2 and the oil storage tank 1.

[0054] Understandably, when oil storage tank 1 reaches its service life, the valve assembly can be controlled to the fifth state, i.e., opening the second valve 10, the third valve 11, and the sixth valve 14 while closing the remaining valves. CO2 is injected into gas storage tank 2 through the third pipe 5 and the second pipe 4. Simultaneously, the CO2 enters oil storage tank 1 through the fifth pipe 7, the sixth pipe 8, and the fourth pipe 6. Under the influence of CO2, crude oil is discharged from oil storage tank 1 through the first pipe 3 and the third pipe 5 to the surface oil storage tank, thus completely filling gas storage tank 2 and oil storage tank 1 with CO2, sealing the wellbore tubing of gas storage tank 2 and oil storage tank 1, and completing the long-term geological sequestration of CO2 in the salt cavern. For example, the service life of oil storage tank 1 is 30 years.

[0055] In summary, this method achieves both the storage and utilization of crude oil and the utilization and sequestration of CO2, ensuring the long-term stability of abandoned salt caverns. Furthermore, compared to traditional brine displacement, using CO2 to displace and extract crude oil avoids water pollution and crude oil waste, effectively improving the utilization rate and economic benefits of salt caverns, and achieving efficient CO2 utilization and geological sequestration.

[0056] In the description of this invention, it should be understood that the terms "upper," "lower," "left," "right," "front," "rear," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or unit referred to must have a specific orientation or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0057] In the description of this specification, the terms "one embodiment," "some embodiments," "specific embodiment," etc., refer to a specific feature, structure, material, or characteristic described in connection with that embodiment or example, which is included in at least one embodiment or example of the invention. In this specification, illustrative expressions of terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0058] The above are merely preferred embodiments of the present invention and are not intended to limit the present invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A crude oil injection-production-storage method, used in a crude oil injection-production-storage system, characterized in that, The crude oil injection-production-storage system includes: Oil storage depots are used to store crude oil; Gas storage facility, used for storing ; The first pipeline assembly forms a first passage to connect the oil storage tank and the gas storage tank, and the first pipeline assembly is connected to a surface storage facility. The second pipeline assembly forms a second passage to connect the oil storage tank and the gas storage tank, and the second pipeline assembly is connected to the surface storage facility; A valve assembly is respectively disposed on the first pipeline assembly and the second pipeline assembly, and is used to control the connection state of the first passage and the second passage; The oil storage facility and the gas storage facility are both salt caverns mined from salt rock strata, while the surface storage facility is used to store saturated brine, crude oil, and... ; The crude oil injection-production-storage method includes: Obtain the oil storage tank and the gas storage tank; Control the valve assembly to the first state to inject oil into the oil storage tank. So that the saturated brine in the oil storage tank is discharged into the gas storage tank, and the saturated brine in the gas storage tank is discharged to the surface storage facility; Controlling the valve assembly to the second state allows crude oil to be injected into the oil storage tank, thereby increasing the oil content in the tank. The gas is discharged into the gas storage tank, and the saturated brine in the gas storage tank is discharged to the surface storage facility. Saturated brine is injected into the gas storage tank to make the gas storage tank contain... The crude oil is discharged into the oil storage tank, and then discharged from the oil storage tank to the surface storage facility.

2. The crude oil injection-production-storage method according to claim 1, characterized in that, The first piping assembly includes: The first pipe body is inserted into the inner cavity of the oil storage tank; The second pipe is inserted into the inner cavity of the gas storage tank; The third pipe is connected to the first pipe and the second pipe to form the first passage, and both ends of the third pipe are connected to the surface storage facility.

3. The crude oil injection-production-storage method according to claim 2, characterized in that, The second piping assembly includes: The fourth pipe is inserted into the inner cavity of the oil storage tank; The fifth tube is inserted into the inner cavity of the gas storage tank; The sixth pipe is connected to the fourth pipe and the fifth pipe to form the second passage, and both ends of the sixth pipe are connected to the surface storage facility.

4. The crude oil injection-production-storage method according to claim 3, characterized in that: The fourth tube is sleeved on the first tube, and a first annular space is formed between the fourth tube and the first tube; The fifth tube is sleeved on the second tube, and a second annular space is formed between the fifth tube and the second tube.

5. The crude oil injection-production-storage method according to claim 1, characterized in that: A seal is provided at the connection between the valve assembly and the first pipeline assembly, and / or a seal is provided at the connection between the valve assembly and the second pipeline assembly.

6. The crude oil injection-production-storage method according to claim 3, characterized in that, The valve assembly includes: The first valve is disposed on the third pipe body and located between the first pipe body and the second pipe body; The second valve is located at one end of the third pipe body near the first pipe body; The third valve is located at one end of the third pipe body near the second pipe body; The fourth valve is disposed on the sixth pipe body and located between the fourth pipe body and the fifth pipe body; The fifth valve is located at one end of the sixth pipe body near the fourth pipe body; The sixth valve is located at one end of the sixth pipe body near the fifth pipe body.

7. The crude oil injection-production-storage method according to claim 1, characterized in that, Also includes: Control the valve assembly to the third state to allow the gas storage tank to... Discharged into the aforementioned surface storage facility; Controlling the valve assembly to the fourth state injects saturated brine into the gas storage tank, so that all the contents of the gas storage tank are filled with brine. Discharged to the aforementioned surface storage facility.

8. The crude oil injection-production-storage method according to claim 7, characterized in that, Also includes: When the oil storage tank reaches its service life, the valve assembly is controlled to the fifth state to inject gas into the gas storage tank. The gas storage tank The crude oil is discharged from the oil storage tank through the second pipeline assembly to the surface storage facility until both the gas storage tank and the oil storage tank are full. The gas storage tank and the oil storage tank were sealed off.

9. The crude oil injection-production-storage method according to claim 8, characterized in that, The steps of acquiring the oil storage tank and the gas storage tank include: Fresh water is injected into the target salt rock formation to form two salt cavern spaces, one of which is an oil storage tank and the other is a gas storage tank.

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