Carbon Dioxide Flooding and Sequestration Simulation Device and Method

Abstract

The present invention provides a simulation device and method for carbon dioxide enhanced oil recovery and storage. The simulation device for carbon dioxide enhanced oil recovery and storage provided by the present invention includes a formation model, a pressure chamber, a carbon dioxide container assembly, a backpressure element, and a monitoring assembly. The formation model is configured to be disposed in the pressure chamber and has pores; the pressure chamber is used to maintain a first preset pressure; the carbon dioxide container assembly is used to introduce a configured supercritical carbon dioxide conductive fluid into the formation model; the backpressure element is communicated with the formation model, and when the pressure in the pores of the formation model reaches a second preset pressure, the backpressure element is turned on. The monitoring assembly is at least used to monitor the changes in the pressure and conductivity inside the formation model during the process of supercritical carbon dioxide conductive fluid enhanced oil recovery and storage. The present invention provides a simulation device and method for carbon dioxide enhanced oil recovery and storage, which can realize the simulation of the process of carbon dioxide enhanced oil recovery and storage and dynamically monitor this process.

Description

Technical Field

[0001] The present invention relates to the field of oil development, and in particular to a simulation device and method for carbon dioxide flooding and sequestration. Background Art

[0002] Indoor physical simulation experiments are one of the important means to simulate the oil and gas field development process, and play an important role in the research of scientific and engineering problems for improving oil recovery in oil and gas fields.

[0003] Among them, the indoor physical simulation experiment technology for gas flooding to improve oil recovery has received more and more attention in recent years. In the prior art, based on similarity criteria, different types of cores, different types of injection gases, different injection-production parameter selections, and different experimental conditions can be used to conduct experimental simulations on various development modes of different types of oil and gas reservoirs, and various experimental results such as the dynamic change of the recovery factor, the dynamic change of the injection-production pressure difference, the change of oil and gas components before and after displacement, and the change of physical properties of the core before and after displacement can be obtained.

[0004] However, so far, the dynamic monitoring of the oil / gas phase saturation and distribution during the gas flooding process has not been realized, and the research and invention achievements in this field are still in the exploration stage. Summary of the Invention

[0005] In order to solve at least one problem mentioned in the background art, the present invention provides a simulation device and method for carbon dioxide flooding and sequestration, which can realize the process simulation of carbon dioxide flooding and sequestration, and conduct dynamic monitoring of the development dynamic characteristics and fluid saturation distribution of this process.

[0006] To achieve the above object, the present invention provides the following technical solutions:

[0007] In a first aspect, the present invention provides a simulation device for carbon dioxide flooding and sequestration, including a formation model, a pressure chamber, a carbon dioxide container assembly, a backpressure element, and a monitoring component. The formation model is configured to be disposed in the pressure chamber, and the formation model has pores; a first opening and a second opening are formed on the formation model. The first opening is used for injecting fluid, and the second opening is used for discharging fluid. The pressure chamber is used to maintain a first preset pressure; the carbon dioxide container assembly is communicated with the pores of the formation model, and the carbon dioxide container assembly is used to configure a supercritical carbon dioxide conductive fluid and introduce the supercritical carbon dioxide conductive fluid into the pores of the formation model, wherein the supercritical carbon dioxide conductive fluid is configured by carbon dioxide and a conductive ionic liquid; the backpressure element is connected to the second opening of the formation model, and when the pressure in the pores of the formation model reaches a second preset pressure, the backpressure element is turned on, and the second preset pressure is less than the first preset pressure. The monitoring component is at least used to monitor the change of the pressure and conductivity inside the formation model during the process of supercritical carbon dioxide conductive fluid flooding and sequestration.

[0008] As an alternative embodiment, the formation model includes a core and a cladding layer. The core is used to simulate the rock structure in the actual formation. The core has pores, and the cladding layer is coated outside the core.

[0009] As an alternative embodiment, the cladding layer is made of epoxy resin.

[0010] As an alternative embodiment, it further includes an adjusting mechanism. The formation model is arranged on the adjusting mechanism, and the adjusting mechanism is used to adjust the spatial attitude of the formation model to change the oil displacement direction of the supercritical carbon dioxide conductive fluid.

[0011] As an alternative embodiment, it further includes a heating device. The heating device includes heating wires arranged inside the pressure chamber. The heating wires are used to heat the pressure chamber and the formation model in the pressure chamber to simulate the temperature in the actual formation.

[0012] As an alternative embodiment, the carbon dioxide container assembly includes a fluid storage container and a fluid configuration container. The fluid storage container is communicated with the fluid configuration container. The fluid storage container stores carbon dioxide and conductive ionic liquid. The fluid configuration container is used to configure carbon dioxide and conductive ionic liquid into a supercritical carbon dioxide conductive fluid and introduce the configured supercritical carbon dioxide conductive fluid into the pores of the formation model.

[0013] As an alternative embodiment, the monitoring assembly includes a pressure monitoring assembly. The pressure monitoring assembly includes a plurality of pressure monitoring points arranged in the formation model. The pressure monitoring assembly monitors the pressure conditions at various locations inside the formation model through the pressure monitoring points.

[0014] As an alternative embodiment, the monitoring assembly further includes a conductivity monitoring assembly. The conductivity monitoring assembly includes a plurality of conductivity monitoring points arranged on the formation model. The conductivity monitoring assembly can monitor the conductivity of the conductivity monitoring points to at least reflect the distribution of the supercritical carbon dioxide conductive fluid injected into the formation model.

[0015] As an alternative embodiment, the monitoring assembly further includes a gas flow meter and a liquid collection container. Both the gas flow meter and the liquid collection container are communicated with the back pressure element. The gas flow meter is used to measure the amount of gas produced from the formation model, and the liquid collection container is used to measure the amount of liquid produced from the formation model.

[0016] In a second aspect, the present invention further provides a method for simulating carbon dioxide enhanced oil recovery and storage. The method for simulating carbon dioxide enhanced oil recovery and storage uses the carbon dioxide enhanced oil recovery and storage simulation device in the first aspect to simulate and monitor carbon dioxide enhanced oil recovery. The method includes the following steps:

[0017] Perform saturated oil treatment on the formation model;

[0018] Adjust the pressure in the pressure chamber to a first preset pressure, adjust the pressure of the backpressure element to a second preset pressure, and adjust the pressure in the formation model to the second preset pressure, where the first preset pressure is greater than the second preset pressure;

[0019] Configure a supercritical carbon dioxide conductive fluid through a carbon dioxide container assembly, and introduce the configured supercritical carbon dioxide conductive fluid into the pores of the formation model to displace crude oil;

[0020] Monitor at least the changes in the pressure and conductivity of the formation model during the process of displacing oil with supercritical carbon dioxide conductive fluid through a monitoring assembly.

[0021] The carbon dioxide flooding and sequestration simulation device provided by the present invention includes a formation model, a pressure chamber, a carbon dioxide container assembly, a backpressure element, and a monitoring assembly. The formation model is configured to be disposed in the pressure chamber, and the formation model has pores; a first opening and a second opening are formed on the formation model. The first opening is used for injecting fluid, and the second opening is used for producing fluid. The pressure chamber is used to maintain the first preset pressure; the carbon dioxide container assembly is in communication with the pores of the formation model. The carbon dioxide container assembly is used to configure a supercritical carbon dioxide conductive fluid and introduce the supercritical carbon dioxide conductive fluid into the pores of the formation model, where the supercritical carbon dioxide conductive fluid is configured by carbon dioxide and a conductive ionic liquid; the backpressure element is connected to the second opening of the formation model. When the pressure in the pores of the formation model reaches the second preset pressure, the backpressure element is turned on. The second preset pressure is less than the first preset pressure. The monitoring assembly is at least used to monitor the changes in the pressure and conductivity at various locations inside the formation model during the process of carbon dioxide flooding and sequestration. When the carbon dioxide flooding and sequestration simulation device provided by the present invention conducts a carbon dioxide flooding and sequestration simulation experiment, the formation model can be saturated with oil, the pressure in the pressure chamber can be adjusted to the first preset pressure, the pressure of the backpressure element can be adjusted to the second preset pressure, and the pressure in the formation model can be adjusted to the second preset pressure, where the first preset pressure is greater than the second preset pressure. In this way, the actual formation overburden pressure environment can be simulated; then, the configured supercritical carbon dioxide conductive fluid in the carbon dioxide container assembly is introduced into the pores of the formation model to conduct an oil displacement and sequestration experiment. Since the supercritical carbon dioxide conductive fluid has conductivity, when the supercritical carbon dioxide conductive fluid flows in the pores of the formation model, the monitoring assembly can monitor the changes in the pressure and conductivity parameters at various locations of the formation model during the oil displacement and sequestration process. Combining the oil displacement data, through multi-parameter inversion, the laws of the migration and evolution of the oil and gas front and the real-time distribution of carbon dioxide sequestration during the whole process of carbon dioxide flooding and sequestration can be intuitively analyzed, and then important parameters such as the sweep efficiency during the carbon dioxide flooding process and the carbon dioxide sequestration efficiency can be quantitatively calculated, providing a more intuitive and reliable theoretical basis and guidance for the actual carbon dioxide flooding and sequestration production process. Brief Description of the Drawings

[0022] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required for the description of the embodiments or the prior art. Obviously, the drawings in the following description are some embodiments of the present invention. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative efforts.

[0023] Figure 1 It is a schematic diagram of the overall structure of a carbon dioxide enhanced oil recovery and storage simulation device provided by an embodiment of the present invention;

[0024] Figure 2 It is a flowchart of a carbon dioxide enhanced oil recovery and storage simulation method provided by an embodiment of the present invention;

[0025] Figure 3 It is a schematic diagram of the change of the recovery degree with the fluid injection volume in a carbon dioxide enhanced oil recovery and storage simulation method provided by an embodiment of the present invention;

[0026] Figure 4 It is a schematic diagram of the change of the carbon dioxide storage efficiency with the fluid injection volume in a carbon dioxide enhanced oil recovery and storage simulation method provided by an embodiment of the present invention.

[0027] Description of the Reference Numerals:

[0028] 100 - Carbon dioxide enhanced oil recovery and storage simulation device;

[0029] 110 - Formation model;

[0030] 111 - First opening;

[0031] 112 - Second opening;

[0032] 120 - Pressure chamber;

[0033] 130 - Carbon dioxide container assembly;

[0034] 131 - Fluid storage container;

[0035] 132 - Fluid configuration container;

[0036] 1321 - Piston;

[0037] 140 - Backpressure element;

[0038] 150 - Monitoring assembly;

[0039] 151 - Pressure monitoring assembly;

[0040] 1511 - Pressure monitoring point;

[0041] 152 - Conductivity monitoring component;

[0042] 1521 - Conductivity monitoring point;

[0043] 153 - Gas flow meter;

[0044] 154 - Liquid collection container;

[0045] 160 - Adjusting mechanism;

[0046] 170 - Heating device;

[0047] 171 - Heating wire. Detailed implementation manner

[0048] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0049] In the application, the orientation or positional relationship indicated by terms such as "upper", "lower", "left", "right", "front", "rear", "top", "bottom", "inner", "outer", "vertical", "horizontal", "lateral", "longitudinal", etc. is based on the orientation or positional relationship shown in the accompanying drawings. These terms are mainly used to better describe the present invention and its embodiments, and are not used to limit that the indicated device, element or component must have a specific orientation, or be constructed and operated in a specific orientation.

[0050] Moreover, in addition to being able to represent the orientation or positional relationship, some of the above terms may also be used to represent other meanings. For example, the term "upper" may also be used to represent a certain attachment relationship or connection relationship in some cases. For those of ordinary skill in the art, the specific meanings of these terms in the present invention can be understood according to specific circumstances.

[0051] In addition, the terms "installed", "set", "provided with", "connected", "connected to" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral structure; it can be a mechanical connection or an electrical connection; it can be directly connected, or indirectly connected through an intermediate medium, or there is internal communication between two devices, elements or components. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0052] In addition, terms such as "first", "second", etc. are mainly used to distinguish different devices, components or parts (the specific types and structures may be the same or different), and are not used to indicate or imply the relative importance and quantity of the indicated devices, components or parts. Unless otherwise specified, "a plurality of" means two or more.

[0053] It should be understood that a large amount of carbon dioxide emissions will lead to global warming, which in turn affects the global ecological balance. By injecting carbon dioxide into oil and gas reservoirs, the oil recovery rate can be increased, and carbon dioxide can be sequestered underground, achieving a win-win effect of oil displacement and storage. Compared with gases such as nitrogen, natural gas, and associated gas in oil and gas field development, carbon dioxide has stronger ability to miscible with crude oil, stronger dissolution and swelling ability, and higher oil displacement efficiency. Therefore, it is very necessary to conduct indoor physical simulation research on carbon dioxide flooding and storage.

[0054] The inventors found that supercritical carbon dioxide has good dissolution and diffusion capabilities. Under certain temperature and pressure conditions, a certain concentration of ionic liquid is dissolved in carbon dioxide to reach a completely miscible state and form a single phase. The mixed-phase fluid in this state has a certain conductivity and can conduct electricity. When using this mixed fluid to displace crude oil, the conductivity tomography scanning system can be used to measure the gas and oil saturations at different positions and different times in the porous medium, as well as the migration of the oil and gas front during the gas flooding process, and then calculate the sweep efficiency of carbon dioxide and the storage efficiency. Moreover, the added ionic liquid is insoluble in crude oil and only soluble in carbon dioxide, and it will not affect or interfere with the oil displacement effect of carbon dioxide and has no impact on the overall oil recovery improvement result.

[0055] In view of this, the present invention provides a simulation device for carbon dioxide enhanced oil recovery and storage, which includes a formation model, a pressure chamber, a carbon dioxide container assembly, a backpressure element, and a monitoring assembly. The formation model is configured to be disposed in the pressure chamber and has pores. The formation model is provided with a first opening and a second opening. The first opening is used for injecting fluid, and the second opening is used for discharging fluid. The pressure chamber is used to maintain a first preset pressure. The carbon dioxide container assembly is in communication with the pores of the formation model and is used to configure a supercritical carbon dioxide conductive fluid and introduce the supercritical carbon dioxide conductive fluid into the pores of the formation model. The supercritical carbon dioxide conductive fluid is composed of carbon dioxide and a conductive ionic liquid. The backpressure element is connected to the second opening of the formation model. When the pressure in the pores of the formation model reaches a second preset pressure, the backpressure element is turned on. The second preset pressure is less than the first preset pressure. The monitoring assembly is at least used to monitor the changes in the pressure and conductivity of the formation model during the process of supercritical carbon dioxide conductive fluid enhanced oil recovery. When conducting a carbon dioxide enhanced oil recovery simulation experiment with the simulation device for carbon dioxide enhanced oil recovery and storage provided by the present invention, the formation model can be saturated with oil, the pressure in the pressure chamber can be adjusted to the first preset pressure, the pressure of the backpressure element can be adjusted to the second preset pressure, and the pressure in the formation model can be adjusted to the second preset pressure, where the first preset pressure is greater than the second preset pressure, so as to simulate the actual formation oil pressure environment in this way. Then, the configured supercritical carbon dioxide conductive fluid in the carbon dioxide container assembly is introduced into the pores of the formation model for an oil displacement experiment. Since the supercritical carbon dioxide conductive fluid has conductivity, when the supercritical carbon dioxide conductive fluid flows in the pores of the formation model, the monitoring assembly can monitor the changes in parameters such as the pressure and conductivity at various locations of the formation model during the oil displacement process, so as to clearly understand the fluid migration and distribution during the carbon dioxide enhanced oil recovery and storage process, providing a more intuitive and reliable theoretical basis for the actual implementation of carbon dioxide enhanced oil recovery and storage.

[0056] Figure 1 It is a schematic diagram of the overall structure of a simulation device for carbon dioxide enhanced oil recovery and storage provided by an embodiment of the present invention; Figure 2 It is a flowchart of a simulation method for carbon dioxide enhanced oil recovery and storage provided by an embodiment of the present invention. Reference can be made to Figure 1 and Figure 2, an embodiment of the present invention provides a carbon dioxide flooding and sequestration simulation device 100, which includes a formation model 110, a pressure chamber 120, a carbon dioxide container assembly 130, a backpressure element 140, and a monitoring assembly 150. The formation model 110 is configured to be disposed in the pressure chamber 120, and the formation model 110 has pores; a first opening 111 and a second opening 112 are formed in the formation model 110. The first opening 111 is used for injecting fluid, and the second opening 112 is used for discharging fluid. The pressure chamber 120 is used to maintain a first preset pressure; the carbon dioxide container assembly 130 is communicated with the pores of the formation model 110. The carbon dioxide container assembly 130 is used to configure a supercritical carbon dioxide conductive fluid and introduce the supercritical carbon dioxide conductive fluid into the pores of the formation model 110, wherein the supercritical carbon dioxide conductive fluid is configured by carbon dioxide and a conductive ionic liquid; the backpressure element 140 is connected to the second opening 112 of the formation model 110. When the pressure in the pores of the formation model 110 reaches a second preset pressure, the backpressure element 140 is turned on. The second preset pressure is less than the first preset pressure. The monitoring assembly 150 is at least used to monitor the changes in the pressure and conductivity of the formation model 110 during the process of supercritical carbon dioxide conductive fluid flooding oil.

[0057] Specifically, the first preset pressure can generally be 2 MPa - 5 MPa greater than the second preset pressure, so that the outer wall of the formation model 110 is generally in a compressed state to mimic the pressure environment of the actual formation. The backpressure element 140 can be a valve structure. When the pressure borne by the valve is greater than the second preset pressure, the valve automatically opens, enabling the fluid in the formation model 110 to flow out successively through the second opening 112 and the backpressure element 140.

[0058] When the carbon dioxide flooding and storage simulation device 100 provided by the embodiment of the present invention conducts a carbon dioxide flooding simulation experiment, the formation model 110 can be evacuated first, and then saturated with oil (fill the cavity of the formation model 110 with oil), and the pressure in the pressure chamber 120 is adjusted to a first preset pressure, the pressure of the backpressure element 140 is adjusted to a second preset pressure, and the pressure in the formation model 110 is adjusted to the second preset pressure, wherein the first preset pressure is greater than the second preset pressure. In this way, the actual formation oil pressure environment is simulated; then the supercritical carbon dioxide conductive fluid configured in the carbon dioxide container assembly 130 is introduced into the pores of the formation model 110 for a flooding experiment. Since the supercritical carbon dioxide conductive fluid has conductivity, when the supercritical carbon dioxide conductive fluid flows in the pores of the formation model 110, the monitoring component 150 can monitor the changes in parameters such as the pressure and conductivity at various parts of the formation model 110 during the flooding process. Through multi-parameter inversion, the migration and evolution laws of oil and gas, as well as the dynamic changes in the real-time distribution of carbon dioxide pore storage, can be clearly and intuitively understood throughout the process of carbon dioxide flooding and storage, providing a more intuitive and reliable theoretical basis and guidance for the actual carbon dioxide flooding and storage production process.

[0059] In the above embodiment, the formation model 110 may include a core and a cladding layer. The core is used to simulate the rock structure in the actual formation, and the core has pores. The cladding layer is coated outside the core. Specifically, the core can be made of a cubic natural or artificial core with the maximum values of length, width, and height being 60 cm respectively. The core can be a porous medium, and the cladding layer can be formed by pouring epoxy resin outside the core. The cladding layer mainly plays a role in sealing, wrapping the core, and preventing wall flow.

[0060] In the above embodiment, an adjusting mechanism 160 may also be included. The formation model 110 is arranged on the adjusting mechanism 160. The adjusting mechanism 160 is used to adjust the spatial attitude of the formation model 110, and can adjust the flooding direction of the supercritical carbon dioxide mixed fluid and the degree of effectiveness of the gravity action. It should be understood that in actual reservoir production, there are various types of injection-production wells, and the relationship between injection-production wells is complex. To simulate the actual development conditions as much as possible, the adjusting mechanism 160 in this embodiment can be adjusted to change the inclination angle of the formation model 110, thereby adjusting the flooding direction of the supercritical carbon dioxide mixed fluid and the degree of effectiveness of the gravity action. At the same time, the cutting and drilling sizes and positions can also be artificially planned on the formation model to simulate different types of injection-production wells and the distribution state of injection-production wells.

[0061] In the above embodiments, a heating device 170 may further be included. The heating device 170 includes a heating wire 171 disposed inside the pressure chamber 120. The heating wire 171 is used to heat the pressure chamber 120 and the formation model 110 in the pressure chamber 120 to simulate the temperature in the actual formation.

[0062] In the above embodiments, the carbon dioxide container assembly 130 may include a fluid storage container 131 and a fluid configuration container 132. The fluid storage container 131 is in communication with the fluid configuration container 132. The fluid storage container 131 stores carbon dioxide and a conductive ionic liquid. The fluid configuration container 132 is used to configure carbon dioxide and the conductive ionic liquid into a supercritical carbon dioxide conductive fluid and introduce the configured supercritical carbon dioxide conductive fluid into the pores of the formation model 110. Specifically, the carbon dioxide gas in the storage container can be pressurized and heated to reach the supercritical state, and then the conductive ionic liquid and the supercritical carbon dioxide are respectively introduced into the fluid configuration container 132. The charged particles in the conductive ionic liquid can be miscible in the supercritical carbon dioxide to form a stable and uniform single phase (supercritical carbon dioxide conductive fluid). When using this supercritical carbon dioxide conductive fluid for oil displacement and storage experiments, an electrical conductivity tomography system can be used to measure and invert the gas and oil saturation at different positions and different times in the formation model, as well as the migration of the oil and gas front during the gas flooding process, and then calculate important parameters such as the sweep efficiency of carbon dioxide and the storage efficiency. Specifically, as Figure 1 shown, the supercritical carbon dioxide conductive fluid in the fluid configuration container 132 can be pressed into the pores of the formation model 110 through a piston 1321 for oil displacement.

[0063] In the above embodiments, the monitoring assembly 150 may include a pressure monitoring assembly 151. The pressure monitoring assembly 151 includes a plurality of regularly distributed pressure monitoring points 1511 drilled and built inside the formation model 110 according to depth requirements. The pressure monitoring assembly 151 can be used to monitor the pressure of the pressure monitoring points 1511 to reflect the pressure conditions at various locations in the formation model 110.

[0064] In the above embodiments, the monitoring assembly 150 may further include an electrical conductivity monitoring assembly 152. The electrical conductivity monitoring assembly 152 includes a plurality of electrical conductivity monitoring points 1521 disposed on the formation model 110. The electrical conductivity monitoring assembly 152 can monitor the electrical conductivity of the electrical conductivity monitoring points 1521 to at least reflect the distribution of the supercritical carbon dioxide conductive fluid entering the formation model 110.

[0065] In the above embodiment, the monitoring component 150 may also include a gas flow meter 153 and a liquid collecting container 154. The gas flow meter 153 and the liquid collecting container 154 are both connected to the back pressure element 140. The gas flow meter 153 is used to measure the volume of gas flowing out of the formation model 110, and the liquid collecting container 154 is used to measure the volume of liquid flowing out of the formation model 110.

[0066] The carbon dioxide recovery and storage simulation device 100 provided in the embodiment of the present invention comprises a formation model 110, a pressure chamber 120, a carbon dioxide container assembly 130, a back pressure element 140 and a monitoring assembly 150. The formation model 110 is used to be arranged in the pressure chamber 120, and the formation model 110 has pores; a first opening 111 and a second opening 112 are opened on the formation model 110, the first opening 111 is used to inject fluid, and the second opening 112 is used to drain fluid, and the pressure chamber 120 is used to maintain a first preset pressure; the carbon dioxide container assembly 130 is connected to the pores of the formation model 110, and the carbon dioxide container assembly 130 is connected to the back pressure element 140 and the monitoring assembly 150. The device assembly 130 is used to configure a supercritical carbon dioxide conductive fluid and introduce the supercritical carbon dioxide conductive fluid into the pores of the formation model 110, wherein the supercritical carbon dioxide conductive fluid is configured from carbon dioxide and a conductive ionic liquid; the back pressure element 140 is connected to the second opening 112 of the formation model 110, and when the pressure of the pores of the formation model 110 reaches a second preset pressure, the back pressure element 140 is turned on, and the second preset pressure is less than the first preset pressure, and the monitoring assembly 150 is at least used to monitor the pressure and conductivity changes at various locations of the formation model 110 during the supercritical carbon dioxide conductive fluid oil recovery process. The carbon dioxide recovery and storage simulation device 100 provided in the embodiment of the present invention can perform oil saturation treatment on the formation model 110 when conducting a carbon dioxide recovery and storage simulation experiment, and adjust the pressure in the pressure chamber 120 to a first preset pressure, adjust the pressure of the back pressure element 140 to a second preset pressure, and adjust the pressure in the formation model 110 to the second preset pressure, wherein the first preset pressure is greater than the second preset pressure, and in this way simulate the actual formation pressure environment; then the supercritical carbon dioxide conductive fluid configured in the carbon dioxide container assembly 130 is introduced into the pores of the formation model 110 to conduct an oil recovery experiment. Since the supercritical carbon dioxide conductive fluid has conductivity, when the supercritical carbon dioxide conductive fluid flows in the pores of the formation model 110, the monitoring assembly 150 can be used to monitor the changes in pressure and conductivity parameters at various locations of the formation model 110 during the recovery process. After numerical inversion, the development effect and the dynamic changes of fluid distribution during the carbon dioxide recovery and storage process can be clearly understood, providing a more intuitive and reliable theoretical basis for the actual implementation of carbon dioxide recovery and storage.

[0067] In addition, if Figure 2As shown, the present invention also provides a method for simulating carbon dioxide flooding and storage. This method for simulating carbon dioxide flooding and storage uses the carbon dioxide flooding and storage simulation device 100 in the above embodiments to simulate and monitor the carbon dioxide flooding and storage process. This method for simulating carbon dioxide flooding and storage includes the following steps:

[0068] S100. Perform oil saturation treatment on the formation model 110.

[0069] During implementation, before oil saturation, the pores of the formation model 110 can be evacuated first, and then the formation model 110 can be filled with oil (oil saturation). After the formation model 110 is fully saturated with oil, the initial oil content V1 (ml) of the formation model can be obtained, and the conductivity values at various locations of the formation model 110 can be monitored using the monitoring component 150. If the conductivity values monitored at this time are equal at each point and are all zero, it proves that the formation model 110 is fully saturated with the experimental oil.

[0070] Among them, the formation model 110 can include a core and a cladding layer. The core is used to simulate the porous structure of the rock in the actual formation. The core has pores, and the cladding layer is coated outside the core. The cladding layer can be formed by pouring epoxy resin outside the core, and the cladding layer mainly plays a role in sealing the core.

[0071] S200. Adjust the pressure in the pressure chamber 120 to a first preset pressure, adjust the pressure of the backpressure element 140 to a second preset pressure, and adjust the pressure in the formation model 110 to the second preset pressure. The first preset pressure is greater than the second preset pressure.

[0072] Among them, the pressure adjustment process in the formation model 110 can be carried out simultaneously with the pressure adjustment in the pressure chamber 120 (the space between the pressure chamber 120 and the outer shell and the formation model 110) to ensure that the internal and external pressure difference borne by the outer wall of the formation model 110 is controlled within a safe range until the pressure in the pores of the formation model 110 is consistent with the preset pressure of the backpressure element 140. Among them, the first preset pressure is generally 2 MPa - 5 MPa greater than the second preset pressure.

[0073] S300. Configure a supercritical carbon dioxide conductive fluid through the carbon dioxide container assembly 130, and introduce the configured supercritical carbon dioxide conductive fluid into the pores of the formation model 110 for oil displacement.

[0074] Among them, the carbon dioxide container assembly 130 may include a fluid storage container 131 and a fluid configuration container 132. The fluid storage container 131 is in communication with the fluid configuration container 132. Carbon dioxide and a conductive ionic liquid are stored in the fluid storage container 131. The fluid configuration container 132 is used to configure carbon dioxide and the conductive ionic liquid into a supercritical carbon dioxide conductive fluid, and introduce the configured supercritical carbon dioxide conductive fluid into the pores of the formation model 110.

[0075] S400. Monitor at least the changes in the pressure and conductivity inside the formation model 110 during the process of supercritical carbon dioxide conductive fluid flooding and sequestration through the monitoring component 150.

[0076] The carbon dioxide flooding and sequestration simulation method provided by the embodiments of the present invention can monitor the changes in parameters such as the pressure and conductivity at various locations of the formation model 110 during the flooding process through the monitoring component 150, so as to clearly understand the dynamic changes in the carbon dioxide flooding and sequestration process, and provide a more intuitive and reliable theoretical basis for the actual implementation of carbon dioxide flooding and sequestration.

[0077] As Figure 1 shown, the monitoring component 150 may specifically include a pressure monitoring component 151. The pressure monitoring component 151 includes a plurality of pressure monitoring points 1511 arranged on the surface of the formation model 110. The pressure of the pressure monitoring points 1511 can be monitored by using the pressure monitoring component 151 to reflect the pressure conditions at various locations of the formation model 110. The monitoring component 150 may further include a conductivity monitoring component 152. The conductivity monitoring component 152 includes a plurality of conductivity monitoring points 1521 arranged on the formation model 110. The conductivity monitoring component 152 can monitor the conductivity of the conductivity monitoring points 1521 to at least reflect the distribution of the supercritical carbon dioxide conductive fluid entering the formation model 110. In addition, the monitoring component 150 may further include a gas flow meter 153 and a liquid collection container 154. The gas flow meter 153 and the liquid collection container 154 are both in communication with the back pressure element 140. The gas flow meter 153 is used to measure the amount of gas produced from the formation model 110, and the liquid collection container 154 is used to measure the amount of liquid produced from the formation model 110.

[0078] Among them, the carbon dioxide flooding and sequestration simulation device 100 may further include an adjustment mechanism 160 and a heating device 170. The formation model 110 is arranged on the adjustment mechanism 160. The adjustment mechanism 160 is used to adjust the spatial attitude of the formation model 110 to change the flooding direction of the supercritical carbon dioxide conductive fluid. The heating device 170 includes a heating wire 171 arranged inside the pressure chamber 120. The heating wire 171 is used to heat the pressure chamber 120 and the formation model 110 in the pressure chamber 120 to simulate the temperature in the actual formation.

[0079] In specific implementation, the moment when supercritical carbon dioxide conductive fluid is injected into the formation model 110 can be counted as the initial moment T0. The pressure data at each pressure monitoring point 1511 inside the formation model 110 and the conductivity data at each conductivity monitoring point 1521 are collected regularly through the pressure monitoring component 151 and the conductivity monitoring component 152 respectively. At the same time, the oil production volume V (ml) and gas production volume V' (ml) are measured and recorded regularly through the liquid collection container 154 and the gas flowmeter 153 respectively. The current moment T and the end moment T1 of the experiment are recorded, and the total oil production volume V2 (mL) and total gas production volume V3 (mL) at the end of the experiment are counted. The recovery degree R, ultimate recovery rate R F and the carbon dioxide storage efficiency C at a certain moment during the experiment and the ultimate storage efficiency C F and other parameters can be calculated. At the same time, according to the field map drawing method, the fluid saturation distribution field map and pressure distribution field map at different experimental moments are drawn, providing a theoretical basis and guidance for the actual carbon dioxide flooding and storage production application.

[0080] Specifically, the gas saturation S g is calculated as follows:

[0081] According to Archie's formula, it can be obtained that:

[0082]

[0083] where I is the resistance increase coefficient, R t is the resistivity of the rock containing oil (measured resistivity), R o is the resistivity of the rock completely saturated with water, S w is the water saturation, b is a coefficient, and n is the saturation index. For pure sandstone, b = 1 and n = 2.

[0084] Since the carbon dioxide is given conductive characteristics in this experiment, Archie's formula can be transformed into:

[0085]

[0086] Therefore, the gas saturation values at each point of the formation model 110 can be calculated. Since there is only the experimental oil and carbon dioxide mixed gas in the porous medium of the formation model 110 in the embodiment of the present invention, then S o +S g = 1. Therefore, the oil saturation S o can be calculated, and the oil and gas distribution field map inside the formation model 110 can be drawn based on this. Where σ t is the conductivity during gas flooding of oil (measured conductivity), σ g is the conductivity of the pure carbon dioxide mixed fluid, S ga is the saturation of carbon dioxide gas, b is a coefficient, and n is the saturation index.

[0087] The calculation method of the recovery factor R is as follows:

[0088] The ultimate recovery factor R F The calculation method is as follows:

[0089] The calculation method of the carbon dioxide storage efficiency C at a certain moment is as follows:

[0090]

[0091] The ultimate storage efficiency C of CO2 F The calculation method is as follows:

[0092]

[0093] Among them, Q is the flow rate in the formation model of supercritical carbon dioxide conductive fluid injection.

[0094] In specific implementation, the formation model 110 can be an artificial homogeneous core cast with epoxy resin with a length, width, and height of 30 cm, 30 cm, and 10 cm respectively. Its permeability is 75 mD, and the porosity is 23%. The formation model 110 is placed upright in the pressure chamber 120 to simulate the top gas injection gravity drive development method. The experiment temperature is 80 °C, the first preset pressure is 22 MPa, the second preset pressure is 20 MPa, the carbon dioxide purity is 99.99%, the crude oil density is 0.82 g / mL, and the viscosity is 15 cP (80 °C).

[0095] Under the above experimental conditions, three groups of top gas injection oil displacement experiments can be carried out. The experimental design table is shown in Table 1. Among them, the purpose of designing two injection fluids is to verify the feasibility of conductivity tomography scanning for the oil displacement of the mixed fluid of carbon dioxide and ionic liquid. The purpose of designing two displacement velocities is to compare the differences in recovery factor, storage efficiency, and the migration characteristics of the oil and gas front under different displacement velocities.

[0096] Table Experimental Design Table

[0097]

[0098] In addition, based on the above three groups of experiments, a schematic diagram of the change of the recovery factor with the injection volume of the fluid (carbon dioxide or the mixture of carbon dioxide and ionic liquid) can also be drawn (for reference, see Figure 3 ), and a schematic diagram of the change of the carbon dioxide storage efficiency with the injection volume of the fluid (carbon dioxide or the mixture of carbon dioxide and ionic liquid) can also be drawn (for reference, see Figure 4 ).

[0099] It can be seen from Figure 3 that the production degree change curves of Experiment 1 and Experiment 2 are almost coincident, and the final recovery rates are basically the same. It can be considered that adding ionic liquid to supercritical carbon dioxide has no influence on the law and effect of carbon dioxide flooding, and ionic liquid cannot change the oil displacement ability of carbon dioxide; there are great differences in the production degree change law and the final recovery rate between Experiment 2 and Experiment 3. The general reason for this result is that a large displacement velocity will form an unstable gas-liquid migration interface and cause rapid gas breakthrough, and the sweep efficiency of carbon dioxide flooding is low, thus resulting in a low recovery rate.

[0100] It can be seen from Figure 4 that the change laws of carbon dioxide storage efficiency of Experiment 1 and Experiment 2 are basically the same. It can be considered that adding ionic liquid to supercritical carbon dioxide has no influence on the carbon dioxide storage law, and ionic liquid cannot change the carbon dioxide storage ability; there are great differences in the carbon dioxide storage efficiency between Experiment 2 and Experiment 3. It can be considered that a large carbon dioxide injection velocity will not only reduce the recovery rate, but also reduce the carbon dioxide storage efficiency.

[0101] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that they can still modify the technical solutions described in the foregoing embodiments, or perform equivalent replacements on some or all of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A carbon dioxide flooding and storage simulation device, characterized in that, The invention comprises a formation model, a pressure chamber, a carbon dioxide container assembly, a back pressure element and a monitoring assembly, wherein the formation model is used to be arranged in the pressure chamber, and the formation model has pores; a first opening and a second opening are opened on the formation model, the first opening is used to inject fluid, and the second opening is used to discharge the fluid, and the pressure chamber is used to maintain a first preset pressure; the carbon dioxide container assembly is connected with the pores of the formation model, the carbon dioxide container assembly is used to configure a supercritical carbon dioxide conductive fluid, and introduce the supercritical carbon dioxide conductive fluid into the pores of the formation model, wherein the supercritical carbon dioxide conductive fluid is configured from carbon dioxide and a conductive ionic liquid; the back pressure element is connected with the second opening of the formation model, when the pressure of the pores of the formation model reaches a second preset pressure, the back pressure element is turned on, the second preset pressure is less than the first preset pressure, and the monitoring assembly is at least used to monitor the pressure and conductivity changes of the formation model during the oil displacement and burial process of the supercritical carbon dioxide conductive fluid.

2. The carbon dioxide flooding and storage simulation device according to claim 1, characterized in that, The stratum model includes a core and a coating layer, wherein the core is used to simulate the rock structure in the actual stratum, the core has the pores, and the coating layer covers the outside of the core.

3. The carbon dioxide flooding and storage simulation device according to claim 2, characterized in that, The wrapping layer is made of epoxy resin.

4. The carbon dioxide flooding and storage simulation device according to claim 3, characterized in that, It also includes an adjusting mechanism, on which the formation model is arranged, and the adjusting mechanism is used to adjust the spatial posture of the formation model to change the oil displacement direction of the supercritical carbon dioxide.

5. The carbon dioxide flooding and storage simulation device according to claim 4, characterized in that, It also includes a heating device, which includes a heating wire arranged inside the pressure chamber, and the heating wire is used to heat the pressure chamber and the formation model in the pressure chamber to simulate the temperature in the actual formation.

6. The carbon dioxide flooding and storage simulation device according to any one of claims 1-5, characterized in that, The carbon dioxide container assembly includes a fluid storage container and a fluid configuration container, wherein the fluid storage container is connected to the fluid configuration container, wherein carbon dioxide and a conductive ionic liquid are stored in the fluid storage container, and wherein the fluid configuration container is used to configure the carbon dioxide and the conductive ionic liquid into the supercritical carbon dioxide conductive fluid, and introduce the configured supercritical carbon dioxide conductive fluid into the pores of the formation model.

7. The carbon dioxide flooding and storage simulation device according to any one of claims 1-5, characterized in that, The monitoring component includes a pressure monitoring component, which includes a plurality of regularly distributed pressure monitoring points drilled and built inside the formation model according to depth requirements. The pressure monitoring component monitors the pressure conditions at various locations inside the formation model through the pressure monitoring points.

8. The carbon dioxide flooding and storage simulation device according to claim 7, characterized in that, The monitoring component also includes a conductivity monitoring component, which includes a plurality of conductivity monitoring points arranged inside the formation model. The conductivity monitoring component can monitor the conductivity of the conductivity monitoring points to at least reflect the distribution of the supercritical carbon dioxide conductive fluid injected into the formation model.

9. The carbon dioxide flooding and storage simulation device according to claim 8, characterized in that, The monitoring component further includes a gas flowmeter and a liquid collection container. Both the gas flowmeter and the liquid collection container are communicated with the backpressure element. The gas flowmeter is used to measure the amount of gas produced from the formation model, and the liquid collection container is used to measure the amount of liquid produced from the formation model.

10. A carbon dioxide flooding and storage simulation method, characterized in that, The carbon dioxide enhanced oil recovery and storage simulation method uses the carbon dioxide enhanced oil recovery and storage simulation device in claim 1 to simulate and monitor carbon dioxide enhanced oil recovery and storage. The method includes the following steps: Perform saturated oil treatment on the formation model; Adjust the pressure in the pressure chamber to a first preset pressure, adjust the pressure of the backpressure element to a second preset pressure, and adjust the pressure in the formation model to the second preset pressure. The first preset pressure is greater than the second preset pressure; Configure a supercritical carbon dioxide conductive fluid through the carbon dioxide container assembly, and introduce the configured supercritical carbon dioxide conductive fluid into the pores of the formation model to displace crude oil; At least monitor the changes in the pressure and conductivity of the formation model during the process of supercritical carbon dioxide conductive fluid enhanced oil recovery and storage through the monitoring component.

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